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in Mobile Devices wireless communications: GPS System Analysis / SERDES consumer electronics: From Smartphone to Aware Phone

November 2007

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An RTC Group Publication

portable power: Fuel Gauging / Charge Management


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1880A0


contents

Rf Tx/Rx Analog Baseband

DRAM

departments

editorial letter dave’s two cents industry news analysts’ pages design idea product feature products for designers

Modem flash

4 7 8 12 15 44 45

DRAM 16 high-speed interfaces Application Processor

flash Antenna Triplexer

Long Trace

Digital Baseband

Pre-LNA

GPS Filter

D’converter

cover feature High-Speed Memory Interfaces in 16 Mobile Devices

Brian Gardner, Denali, Inc.

wireless communications

DMF

CDMA 1900 Transceiver

DMF

CDMA 800 Transceiver

20 mobile handset integration

Simultaneous GPS System Analysis and 20 Sensitivity Improvement for Single-Antenna, Tri-Band, Dual-Mode CDMA Handsets

Won Kyu Kim and Allen Chien, Avago Technologies

The Effect of Differential Impedance on 26 SerDes in Handheld Electronics

Seth Prentice, Fairchild Semiconductor

consumer electronics

From Smartphone to Aware Phone 30

Michelle Kelsey, Freescale Semiconductor

M4K 32-bit Core 34 fuel gauging 72 MHz, 1.5 DMIPS/MHz 5 Stage Pipeline, 32-bit ALU Trace

portable power

JTAG

32-bit HW Mul/Div

32 Core Registers Shadow Set

How to Meet Host-Side Fuel Gauge System 34 Design Challenges for Portable Devices

DMA 4 Ch.

2-Wire Debug

VREG

Bus Matrix

Jinrong Qian and Michael Vega, Texas Instruments

Intelligent Li-Ion Charge-Management 40 Systems Overcome Challenges in Powering Portable Devices Brian Chu, Microchip Technology Inc.

Prefetch Buffer Cache

Flash

Interrupt Controller

SRAM

GPIO (85)

Peripheral Bus 16-bit Parallel Port

16 Ch. 10-bit ADCs 44

RTCC

Input Capture

(5) product feature

(2) 12C

(2) UARTs

Output Compare PWM (5)

NOVEMBER 2007

(2) SPI



16-bi Timer (5)


editorial letter

L

I had the pleasure recently of spending a couple of days at the 2007 Software Defined Radio Technical Conference and Product Exposition, otherwise known as the SDR Tech Forum. While SDR has so far been too power hungry to make it into handsets—ADI’s GSM/TD-SCDMA chipset being an early exception—it’s widely used in multi-protocol basestations. The latest prediction is that widespread adoption of 3G handsets that need to cover four or more waveforms on different frequency bands will make SDR techniques inevitable, by which time much of the power problem will have been addressed. The ability to make a single, flexible, inexpensive cellular platform that is easily upgraded and that works in all geographies—long the Holy Grail for handset makers—in only possible through SDR. The day one keynote speaker was Dr. Joseph Kielman, the Basic/Futures Research Lead in the Command, Control and Interoperability (CCI) office of the Science and Technology Directorate of the Department of Homeland Security (DHS); Kielman is also in charge of The Office for Interoperability and Compatibility (OIC). (I’m sorry, does that sound like a bureaucracy or what?) The OIC is working with the emergency response community and Federal partners to improve local, tribal, state and Federal emergency preparedness and response. First responders are all over SDR. At last year’s Tech Forum in Orlando, there were plenty of horror stories about the communications chaos surrounding Hurricane Katrina. This year in Denver the fires in Southern California featured prominently. Firefighters from different jurisdictions often couldn’t communicate with each other or with the police or National Guard, all of whom use different frequencies and modulation techniques. One short-term fix was SDR basestations that acted as translators, enabling diverse emergency teams to coordinate their activities. Kielman noted that there are over 80,000 different public safety jurisdictions in the United States, all of whom have different budgets and communications equipment. Being able to ensure voice and data interoperability between them is at best an Excedrin headache, and an expensive one at that. The SDR approach with the most traction in that space is APCO-25, a suite of standards for digital radio communications for use by federal, state and local public

Can Software Define Radio? john donovan, editor-in-chief

Portable Design blog For more detailed coverage of the SDR Tech Forum, including videos and podcasts, check out my new blog at www.portabledesign. blogspot.com.

safety agencies in North America. While not a fully adopted standard, the Department of Homeland Security will only fund equipment upgrades that are APCO-25 compliant. Kielman announced at the conference that DHS is setting aside $1B to help fund these upgrades. While Kielman admitted to Portable Design that the money was only enough to kickstart the conversion, it’s still a pretty big carrot and a notable endorsement of SDR techniques. The second keynote speaker was Dr. Shuzo Kato, the Program Director, Ubiquitous Mobile Communications, at Japan’s National Institute of Information and Communications Technology (NICT). Dr. Kato analyzed the use of cognitive radio (CR) techniques for dynamic spectrum utilization, an area where cognitive radio has proven quite capable. Being able to sense unused spectrum and dynamically share it without causing interference can go a long way toward increasing spectrum efficiency, which is a growing problem with urban cellular networks in general and the unlicensed ISM bands in particular. The highlight of the event for a lot of us was the Smart Radio Challenge Awards. Teams of grad students from around the world competed to solve the problems that Keilman, Kato and others highlighted. The winners were: 1. Virginia Tech CWT (Center for Wireless Telecommunications), which developed a smart radio system that will automatically find available spectrum within a predefined band and transmit voice or data over that band (the CWT team also won the Grand Prize); 2. Pennsylvania State, for developing a smart radio terminal that can automatically provide interoperability between radios with different modulations, and which knows how to forward messages to the proper network, whether commercial or civil; and 3. The Royal Institute of Technology (Stockholm), which developed a smart radio system that can detect the location of many vehicles within the city, assess their velocity along common roadways, and then provide user-specific route guidance that will minimize total fuel consumption. Right now SDR and CR are tackling some of the hardest and most interesting RF problems out there. Enabling you to step off a plane anywhere and expect your cell phone to work seamlessly is a much easier problem to solve. So in case there’s still any question, yes, software can define radio, and it will define its future, too.


Intersil Handheld Products High Performance Analog

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Analog Mixed Signal: Amplifiers DCPs Light Sensors Real-Time Clocks RS-232 Interface Sub Ohm Analog Switches Switches/MUXes Video Drivers Voltage References

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Intersil – An industry leader in Switching Regulators and Amplifiers. ©2007 Intersil Americas Inc. All rights reserved. The following are trademarks or services marks owned by Intersil Corporation or one of its subsidiaries, and may be registered in the USA and/or other countries: Intersil (and design) and i (and design).

Power Management: Backlight Drivers Battery Authentication Battery Chargers Fuel Gauges Integrated FET Regulators LCD Display Power LDOs Memory Power Management Overvoltage and Overcurrent Protection Voltage Monitors


team editorial team

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Warren Andrews, warrena@rtcgroup.com John Donovan, johnd@rtcgroup.com Marina Tringali, marinat@rtcgroup.com Rochelle Cohn

art and media team Jason Van Dorn, jasonv@rtcgroup.com Kirsten T. Wyatt, kirstenw@rtcgroup.com Christopher Saucier, chriss@rtcgroup.com Marke Hallowell, markeh@rtcgroup.com Brian Hubbell, brianh@rtcgroup.com

management team

Untitled-4 1

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Marina Tringali, marinat@rtcgroup.com Aaron Foellmi, aaronf@rtcgroup.com Stacy Gandre, stacyg@rtcgroup.com Lauren Trudeau, laurent@rtcgroup.com Nancy Vanderslice, nancyv@rtcgroup.com Shannon McNichols, shannonm@rtcgroup.com

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portable design advisory council Ravi Ambatipudi, National Semiconductor Doug Grant, Analog Devices, Inc. Dave Heacock, Texas Instruments Kazuyoshi Yamada, NEC America

corporate office WWW.EMBEDDEDCOMMUNITY.COM

The RTC Group 905 Calle Amanecer, Suite 250 San Clemente, CA 92673 Phone 949.226.2000 Fax 949.226.2050 www.rtcgroup.com

For reprints contact: Marina Tringali, marinat@rtcgroup.com. Published by the RTC Group. Copyright 2007, the RTC Group. Printed in the United States. All rights reserved. All related graphics are trademarks of the RTC Group. All other brand and product names are the property of their holders. Periodicals postage at San Clemente, CA 92673. Postmaster: send changes of address to: Portable Design, 905 Calle Amanecer, Suite 250, San Clemente, CA 92673. Portable Design(ISSN 1086-1300) is published monthly by RTC Group 905 Calle Amanecer, Suite 250, San Clemente, CA 92673. Telephone 949-226-2000; 949226-2050; Web Address www.rtcgroup.com. embeddedcommad_14v.indd 1  PORTABLE DESIGN

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dave’s two cents

W

When I was growing up, our television was as much a piece of furniture as it was something to watch. When purchasing the family set, it was quite important to match it with other furniture in the family room. Designed as floor models, children would conveniently watch TV by sitting on the floor. This provided lots of flexibility for how close you could be to the screen. The main thing that limited the distance was the “Mom factor.” If you were too close, or if she thought you were too close, you were told to move back and were warned that sitting too close would make you go blind. Just the threat of going blind was enough to cause us to move back a considerable distance. As a teenager, I thought this warning was baseless, since no one I knew went blind by sitting too close. I decided the real reason was so that my parents could watch TV from the couch without little heads obstructing the view. Today we have lots of screens to watch throughout the day, both at work and home—with no Mom to warn us to back away from the screen. At the 2007 Portable Design Conference, a roundtable ensued about “The Challenge of Ultra-Mobile Devices.” The discussion centered on portable energy and how best to use it to meet market expectations of “Internet everywhere,” highperformance audio and high-definition video. The roundtable concluded that battery technology would not come to the rescue anytime soon. Target consumption is less than 3W with portable energy ranging from 12 to 15 WHr. A display may use half, and a power budget of less than 500 mW was given to processing. The discussion centered on how to better spend the processing power. Would a hardware engine be the best approach to decode the various audio and video? Or would a more flexible programmable approach be better? Would an integrated approach be better? Or would using an ASSP device be a more optimal solution? I am not sure there was a conclusion, but there did seem to be intense effort to create the right solution from many directions. While power can be a real challenge, ergonomics can be an even greater challenge. Ergonomics will drive power consumption—and the primary culprit is the display. The display can determine the success of these portable connectivity and computing

devices. I recently read an interesting article in the China Post from Taipei titled “Nearsightedness among children reaches all-time high.” It described how the percentage of first graders who are nearsighted (myopia) has increased by seven times in the last 20 years. And about 85 percent of high school seniors need corrected lenses. The report ties this change to increased use of computer displays. The article suggests a 10-minute rest after 30 minutes of use. Many factors may contribute to the susceptibility of becoming nearsighted. The percentage of nearsighted population does seem to be

dave’s two cents on...

We Still Need Our Moms on the rise. Making smaller displays that must be read at a closer range may not help matters. Eye stress related to using computer displays is certainly a topic for more discussion. Everything from not blinking while playing video games to reading small fonts can result in eye discomfort. I certainly am ready for a highly connected, high audio and video performance ultra-portable device. However, we do need to work on the human interface to find a better way. With the computing power of the new ultra-mobile devices, I think we should be able to do more. For my two cents, the next generation of any new device should interface better with us humans. Otherwise, we’ll need to incorporate the “Mom factor” reminding us to back away from the display, limit our watching time, or turn up the ambient light. Hey, I just noticed when I glanced away from this screen, the dog looked fuzzy. Dave Freeman, Texas Instruments

NOVEMBER 2007




news Texas Instruments Acquires POWERPRECISE

Texas Instruments (TI) Incorporated announced that it has acquired POWERPRECISE Solutions, Inc., a fabless portable power management integrated circuit (IC) solutions company based in Herndon, Virginia. The acquisition combines POWERPRECISE advanced technologies, design expertise and innovative products with TI’s extensive analog and power management portfolio. Acquiring POWERPRECISE allows TI to accelerate development of battery and power management ICs for consumer, automotive, medical, computing and industrial applications, such as robotics, power tools, electric bicycles, as well as large battery systems, such as those used in hybrid-electric vehicles (HEVs) and uninterruptible power supply (UPS) systems. “Designers continue to demand innovative power management solutions to address complex battery power challenges,” said Dave Heacock,

nd

er exploration ether your goal speak directly ical page, the ght resource. technology, es and products

senior vice president of TI’s high-volume analog business. “Adding POWERPRECISE’s products and expertise expands our large portfolio of complete battery management ICs that support a range of end applications from portable media players to power drills to automotive designs.” companies providing solutions now POWERPRECISE was founded in 2002, exploration into products, technologies and companies. Whether your goal is to research the latest datasheet from a company, mp to a company's technical page, the goal of Get Connected is to put you in touchand withcurrently the right resource. Whichever of has offices inlevel Herndon, Virginia; gy, Get Connected will help you connect with the companies and products you areTaipei, searchingTaiwan; for. and San Jose, California. The onnected company, which has 28 employees, offers innovative battery and energy management mixedsignal ICs for primary and rechargeable battery packs used in various consumer, industrial and computing applications.

ed

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Texas Instruments Inc., Dallas, TX. (800) 336-5236. [www.ti.com].

IMEC Extends its CMOS Device Scaling Program with Research on DRAM Technology

IMEC has initiated research on next-generation DRAM MIMCAP (metal-insulator-metal

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capacitors) process technology as part of its (sub-)32 nm CMOS device scaling program. This research will enable IMEC and its partners to address the material and integration requirements to scale DRAM MIMCAP to future technology generations. This newly added focus follows an earlier extension of its traditional logic- and SRAM-oriented program with a DRAM periphery transistor sub-program in November 2006. The objective of the latter sub-program is to research high-k and metal gate options sustaining a DRAM-oriented process flow. In order to scale DRAM toward the 50 nm node and beyond, MIMCAP dielectrics require materials with a higher dielectric constant compared to current industrial materials such as ZrO2. By mid-2008, an effective oxide thickness of 0.5 nm is targeted for the MIMCAP dielectric in the sub-50 nm technology node, going down to 0.3 nm in 2009 for the sub-45 nm node. Scaling the dielectric equivalent oxide thickness while attaining very low leakage currents is one of the major bottlenecks the DRAM industry is facing. Building on its expertise in high-k dielectrics and memory research, IMEC expands its CMOS device scaling program to address these challenges. In a first phase, a baseline process for MIMCAP evaluation is set up based on TiN electrode and ZrO2 as the capacitor dielectric. This baseline process is used as a vehicle for screening new electrode materials such as W, Mo, TaC, Ru, etc. Secondly, new material stacks combining high-k and electrodes will be screened theoretically and experimentally for potential integration. The stringent DRAM specifications as dictated by the ITRS will be used as selection criteria. They include leakage current lower than 1 fA/cell and a total physical MIM thickness smaller than 20 nm.


Finally, a MIMCAP deposition process will be developed looking at major integration issues and mimicking as much as possible the effect of full DRAM integration such as passivation, anneal, etc. MIMCAP test structures will be integrated and characterized on electrical and reliability performance. Both MOCVD (metal-organic chemical vapor deposition) and ALD (atomic-layer deposition) will be used since they allow depositing high-quality thin films. The DRAM MIMCAP sub-program is part of the CMOS device scaling program within IMEC’s (sub-)32 nm CMOS research platform. The platform brings the top five leading memory suppliers together with the world’s leading logic IDMs and foundries including Elpida, Hynix, Infineon/Qimonda, Intel, Micron, NXP, Panasonic, Samsung, STMicroelectronics, Texas Instruments and TSMC. IMEC, Leuven, Belgium. +32 16 28 12 11. [www.imec.be].

Freescale Semiconductor Expands Operations in China

Freescale Semiconductor recently celebrated the opening of a new design center in Chengdu, China. The opening follows several recent expansions in the Chinese market, including a thriving assembly and test operation in Tianjin and a growing operation in Shanghai, which has tripled in size since opening two years ago. Freescale has maintained operations in China since 1992. The company was the first U.S.based corporation to establish a semiconductor manufacturing facility in the nation and the first company to set up a joint-venture integrated circuit (IC) design center. Freescale’s China operations encompass the entire semiconductor supply chain—from IC design, foundry, assembly and test, to sales and marketing. In addition, the company operates eight design labs in five design locations—Beijing, Tianjin, Shanghai, Suzhou and Chengdu. China is now the world’s top market for semiconductor consumption and broadband connections and is expected to be the world’s largest automotive market by 2015. According to the China Ministry of Information Industry, the number of mobile phone users now stands at more than 508 million. Investments in telecommunication infrastructure have reached $42.5B RMB, representing a 14.8-percent growth com-

Proposals to the forthcoming World Radiocommunication Conference (WRC-07) will be requesting additional spectrum for the deployment of the IMT 3G-type systems worldwide and will take into account the new IMT-2000 OFDMA TDD WMAN standards derived from the IEEE 802.16 mobile component. pared to the same period last year. And two new 3G standards have recently emerged in addition to the indigenous TD-SCDMA standard. Freescale Semiconductor, Austin, TX. (800) 521-6274. [www.freescale.com].

