Design Ideas: Serving Multicell Apps & Thermal

Design Ideas: Serving Multicell Apps & Thermal Management

Embedded Software WIRELESS COMMUNICATIONS:

ZIGBEE NETWORKS CONSUMER ELECTRONICS:

DIGITAL IMAGING PORTABLE POWER:

POWERING BACKLIGHTS August 2007

Featured Product:

ARC VRaptor

www.portabledesign.com

Video Subsystems

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editorial letter 0 dave’s two cents Design industry news analysts’ pages product feature products for designers design idea

6 8 10 14 42 44 48

Code/UT

cover feature Integrated Static Analyzers: 18 A New Breed The Multimedia User Interface: 22 A Look at Things to Come Neil Henderson and Geoff Kendall, Mentor Graphics Corporation

wireless communications

18 embedded software

Analog or Digital Interface

Digital Interface

Wireless Interface ZigBee Sensor Network

26 wireless telemetry Sensor op

Maxim Sig Photon Noise

Srini Krishnamurthy, Airbee Wireless, Inc. Dark/Read noise

consumer electronics Wide Dynamic Range Imaging Techniques 32 Venkata Raghavan S., Cypress Semiconductor

portable power

Radiocrafts

802.15.4 Radio + MCU + ZigBee Networking Stack

Platform-Independent Software Enables True 26 Interoperability in ZigBee Networks

ZigBee Network Module

Sensor Board

Noise Floor

Post Release

David N. Kleidermacher, Green Hills Software, Inc.

Beta Test

Phase

Sensors

Integration

10

32

Noise Signal image

100

sensors

1,000 10,000 Photons Log Scale

Powering Backlights in Portable Devices 36 Tomi Koskela, National Semiconductor Finland

44 products for designers

AUGUST 2007

team editorial team

Editorial Director Editor-in-Chief Senior Editor Managing Editor Copy Editor

Creative Director Art Director Graphic Designer Director of Web Development

Web Developer

Warren Andrews, warrena@rtcgroup.com John Donovan, johnd@rtcgroup.com Dave Cotton, davec@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

Associate Publisher Product Marketing Manager (acting) Advertising Sales Manager

2/7/07 2:57:41 PM

Circulation

Chief Executive Officer Vice President Vice President of Finance Director of Corporate Marketing Director of Art and Media

Marina Tringali, marinat@rtcgroup.com Aaron Foellmi, aaronf@rtcgroup.com Michael Bognacki, michaelb@rtcgroup.com Shannon McNichols, shannonm@rtcgroup.com

executive management

#OMPLETE ,INE OF 0ORTABLE !UDIO 3OLUTIONS

)NNOVATION AND )NTEGRATION WITH 9OUR $ESIGN IN -IND 0RODUCTS

&EATURES

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s )NTEGRATED (0 AND 3PEAKER !MPLIFIERS s ,OW 0OWER #ONSUMPTION s (IGH 0ERFORMANCE !$#S AND $!#S s !DVANCED -ULTIBIT $ELTA 3IGMA !RCHITECTURE s 'ROUND #ENTERED /UTPUTS s 3IMPLIFIED 0OWER #ONNECTIVITY s 3MALL 0ACKAGE 3IZES

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WWW CIRRUS COM .ORTH !MERICA ʳ£ÊnĂ¤Ă¤Â‡ĂˆĂ“x‡{än{ !SIA 0ACIFIC ĂŠÂłnxĂ“ĂŠĂ“ĂŽĂ‡ĂˆÂ‡Ă¤nä£ *APAN ĂŠÂłn£Ê­ÎŽÊxĂ“Ă“ĂˆÂ‡Ă‡Ă‡xÇ %UROPE 5+ ĂŠÂł{{ĂŠÂ­Ă¤ÂŽĂŠÂŁĂˆĂ“n‡n™£‡Îää ÂĽ #IRRUS ,OGIC )NC !LL RIGHTS RESERVED #IRRUS ,OGIC #IRRUS AND THE #IRRUS ,OGIC LOGO DESIGNS ARE TRADEMARKS OF #IRRUS ,OGIC )NC !LL OTHER BRANDS AND PRODUCT NAMES MAY BE TRADEMARKS OR SERVICE MARKS OF THEIR RESPECTIVE OWNERS

PORTABLE DESIGN #IRRUS?#3 , 0$? INDD

John Reardon, johnr@rtcgroup.com Cindy Hickson, cindyh@rtcgroup.com Cindy Muir, cindym@rtcgroup.com Aaron Foellmi, aaronf@rtcgroup.com Jason Van Dorn, jasonv@rtcgroup.com

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

corporate office 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.