ITU Approves WiMAX for 3G

The ITU Radiocommunication Assembly has included WiMAX-derived technology in the framework of the IMT-2000 set of standards. This agreement paves the way for the deployment of a range of voice, data and multimedia services to both stationary and mobile devices. Significantly, it opens the door to mobile Internet, catering to demand in both urban and rural markets. The ITU Radiocommunication Assembly (RA-07) formally recognized technology derived from IEEE 802.16 by incorporating it as the sixth terrestrial IMT-2000 radio interface. This is the first addition to IMT-2000 since the original five were adopted years ago as part of the 3G radio standards being used globally, and significantly pushes the technological envelope of IMT-2000 capabilities. IMT-2000—“International Mobile Telecommunications”—is a global standard defined by ITU in a set of interdependent ITU Recommendations, which include the specifications for the radio interfaces of advanced wireless communications systems such as 3G mobile. An initial application for the IMT-2000 Advanced standard was made at the ITU-R WP8F meeting in Kyoto, Japan, in January of this year. The adoption of the latest radio interface was the culmination of tireless effort among administrations, industry and ITU experts. The new technology will facilitate delivery of broadband wireless services at lower cost and include multiple wireless broadband Internet services, including VoIP (Voice over Internet Protocol). The specific terminology of the IEEE 802.16 standard in the ITU-R M.1457 Recommendation is “IMT-2000 OFDMA TDD WMAN.”

Future Direction of Radio Communication The Radiocommunication Assembly closed earlier this month in Geneva after deliberating for a week on new directions in radiocommunications. Held every three to four years, RA-07 deliberated the future direction of radiocommunications, including a new Study Group structure and the establishment of a work plan for the study groups of ITU’s Radiocommunication Sector. Discussions covered several areas: 1. The working methods and procedural issues of the Study Groups with review of the ITU-R Resolutions that describe the structure, working methods and work program of the ITU-R Study Groups. 2. Technical issues that included International Mobile Telecommunications (IMT) for which two new draft ITU-R Resolutions were approved relating to future studies on IMT. 3. Emergency communications and disaster relief: Since the tsunami of December 2004, attention focused on increasing the effectiveness of telecommunications in emergency situations and in responding to disaster relief. Two new Resolutions were approved placing on a sound footing the activities of the Study Groups on this topic. New or revised ITU-R Recommendations were approved, covering areas such as spectrum management, radio-frequency sharing systems, regulatory and procedural matters and new radio standards. Among the important decisions made at this year’s Assembly were refining many of the basic Resolutions describing the working methods of the Study Groups. In particular, Resolution ITUR 1 been brought up-to-date to reflect current practices within the Sector and Bureau. With respect to the new structure, the Assembly agreed on two new Study Groups—one dealing with Terrestrial Services; the other with Satellite Services, as reflected in Resolution ITU-R 4: NOVEMBER 2007




news Study Group 1: Spectrum Management Study Group 3: Radiowave Propagation Study Group 4: Satellite Services Study Group 5: Terrestrial Services Study Group 6: Broadcasting Service Study Group 7: Science Services Coordination Committee for Vocabulary—CCV International Telecommunications Union (ITU), Geneva, Switzerland. +41 22 730 5046. [www.itu.org].

ON Semiconductor to Acquire CPU Voltage and PC Thermal Monitoring Business from Analog Devices, Inc.

ON Semiconductor Corporation has signed a definitive agreement to acquire voltage regulation and thermal monitoring products for computing applications from Analog Devices Inc. (ADI). Pursuant to the agreement, ON Semiconductor will acquire certain assets and intellectual property related to the product line and will enter into a one-year manufacturing supply arrangement for a total consideration value of approximately $185 nd million in cash. This amount also includes consideration for the one-year manufacturing er exploration ether your goal supply arrangement. These products represpeak directly sented approximately $80 million in revenue ical page, the ght resource. for ADI through the twelve months ended technology, Nov. 3, 2007. es and products “The technical expertise of the staff is a ed critical aspect of this transaction,” said Keith Jackson, ON Semiconductor president and CEO. “This additional talent will help ON Semiconductor expand its overall computing power management business and accelerates our notebook power management revenue companies providing solutions now growth. with products and technolexploration into products, technologies and companies. Whether your goal is to research the latestAlong datasheet from the a company, mp to a company's technical page, the goal of Get Connected is to put you in touchogy, with this the right resource. Whichever level of Semiconducteam complements ON gy, Get Connected will help you connect with the companies and products you aretor’s searching for. existing Computing Products Group and onnected will provide increased value-add and scale to our customers.” Pursuant to the agreement, ON Semiconductor will also acquire several ADI-issued patents and patent applications related exclusively to the business and receive appropriate intellectual property licenses from ADI in order to continue to conduct and grow the business. The acquisition is expected to close in December upon the satisfaction of regulatory requirements and other customary closing conditions. Get Connected

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ON Semiconductor, Phoenix, AZ. (602) 244 6600. [www.onsemi.com].

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SDR Forum Announces Smart Radio Challenge Winners

The SDR Forum has announced the winners of its 2007 Smart Radio Challenge. The Smart Radio Challenge challenged entrants to tackle some of the knottiest RF problems to which SDR offers potential solutions. These are all real-world problems whose importance has been underscored by recent events. Problem 1: Spectrum Access for First Responders The Scenario: You are a first responder on the scene following a major earthquake. To effectively do your job, you need to share significant amounts of data with other first responders including, for example, digital video, high-resolution pictures, high-resolution maps and building floor plans. However, given the number of responders on the scene, the airwaves are clogged and you can’t send or receive the necessary data in a reliable manner using your conventional radio technology, and communications is compounded by urban propagation conditions. You are very concerned that your inability to communicate information quickly to the proper recipient is costing peoples lives. The Challenge: Develop a smart radio system that will automatically find available spectrum within a predefined band and transmit data over that band with a pre-defined QoS. The Winners: The Virginia Tech Team: VT-CWT – Mark Silvus, Terry Brisebois, Chen Chen, Quinquin Chen, Feng Ge, Gladstone Maraballie, Ying Wang, Alex Young and Charles Bostian. Problem 2: Communications Interoperability The Scenario: A major forest fire has occurred in Southern California. This fire has spread out of control and has forced a number of local communities to evacuate as the fire approaches their homes and offices. Firefighters and other emergency responders from organizations and jurisdictions nationwide have responded to this emergency, with each group bringing their own equipment. Unfortunately, the radio equipments from the various jurisdictions are not interoperable with each other or with the civilian radio infrastructure, and this lack of interoperability is causing


guidance from starting point to ending point, which will minimize total fuel consumption. The system must be future proof, to allow new features and capabilities to be added over an expected 10-year life span of the vehicle without requiring a visit to the dealer. The Winners: The KTH Team: Delia Gonzales, Chithrupa Ramesh, Sandeep Srinivasan, Georgios Panagiotou, Liu Xin and Abdullah Mansoor. SDR Forum, Denver, CO. (303) 628-5461. [www.sdrforum.org].

Qimonda Ships First GDDR5 Samples a huge problem in coordinating efforts. Without a way to allow these various radio equipments to interoperate, this lack of coordination has put the responders at risk, and has forced many front line responders to carry several radios to allow an appropriate level of inter-organizational communication. The Challenge: Develop a smart radio terminal that can automatically provide interoperability between radios with different modulations, voice and network protocols, and which knows how to forward messages to the proper network—be it commercial or civil. The Winners: The Penn State team: Eric Menendez, Ohktay Azarmaresh, Mathew Sunderland, Sven Bilen and Julio Urbina. Problem 3: Traffic Management The Scenario: You are driving into work, and the freeway is a parking lot. You listened to the traffic report on the radio, but given that the weather is poor, there are a lot of accidents, and as such there wasn’t really a lot you could go on to choose an alternate route. As you sit there with your engine running, watching your gas gauge move toward empty, you think to yourself that there must be a better way to manage these kinds of traffic problems. The Challenge: Develop a smart radio system that can, using available spectrum, accurately detect the location of many vehicles within the city and assess the velocity along common roadways. The system will then provide user-specific route

Qimonda AG has announced that the company has shipped the industry’s first 512 Mbit GDDR5 (Graphics Double Data Rate 5) samples to customers. “We are pleased that we can support the GDDR5 activities of our customers with this first sample shipment, which is a major step to ensure the fast introduction of GDDR5 into the Graphics Market,” said Robert Feurle, vice president of Business Unit Graphics at Qimonda. GDDR5 is targeted to become the next predominant graphics DRAM standard and will boost memory bandwidth of graphics applications to a new dimension. The GDDR5 standard is about to get finalized in JEDEC where industry participants jointly defined this leading-edge graphics standard over the last years. GDDR5 will be available with data rates up to 20 Gbytes/s per component, which is more than double the bandwidth of the fastest GDDR3 memories today and comes with a multitude of advanced power-saving features. First products with GDDR5 memories are expected for 2008. GDDR5 is targeting a variety of applications, starting with High Performance Desktop Graphic cards followed by Notebook graphics. Later on, the introduction in Game consoles and other graphics intensive applications is also planned. Qimonda North America, Inc., San Jose, CA. (408) 501-7000. [www.qimonda.com].

Intel Opens First High-Volume 45 nm Microprocessor Manufacturing Factory

Production of a new generation of microprocessors for PCs, laptops, servers and other computing devices officially began today inside of Intel Corporation’s first high-volume

45 nanometer (nm) manufacturing factory in Chandler, Arizona. Called “Fab 32,” the $3 billion factory will use Intel’s innovative 45 nm process technology based on Intel’s breakthrough in “reinventing” certain areas of the transistors inside its processors to reduce energy leakage. The 45 nm transistors use a Hafnium-based high-k material for the gate dielectric and metal materials for the gate, and are so small that more than 2 million can fit on the period at the end of this sentence. Millions of these tiny transistors will make up Intel’s faster, more energy efficient lead- and halogen-free processors for PCs, laptops and servers, as well as ultra-low-power processors for mobile Internet and consumer electronic devices, and low-cost PCs. The first of the company’s 45 nm processors is scheduled to be introduced on Nov. 12. Fab 32 is Intel’s sixth 300 mm wafer factory and its second factory to produce 45nm chips. Intel first produced 45 nm processors in its Oregon development facility, called D1D, in January, and is now moving into high-volume production with the opening of Fab 32. Two additional 45 nm, 300 mm manufacturing factories are scheduled to open next year in Kiryat Gat, Israel (Fab 28) and Rio Rancho, NM (Fab 11x). Using 300 mm wafers lowers the production cost per chip while diminishing overall use of resources. With 184,000 square feet of clean room space, the completed Fab 32 structure measures 1 million square feet, so large that more than 17 U.S. football fields could fit inside the building. More than 1,000 employees will operate the factory in such positions as process, automation and yield engineers and senior manufacturing technicians. Intel Corporation, Santa Clara, CA. (408) 765-8080. [www.intel.com].

NOVEMBER 2007

11


analysts’ pages

The largest pure-play foundry in the world, TSMC, jumped one spot in 3Q07 as compared Flash Market Surge Propels Toshiba to Third to the full-year 2006 ranking as the company Place; AMD Jumps into Top 10 recorded a strong 3Q07/2Q07 sales increase of According to IC Insights’ November Mc- 21%. It should be noted that after operating at Clean Report, there was a big shakeup in the only 83% capacity utilization in 1Q07, TSMC 3Q07 top 10 semiconductor supplier rankings surpassed its company-defined, 100% capacity (Table). Toshiba moved past TI and ST to be- utilization level in 3Q07! come the third largest semiconductor supplier If pure-play foundry TSMC were excluded in the world, while AMD moved into the top from the ranking, NXP would move into the 10 ranking for the first time in its history. High- tenth position. lights of some of the changes that took place in In spite of 3Q07 DRAM pricing weakness, 3Q07 are shown below: Hynix took advantage of its strong NAND Toshiba rode the coattails of a 46% 3Q07/ flash marketshare to move from 7th to 6th place 2Q07 NAND flash memory market surge to in the ranking. post an amazing 40% 3Q07/2Q07 semiconducFreescale continues to feel the pain of its bigtor sales increase. This increase helped propel gest customer, Motorola, as the company went from being ranked as the 9th largest semiconductor supplier in 3Q07 Top 10 Semiconductor Sales Leaders ($M) the world in 2006 to 3Q07 Tot 3Q/2Q070 3Q07 2006 Tot 1Q07 Tot 2Q07 Tot 2Q/1 Q07 16th in 3Q07. Un2006 Rank Company nd Rank Semi Semi Semi % Chng. Semi % Chng. fortunately for Fre1 1 Intel 32,268 8,072 7,916 -2% 9,203 16.3% escale, Motorola has er exploration ether your goal 2 2 Samsung 19,670 4,697 4,552 -3% 5,387 18.3% gone from holding a speak directly 22% share of cellular 3 5 Toshiba 9,782 3,249 2,510 -23% 3,521 40.3% ical page, the ght resource. phone unit shipments 4 3 TI 13,200 3,115 3,257 5% 3,461 6.3% technology, in 3Q06 (53.7 million) es and products 5 6 TSMC* 9,748 1,922 2,258 17% 2,724 20.6% to securing only a 13% 6 7 Hynix 8,009 2,569 1,998 -22% 2,621 31.2% ed share in 3Q07 (37.2 7 4 ST 9,854 2,269 2,409 6% 2,555 6.1% million). TI, ST and Renesas 8 8 Renesas 7,900 1,949 1,984 2% 2,041 2.9% were the only top 10 9 10 Sony 6,019 1,716 1,573 -8% 1,780 13.2% companies to register 10 13 AMD 5,649 1,233 1,378 12% 1,632 18.4% less than double-digit companies providing solutions now Total 122,099 30,791 29,835 -3% 34,925 17% 3Q07/2Q07 sequenexploration into products, technologies and companies. Whether your goal is to research the latest datasheet from a company, mp to a company'sSource: technical IC page, the goal of Get Connected tial sales growth rates. Insights, company reports is to put you in touch with the right resource. Whichever level of *Foundry gy, Get Connected will help you connect with the companies and products you are searching for. Each of these compaonnected nies is a top-ten supplier to the currently Toshiba to a third-place ranking, its highest slow-growing analog IC market. since being ranked as the second largest semiThe top 10 listing consists of three U.S., conductor supplier in 2000. three Japanese, two Korean, one European, and AMD continues to display a nice recov- one Taiwanese company. ery this year with its 3Q07 sales increasing Through the end of 2007, IC Insights expects 18% over 2Q07, which follows a 12% se- to see pricing stability return to the DRAM quential increase in 2Q07/1Q07. As part of memory market, surging IC demand for PCs its continuing MPU marketshare battle with and high-end cellular phones, and a continuaIntel, AMD is expected to announce a major tion of the seasonal rebound in overall semiGet Connected with companies mentioned in this article. manufacturing/foundry deal in the second conductor demand that began in August. Towww.portabledesign.com/getconnected half of 2007. gether, these three factors are forecast to close

Big Shakeup in 3Q07 Top 10 Semiconductor Supplier Ranking

End of Article

12

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Get Connected with companies mentioned in this article.


IC Insights, Inc., Scottsdale, AZ. (480) 348-1133. [www.icinsights.com].

DSP Shipments Turn the Corner

The good news is that third-quarter DSP chip shipments were up almost 11% in dollars. But, all of the growth was in Asia Pacific, with U.S. growth flat, Europe down 5% and Japan down just over 11%. The bad news is that overall DSP ASPs dropped another 5.8% in the quarter, and down 14% compared to last year’s Q3 figure. Most of that drop is attributable to the greater shipments of inexpensive cellphones (compared to smartphones and feature phones), mostly in Asia. Cellphone DSP shipments (the largest DSP market segment) were up over 10% for the quarter in spite of an ASP drop of about 5%. Wireless infrastructure DSP shipments were up a respectable 13% in revenue, in spite of an almost 8% drop in ASPs. The only “down” market was wired communications. With revenues down almost 17% on an increase in ASP of about 12% is truly odd, with unit shipments dropping by 25%. The telecommunications infrastructure business continues to be a tough market. The other “up” DSP markets included consumer, with revenues up 16%, in spite of a 6% decline in ASP. Clearly, these were shipments to China and Korea, not Japan (which was down 11%). We suspect that increasing production in China by Japanese companies is the reason for the disparity. Computer DSP chip revenues were up just over 30% on steady ASPs. Computer DSPs are mostly in hard disk driver controllers, so the pickup in PC shipments has helped that market segment. Automotive shipments were up almost 10% with a 7% increase in ASP, in spite of lower 2007 automobile unit production. We believe that this indicates more higher-end multimedia revenue is going into dashboards and increasing use of DSPs going into powertrain and safety-related applications. Finally, the so-called multipurpose DSP chip market was up 15.5% with a steady ASP. This market segment tends to be catalog and

off-the-shelf chips in relative small quantities, but includes some of the highest performing (read: expensive) chips for high-end audio and video processing as well as industrial and military applications. Forward Concepts, Tempe, AZ. (480) 968-3759. [www.fwdconcepts.com].

Motorola Invests in UIQ: Does This Signal a Continued Dominance for Symbian?

Recently, Motorola took a stake in UIQ, a user interface solution for mobile devices pre-integrated with the Symbian mobile operating system. Symbian has long been considered a company dominated by the agenda of Nokia; and Motorola’s apparent “buy in” to the ecosystem looks to be (at face value) a knee-jerk reaction to its current poor performance. But ABI Research asks: Why would Motorola entertain strengthening the competitive position of its biggest competitor, Nokia? Research director Stuart Carlaw answers, “Motorola could be characterized as a blue-sky thinker, which is good with respect to longterm planning, but falls short on the here-andnow trends. Conversely, Motorola may look to release compelling multimedia phones to the market quickly, in order to combat softness in this segment of its portfolio.” “It is prudent for them to keep all OS options open with support for Linux, Mi-

crosoft and Symbian, as these are the triumvirate of technologies that will shape the future mobile software market. It is interesting to see some tiering of the OS in Motorola’s platform strategy, with Linux becoming the mid-tier choice whilst Symbian and Microsoft temporarily occupy high-end devices.” ABI Research found that Symbian looks set to enjoy a solid market share of 70% or more of the smartphone OS market for the next few years. “However,” adds Carlaw, “Linux is forecast to encroach upon its position in the latter periods, with Microsoft occupying a solid third position. How interesting it would be if Motorola placed UIQ on top of a Linux OS.” ABI Research, Oyster Bay, NY. (516) 624-2500. [www.abiresearch.com].

LEDs Poised to Drive a New Lighting Revolution

After two years of moderate single-digit revenue growth in 2005 and 2006, the solidstate lighting industry is poised to propel LED revenue to a double-digit expansion rate in 2007.

Worldwide LED Market Forecast, 2001-2012 (Millions of U.S. Dollars) $14,000 Millions of U.S. Dollars

out 2007 on a positive note for the major semiconductor suppliers.

$12,000 $10,000 $8,000 $6,000 $4,000 $2,000 0

2001 2002 2003 2004 2005 2006 2007 2008 2009 2010 2011 2012

NOVEMBER 2007

13


analysts’ pages iSuppli Corp. forecasts total LED market revenue will grow by about 13.7 percent in 2007 and will expand at a Compound Annual Growth Rate (CAGR) of approximately 14.6 percent between 2006 and 2012 to reach $12.3 billion. Global LED market revenue rose by only 2.1 percent in 2005 and by 8.7 percent in 2007. These figures encompass all SurfaceMount Device (SMD) and through-hole packaged Light Emitting Diode (LED) lamps and alpha-numeric display LEDs— including standard brightness, High Brightness (HB) and Ultra-High Brightness (UHB) LEDs. A significant portion of this growth will be driven by UHB and HB LEDs used for lighting applications. In 2012, UHB LEDs will account for approximately 31 percent of total LED revenue—up from 4 percent in 2005. Key Drivers for Market Growth “The new phase of LED growth will be driven by the continued strong demand for solid-state lighting for the backlighting of keypads and displays in mobile devices,” said Dr. Jagdish Rebello, director and principal analyst with iSuppli. “It also will be propelled by new emerging markets for LEDs in the interior lighting of automobiles and in the backlighting of large-screen LCDs for televisions and notebook computers. Furthermore, continuous advances in solid-state lighting technology will allow LEDs to target new applications in the decorative-illumination and architectural-lighting markets.” For the immediate future, the backlighting of small-screen LCD displays and of keypads in mobile devices remains the single largest application market for LEDs. In 2007, this application will account for more than 25 percent of total LED market revenue. iSuppli Corporation, El Segundo, CA. (310) 524-4000. [www.isuppli.com].

Thin-Film/Printable Battery Markets to Reach $5.6 Billion by 2015

According to a newly released report from NanoMarkets, the value of the thin14

PORTABLE DESIGN

film and printed battery market will reach $5.6 billion by 2015. The report, “Thin Film and Printed Battery Markets” is the next in NanoMarkets ongoing series that covers the emerging markets for thin film, organic and printable electronics. According to NanoMarkets, thin-film and printed batteries with their customizable shapes, flexible form-factors and ultra-low weight are enabling new functionality to be added to a broad range of electronic products, such as smartcards, RFID and sensors both increasing their usefulness and the size of their addressable markets. While many of the players in this space are smaller firms, several big name firms including Air Products, Dow Chemical, Intel and NEC have invested in this space underscoring its strategic importance. This technology segment is also one where volume is everything both in terms of manufacturability and sales prospects. Thin film and printable batteries can be delivered at attractive price points when produced in significant quantities and with the right processes. For technologies such as RFID, sensors, smart cards and medical devices that are also high volume and cost sensitive, the ability for manufacturers to add cheap power sources is crucial. When you also factor in the ability for these batteries to extend these applications beyond their current usage, battery manufacturers can create a winning proposition for their customers. In terms of market potential, NanoMarkets reports projects that the thin-film and printed battery markets will be driven primarily RFID, which by 2015 will generate $4.6 billion revenues; smart cards, which will generate $346 million in revenues; and sensors, which will create $434 million in revenues. The NanoMarkets study predicts that printing will have a growing role in the next generation of smart batteries resulting in the growth in demand for zinc manganese dioxide or carbon zinc inks. The study also predicts that there will be a growing number of alternatives for the dominant LiPON electrolytes, with improved conductivity and thermal properties. While thin-film batteries using conventional lithium-based ma-

terials will remain the dominant factor, non lithium battery revenues will grow to $2.5 billion by 2015. Nanomarkets, Glen Allen, VA. (804) 360-2967. [www.nanomarkets.net].

Size and Growth of Smartphone Market Will Exceed Laptop Market for Next Five Years

Smartphone OS-based phones will grow at more than a 30% compound annual growth rate for the next five years globally, taking an increasing share of the overall phone market that is otherwise growing in single digits, reports In-Stat. The unit volume of smartphones globally also exceeds the unit sales for laptops. Users are experiencing significant value from their smartphones, the high-tech market research firm says. As a result they are downloading more applications and generating higher usage as measured by average revenue per user (ARPU) for wireless carriers. “Because of the value users are finding, organizations are slowly taking ownership of smartphones and data applications used for business purposes,” says Bill Hughes, In-Stat analyst. “Rather than having overcomplicated reimbursement plans, more organizations are finding it more expedient and economical to treat wireless voice and data services as a business expense when they use smartphones.” Recent research by In-Stat found the following: • All Smartphone OSs (other than the Palm OS) will grow at double digits over the next five years. • A smartphone user that travels has twice the ARPU of a typical feature phone user. • Smartphone use will grow mostly from use as a laptop replacement, and as a tool to help manufacturers develop feature phones. In-Stat, Scottsdale, AZ. (480) 483-4440. [www.in-stat.com].


design idea Using Bus-Port Protection Arrays in Portable Electronics for Active ESD Protection

figure 1 A

by Jochen Krieger, Vishay Intertechnology I/O

C VBUS

I/O D

Gnd

D1

D1

ZD

Z-Diode with PN-diode provides unidirectional protection

ZD

I/O D2

ZD

D2

Gnd

Gnd

Z-Diode with two PN-diodes provides bidirectional protection

Z-Diode connected to supply voltage for minimum capacitance

Clamping diode current flow.

figure 2

6

5

4

1

2

3

RECEIVER IC

VBUS D1+ D1Twin USB Port

Many portable applications require ESD protection in excess of 8 kV, while at the same time maintaining capacitance lower than 5 pF. By themselves, Z-Diodes are incapable of meeting this requirement, but when they are combined with a low-capacitance PN-diode, such as a switching or junction diode, both requirements of the application can be met: low capacitance with high ESD and surge immunity. This combination of a Z-Diode with a small PN-diode provides a unidirectional protection device. The clamping current can only flow in one direction—the forward direction of the PN-diode—as the reverse path is blocked (Figure 1). Adding another PN-diode opens the back path so the protection device becomes bidirectional. As clamping voltage levels in the forward and reverse directions are different, such a device has a bidirectional and asymmetrical clamping behavior (BiAs) (Figure 1). At the very first moment, when all three diodes are completely discharged (diode capacitances are empty), the first signal pulse with a 0.5V amplitude will drive the upper PN-diode (D1) in a forward direction, filling or loading the empty and big capacitance of the Z-Diode (ZD). Depending on the duration of the pulse and the pause until the next one, the Z-Diode’s capacitance is already charged up to a higher level so that the next pulse has less capacitance to charge up. After a few pulses, the ZDiode is completely charged so that the following pulses see only the low capacitance of the two PN-diodes. Varying capacitance is not a problem for some portable applications, but for others capacitance must be the same for every pulse. For these applications, the Z-Diode can be connected to the supply voltage, such as the VBUS at the USB port (Figure 1), where the supply voltage charges Z-Diode up, and both PN-diodes remain in reverse mode, keeping capacitance to a minimum. The diode array shown in Figure 2 (VBUS054B-HS3), can protect a double, high-speed USB port against transient voltage signals. The array clamps negative transients close below the ground level while positive transients are clamped close above the 5V working range. The Z-Diode clamps the supply line (VBUS at Pin 5) to ground (Pin 2), and high-speed data lines (D1+, D2+, D1- and D2-) are connected to Pin 1, 3, 4 and 6. As long as the signal voltage on the data lines is between the ground and the VBUS level, the low-capacitance PN-diodes offer a very high isolation to VBUS, ground, and to the other data lines. However, as soon as any transient signal exceeds this working range, one of the PN-diodes reverts to forward mode and clamps the transient to ground or the avalanche breakthrough voltage level. As a result, the VBUS054B-HS3 can offer a high ESD immunity of ±15 kV while offering a typical capacitance of <1 pF for portable electronics applications. The VBUS054B-HS3 is a single chip solution, so differences among line capacitances are very low. This is important for the two data lines D- and D+, since this “data line couple” transmits the same data pulses at the same time, but with opposite polarity.

B

D2+ D2GDN

VBUS054B-HS3 bus-port protection array protects a high-speed USB port against transient voltage signals.

Vishay Intertechnology, Inc., Malvern, PA. (402) 563-6866. [www.vishay.com].

NOVEMBER 2007

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cover feature high-speed interfaces

High-Speed Memory Interfaces in Mobile Devices Today’s cell phone requires over 100 interface signals running different protocols at different frequencies. The memory controller is the key to managing high-speed memory access. by Brian Gardner, Vice President of the IP Group, Denali, Inc.

T

The cell phone of today has become an almost indispensable part of life for nearly two billion users around the world. The 3G-based cell phones and similar mobile devices of tomorrow hold the promise to be the central portable device, capable of hosting online gaming, capturing pictures and video, handling video conference calls and offering seamless connection to the Internet. Additionally, the emerging DVB-H terrestrial digital TV and H.263 scalable compression standards will allow for watching broadcast television, or downloading movies for future viewing. Thus, the mobile architecture will require challenging high-speed memory interfaces that enable large data bandwidths while continuing to offer long battery life in a small form-factor. The system architect of future mobile devices will have to pay special attention to the memory subsystem—DRAM, flash and memory controller(s)—to ensure proper performance at the right power, size and price.

16

PORTABLE DESIGN

Today’s cell phone requires over 100 interface signals running different protocols at different frequencies. These signals burn power and must be designed with complex signal integrity issues in mind. As new features are added, the amount and speed of off-chip memories are increasing at a dramatic rate. At the same time, battery life and overall phone size must be maintained, or even improved.

Memory Interfaces in Mobile Devices

Figure 1 shows a typical, simplified mobile phone block diagram. The salient block is the digital baseband domain, which includes the modem and application processing blocks. The modem block includes a DSP and processes voice and data from the various radio standards. The application processing block provides the user interface


and operating system for the phone. Most new applications will run on this block, and processing resources (extra CPUs and hardware assist modules) will most likely be added here. Typical interfaces are explained below. Modem memory interfaces: The modem of today typically requires non-volatile flash memory (stored data persists after power down), which contains the instructions—the code—that operate the modem. Most often that interface is shared with a DRAM device (where the data need not persist after power down), which holds temporary “scratch” data needed for modem algorithms. For the flash device, the DSP or CPU must be able to execute instructions directly out of this memory (“execute in place” or XiP), meaning it must be capable of fast random accesses, providing instruction or data bytes on demand. The non-volatile memory must be able to be field-reprogrammed. The DRAM should be capable of fast random access and the data does not need to persist after power down. In some cases, this memory is small enough to be placed on-chip (e.g., Low-Power DDR SDRAM, Low-Power SDR SDRAM, on-chip SRAM, asynchronous and synchronous SRAM and PSRAM.) Application processor memory interfaces: This is the memory interface used by the useroriented applications. As with the modem, flash memory is necessary to store the instructions even when power is off. Additionally, other data (e.g., pictures, contact lists, video) may also require storage. The flash must be able to be read and written to in a reasonable amount of time so that the user experience does not suffer. In some cases, code might execute directly from the flash, while in other cases blocks of instructions are moved from flash to DRAM, and the code executes from the DRAM. The DRAM interface must be capable of fast random accesses and does not need to persist after power down. The size and bandwidth requirements of this DRAM are increasing dramatically.

table 1 Memory Type

Description

Max Freq Signal (Mbytes/s) Width

Synchronous DRAM (SDR)

Older, slower asynchronous SRAM has yielded to faster, synchronous SRAM that uses a synchronous clock to read/write data reliably at much higher speeds. A derivative has been developed for mobile applications called mobileSDR, to which low-power features have been added. It uses a smaller memory cell, so larger sizes are available at lower cost/Mbyte.

133

62

PseudoSynchronous RAM (PSRAM)

Developed exclusively for low-power, mobile applications. The design uses a smaller, DRAM-style memory cell that must be internally refreshed. The parts are pin-compatible with SRAM and larger in size for a similar price point. The read/writes accessed are similar to older SRAM products, but a burst mode has been added for faster reads in certain applications

133

66 43 (muxed address and data)

LP-DDR1

Dynamic RAM-double data rate (DDR): Data is read/written on each clock edge (two times the data clock frequency.) The derivative developed from the mainstream DDR especially for mobile applications is called LP-DDR (JEDEC 42.4), to which low-power features have been added. The product uses the smallest memory cell, so very large sizes are available at a low cost/Mbyte.

266 (going to 400 soon)

LP-DDR2

Next-generation version of LP-DDR (JEDEC 42.6) that increases interface speed, reduces power (lower Vdd) and adds protocol extensions for NVM devices.

1066

NOR

Non-volatile memory (data persists after power down) that can be randomly read and out of which CPU/DPS units can execute. Owing to a larger cell area, this type of non-volatile memory is larger, costlier and faster than NAND flash. Cheaper versions are planned.

108

64 40 (muxed address and data)

NAND

Non-volatile memory (data persists after power down) with slower, block-level reads/writes. Owing to a smaller cell area, this type of non-volatile memory is smaller, cheaper and slower than NOR flash. Faster versions are planned.

50

23 (16-bit)

DRAM

Flash

The past and future memory interface roadmap.

NOVEMBER 2007

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cover feature

The Mobile System Memory Roadmap figure 1 Rf Tx/Rx Analog Baseband

DRAM Modem flash

DRAM Application Processor

nd

flash

er exploration ether your goal Digital Baseband speak directly ical page, the ght resource. technology, A typical, simplified mobile phone block diagram. es and products

On average, over the next 5 years, the cost of memory components will increase from 22% to 28% of the cell phone bill of material. The average size of the DRAM will increase from 16-32 Mbytes to up to 1 Gbyte. The growth in the size of flash will be even more dramatic, from under 10 Mbytes to over 10 Gbytes and above. Bandwidth requirements will also see steep growth. Modem needs will increase as higher bandwidth radio protocols are rolled out, increasing the bandwidth requirements beyond the 100 Mbytes/s needed for today’s 3G modems. Graphics at the VGA level will need over 300 Mbytes/s, and QVGA levels are on the horizon; faster, better cameras may require upwards of 150 Mbytes/s. While new features will require much faster and potentially wider interfaces, battery life must not suffer as the form-factor of the phone will not grow.

Memory Interface Roadmap - Past and Present

The DRAM trend for the future is to use larger and faster DRAM with advanced power management features, and to share this memory among several clients. Flash memory elements of the system must be much larger and have higher bandwidth. These larger flash memories will use new, denser cell types companies providing solutions now (multi-level bits or that will require adexploration into products, technologies and companies. Whether your goal is to research the latest datasheet fromMLC) a company, mp to a company's technical page, the goal of Get Connected is to put you in touchvanced with the error right resource. Whichever level ofInterfaces will correction (ECC). gy, Get Connected will help you connect with the companies and products you arebe searching for. faster, lower voltage/power, multiplexed onnected and shared between flash and DRAM if possible. New power management features will be added. Table 1 represents the past and future memory interface roadmap.

ed

End of Article Get Connected

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18

Power vs. Energy

For mobile applications, battery life is very important. That concern generally leads to a quest for the lowest power solution. More precisely, it is energy that is the real concern. Energy is power over time, and the total charge of a battery is best expressed as an amount of energy. This detail

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is important because faster, higher power memory types might actually provide a lower energy solution for a given task. A 300 MHz DDR memory might use twice the power of a 100 MHz SDR; but, if it moves a given file six times faster, it provides a net energy savings.

Memory Controller Challenges

To enable the cell phone of the future, sophisticated memory controllers will be needed. The controller must be able to move data from high-bandwidth DRAM to many bandwidth-hungry modules, while maintaining excellent memory utilization to ensure performance and low power. Additionally, the controller must manage blocks of flash data, moving the data at high speeds while correcting multi-bit errors and ensuring wear leveling algorithms.