0-

Intersil Battery Authentication High Performance Analog

We’re On It.

Intersil’s ISL9206 FlexiHash+TM Engine delivers high-security battery authentication at a low cost.

Intersil’s ISL9206 is an easy-to-use, robust, and inexpensive battery authentication solution for 1-cell Li-Ion/Li-Polymer or 3-cell NiMH series battery packs.

64-bit Secret 32-bit Hash Function 32-bit Hash Function

32-bit pseudo-random challenge word from host FlexiHash+ Engine

8-bit authentication code

ISL9206 Key Features: Challenge/response-based authentication scheme using 32-bit challenge code and 8-bit authentication code.

Oscillator

1-Wire Comm Interface

FlexiHash+ engine uses two sets of 32-bit secrets for authentication code generation.

16x8 OTP ROM

FlexiHash+ Engine

POR/2.5V Regulator

Control Register

16x8 one-time programmable ROM memory.

Additional programmable memory for storage.

Go to www.intersil.com for samples, datasheets and support

Intersil – Switching Regulators for precise power delivery. ©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).

Patent pending FlexiHash+ engine consists of four separate programmable CRC calculators. Two sets of 32-bit secret codes are used for authentication code generation.

XSD single-wire host bus interface communicates with all 8250-compatible UARTs or a single GPIO pin. Supports CRC on read data and transfer bit-rate up to 23Kbps.

16 bytes of one-time programmable ROM memory for storage of pack information and ID, device authentication secrets, device default settings, and factory-programmed trim parameters.

editorial letter

N

Not long ago every start-up company dreamed of “going public.” You started off with private equity—mortgaging your house, borrowing from “angel investors” or venture capitalists— and, if you were lucky, you would end up going public, achieving a valued stock ticker and access to a wide pool of equity financing. Tech IPOs were still popular in 2006; Infineon spun off Qimonda last August with a NYSE listing that brought in $546 million.

Now, suddenly, more and more publicly traded electronics and semiconductor companies are dreaming of “going private” again.

Right after the Qimonda listing, Philips spun off NXP to a consortium of private investors.

Having lost its own bid for NXP, Freescale soon decided to go private itself, agreeing in December to be purchased by a consortium led by the Blackstone group for $17.6B. Suddenly CEOs of publicly traded tech

Is Private Equity the Wave of the Future? john donovan, editor-in-chief

companies—tired of being slaves to quarterly conference calls, Sarbanes-Oxley reporting requirements, proxy fights and the threat of shareholder lawsuits—started looking at going private. As of this writing, AMD, Micron, Lexmark and Cadence are all rumored to be considering going this route. Kohlberg Kravis Roberts (KKR) and the Blackstone Group—two of the largest private equity firms—are reportedly on the prowl for more tech company acquisitions.

Is this the wave of the future? And is that good or bad for the electronics industry in general and the semiconductor industry in particular?

Companies have traditionally turned to the stock market to raise capital for expansion.

They’ve then been able to use stock options to help retain staff. Silicon Valley firms in particular used to give them out like candy, until the tech crash of 2001, and the more recent backdating scandal made options a lot less attractive than cash. The only alternative to the stock market used to be banks, but their role has been largely replaced by private equity firms, often fueled by hedge fund money. Pri

PORTABLE DESIGN

vate equity firms raised an estimated $240B in the first half of 2007 in the U.S. alone, where their deals made up over a third of all mergers and acquisitions.

The arguments in favor of private equity are strong. Going private relieves executives of the need to constantly look over their shoulders at government regulators, shareholder lawyers, short sellers and irksome reporters who might cause their share prices to plunge. They now have only one boss with one agenda, not a spectrum of bosses with conflicting agendas. Now if the company makes a profit, it can re-invest it in R&D without being hammered by investors to give it back to them. Strategic planning can now be focused on capital investments that will be of long-term benefit to the company, not worrying about the hit that will result in the next quarter.

The arguments against private equity are equally strong. Private equity firms are often accused of “asset stripping,” selling off parts of a company to turn a quick profit. In all fairness, this is often the case with any acquisition, selling off loss-making parts of business to help restore the company to profitability. Despite early fears, that hasn’t been the case with either NXP or Freescale, who began pruning such operations as far back as 2000.

The larger problem is that private equity firms load up their acquisitions with more debt than any publicly traded firm would be allowed to accept. Paying down that debt load can cause serious problems in a notoriously cyclical industry like semiconductors. Freescale now carries a long-term debt of $9.4B, over 10x larger than before the LBO. They acknowledged in their March S-4 filing that their debt load from the merger may limit their ability “to obtain additional funding,” something that was not a problem when they had access to equity markets.