Modern Memory Controller Architectures

The Databahn DRAM memory controller IP core from Denali Software demonstrates some novel approaches to handling memory interface problems in modern mobile architectures. Databahn is a multi-ported design platform with an array of configurable options allowing for extensive customization and performance versus gate count tradeoffs. It supports various memory and storage types. The design provides comprehensive low-power management options, and includes an integrated, low-power physical interface (PHY). The controller manages both DRAM and flash, handles advanced ECC algorithms and integrates seamlessly with driver software. The architecture is a fully pipelined design with flow control for commands and data. Transactions can occur on every cycle. Set up and tuning are integrated into the controller, using information from Denali’s database of over 10,000 memory models spanning the widest array of DRAM and flash devices. Advanced elements include: 1) Prioritization Engine – port traffic can be prioritized and weighted by selecting among bandwidth


cover feature The mobile device of tomorrow will require careful attention paid to the memory subsystem. Low cost, small size and low power will be challenging design goals.

weighted algorithms; 2) Ordering Engine â&#x20AC;&#x201C; commands are reordered to optimize bandwidth while maintaining relative priority and memory coherency; and 3) Sequencing Engine â&#x20AC;&#x201C; keeps track of pages and banks, and sequences in order to help reduce lost cycles and latency. Many of the new low-power memory devices provide a feature that enables a device to refresh only parts of the memory array, thus saving power on unnecessarily refreshing the entire memory contents. The Databahn controller includes additional logic in the controller that tracks and maintains information about the critical arrays in each device, and determines when to put the memory device into this special mode. The new mobile devices do not include the power-hungry DLL (Delay Locked Loop) found in typical DDR devices. In a standard DDR device, the purpose of the DLL is to constrain the data output timing with respect to the clock of the DRAM, reducing the skews in the system. Lacking the DLL, these new low-power devices exhibit a much broader skew in the data timing relative to the DRAM clock. In turn, this adds significant complexity to the read capture logic that has to be developed by the memory controller designer. The Databahn controller contains a DLL circuit. To reduce power consumption, Databahn uses mostly digital elements for

adjusting timing instead of power-hungry analog devices. To conserve power, Databahn controllers control the gating of clocks to the memories and to the controller itself. Additional logic is included to manage the various power modes and complex features needed for low-power memory devices. In general, the three main sources of power consumption in these memory systems include the power consumed by the memory devices, power consumed by the clock activity, and power consumed by the DDR controller logic itself. Achieving an optimally low-power memory system requires a memory controller design, or IP core, that addresses all of these issues. Databahn controllers incorporate a scheme for automatically transitioning into various levels of power saving modes, depending on the activity of the system, progressively reducing power consumption. In addition to automatically controlling power modes, the controller also provides a mechanism to enable software or firmware designers to force the memory system into any particular mode based on the anticipated activity in the system. In conclusion, the mobile device of tomorrow will require careful attention paid to the memory subsystem. Low cost, small size and low power will be challenging design goals, especially while adding so many high-performance features. By picking the proper memory interfaces, these goals can be met. A key ingredient of success will be the configurable, multi-ported memory controller, with comprehensive low-power functions and a low-cost, low-power physical interface. Denali Software, Inc., Palo Alto, CA. (650) 461-7200. [www.denali.com].

NOVEMBER 2007

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wireless communications mobile handset integration issues

Simultaneous GPS System Analysis and Sensitivity Improvement for SingleAntenna, Tri-Band, DualMode CDMA Handsets Implementing S-GPS in a CDMA handset isn’t easy, but it’s well worth the effort. by Won Kyu Kim and Allen Chien, Avago Technologies

T

Today more 911 calls are made from cell phones than from landlines, and the percentage is only expected to increase over time. This creates a serious problem for emergency responders, such as policemen and firefighters, because at times the 911 operator may only have a vague idea of where the person is calling from. As a result, “enhanced 911,” or simply E911, was created by the FCC so that an accurate location fix could be obtained by emergency responders when the cellular caller either doesn’t know or is unable to determine their exact location. Location fix is typically accomplished either by radio triangulation between radio base station towers, or by using a GPS (at 1575.42 MHz) device built into the phone itself. GSM/ TDMA network operators, such as AT&T and T-Mobile, tend to use the triangulation method while CDMA network operators, such as Verizon and Sprint, tend to use the handset-based GPS method. Handset-based GPS receivers

20

PORTABLE DESIGN

have mostly worked to date in a time multiplexed manner (TM-GPS), as shown in Figure 1, where the GPS signal and the CDMA telephone call signal sequentially toggles back and forth. This method is attractive because only one RF radio is working at a time and is easy to implement. However, several factors are driving the adoption of simultaneous GPS (S-GPS) to replace TM-GPS. In S-GPS, both GPS and CDMA radios simultaneously operate. This provides ~4 dB improved sensitivity over TM-GPS due to its dedicated GPS receiver chain and longer satellite search times. This sensitivity enhancement is especially critical to compensate for the increasing use of internal antennas, which tend to have reduced sensitivity versus their external counterparts. Secondly, voice quality is improved because S-GPS operation does not require disconnection of the CDMA voice signal. Finally, S-GPS enables LBS (Location Based Service)


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wireless communications

because its dedicated GPS receiver can receive the required information continuously without dropping the actual phone call. S-GPS capable chipsets from manufacturers, such as Qualcomm, have been commercially available since 2004 and are being widely adopted in today’s CDMA handsets. This article will describe the important design issues when implementing S-GPS in single-antenna, tri-band, dual-mode

figure 1 TM-GPS st

1 Visit

GPS

GPS CDMA

CDMA

nd

2

Visit

GPS

CDMA

3rd Visit

GPS

CDMA

4th Visit

GPS

CDMA

CDMA

S-GPS 1st Visit 2nd Visit 3rd Visit 4th Visit

GPS

GPS

nd

GPS

GPS

CDMA

CDMA

er exploration ether your goal speak directly ical page, the ght resource. technology, es and products

GPS

Satellite search flow for TM-GPS and S-GPS.

CDMA handsets and demonstrate solutions on how to best overcome them. In general, with any phone design, the manufacturer is looking for compact size, low price, ease of design, sufficient performance margin for high yield in production, and multiple supcompanies providing solutions now pliers of each component. Thus highly integratexploration into products, technologies and companies. Whether your goal is to research the latest datasheet from a company, mp to a company's technical page, the goal of Get Connected is to put you in touchedwith the right resource. Whicheverincreasingly level of modules are becoming adopted gy, Get Connected will help you connect with the companies and products you arebecause searching they for. solve many of the problems listed onnected above. A single antenna is generally utilized per phone because of lower costs and smaller space utilization. Figure 2a illustrates a generic block diagram for a single-antenna tri-band phone. The GPS receive chain consists of a GPS fil-

ed

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PORTABLE DESIGN

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NF tot = 1 + ( NF 1 − 1 ) +

ter, a low noise amplifier (LNA), an inter-stage filter and down converter (D’converter) with each component contributing to the overall system sensitivity. 1) 1st GPS filter: acts to filter the GPS signal coming in from the antenna and blocks jammers, such as CDMA Tx signal leakage. This filter is typically found embedded in a triplexer or quintplexer, which also routes and/or filters the PCS and Cellular band CDMA signals. 2) LNA: comes directly after the 1st filter, amplifies the very weak GPS signal with minimal additional noise to minimize the total system noise. It needs to have good linearity (IIP3) to withstand incoming interferers that leak into the receiver chain. 3) Inter-stage filter (2nd GPS filter): located between LNA and D’converter and provides filtering against blockers amplified after the LNA, which would result in intermodulation distortion (IMD2) products and gain compression at the D’ converter. 4) D’converter: converts the RF signal into the baseband signal. Enough isolation is required to suppress any IMD2 noise and cross modulation jammers that come through the inter-stage filter.

Variables That Govern System Sensitivity

The term GPS sensitivity is defined as the lowest signal power level at the antenna port where the handset should be able to locate the GPS satellite 98% of the time. The handset baseband should detect +13.7dB-Hz C/N0 for the deepest control plane mode. To understand GPS sensitivity, key factors that control the system sensitivity performance are examined in the following section. In a generic multi-stage system, the overall system noise figure (NFtot) is governed by the Friis equation shown below.

NF 2 − 1 AP 1

+ ... +

NF m − 1 A p 1 . . . AP (m −1)

,

where , A p : Available power gain , NF m : noise figure of m stage


(2)

NF tot = NF1st filt +

NFLNA − 1 −1 L 1st filt

+

(3)

= L 1st filt + (NFLNA − 1 ) · L 1st filt +

(4)

= L 1st filt · NFLNA +

(5)

L 1st

filt

GLNA

· G LNA

filt

GLNA

L 1st filt GLNA

+

NF D'conv − 1 −1 L 1st filt

−1

· GLNA · L 2 nd filt

· (( NF2 nd filt − 1 ) + ( NFD'conv − 1 ) · L 2 nd filt )

· (( NF2 nd filt − 1 ) + ( NFD'conv − 1 ) · L 2 nd filt )

= L 1st filt · NFLNA

Fortunately, GLNA is in reality sufficiently large to drive the term L 1st

(FBAR), FBARs have in general demonstrated higher Q and lower IL values. A new important factor in S-GPS operation

NF2 nd filt − 1 −1 L 1st filt

wireless communications

If the actual components shown in Figure 2 are applied to equation (1), then the system noise figure equation becomes,

· (( NF2 nd filt − 1 ) + ( NFD'conv − 1 ) · L 2 nd filt )

in equation (4) effectively to zero. Therefore, you end up with equation (5) where the dominant factors contributing the system noise simply become the 1st GPS filter’s IL and LNA NF. The 2nd GPS filter’s IL and D’converter NF almost have no effect on the total system noise. Figure 3a illustrates how the total system noise is impacted by each of the discrete components. Since the 1st filter’s insertion loss and LNA NF directly affect the GPS system noise, those values should be minimized during component selection. GaAs LNAs exhibit lower NFmin than Si LNAs, and should be preferred for GPS applications. Si LNAs are generally already integrated in the RFIC (i.e., they are free and don’t take up additional space) and are usually more than sufficient for most applications. Filter insertion loss is governed by the quality factor “Q” of the filter, with the higher the Q the better. Of the two filter technologies used in cell phones today, surface acoustic wave (SAW) and film bulk acoustic resonator

table 1 LNA IIP3

1st filter Isolation

LNA Gain compression

+5 dBm

46 dB

0.078 dB

0 dBm

50 dB

0.031 dB

-5 dBm

55 dB

0.078 dB

Required 1st filter isolation to CDMA TX channels according to LNA IIP3.

is that the GPS receiver chain will experience high-strength out-of-band jammers, which may saturate the GPS receiver and degrade sensitivity. In TM-GPS operation, this is not a problem since the GPS search and CDMA phone operation is done in a sequential manner with each section’s operation not affecting the other. In S-GPS, the most important out-of-band jammers are the PCS/Cell band Tx signal leakage and Tx + Jammer cross-modulations signals. Rejection of these signals is critical to prevent LNA gain compression and preserve good system sensitivity. Figure 3b illustrates how LNA/ D’converter gain compression is extremely sensitive to the combination of LNA IIP3 and 1st GPS filter isolation to the CDMA Tx chanNOVEMBER 2007

23


table 2 Parameters

Triplexer + discrete GPS filter solution

Multiplexer + Comparison LNA filter module solution

Cascade Gain

+38.97 dB

+40.06 dB

1.09 dB

Cascade NF

4.49 dB

1.97 dB

2.52 dB

Rej. of CDMA 800 MHz

102.88 dBc

122.95 dBc

20.07 dB

Rej. of CDMA 1900 MHz

91.64 dBc

112.92 dBc

21.28 dB

SGPS Sensitivity

-155.4 dBm

-157.6 dBm

2.20 dB

Performance comparison of the two GPS receiver chains.

figure 2 (a)

Antenna 1st GPS Filter

LNA

2nd GPS Filter

D’converter

(b)

Antenna Triplexer

DMF

DMF

Long Trace

Pre-LNA

GPS Filter

D’converter

CDMA 1900 Transceiver

CDMA 800 Transceiver

(c)

Antenna Multiplexer

LNA+Filter Module

Pre-LNA

nels. Table 1 shows some typical tradeoffs of IIP3 and filter Isolation that a phone designer will need to choose from to prevent LNA gain compression. To achieve maximum GPS sensitivity, it is recommended to choose the best possible IL filter and IIP3 LNA values available and trade off as much out-of-band Isolation as possible. Other system factors to consider include the frequency fluctuations of the TCXO in the D’converter. The two major contributors to frequency fluctuations are frequency drift due to thermal transients caused by the power amplifier, and control signal variation from corrupted DC power sources. To minimize this noise source, the phone designer should locate the voltage controlled temperature compensated crystal oscillator (VCTCXO) as far as possible from heat sources, such as power amplifiers, and add thermal isolation material around the VCTCXO. The post LNA (2nd GPS) filter should be selected to emphasize its out-of-band rejection characteristics over IL since its primary function is to block any jammers that get amplified by the LNA. These post LNA blockers could contribute to IMD2 products in the D’converter. The amount of IMD2 products should be minimized because they can act to demodulate the AM component of the signal as it gets down-converted to the baseband level, which results in degraded bit-error-rate (BER). IMD2 is related to the Tx leakage power that hits the D’converter (Tx leakage) and the IIP2 of the D’converter in equation (6). These are the final two factors to take into consideration during GPS receiver design.

D’converter

(6)

CDMA 1900 Transceiver

CDMA 800 Transceiver

Various block diagrams of GPS Receive Chain using (a) generic components, (b) Triplexer + discrete GPS filter solution and (c) highly integrated multiplexer + LNA filter module solution.

24

PORTABLE DESIGN

IMD 2 t 2 × Txleakage − IIP 2

GPS Sensitivity Improvement

Figures 2b & 2c examine two solutions for single-antenna tri-band phones. Solution one uses a triplexer that has ~1.8 dB GPS IL, a long RF trace to connect it to the LNA, which contributes additional loss, and 48 dB isolation to CDMA Tx jammers. The built-in LNAs in the transceiver chips often have IIP3 values close to 0 dBm. The combination of the above filter and LNA values usually


wireless communications

results in 0.2 dB gain compression of the LNA and the degraded performance of internal antennas. the noise figure of the 1st two stages becomes ~4.1 S-GPS architectures enable sensitivity improvedB. The inter-stage GPS filter rejection of 47 dB ments and enable LBS services important for inbecomes insufficient to prevent D’converter gain creased revenue per user for the service provider. compression further downstream. The total system However, simultaneous use of GPS and CDMA gain and NF of this solution are 38.97 dB and 4.49 radios imparts new constraints to component sedB respectively. The expected overall GPS senfigure 3 sitivity of this system is -155.4 dBm, which may Total System Noise Gain Compressoin vs. (Filter Isolation) be insufficient to meet 9 1.6 E911 accuracy require1st Filter LNA (-1dBm LNA IIP3) ment (50 meter for 67% 1.4 8 of the calls) when used LNA (+2dBm LNA IIP3) in conjunction with in1.2 LNA (+5dBm LNA IIP3) ternal antennas. 7 DNA 1.0 Improved GPS sensiD’converter (46dB 1st Filter Isolation) tivity is expected if the 6 0.8 D’converter (48dB 1st Filter Isolation) multiplexer solution is used as shown in Figure D’converter (50dB 1st Filter Isolation) 0.6 2nd Filter 5 2c. The 1st GPS filter in the multiplexer (Avago 0.4 D’converter Technologies, ACFM4 0.2 7102) has lower IL of ~0.9 dB and better than (a) (b) 0.0 3 -52 dB of isolation to 36 60 40 44 48 52 56 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0 4.5 5.0 5.5 6.0 both CDMA Tx channels. An external GaAs LNA filter module (a) Plot of system noise versus each component’s insertion loss or noise figure showing the importance of 1st GPS filter IL and LNA NF. (b) Plot of LNA and D’converter gain compression versus 1st GPS filter isolation to CDMA Tx-band channels and LNA (Avago Technologies, IIP3. ALM-1412) can then be positioned next to the multiplexer GPS port so no additional loss is experienced due to long RF lection used in the phone. The main new considline lengths. The LNA filter module utilized has 54 eration is rejection of strong out-of-band jammers dBc rejection, 0.8 dB NF, and improved linearity such as Tx signal leakage of the Cell or PCS Tx value of +5 dBm IIP3. The resulting overall system chain. The Friis equation is used to show that the gain and NF then become 40.06 dB and 1.97 dB two most important factors in GPS sensitivity are respectively. This solution has enough rejection to 1st-stage GPS filter loss and LNA NF. Utilizing an the CDMA Tx jammers such that there is negligi- LNA with good linearity and selecting filters with ble gain compression in the LNA and D’converter, sufficient rejection to CDMA Tx channels are reand the expected overall GPS sensitivity is ~ -157.6 quired to prevent gain compression of the LNA. dBm. This improvement of 2 dB in GPS sensitiv- Two GPS receiver architectures are presented ity provides a solution that should be sufficient for with the highly integrated, compact multiplexer/ satisfying E911 requirements when utilizing an in- GPS LNA filter module solution demonstrating ternal antenna. The system results for the two solu- 2.2 dB GPS sensitivity improvement over the tritions are summarized in Table 2. plexer solution, making it a more robust, attractive solution to comply with E911 requirements.

Conclusion

Handset designers are tasked with improving overall GPS system sensitivity to compensate for

Avago Technologies San Jose, CA. (408) 435-7400. [www.avagotech.com].

NOVEMBER 2007

25


wireless communications mobile handset integration issues

The Effect of Differential Impedance on SerDes in Handheld Electronics Moving high-speed serial data reliably requires a balanced transmission line. This article examines the issues involved in designing one.

by Seth Prentice, Applications Engineer, Fairchild Semiconductor

M

Many handheld electronics today are incorporating SerDes (Serializer/Deserializer) technology for the LCD, cameras and keypad interfaces. This technology allows portable electronic manufacturers to reduce the amount of signals through the hinge or slide mechanism. This, in turn, enables new hinge and slide features and reduces cost. This switch from parallel lines to differential transmission lines has resulted in a differential impedance challenge. Differential impedance can significantly impact the signal integrity of a differential signal. This impact can cause flickering LCDs, susceptibility to RF and marginality in the device. This article will discuss the impacts of differential impedance on high-speed signals in handheld devices. It will also describe how to measure, debug and correct these issues. Serializer and deserializer devices are typically designed to operate with a 100-ohm differential impedance transmission line. The

26

PORTABLE DESIGN

challenge arises when trying to achieve this 100 ohms in a handheld device. For example, in flip or slider mobile phones the transmission lines must cross the baseband PCB, a flex for the hinge, and the LCD PCB or rigid flex. Keeping a consistent 100-ohm differential impedance through each one of these mediums is difficult. There are multiple variables that affect differential impedance trace width: adjacent ground traces, and the dielectric constant. But the most significant variable is ground planes: one or two ground planes (microstrip or stripline construction) and the distances between the transmission line and the ground plane. This can be a major issue in RF environments. These applications require isolation grounding on most electronic surfaces to isolate the device from EMI. This grounding can cause a significant drop in differential impedance, down to 50 ohms or lower.


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Wasteman!


wireless communications

Low Differential Impedance

Lower differential impedance presents many challenges for the signals. The first challenge is that the impedance mismatch will cause a reflection on the signal, but there are two other issues of greater importance in a RF environment. Lower differential impedance is capacitive, which loads the signal and reduces the amplitude of transitioning signals such as the clock. This lower amplitude will reduce the robustness to the RF from the radio. For example in a GSM phone, a reduced signal amplitude can figure 1 have a significant impact on the serialized data. A GSM radio transmits at a maximum of 32.5 dBm; at that level a significant amount of RF can be coupled onto the serial lines. If the amplitude nd of the SerDes signal is reduced from low difer exploration ether your goal ferential impedance, speak directly there will be data bit ical page, the ght resource. errors, which can cause technology, a flickering LCD. es and products The third issue that ed occurs is the skew between clock and data (Figure 1). In Figure 39-ohm differential impedance flex clock to data skew. 1, the clock is always transitioning and will have reduced amplicompanies providing solutions now tude caused by from the alow differential impedexploration into products, technologies and companies. Whether your goal is to research the latest datasheet company, mp to a company's technical page, the goal of Get Connected is to put you in touchance, with the right resource. Whichever of but the data does notlevel always transition. gy, Get Connected will help you connect with the companies and products you areWhen searching for. the data does not transition for 2 or 3 onnected bit times, it will reach the full signal amplitude. When data transitions, a skew between the clock and the data will occur, which is caused by the transmission line charge. This may not seem significant, but typical SerDes are designed with +-150 ps of skew margin. The 39-ohm differential impedance in Figure 1 consumes all of the skew margin. Additionally, the skew between clock and the data can cause data errors and reduce the robustness to RF intrusion. To help ensure Get Connected with companies mentioned in this article. that a serialized solution works in an RF www.portabledesign.com/getconnected environment, work must be done to resolve

End of Article

28

PORTABLE DESIGN

Get Connected with companies mentioned in this article.

drops in differential impedance and devices must be chosen with the greatest amount of skew margin.

High Differential Impedance

Where lower differential impedance is caused by over grounding, higher differential impedance is caused by under grounding. Ground shielding is not the only variable, wide trace widths and the dielectric constant can add to increasing the differential impedance, but ground shielding is the major factor. Typically higher differential impedances are seen on flexes with no ground shielding (ribbon cables) or flexes with air gaps. Air gaps are flexes that have multiple layers and require bending. Adhesive is removed between the flex layers at the bend locations. Typically the serial lines will be on an inner layer referencing a ground shield on an outer layer. The distance between the serial lines and ground shield can be considerate causing an increase in differential impedance. Where lower differential impedance is capacitive, higher differential impedance is inductive. A high differential impedance results in two major issues. The first is that the impedance mismatch causes a reflection. The second is that the high differential impedance causes an overshoot and undershoot (Figure 2). If the overshoot/undershoot is significant, it will drive the signal out of the common mode range causing data errors. This will also make the signal less robust to crosstalk and RF. For example, if the serialized signal is close to the common mode range, only a small amount of crosstalk energy is required to drive the serialized signal out of the common mode. In RF applications the largest potential for high impedance is in air gap flex design.

EMI

When resolving drops in differential impedance, it may require a single-sided ground shielding. Many RF engineers cringe at the thought of reducing the amount of ground isolation for two reasons. One is that they are concerned about the high-speed signalâ&#x20AC;&#x2122;s RF emissions causing issues with the phoneâ&#x20AC;&#x2122;s radio channels. Second, they are concerned about


Designing 100-Ohm Differential Impedance

If too much ground shielding causes lower differential impedance and reduced ground shielding causes higher differential impedance, how can a phone be designed and what products will support this environment? Choosing a device that works in a wide range of differential impedances such as Fairchild’s µSerDes is imperative. Many serial technologies require 100 ohms +- 10%, this is virtually impossible to design to. The uSerDes technology is based on a constant current I/O instead of voltage and allows differential impedances of 70 to 120 ohms. When laying out the serial transmission lines on PCB or FPCB, using a differential impedance calculator is extremely useful. For the most accurate simulation, there are professional calculators that incorporate adjacent grounds and magnetic fields. If this is not available, there are many Web sites that calculate differential impedance based on basic industry known formulas. The formulas are typically close to the professional calculators as long as you remain within the formula’s limits. After the boards and flex have been designed, manufactured and populated, performing a TDR (Time Domain Reflectometry) measurement is highly suggested. A TDR is an extremely useful tool to resolve differential impedance is-

sues. When probing a pair of differential lines the tool transmits a differential signal down the transmission lines. The tool measures reflections caused by impedance mismatches. At this time it is best to resolve any drops in differential impedance. As we previously discussed, drops in differential impedance are typically caused by ground shielding. The most direct way to resolve this issue is to review the Gerber files and identify the grounding that is causing the issue. Typically the areas of greatest concern are on buried serial traces on PCB, at connectors, and the dynamic area of flexes with dual ground shields. • Buried serial traces will typically have an isolation ground in the layers above and below the serial lines. • Connects offer a difficult layout challenge where 40 or more lines must all be routed to the connector. Many times this will result in some extra grounding above or below the serial lines. • Flexes typically are very thin in the dynamic area, grounding above and below the serial lines significantly reduces the differential impedance.

wireless communications

the RF susceptibility of the high-speed signals. Both of these concerns are legitimate. To resolve these issues SerDes manufacturers use differential signaling for the cancellation and signal robustness attributes and strive for a frequency that misses the radio bands. The issue arises when there is too much or too little grounding. As we have discussed earlier, too much grounding will reduce the amplitude of the serial signal. This will make it weak to any RF and cause data bit errors. Too little grounding can open the potential for greater levels of RF coupling on to the serial signals. A good balance between these two issues can be achieved by using signal-sided grounding (microstrip layout) or a mesh grounding scheme. These two methods allow the differential impedance to be close to 100 ohms while providing some isolation.

figure 2

Overshoot and undershoot caused by high differential impedance.

A first defense to resolve these issues is to remove ground shielding or increase the distance between the serial lines and the ground shield. If removing the ground shielding is not a possibility, there are other methods to slightly increase the differential impedance. For example, if the trace width is 4 mils, reducing the trace width to 3mils will increase the differential impedance by about 10 ohms. Another possibility is to use mesh ground shielding instead of solid copper. Mesh shielding will provide isolation while helping to increase the differential impedance by about 10 ohms. As more handheld electronics incorporate serialization, differential impedance is becoming a greater issue. Identifying these signals in the beginning of the PCB and FPCB layout is critical. Balancing the priorities of signal amplitude, susceptibility and emissions will provide a robust serial solution. Fairchild Semiconductor Corporation. South Portland, ME. (207) 775-8100. [www.fairchildsemi.com].

NOVEMBER 2007

29


consumer electronics motion sensors

From Smartphone to Aware Phone Accelerometers can add a considerable amount of intelligence to consumer applications. by Michelle Kelsey, Marketing Manager for Consumer and Industrial Inertial Sensors, Freescale Semiconductor

S

Sensor technology has revolutionized many industries, providing new built-in awareness for commodity products that have been with us for a long time. Automotive electronic engine management and a number of safety systems, such as airbags and active suspension, wouldnâ&#x20AC;&#x2122;t even exist without sensor technology. Washers and refrigerators wouldnâ&#x20AC;&#x2122;t be nearly as reliable, intelligent, or feature-rich as they are today without sensors. But just as importantly, sensors expand the capabilities of new technologies to provide services that were never envisioned in the original designs. Cell phones, for instance, have evolved well beyond voice communications, and many of the new features are directly related to sensor technology. Such things as fall detection and shock protection, intelligent ringers, image rotation and camera stabilization have already been incorporated in a number of models. However, there are emerging applications that sen-

30

PORTABLE DESIGN

sors are helping introduce into mobile phones. New accelerometers can enable such features as tap to mute, pedometers and GPS backup.

Accelerometer Basics

An accelerometer measures acceleration and deceleration. A three-axis accelerometer utilizing algorithms on an 8-bit microcontroller (MCU) can function as a motion recognition system by distinguishing various combinations, such as tilt, direction, velocity, shock, vibration and freefall. For instance, Freescale Semiconductorâ&#x20AC;&#x2122;s three-axis accelerometers have a single-mass microstructure that measures acceleration along the X and Y axes with parallel finger-like micro-electromechanical (MEMs) structures. In addition, the entire structure teeter-totters on a hinge to measure acceleration on the Z axis. This enables multiple measurements from a single accelerometer, which broadens the functionality of the motion recognition system in cell phones and similar applications.


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Tap to Mute

It’s happened to all of us. Your cell phone starts ringing in the middle of a meeting, and you fumble around for the button to mute the ring, which, of course, is getting louder with each repeat. An alternative is to just tap the phone to mute the ring. The tap can be detected by an accelerometer, which has been programmed to react to a certain shock threshold level. For instance, a 6g accelerometer yields a minimum acceleration range of -6g to +6g. The threshold level can be set by hardware circuitry or by a software algorithm. A hardware solution can minimize additional code, however, the software option will allow the user to program the desired shock threshold level. The hardware can be simplified by programming for just one-direction tapping (the top of the phone, for instance). The increased flexibility of the software solution allows the system to recognize tapping from the top (a negative shock level) or the bottom (a positive shock level), so that no matter how the phone is situated in your pocket or on your belt clip, a tap on either side will mute the ring. Tap to mute will also work in silent mode, although the vibrating will not trigger the muting as its output is generally limited to ±2g.

nd

er exploration ether your goal speak directly ical page, the ght resource. technology, es and products

Tap to Control

Similar to tap to mute, replacing a dedicated button with an accelerometer can enable easy ed control of various functions when the phone or electronic device is in different modes. For example, the volume control on a wireless headset can be controlled by the phone, but, with an accelerometer designed inside the ear piece, volume can be controlled easier by tapping the companies providing solutions now back of the ear piece turn the volume down, exploration into products, technologies and companies. Whether your goal is to research the latest datasheet from atocompany, mp to a company's technical page, the goal of Get Connected is to put you in touchthe withfront the right resource. of tapping twice to turn theWhichever volumelevel up or gy, Get Connected will help you connect with the companies and products you arefrom searching for. the side to mute the piece. onnected Both tap to mute and tap to control can be factory programmed, or software can allow the user to customize the device configuration. This allows the user to allocate multiple functions from a single accelerometer. For example, using the g-select feature on Freescale’s 3-axes accelerometer, 6g sensing can enable tap control functions, 1.5g allows tilt sensing and so on.

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32

Mechanical pedometers generally employ a lever arm with a coiled spring or thin hairspring mechanism to measure foot strikes. The num-

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ber of strikes is multiplied by an established length of stride to determine distance. This is a relatively inaccurate measurement since it doesn’t take into account varying strides due to changing terrain and running in place (at a stop light, for instance) among other factors. And besides, these pedometers are far too large to integrate into a cell phone. An accelerometer-based pedometer is more accurate and can be efficiently integrated into a cell phone design. A dual axis accelerometer can measure step strikes through z-axis (vertical) measurements and lateral movement through x-axis (horizontal) measurements. A simple 8-bit MCU can calculate the approximate distance traveled from a fixed starting point far more accurately than a mechanical pedometer. What’s more, the accelerometer/ MCU system is compact enough to be integrated into the cell phone architecture, and it can perform additional sensing and processing functions.

Dead Reckoning

With the benefit of GPS, service providers can provide a new type of service category— location-based services. This is particularly useful for managing a fleet of vehicles and tracking the location of company owned cars, trucks and construction equipment. In addition, from a consumer level, point-to-point navigation can help users find an exact street corner with a high degree of accuracy and, in the future, locate a specific room inside a building. Accelerometers can play a significant role in augmenting the accuracy of GPS localization, especially when the GPS signal is compromised when the user enters a building or parking garage. This application of sensor technology is called “dead reckoning.” It can be cost-effectively integrated into a cell phone design using three different sensors—magnetic compass, accelerometer and a pressure sensor—plus a DSP or microprocessor for data processing and GPS interface. All sensor measurements are used to detect changes in the external environment to determine position and direction. The accelerometer can detect the acceleration and motion signature of a person walking or running. It can also detect vibration signatures for a person standing on a moving platform or escalator. When working in concert with a barometric pressure sen-


consumer electronics

sor, it can detect vertical motion, such as an elevator or a flight of stairs. With assistance from a magnetic sensor, the heading can be easily determined so that motion can be localized to a specific direction. When a person is beyond GPS tracking systems, dead reckoning can track movements indefinitely until a GPS signal is reacquired. Dead reckoning can also be used in conjunction with GPS for more accurate readings.

Elderly Monitoring

As the elderly population increases in size, and more and more people are entering retirement, there is an increasing need for devices that help protect a person’s health without encroaching on personal freedoms. The same accelerometers that can provide dead reckoning functions can also monitor people’s condition as well. Are they sitting? Are they standing too long? Are they sleeping? Have they fallen, and have they stopped moving? This capability is priceless for loved ones, but it can be easily integrated into portable devices, such as cell phones that already provide dead reckoning, pedometer and tap to mute or tap to control functionality. In addition, the added benefit of being part of the cell phone’s architecture enables a call for help feature to initiate when a fall is detected and an unconscious state suspected.

The Aware Phone

Incorporating sensor technology helps make operating a smartphone easier and more convenient, but it can also make the phone aware of where it’s going, how fast it’s going and how far it’s gone. Combining this with advanced digital communications helps make the cell phone in your pocket a safety device that can not only help detect when something is physically wrong with you but can also contact the needed emergency services and guide them to your location. A few years ago mobile phones stepped out beyond simple voice communications, providing advance digital connectivity that can rival that of a laptop computer. Now, by adding more sensor technology, it can provide conveniences and services that go beyond the laptop. Freescale Semiconductor. Austin, TX. (800) 521 6274. [www.freescale.com].

NOVEMBER 2007

33


portable power fuel gauging

How to Meet HostSide Fuel Gauge System Design Challenges for Portable Devices In order to get the most out of small batteries, you need to improve fuel gauge accuracy and host-side battery management. This article explains how. by Jinrong Qian and Michael Vega, Battery Management Applications, Texas Instruments

S

Smart phones, portable media players (PMPs) and personal digital assistants (PDAs) are essential to most everyone’s life today. Determining the remaining battery capacity for these portable devices is just as critical. Users need to know with relative accuracy the remaining capacity or battery run-time over a battery life. Previously, many portable devices relied on voltage measurement alone to approximate the remaining battery capacity. The host-side fuel gauge, versus the traditional pack-side fuel gauge, has become much more attractive for this reporting. The host-side fuel gauge can reduce the end user’s total cost for buying a replacement battery pack when the original battery life has expired. This article discusses how to improve fuel gauge accuracy and host-side battery management system design challenges including how to detect the battery’s initial capacity upon insertion, coordinate operation

34

PORTABLE DESIGN

with battery charging system, and minimize power consumption.

Problems of Existing Gas Gauge

The traditional fuel gauge is located in the battery pack as shown in Figure 1. It is always connected to the Lithium-Ion (Li-Ion) cell, and monitors the charging and discharging activity to report the remaining capacity with embedded algorithm in the fuel gauge. When the battery expires, the battery cell (along with the pack electronics circuit) will be thrown away. The fuel gauge is wasted, even though still in good operating condition. When end users have to buy another battery pack, they also must pay for another fuel gauge as well. With the host-side fuel gauge system, the fuel gauge is located in the portable device’s motherboard, while the battery cell and pack protection circuit are in the pack side (Figure 2). For this configuration, the user does


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not have to pay for another fuel gauge when purchasing a replacement battery pack. When doing this, however, there are several design challenges involved. This includes the battery chemistry detection, initial battery capacity

figure 1

by a factor of two after approximately one hundred cycles. A direct effect of an aged batteryâ&#x20AC;&#x2122;s higher resistance is a higher internal voltage drop in response to a load current. As a result, the aged battery reaches the minimum system operating voltage, or the battery cuts off voltage earlier than a fresh battery does. Conventional fuel gauging technologies, mainly the voltage-based and the coulomb counting algorithms, have obvious limitations in the gauging performance. Widely adopted in handheld devices such as cellular phones, the voltage-based scheme suffers from the battery resistance change over time due to low cost and simplicity. The battery voltage is given by: V BAT = V OCV - I x R BAT

nd

er exploration ether your goal speak directly ical page, the ght resource. technology, es and products

ed

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exploration into products, technologies and companies. Whether your goal is to research the latest datasheet from a company, mp to a company's technical page, the goal of Get Connected is to put you in touch with the right resource. Whichever level of gy, Get Connected will help you connect with the companies and products you are searching for.

Traditional battery pack electronics.

onnected

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36

detection when it is inserted, and coordinating operation with the battery charger. Another common misunderstanding about Li-Ion batteries is that the shrinking run-time of a battery in use is primarily due to the battery capacity fading. Contrary to this popular thinking, it generally is not capacity loss, but an increase in battery impedance that results in early system shutdown. The battery capacity actually drops by less than five percent while the batteryâ&#x20AC;&#x2122;s internal DC resistance increases

PORTABLE DESIGN

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where VOCV is the battery open circuit voltage and RBAT is the battery internal DC resistance. Figure 3 shows that the battery voltage is lower with an aged battery, and causes the system to shutdown earlier than a fresh battery. Load condition and temperature variation can change the available capacity by up to 50 percent. Most end users have experienced sudden system shutdown in portable devices without a true fuel gauge. On the other hand, the coulomb counting scheme takes the alternative approach by continuously integrating coulomb to compute the consumed charge and state-ofcharge (SOC). With a pre-learned knowledge of full capacity, the remaining capacity can be obtained. The drawback of this approach is that self-discharge is difficult to model with accuracy. Without periodic full-cycle calibration, the gauging error accrues over time. None of these algorithms address resistance variation of the battery. The designer must terminate system operation prematurely by reserving more capacity to avoid the unexpected shutdown, leaving a significant amount of energy unused.

Single Cell Impedance Track Fuel Gauge

What makes the Impedance Track (IT) technology unique and much more accurate than existing solutions? It is a self-learning mechanism that accounts for the aging effects that cause the batteryâ&#x20AC;&#x2122;s resistance to change and the no-load chemical capacity (QMAX). Impedance


SOC 1 =

Q1 Q MAX

portable power

Track implements a dynamic modeling algorithm to learn and track the battery characteristics by first measuring and then tracking the impedance and capacity changes during actual battery use. With this algorithm, no periodic full-cycle capacity calibration is required. Compensation for load and temperature is modeled accurately with the aid of cell impedance knowledge. Most importantly, fuel gauging accuracy can be maintained during the whole lifetime of the battery as a result of the dynamic-learning of battery parameters. With the accurate gauging from IT, system design can be relieved from the conservative shutdown scheme, and the battery capacity will be fully utilized. Impedance Track performs far better than coulomb counting or cell voltage correlation alone to determine the battery’s remaining capacity. It actually uses both techniques to overcome the effects of aging, self-discharge and temperature variations. For IT to work, a database of tables must be constantly maintained for keeping battery resistance (RBAT) as a function of depth of discharge (DOD) and temperature. To understand when these tables are updated or utilized, you need to know what operations occur during different states. Several current thresholds are programmed into the gauge’s non-volatile memory to define a charge, discharge and relaxation. “Relaxation time” allows the battery voltage to stabilize after ceasing charge or discharge. Before a handheld device is turned “on,” the exact state-of-charge should be determined by measuring the battery open circuit voltage (OCV), then correlating with the OCV(DOD,T) table. When the device operates in an activemode and a load is applied, current integration-based coulomb counting begins. The SOC is continuously calculated by integrating the passed charge measured by the coulomb counter. The total capacity QMAX is calculated through two OCV readings taken at fully relaxed states when the battery voltage variation is small enough before and after charge, or discharge activity. As an example, before the battery is discharged, the SOC is given by:

After the battery is discharged with a passed charge of ΔQ, then the SOC is given by: SOC 2 =

Q2 Q MAX

Subtracting these two equations yields: Q MAX =

ΔQ SOC 1 - SOC 2

where ΔQ = Q 1 - Q 2

This equation illustrates that it is not necessary to have a complete charge and discharge cycle to determine the battery’s total capacity, and it can eliminate the time-consuming battery learning cycle during the pack manufacturing. The battery resistance RBAT(DOD,T) table is updated constantly during discharges and the resistance is calculated as: R BAT (DOD, T )=

OCV(DOD,T) - Battery Voltage Under Load Average Load Current

This enables IT to figure 2 compute when termination voltage will be reached at the present Power load and temperature. Battery Management Charger With battery resistance DC/DC bq24032A Converters information, we can determine the remainBattery Pack ing capacity (RM) PACK+ using a voltage-simuHost-Side Microprocessor Gas Gauge lation method in the T TI OMAP Safety bq27500 firmware. Simulation Protector starts from the present 103AT SOCSTART and calculates PACKthe future battery voltHost age profile under the same load currents with a SOC decrement conPortable power system block diagram with host-side fuel gauge. secutively. When the simulated-battery voltage VBAT(SOC1T) reaches the battery termination voltage, which is typical of 3.0V, the SOC corresponding to this voltage is captured as SOCFINAL. The remaining capacity RM is calculated by: RM = (SOCSTART - SOC FINAL ) x Q MAX

NOVEMBER 2007

37


portable power

Host-Side Battery Fuel Gauging and Charging System Design Challenges and Solutions

Figure 4 shows a circuit diagram of the hostside battery management system including the

figure 3 4.2

3.9

Cycle 1 Open Circuit Voltage

3.6 Battery Voltage (V)

I X RBAT 3.3 Cycle 200 3.0

nd

Shutdown Voltage

2.7

er exploration ether your goal speak directly ical page, the ght resource. technology, es and products

2.4

Battery Capacity

ed Battery discharge characteristics over cycles.

battery charger and fuel gauge bq27500. The bq24032A is a power path management battery thatfrom is able to power the system exploration into products, technologies and companies. Whether your goal is to research the charger latest datasheet a company, mp to a company's technical page, the goal of Get Connected is to put you in touchwhile with thecharging right resource.the Whichever level simultaneously. of battery gy, Get Connected will help you connect with the companies and products you areThere searchingare for. several host-side gauging system onnected design challenges. The first is to get the battery initial capacity when a battery is inserted. Since there is a solid correlation between the battery OCV and SOC, we need to measure the OCV before the battery charging or discharging starts. In order to accurately measure the OCV, the battery is not allowed to be charged or discharged after it is inserted. The fuel gauge first determines if the battery is present or not. It will first put BI/TOUT in high impedance mode. No battery Get Connected with companies mentioned in this article. presence is detected if the BI/TOUT pin voltwww.portabledesign.com/getconnected age is high. Battery insertion is detected when

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38

PORTABLE DESIGN

Get Connected with companies mentioned in this article.

its voltage is pulled low. The open drain output BAT _ GD is pulled high and turns off MOSFET Q1 to prevent battery discharging for a certain amount of time until the OCV reading is made by the fuel gauge. The battery charging is also disabled by pulling the temperature monitoring pin to ground by turning on MOSFET Q2. After OCV reading is finished and the initial battery capacity is accurately learned, BAT _ GD is pulled low, which turns on MOSFET Q1 and turns off MOSFET Q2 to allow battery charging or discharging, which is dependent on the system conditions. The second design challenge is how to monitor the battery temperature for charging qualification and adjusting the battery capacity. To minimize battery degradation, battery charging is prohibited when the cell temperature is typically out of 0°-45°C range. Conversely, the fuel gauge also must monitor the cell temperature for adjusting the battery impedance and capacity. The fuel gauge bq27500 can be configured to monitor the cell temperature through its TS pin, while the temperature threshold to qualify charging can be set through the data flash constants. In order to minimize power consumption, cell temperature is measured every one second by internally pulling BI/TOUT high and measuring the voltage across the TS pin. If the cell temperature falls outside of the preset range, BAT _ GD will be pulled high and turns on the MOSFET Q2 so that the battery charger is disabled until the cell temperature recovers. In the mean time, temperature information is used for normalizing cell impedance and adjusting capacity. Another design consideration is how to minimize total power consumption by the fuel gauge, since the fuel gauge is always connected to the battery, as long as the battery is inserted. There are four operation modes: NORMAL, SLEEP, HIBERNATE and BAT INSERT CHECK. In normal mode, current, voltage and temperature measurements are taken, and the interface data set is updated periodically. Decisions to change states are also made. It consumes the most power typical of 80 ΟA. When the SLEEP mode bit is set, and the average current is below a programmable sleep current, the bq27500 enters SLEEP mode. It periodically wakes to take data measurements and update the data set; then it returns


portable power

to sleep to minimize the current consumption down to typical of 10 ÎźA. To further reduce current consumption, the fuel gauge enters HIBERNATE mode and consumes only 1 ÎźA, if the average current is less than the hibernate current value programmed in flash, and the hibernate bit is set. Also, a cell voltage measured lower than the hibernate voltage value programmed in flash can replace the hibernate bit requirement. The BAT INSERT CHECK mode manages when charge and discharge are allowed so that OCV measurements can be taken when inserting a battery pack into the system. No gauging occurs in this mode. Once battery insertion is detected and OCV readings are complete, the gauge proceeds to NORMAL mode. An important design challenge is how to safely and accurately indicate the low battery capacity for data saving and system shutdown. Traditionally, the battery low indication is purely based on the battery voltage because of simple hardware implementation and low cost. When the battery voltage is below the preset threshold, the BAT_LOW changes the state so it can be used to control the system for possibly reducing functionality and providing a warning signal to end users. However, it may not be accurate since the battery voltage is a function of the load current, aging and temperature. The status indication may flicker for pulsating load in handheld applications. BAT_LOW also could be configured based on the relative SOC, which is more accurate than the pure voltage measurement. BAT_LOW changes its state when either the battery voltage or relative state-of-charge reaches the preset threshold. Therefore, the microprocessor can safely prepare for data saving and system shutdown in advance.

figure 4

Summary

Host-side impedance track fuel gauging system provides high-accuracy gauging and a low system cost solution, which is an ideal solution for smart phones, PMP and portable scanners applications. Understanding the impedance track technology and host-side design challenges is critical.

Host-side battery fuel gauging and charging system.

Texas Instruments Inc., Dallas, TX. (800) 336-5236. [www.ti.com].

NOVEMBER 2007

39


portable power charge management

Intelligent Li-Ion ChargeManagement Systems Overcome Challenges in Powering Portable Devices An MCU and PWM-based charge management system can overcome the limitations of single-chip solutions. by Brian Chu, Applications Engineer, Analog & Interface Products Division Microchip Technology Inc.

T

Trends in portable consumer-electronics devices are driving toward improved performance and increased functionality, while achieving maximized run-times out of each battery charge cycle. With the growing number of features being added to portable electronic products, battery capacity demands for powering portable devices are also increasing. The high cell voltage, high density, long shelf life and maintenance-free nature of Li-Ion batteries make them ideal for a variety of portable-electronic applications. In addition to the popular 4.2V charge voltage regulation 1C maximum charge/discharge rate, new technology in LiIon batteries may require different charge voltages and deliver higher C-rates. This article will discuss some potential new trends in Li-Ion batteries and show how portable product designers can overcome these challenges by designing a flexible Li-Ion battery charge-management system, using a mi-

40

PORTABLE DESIGN

crocontroller (MCU)-controlled Pulse Width Modulation (PWM) module or a stand-alone integrated battery charge-management controller-based solution.

Portable Power Design Challenges With Li-Ion Batteries

Challenges in portable power design with Li-Ion batteries include, but are not limited to, safety concerns, battery chemistries, available space and required features. Portable product designers have to use their best knowledge and experience available to make decisions to overcome every possible hurdle. For rechargeable Li-Ion batteries, one must also consider the charge/discharge rate, life cycles, maintenance and charge algorithm. In order to maximize the capacity after each charge cycle, charge voltage-regulation accuracy is important. Figure 1 shows that an undercharged battery voltage of 0.6% can result in 5% capacity loss for Li-Ion


MCU + PWM Controller ChargeManagement System

If flexibility is important for product development, and the ability to make changes during a project is necessary, a MCU-directed PWM controller battery charge-management system is a perfect fit for these applications. Figure 2 demonstrates a typical Single Ended Primary Inductor Converter (SEPIC) topology multi-cell, multi-chemistry chargemanagement system using the MCP1631 highvoltage PWM (part # MCP1631HV) and the PIC12F683 general-purpose MCU. Some advanced MCUs are available for more GPIOs and ADCs for additional sensing and output status. SEPIC is a switching topology that delivers better efficiency and less power dissipations when input/output voltage difference is wide and current flow is significant. For example, operating a 9V input voltage when VBAT is 4V and ICHARGE is 1A, the power dissipation for popular linear solutions is (9V-4V) x 1A = 5W and the same condition for a switching solution with 90% efficiency is only 4W x (0.1/0.9) = .44W. Cooling a 1/2W solution is much easier than cooling a 5W system. The following

portable power

equations show the calculations for linear and switching power dissipations that are applied in the above example. PDissipation_Linear = ( VIN − VBAT ) × ICHARGE PDissipation_Switch = POUT ×

1 − Efficiency Efficiency

POUT = VBAT × ICHARGE

Figure 3 depicts a typical charge profile of a MCU-directed PWM controller for a singlecell 1700 mAh Li-Ion battery with constant current/constant voltage (CC-CV) algorithm at 1A charge rate. The algorithm starts with precondition if the battery voltage is below the preconditioning threshold. Once it passes the figure 1 preconditioning stage, the system goes into 10% constant-current stage 9% until a regulated volt8% age is detected. The charge termination 7% value in this example 6% is 200 mA. The system 5% continues monitoring 4% the battery voltage and 3% recharges when it falls 2% below the recharge 1% threshold voltage, to 0% 0.0% 0.4% 0.8% 0.2% 0.6% 1.0% 1.2% limit the number of Undercharge Voltage % charge/discharge cycles and prolong the battery’s life, while keeping its voltage at Capacity loss vs. undercharge voltage for Li-Ion batteries. a safe level. Capacity Loss - %

batteries. However, an overcharged Li-Ion battery is not recommended and can be dangerous. Battery manufacturers, such as Panasonic, recommend undercharging a 4.2V regulated LiIon battery at 4.1V, to extend its life for backup energy applications. Production challenges are often associated with time-to-market, total system cost and reliability. Time-to-market is significant for most consumer products, for which the product life cycle is short. A fast response to market changes is important in today’s fastpaced world. The short time permitted from concept to final products also minimizes the resources used and reduces cost by saving design time. Additional components may result in extra failure factor points and in some cases, increasing costs. Although, it’s not true in all applications, saving space by creating highly integrated solutions may cost more than a system built from discrete components. Thus, reliability should always come first when designing a product, if performance is the trade-off.

table 1 MCU+PWM Controller

Stand-alone Charger IC

Required Space

Large

Small

Flexibility

Flexible

Fixed

Cost

High

Low

Time to Market

Slow

Fast

Designer Technical Level

High

Low

Software Requirement

Yes

No

MCU + PWM controller vs. stand-alone charger IC.

NOVEMBER 2007

41


Stand-Alone IC ChargeManagement System for Li-Ion Batteries

The main reasons that designers select fully integrated, single-chip battery charge-management systems are compact size, low cost and minimum design time/effort/resources. The stand-alone Li-Ion battery charger IC, especially for the linear topology, may require only SMD capacitors to maintain AC stability and provide compensation when a battery load is not present. Thus, the required PCB board

figure 2

space and associated components are minimized when using an integrated solution. Figure 4 shows a typical application circuit when a fully integrated battery-management controller is applied as a stand-alone battery charger. Since the charge algorithm and housekeeping circuits are built inside the IC, no firmware is required and the design is straightforward. Semiconductor companies typically deliver good product support in the form of detailed datasheets and application notes to help designers implement the battery charger IC into the system. This saves time-to-market and reduces cost by shortening development time and eliminating software development. On the flip side, inflexibility is a major barrier to stand-alone charge management ICs in todayâ&#x20AC;&#x2122;s rapidly changing battery world.

How Each Solution Overcomes Challenges VIN AVDD_OUT PVDD

VEXT CS PGND

OSCIN

ISIN

ISOUT

OVIN

NC

VSIN

FB

VREF

NC

SHDN

COMP

OSCDIS

AGND

VSOUT

VDD

GP1/C

CCP1

GP3

CP4

GP5

GND

GP0/C

Typical MCU + PWM controller-based multi-cell, multi-chemistry charge-management application circuit.

42

PORTABLE DESIGN

The nominal voltage and charge voltages of rechargeable batteries are dependent upon chemistry. The differences between chemicals that are used for anode and cathode potentials determine battery voltage and other associated characteristics, such as energy density, internal resistance, etc. For example, the recommended charge voltage from battery manufacturers for cobalt and manganese Li-Ion batteries is 4.2V, while the phosphate Li-Ion batteries are recommended to be charged at 3.6V. Although phosphate-based Li-Ion batteries can be charged at a higher regulated voltage to maximize the capacity after each cycle, battery life will decrease as a trade-off. The microcontroller-managed system can easily modify voltage regulation, preconditioning threshold voltage, maximum charge current and other parameters, without changing hardware. The system can be easily modified for Ni-MH, Ni-Cd Sealed Lead Acid (SLA) and other secondary battery chemistries, with the proper firmware and some minor hardware updates. The MCU enables other system intelligence beneficial to portable devices, such as system monitoring and providing output signals, authentication and communication to avoid end-users accidentally using low-quality or counterfeit batteries. Lack of flexibility makes it difficult for the integrated systems to compete against the MCU and PWM-based charge management system. IC design houses and semiconductor manufacturers often try to overcome these issues by offering different preset voltages, selectable or programmable currents (Preconditoning Current, Charge


figure 3 5.0

1.4 4.2V Constant Voltage 1.2

4.0

1

3.0

Constant Current 0.8 0.6

2.0 1.0 0.0

Precondition

20% Termination

0.4

Battery: 1700 mAh Charge Current: 1A Voltage Regulation: 4.2V Charger: PIC12F683 + MCP1631HV

0

20

40

Charge Current (A)

Battery Voltage (V)

Current and Termination Current) and using external resistors and capacitors to program certain parameters. Often, the charge management ICs employ the battery manufacturer’s recommended CC-CV charge algorithm. Safety timers can either be programmable or selectable. The system raises a fault flag or shuts down when the safety timer expires before termination. The safety timer is available to prevent hazards from overcharging Li-Ion batteries and to identify a dead battery. For example, healthy Li-Ion batteries move into constant-current stage in a short period of time when proper voltages are applied. If safety timers expire during precondition, the battery may need to be replaced. Figure 5 depicts a typical stand-alone linear Li-Ion battery charge-management controller’s complete charge profile. The total charge time required can vary based upon different termination options. At the beginning of each charge profile, the thermal foldback regulates the device temperature when internal power dissipation is high. The constant current resumes to its maximum programmed value when the device temperature is below the maximum value, which improves the charger’s reliability and safety. The trade-off for this feature is that the full-charge period increases slightly. In comparing Figures 3 and 5, the thermal-regulation feature actually delays the full profile by approximately 7 minutes, which is not significant in most applications when the completed charge cycle is about 3 hours.

0.2 0

60 80 100 Time (Minutes)

120

140

160

Typical MCU + PWM controller with CC/CV algorithm charge profile.

figure 4

VDD

VBAT

STAT1

THERM

STAT2

PROG

PG

VSS

Conclusion

Microchip Technology Inc. Chandler, AZ. (480) 792-7200. [www.microchip.com].

Typical stand-alone charge-management controller application circuit.

figure 5 6.0

Constant Current Constant Voltage

5.0 Battery Voltage

Fully integrated ICs can help designers implement the battery-charging function quickly and at low costs. However, these standard devices do not meet the needs of all portable device designs and designers. A product designer may often have difficulties finding a battery-charging solution that meets all of the design requirements. A battery charge-management controller IC is usually designed for general applications—it is not application-specific. Some manufacturers attempt to provide single-chip multi-chemistry solutions, however, the built-in algorithms associated with these solutions are either too expensive or not user friendly. A MCU plus PWM controller-based system is ideal for high-end battery charge-management systems, or designs where the battery chemistry may change with future revisions of the product.

4.0 7.5% Termination Ratio

Thermal Regulation

10% Termination Ratio

3.0

20% Termination Ratio

2.0 1.0 0.0

Precondition Battery: 1700 mAh Charge Current: 1A Voltage Regulation: 4.2V Charger: MCP73833

0

30

60

90 120 Time (minutes)

150

180

210

Typical charge profile of a fully integrated stand-alone charger IC.

NOVEMBER 2007

43


product feature Microchip Enters the 32-Bit Fray MIPS-Based PIC32 product line offers easy migration path, extensive tool support. by John Donovan, Editor-in-Chief

Microchip, currently king of the 8-bit microcontroller market, has dealt its way into the high-end 32-bit segment with the introduction of the PIC32 family of 32-bit MCUs based on the MIPS architecture. The move comes two years after Microchip introduced its 16-bit product line, aimed at providing a smooth migration path for legacy PIC 8-bit applications, of which there are many. Now the elevator goes all the way to the top. The announcement is also a major design win for MIPS, who are late coming to the MCU market, and a smart move for Microchip, who are—to be honest—late in coming to the 32-bit market. Max Baron, principal analyst at In-Stat, is impressed with the move. “Microchip gets a great architecture, while MIPS gets to be part of a series of MCUs from a company that is very successful in the MCU market. It’s a win-win for both companies.” Portable Design agrees. The MIPS32 M4K core can achieve 1.5 DMIPS/MHz operation, due to its efficient instruction-set architecture, 5-stage pipeline, hardware multiply/accumulate unit and up to 8 sets of 32 core registers. To reduce system cost, the PIC32 supports MIPS16e 16-bit ISA— enabling code-size reductions of up to 40%. Launching with seven general-purpose members, the PIC32 family operates at up to 72 MHz and offers ample code- and data-space

M4K 32-bit Core 72 MHz, 1.5 DMIPS/MHz 5 Stage Pipeline, 32-bit ALU Trace JTAG

32-bit HW Mul/Div

32 Core Registers Shadow Set

DMA 4 Ch.

2-Wire Debug

VREG

Bus Matrix Prefetch Buffer Cache

Flash

Interrupt Controller

SRAM

GPIO (85)

Peripheral Bus 16-bit Parallel Port

16 Ch. 10-bit ADCs

RTCC

(2) 12C

Input Capture (5)

(2) UARTs

Output Compare PWM (5)

(2) SPI

16-bit Timers (5)

capabilities with up to 512 Kbytes flash and 32 Kbytes RAM. The PIC32 family also includes a wide range of integrated peripherals, including a variety of communication peripherals, a 16-bit Parallel Master Port supporting additional memory and displays, as well as a single-supply on-chip voltage regulator. As a purely defensive measure, the new product line makes a great deal of sense. Microchip has a huge installed base, and creating a migration path is critical to hanging onto those customers. Microchip has paid a lot of attention to tool compatibility, with one toolset supporting 8-, 16- and 32-bit applications. In addition to Matlab support via Microchip’s free MPLAB IDE, complete tool chains are also available from Ashling, Green Hills and Hi-Tech—including C and C++ compilers, IDEs and debuggers. RTOS support is available from CMX, Express Logic, FreeRTOS, Micrium, Segger and Pumpkin. Graphics tools providers include EasyGUI, Segger, RamTeX and Micrium. To kick-start usage, Microchip offers the PIC32 Starter Kit, complete with a USB-powered MCU board, the MPLAB IDE and MPLAB C32 C complier, documentation, sample projects with tutorials, schematics, and 16-bit compatible peripheral libraries. Application expansion boards are also being made available, which plug into the expansion slot on the bottom of the MCU board. It’s unusual to see a new product line launched with such depth of support; it usually takes a while for the “ecosystem” to catch up, or even form. Microchip deserves kudos for execution. The PIC32 line is more than a marketing fix, it’s a serious new contender. But while the new family is quite capable, it’s walking into some serious competition. It’s going up against Freescale’s heavily promoted “Controller Continuum”—which Microchip maintains is hardly continuous—and ARM’s diverse and heavily entrenched processor lineup. At the very least the PIC32 family will provide an architectural alternative for designers who aren’t married to ARM. With the advent of their new MIPS32 products, Microchip is dealing itself into a segment that is much more lucrative than the commoditized 8-bit market to which it owes its success to date. While admittedly playing catch-up, Microchip is looking to be a major player from Day One. Its new product family is an excellent start. Microchip Technology Inc., Chandler, AZ. (480) 792-7200. [www.microchip.com].

44

PORTABLE DESIGN


products for designers Revolutionary Metal Matrix Composite CPS Corporation has introduced AlSiC (Aluminum Silicon Carbide), a metal matrix composite that provides highly reliable and cost-effective solutions for the housing, interconnection and thermal management of microelectronic, optoelectronic and power electronic devices. AlSiC has been tested and meets the requirements of the Restriction of Hazardous Substances Directive (RoHs-compliant) of the European Parliament. Unlike traditional packaging materials, AlSiC enables a tailored coefficient of thermal expansion (CTE), offering compatibility with various electronic devices and assemblies. The isotropic CTE value of AlSiC can be adjusted for specific applications by modifying the Al-metal/SiC-particulate ratio. AlSiC’s CTE matching capabilities eliminate the need for thermal interface stacking, increasing reliability in the field. AlSiC also exhibits a high thermal conductivity that results in extremely efficient thermal dissipation. Coupled with its superior CTE matching, AlSiC’s high thermal conductivity prevents the bowing and flexing of packaging and substrate material that can lead to failure. Traditional packaging materials with lower thermal dissipation can cause delamination, leading to air gaps and poor reliability. The CPS AlSiC near and net-shape fabrication process both produce the composite material and fabricates the product geometry, resulting in a cost-effective product and allowing rapid prototyping for high volume advanced thermal management solutions. The unique casting process enables integration of very high thermal conductivity inserts (>1000 W/mK) or cooling tubes for more advanced thermal management solutions. CPS Corporation, Norton, MA. (508) 222-0614. [www.alsic.com].

Low Voltage Voice Coil Motor Driver with I2C Interface Allegro Microsystems has announced the first device in a series of voice coil motor drivers with I2C serial interface designed for camera auto focus and zoom applications. The operating voltage range is 2.4V to 5.5V and the maximum output current is 127 mA. Allegro’s A3904 internal protection features include thermal shutdown and under voltage lockout. Logic input levels are independent of the supply voltage and the operating temperature range is -40° to +85°C. Output current is programmed via the I2C interface in 500 µA increments with clock rates up to 400 kHz. I2C inputs set the internal DAC output voltage used as a reference for linear current control using a MOSFET output sink transistor. A logic low input on the SLEEPZ input will put the A3904 into sleep mode and reduce the supply current to <0.5 µA. The A3904 is supplied at three levels of packaging: 6-contact DFN package (suffix EW) with thin profile (0.38 mm nominal overall height) and exposed tab for enhanced thermal dissipation, bare die form on wafer (suffix CW), and 6-ball wafer level chip scale (WLCSP) bumped package (suffix CG). All package options are Pb (lead)-free. The EW and CW packages are available now. Samples of the CG are currently available and production shipments are expected to begin in December 2007. Targeted at the consumer, telecommunications, industrial and office automation markets, this new device is priced at $0.57 in quantities of 1,000 and has a 12-week typical lead time to market.

Ultra-Low Capacitance ESD Protection for Portable Devices ON Semiconductor has introduced the first member of its new, ultra-low capacitance, Electrostatic Discharge (ESD) protection family of devices. The new ESD9L is a single-line ESD protection device that offers 0.5 pico farad (pF) capacitance and industry-leading low clamping voltage. Available in the industry’s smallest package for ESD protection, this part is ideal for safeguarding high-speed data lines in portable applications such as cell phones, MP3 players, PDAs and digital cameras. New generations of portable products are increasingly sensitive to damage from ESD voltage as newer integrated circuit (IC) technologies employ smaller geometries and lower working voltages. At the same time, portable electronics systems are requiring lower capacitance in order to maintain the signal integrity of their highspeed data line applications. Traditional off-chip protection solutions based on silicon TVS diodes offer low ESD clamping voltage and fast response time, but their high capacitance limits their use in high-speed applications. Competing off-chip protection technologies such as polymer and ceramic-based varistors offer low capacitance, but their high ESD clamping voltage limits their ability to protect the most sensitive ICs from ESD damage. In order to overcome the limitations of traditional silicon TVS diodes, ON Semiconductor has employed a breakthrough process technology to integrate ultra-low capacitance pin diodes with high-power TVS diodes into a monolithic die that can be used as a high-performance off chip ESD protection solution. This new integrated ESD protection technology platform preserves the excellent clamping and low leakage performance of traditional silicon TVS diode technology while reducing the capacitance from 50 pF to 0.5 pF. The total capacitance of 0.5 pF makes the ESD9L suitable for high-speed applications such as USB2.0 high-speed (480 Mbits/s) and HDMI (1.65 Gbits/s). The ESD9L clamps an input ESD waveform of 15 kilovolts (kV) per the IEC61000-4-2 standard, to less than 7V in a matter of nanoseconds. This leads the industry in clamping voltage performance and ensures protection for the most sensitive integrated circuits. ON Semiconductor’s integrated ESD protection platform uses proprietary design techniques to enhance clamping performance while maintaining a small die size enabling it to fit in a SOD-923 package measuring a mere 1.0 mm x 0.6 mm x 0.4 mm. This ultra-small single-line ESD protection package gives designers ultimate flexibility in size. This coupled with leading-edge capacitance and clamping voltage performance makes this device the premier solution for high-speed applications in space-constrained products such as cell phones, MP3 players, PDAs and digital cameras. The ESD9L5.0ST5G is available in a SOD-923 package and is priced at $0.15 per unit in 10,000 unit quantities. ON Semiconductor, Phoenix, AZ. (602) 244 6600. [www.onsemi.com].

Allegro MicroSystems, Inc., Worcester, MA. (508) 853-5000. [www.allegromicro.com]. NOVEMBER 2007

45


products for designers

Dual, 300 mA Low Dropout (LDO) Regulator

1 Amp Buck-Boost, 600 mA Buck Dual Synchronous DC/DC Converter Extends Battery Run-Time

Catalyst Semiconductor, Inc., a supplier of analog, mixed-signal and non-volatile memory semiconductors, rolls out its newest low dropout (LDO) regulator—the CAT6221 300 mA, dual-output LDO. Announced just weeks after its CAT6217 and CAT6218 single-output LDO regulators, the CAT6221 integrates two 300 mA regulators in a tiny, 6-lead, 0.8 mm height TSOT-23 package, providing a smaller, costeffective option for cell phones, battery-powered devices and other portable consumer products requiring two LDOs. Each LDO in the CAT6221 has an independent enable pin and, combined, offer low quiescent current, 1 percent initial accuracy, and a ver y low typical dropout voltage of 210 mV at a 300 mA load. Zero shutdown current, a low quiescent current of 100 uA reduce power, and small, 1uF ceramic output capacitors provide stable operation and minimize board space and component costs. Additional features include fold-back current limit and protection against short-circuit and thermal overload fault conditions. The CAT6221 LDO regulator is available in standard output voltage combinations of 2.8V/1.8V and 3.3V/1.8V. Additional output voltage combinations are available as special orders. Key features include: • Low drop out voltage of 210 mV typical at 300mA • Quick-start feature for fast turn-on time (<150 µs) • Under-voltage lockout • No-load ground current: 100 uA typical • ±1.0% output voltage initial accuracy, ±2.0% accuracy over temperature • Fold-back current limit and thermal protection • Packaging: 6-lead TSOT-23, 0.8 mm height The CAT6221 LDO regulators are priced at $0.37 each in 10,000 piece quantities for the 2.8V/1.8V and 3.3V/1.8V standard output voltage combinations. Samples are available now. Projected lead-time for production quantities is currently 6 to 8 weeks ARO.

Linear Technology has announced the LTC3520, a dual channel, 2 MHz synchronous converter. One channel utilizes a synchronous buck-boost topology, which can deliver up to 1A of continuous output current with inputs above, equal, or below the output. In single-cell Li-Ion applications requiring a 3.3V output, the buck-boost topology can enable over 25% longer battery run-times compared to a standard buck converter. The second channel is a synchronous buck regulator that can deliver up to 600 mA of continuous output current to voltages as low as 0.80V. An uncommitted gain block can be configured as an LDO or a battery-good comparator. This combination is ideal for powering applications such as DSPs/microcontrollers that require both a 3.3V I/O rail and a 0.8V to 1.8V rail for the core voltage. The LTC3520 operates from 2.2V to 5.5V inputs while switching frequency is user-programmable between 100 kHz and 2 MHz, enabling designers to maximize efficiency while keeping externals small. The combination of its high switching frequency and a 4 mm x 4 mm QFN package ensures a very compact solution footprint for handheld applications. The LTC3520’s unique synchronous buck-boost topology on its 1A channel enables it to regulate a constant output voltage when the input voltage is above, equal to, or below the output, enabling complete use of the Li-Ion battery’s stored energy. The LTC3520 utilizes automatic BurstMode operation to offer only 55 uA (both channels) of no-load quiescent current. For applications requiring very low noise, the Burst Mode operation can be defeated and replaced with a forced continuous mode. Shutdown current is less than 1 uA, further extending battery life. Each channel has independent internal soft-start, enabling design flexibility. Other features include short-circuit protection and over-temperature protection. Summary of Features: LTC3520 • Dual High Efficiency DC/DC Converters: - Buck-Boost (VOUT: 2.2V to 5.25V, IOUT = 1A at VOUT = 3.3V, VIN ≥ 3V) - Buck (VOUT: 0.8V to VIN, IOUT = 600 mA) • Uncommitted Gain Block for LDO Controller, Battery Good Indication or Sequencing • 2.2V to 5.5V Input Voltage Range • Pin-Selectable Burst Mode Operation • Programmable 100 kHz to 2 MHz Switching Frequency • 55 uA Total Quiescent Current for Both Converters in Burst Mode Operation • Thermal and Overcurrent Protection • < 1 uA Current in Shutdown • 24-Lead 4 mm × 4 mm QFN Package LTC3520EUF is available from stock in a 24-lead QFN package. Pricing is $3.50 each for 1,000 piece quantities.

Catalyst Semiconductors Inc., Santa Clara, CA. (408) 542-1000. [www.catsemi.com].

Linear Technology, Milpitas, CA. (408) 432-1900. [www.linear.com].

Non-Volatile Digital Potentiometers with SPI Interface Microchip Technology Inc. has announced the MCP4141/2, MCP4241/2, MCP4161/2 and MCP4261/2 (MCP41XX/42XX) nonvolatile digital potentiometers. The 7- and 8-bit devices have a SPI interface and are specified over the extended industrial temperature range of -40° to 125°C. They are available in several industry-standard packages, including the popular 3 mm x 3 mm DFN package. Unlike mechanical potentiometers, the MCP41XX/42XX devices can be controlled digitally, through an SPI interface. This increases system accuracy, flexibility and manufacturing throughput, while decreasing manufacturing costs. Non-volatile memory enables the devices to retain their settings at power down, and their low static current consumption of just 5 microamperes, maximum, helps to extend battery life. The MCP41XX/42XX digital potentiometers are well suited for a wide variety of consumer and industrial applications, such as power-supply trim and calibration, set-point and process control, closed-loop servo control, PC peripherals, portable instrumentation, instrumentation offset adjust and signal conditioning. Prices range from $.58 to $.87 in 10K quantities. Samples and production quantities are available now in a variety of package options. Microchip Technology Inc., Chandler, AZ. (480) 792-7200. [www.microchip.com].

46

PORTABLE DESIGN


National Semiconductor Corporation has introduced five precision operational amplifiers (op amps) for portable test and measurement, industrial and medical systems that require signal-conditioning and sensor interface accuracy at gains of 6 V/V or higher. The LMP7707 single, LMP7708 dual, LMP7709 quad, LMP7717 single and LMP7718 dual are the latest additions to the company’s PowerWise energy-efficient product family. The LMP7717 delivers 88 MHz gain bandwidth while consuming only 1.15 mA of quiescent current, while the LMP7707 provides 14 MHz gain bandwidth at 0.715 mA of quiescent current. These high bandwidthto-power ratios enable unparalleled power efficiency for extending battery life in portable devices. Additionally, the precision of the LMP7717 and LMP7718 supports data acquisition systems of 16-bits or greater. In these high-resolution data acquisition systems, the designer commonly scales the output of a sensor to the full-scale input of an analog-to-digital converter (ADC) to ensure optimum sensitivity. The new LMP precision op amps are built on National’s proprietary VIP50 BiCMOS process technology. VIP50 allows National to design higher-performance precision op amps, along with the most power-efficient, low-voltage amplifiers on the market. Key Features – LMP7717/18 Precision Op Amps The LMP7717 single and LMP7718 dual are low-noise, CMOS input operational amplifiers that offer a low-input voltage noise density of 5.8 nV/sqrt Hz. These devices are stable at a gain of 10 and higher. The LMP7717 and LMP7718 have a supply voltage range of 1.8V to 5.5V and can operate from a single supply or dual supplies. By providing an input bias current of only 100 femtoamps (fA), these precision amplifiers provide optimal performance in low-voltage and low-noise systems. Their precision DC specifications include an input offset voltage of less than 180 uV to improve overall system accuracy. The LMP7717 is offered in 5pin SOT23 or 8-pin SOIC packages, while the LMP7718 is offered in 8-pin SOIC or 8-pin MSOP packages. Key Features – LMP7707/08/09 12V Precision Op Amps The LMP7707 single, LMP7708 dual and LMP7709 quad are low offset voltage, rail-to-rail input and output (RRIO) precision amplifiers. They provide an operating voltage range up to 12V for single or dual supply applications and are stable at a gain of 6 V/V and higher. These high-speed amplifiers feature CMOS input and offer the key specifications required for superior performance and signal conditioning accuracy, including low-input noise density of 9 nV/sqrt Hz, guaranteed low offset voltage of less than 200 uV and a guaranteed low input bias current of less than 1 picoamp (pA). The LMP7707/08/09 devices exceed 100 dB for common-mode rejection ratio (CMRR), power supply rejection ratio (PSRR) as well as large signal voltage gain (Avol). The LMP7707, LMP7708 and LMP7709 are offered in 5-pin SOT23, 8-pin MSOP and 14-pin TSSOP packages, respectively. All five new products are available now with prices ranging from $1.05 to $2.45 in 1,000-unit quantities.

Smallest Licensable 32-bit Core Tensilica, Inc. has introduced the industry’s smallest licensable 32-bit processor core based on an industry-standard architecture. The new Diamond Standard 106Micro core takes up only 0.26 mm2 in a 130-nm G process and only 0.13 mm2 in a 90-nm G process, which makes it smaller than the ARM7 or Cortex-M3 cores, yet at 1.22 Dhrystone MIPS/ MHz, it delivers higher performance than the ARM9E cores. The low-power Diamond Standard 106Micro is designed for simple controller applications in SoC (system-on-chip) designs, and is an ideal choice for designers migrating from 8-bit and 16-bit microcontrollers to 32-bit processors. All Diamond Standard processors are supported by an optimized set of Diamond Standard software tools and a wide range of industry infrastructure partners, who provide support with operating systems, design services, hardware prototyping and emulation, libraries and memories, EDA tools and peripherals. The Diamond Standard 106Micro is an extremely low power, cache-less controller. It employs a 5-stage pipeline so it can easily achieve 250 MHz in 130G process and up to 400 MHz in 90G process technology. By modelessly switching between 24- and 16-bit narrow instructions, it achieves a higher code density than other 32/16-bit architectures. While it’s smaller and more area-efficient than other 32-bit commercial microcontrollers, the Diamond 106Micro is a fully equipped controller. Using a traditional Harvard architecture, it features separate local, tightly coupled, instruction and data RAMs to eliminate memory contention and provide fast performance on performance-critical code and interrupt handling routines. RAM size is user selectable up to 128 Kbytes. It features a 32-bit iterative multiplier for arithmetic operations, a trace port for debug, an integrated timer, and a rich interrupt architecture with 15 interrupts at two priority levels for flexible and fast interrupt handling. All Tensilica Diamond Series cores are available with either the native high-performance Tensilica PIF processor interface, suitable for bridging to any on-chip bus (e.g., OCP, CoreConnect) or with an AMBA AHB-Lite interface. SoC designers therefore can choose any common on-chip bus and leverage existing infrastructure and peripheral component sets. The Diamond Standard 106Micro is available now from Tensilica and its partners. Tensilica Inc., Santa Clara, CA. (408) 986-8000. [www.tensilica.com] .

National Semiconductor Corporation, Santa Clara, .CA (408) 721-5000. [www.nsc.com].

NOVEMBER 2007

47

products for designers

Low-Offset, Precision Amplifier Family with High Bandwidth-to-Power Ratios for Portable Applications


products for designers

ESL 2.0 Technology Release for the Design of Processor- and Software-Intensive Electronic Platforms CoWare has announced the first product release supporting companies in their transition from the “proof-of-concept ESL era” to ESL 2.0. ESL 2.0 refers to a second generation of ESL solutions, which aim to facilitate the design and development of processor-centric, software-intensive products with complex interconnect and memory architectures, in a production environment. Virtual hardware platforms are at the core of ESL 2.0, which is characterized by the combination of the application of ESL technologies and methodologies to a larger community of users including architect and hardware development teams (at the origin of ESL), and now extended to software development, system integration and test teams; the rapid rollout and use of these technologies and methodologies in a production environment; and the use of virtual hardware platforms by the larger enterprise and its ecosystem through marketing and business development functions. CoWare is releasing six updated, integrated ESL solutions: Platform Architecture Design, Software Development, Platform Verification, Application Sub-System Design, Processor Design and DSP Algorithm Design. The new release delivers the required capabilities for a production use environment. First, through improved modeling productivity, including 50 percent improvement in user ramp-up time required for the larger production teams through design starter kits; 10x productivity improvement for the modeling of multicore platforms through SystemC Component Wizard with automatic test bench creation; Bus Library Wizard for fast and easy interconnect set up; Easy Connect for automatic resolution of point to point links; an intuitive environment for library management, block diagram editing and platform configuration; and expanded IP model library including new processor, interconnect, and peripheral IP models and a new Long-Term-Evolution (LTE) wireless library for DSP algorithm design. Second, through improvements focused on design task productivity and quality of design including: up to 200 percent platform simulation performance improvement and 400 percent stand-alone Instruction Set Simulator (ISS) performance improvement; easier and faster debug and analysis, through powerful new capabilities including the new SystemC Explorer platform debugger and the enhanced Virtual Platform Analyzer: simulation restart, memory map view and software analysis; finally 50 percent power consumption reduction and 30 percent performance improvement with new processor design features. The new CoWare ESL 2.0 solution is available now from CoWare. Pricing varies depending on the solution configuration required by the customer. CoWare, Inc., San Jose, CA. (408) 436-4720. [www.coware.com].

48

PORTABLE DESIGN

Low-Power Wi-Fi Solution for Mobile Devices Atheros Communications, Inc. has announced the Atheros ROCm single-chip AR6002 family, which features breakthrough low power for mobile WLAN solutions. The AR6002 draws near-zero standby power and has nominal impact on battery life even in active mode, both key considerations in the design of Wi-Fi-enabled mobile products. Based on consistently repeated, actual power demonstration measurements, the Atheros AR6002 consumes 70 percent less power than competitive solutions on the market in active mode while downloading content. This substantial power reduction results in longer battery life, enabling significantly more downloads and longer talk time between mobile device charges. For example, the AR6002 solution will take more than 100 hours to deplete a standard 3.7V, 800 mAh phone battery in continual VoIP mode. In another application using the AR6002, 200 gigabytes of data can be downloaded before depleting the same battery. In addition, the AR6002 significantly extends battery life by drawing virtually zero power in standby, relieving users from having to switch the Wi-Fi function on and off. As a result of its substantial power advances, Atheros’ newest ROCm Wi-Fi family generates near-zero battery impact in power-sensitive mobile devices. This performance achievement effectively eliminates the power consumption challenge facing mobile designers when determining whether to include Wi-Fi in devices like smartphones, personal media players, digital still cameras, gaming and other portable consumer devices. Atheros’ AR6002 single-chip solution is available in single (2.4 GHz) and dual-band (2.4/5 GHz) options in CSP or BGA packages to satisfy a wide array of application design requirements. The AR6002 features substantial RBOM integration onto the chip with integrated power amplifier (PA), low noise amplifier (LNA) and RF switch in a leading total solution footprint of less than 50 mm2. Atheros’ AR6002 second-generation ROCm solutions are currently sampling and will be in volume production in the first quarter of 2008. Atheros Communications Inc., Santa Clara, CA. (408) 773-5200. [www.atheros.com].


Xilinx Launches Embedded Processing Platform

Analog Devices, Inc. has introduced RF-to-digital baseband transceivers designed to enable the IEEE 802.16d/e mobile WiMAX (Worldwide Interoperability for Microwave Access) standard for mobile communications devices, such as cell phones, personal digital assistants (PDAs) and handheld multimedia devices. Building on ADI’s AD9352 and AD9353 family of integrated WiMAX transceivers introduced in 2006, the AD9354 and AD9355 consume less power than other transceivers in their class and are available in a 20 percent smaller package, while adding an additional receiver path for multiple-input multiple-output (MIMO) support. The power and space savings of the AD9354 and AD9355 enable manufacturers to incorporate WIMAX functionality into handsets, thumb drives or PCMCIA cards. By integrating ADCs, DACs and real-time control and calibration loops, the transceivers enable designers to eliminate all analog and RF functionality from their baseband processors. With separate digital and analog blocks, the communications and applications processors can be manufactured in the most cost-effective digital CMOS process technologies, reducing power, package size and system design complexity. The AD9354 and AD9355 transceivers integrate two direct-conversion receivers that provide support for MIMO technology, which ensures mobile devices achieve uninterrupted WiMAX service. The direct-conversion transmitter architecture achieves state-of-the-art error vector magnitude (EVM), maximizing network throughput. The transceivers communicate with a WiMAX terminal’s baseband ASIC or FPGA using the industry standard JESD207 digital interface that Analog Devices helped to define. The data bus requires 13 pins, which is comparable to competitive products employing analog interfaces. The AD9354 and AD9355 operate in the 2.3 to 2.7 GHz and the 3.3 to 3.7 GHz ranges and support channel bandwidths of 3.5, 4.375, 5, 7, 8.75 and 10 MHz. The devices have an excellent 3.25 dB noise figure (NF) and best-in-class linearity, both of which enable optimum real-world performance as WiMAX network traffic increases. The smart partitioning architecture enables autonomous AGC (automatic-gain control), transmit-power control (TPC) and calibration routines that dramatically reduce the RF driver development effort. Additionally, the highly accurate closed-loop power control enables 1-point factory calibration of transmit power. In contrast, other transceivers require 8 to 10 calibration points, which increase final test costs and extended development times. The AD9354 and AD9355 mobile WiMAX transceivers are sampling now. The devices are priced at $11.45 per unit in sample volumes. The AD9354 and AD9355 are housed in an 8 mm × 8 mm, 64-lead LFCSP (lead-frame chip-scale package).

Xilinx has announced its next-generation Embedded Processing Solutions, providing design teams with enhanced system-level performance, expanded flexibility and increased design environment productivity covering a broad range of applications. Anchored by an enhanced 32-128-bit Processor Local Bus (PLB), a component of the IBM CoreConnect bus standard, the platform delivers increased performance and scalability for future performance and feature requirements from Xilinx. The MicroBlaze 32-bit processor now includes the industry’s only configurable Memory Management Unit (MMU) that enables commercial-grade operating system (OS) support and is supported by a host of upgraded IP and design tools delivered with the Embedded Development Kit (EDK) version 9.2. In support of the full memory management capabilities, LynuxWorks also announced today that its BlueCat Linux v2.6 supports the MicroBlaze processor as well as the PowerPC 405 processor embedded in Virtex-4 FX devices. Version 7 of the MicroBlaze processor builds upon previous versions while maintaining instruction set backward compatibility. With the new MMU, designers can use commercial-grade embedded operating systems when implementing their designs in both the Spartan family of low-cost FPGAs for high-volume applications, as well as the high-performance Virtex family. To enhance system performance in designs targeting Virtex devices optimized for embedded applications, a direct interface to the enhanced PLB is included to extend peripheral re-use with the onboard PowerPC processor. Xilinx’s Platform Studio (XPS) provides a common, fully integrated hardware/ software development environment that supports the complete range of Xilinx possessing solutions. Included in the EDK, the scalable XPS enables designers to easily develop, integrate and debug their entire embedded system. The EDK is a complete embedded development solution that includes the XPS tool suite, the MicroBlaze processor, a library of peripheral IP cores, an integrated software development environment based on the Eclipse framework, GNU compiler, debugger and other tools for a wide range of applications. The upgraded MicroBlaze Development Kit, Spartan-3E 1600E FPGA Edition is a comprehensive kit featuring an embedded Spartan-3E 1600 FPGA board with a MicroBlaze soft processor and a complete embedded development suite for customers to get started easily. The EDK 9.2 release is immediately available for $495, and includes the MicroBlaze v7 processor core, XPS 9.2 tool suite with processing IP libraries, software drivers, documentation and reference design examples. XPS 9.2 supports MicroBlaze and PowerPC processing design for Virtex5, Virtex-4, Virtex-II Pro and Spartan-3 FPGAs. XPS 9.2 supports a broad range of computing platforms, including Windows XP (32-bit) SP1, SP2, Linux Red Hat Enterprise (32-bit 5.0 & 4.0, 64-bit 5.0) as well as Solaris 9 (2.9/5.9). The MicroBlaze Development Kit, Spartan-3E 1600E FPGA Edition is available now for $595.

Analog Devices, Norwood, MA. (781) 329-4700. [www.analog.com].

Xilinx, San Jose, CA. (408) 559-7778. [www.xilinx.com].

NOVEMBER 2007

49

products for designers

RF Transceivers for Mobile WiMAX Applications


event calendar 11/26-30/07

IEEE Globecom Washington, DC www.ieee-globecom.org 12/03-12/07

advertiser index

CISSE 2007 Bridgeport, CT www.cisse2007online.org 12/04/07

Real-Time & Embedded Computing Conference Seattle, WA www.rtecc.com/seattle 12/04/07

Atmel www.atmel.com

27

EmbeddedCommunity.com www.embeddedcommunity.com

6

Intersil Corporation www.intersil.com

5

Linx Technologies, Inc www.linxtechnologies.com

6

Arc ConfigCon Santa Clara, CA www.arc.com/configcon/ 12/06/07

Real-Time & Embedded Computing Conference Portland, OR www.rtecc.com/portland 01/22/08

Real-Time & Embedded Computing Conference Santa Clara, CA www.rtecc.com/santaclara 01/29-31/08

Mountain View Alliance www.mountainviewalliance.org www.mvacec.com

31

Mouser Electronic www.mouser.com

21

National Semiconductor www.national.com

52

Real-Time & Embedded Computing Conference www.rtecc.com

35

Rogers Corporation www.realporon.com

51

Tensilica www.tensilica.com

33

Electronics West Anaheim, CA www.electronicswestshow.com 02 to 03/08

13th Annual Intâ&#x20AC;&#x2122;l IC-China Conference & Exhibition Chengdu, Shenzhen, Beijing and Shanghai www.embedded.com 02/05-07/08

AFCEA West 2008 San Diego, CA www.afcea.org 03/11-12/08 *NEW*

Mountain View Alliance Comms. Ecosystem Conference San Francisco, CA www.mvacec.com

If you wish to have your industry event listed, contact Sally Bixby with The RTC Group at sallyb@rtcgroup.com

50

PORTABLE DESIGN

Texas Instruments www.ti.com

2


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