What will be the effect of private equity on the semiconductor market? NXP is a more profitable, nimble competitor since going private, as is Freescale. Both companies are moving to a “fab light” model and working with partners to cut the enormous CAPEX involved in moving to smaller geometries. Both have laid off a large number of employees, though this is true in the case of most acquisitions. The overall effect of private equity would seem to be beneficial as long as the debt service remains tolerable.

Most private equity firms intend to re-list their acquisitions again in 3-5 years—the traditional “exit strategy” of venture capitalists, which is what they are. We’re in the early stages of a 3-5 year experiment that will ultimately bring us back to where we started.

Intersil Handheld Products High Performance Analog

We’re Hip to Handheld.

Improve your performance in portable media players with Intersil’s high-performance analog ICs.

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

Go to www.intersil.com for samples, datasheets and support

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

dave’s two cents

V

Vacations are a good time to watch people and how they use portable products. This year was the first time I noticed more women using cameras than men. Right after Mother’s Day I went to a major discount store to buy a package of plastic protection sheets for small LCD screens, but they were sold out. It would be another week before their camera accessories would be restocked after the recent camera buying frenzy.

At the time, I thought a digital camera would be a nice gift, but may be seldom used.

Wow, was I wrong! My vacation observations showed that about three-fourths of the photographers were female, often using more advanced Digital SLRs versus the simple point-and-shoot models. On the plane ride to our destination, a

dave’s two cents on...

Women Driving Digital Camera Features and Technology woman sitting in front of me spent nearly a full three hours reading the user manual for her new DSLR. I wondered what my camera manual said that I didn’t know. While disembarking, I asked if she was ready to enjoy her new camera. She said yes, and was eager to experiment with the new modes of operation. Her husband spent his time reading newspapers.

Info Trends reported last year that digital camera sales would peak in 2006; predicted that 2007 and beyond will have flat or declining sales; and that several digital camera companies will have forgone the low-cost, point-and-shoot market. This may be due to the increasing number of repeat buyers looking to upgrade their equipment. They represent more than 34 percent of a growing market. New camera technologies play a big role in repeat buying decisions. If the buyer moves into DSLRs, lenses could help to influence product loyalty. However, new technology continues to be an important factor.

Recently several announcements were made concerning new technology for digital cameras.

In particular, Kodak announced a new sensor

PORTABLE DESIGN

filter that can greatly improve low-light performance. It uses one monochromatic pixel for every color pixel. The traditional filter (Bayer pattern) uses two green, one blue and one red pixel to create RGB values. This innovation uses half the pixels to acquire luminance information and the other half for color information using the Bayer pattern ratio in order to process a color photo using Kodak-developed algorithms. This sensitivity improvement can be two to four times better than that obtained with the Bayer pattern filter. The benefits are faster shutter speeds for less motion blurring, much less noise at the same shutter speed and higher pixel count for the same size image. This innovation also has applications in cell phone cameras with small aperture lenses. Kodak plans to release the first cameras with this technology in 2008.

Improved low-light sensitivity can be coupled with image stabilization (IS), another valuable feature found on many new cameras.

Initially, IS was found mostly on cameras with a 5X or better zoom. However, IS is also good for low-light and corresponding slow shutter speeds. Image stabilization enables either the lens to be stopped down by two to three Fstops or the shutter time to be four to six times longer. However, few hands can do better than 1/10 second, even with IS. While visiting the Maine State Aquarium, I think I was the only male taking pictures out of the 10+ people with cameras. Many photographers experienced frustration because either the flash bounced off the glass or the aquarium was too dark. But that did not stop the clicking shutters; it just resulted in more pictures being taken. Coupling IS with Kodak’s new filter and processing algorithm could improve light gathering by as much as 10X by using more light and longer shutter speeds, resulting in brighter photos without a flash. This convenience certainly may motivate the repeat buyer—making many moms much happier.

For my two cents, photography used to be all about the lenses and the film. The recreational photographer would shoot a couple of rolls and hope that they had a few good pictures. Now, with digital photography, many more pictures are being taken with the hopes for a higher ratio of good pictures. I think it will become increasingly important to appeal to the recreational female photographer who won’t want the camera to get in the way of a good memorable picture. For now, I think I’ll get my wife to read my camera’s owners manual and tell me what I don’t know.

Dave Freeman, Texas Instruments

INDUSTRY’S FIRST NEGATIVE WHITE-LED CHARGE PUMPS ACHIEVE HIGHEST EFFICIENCY Independent Adaptive Mode Switching for Each LED Improves Efficiency by 12%

The MAX8647/MAX8648 utilize a negative charge-pump architecture to reduce in-line resistance and maximize efficiency by delaying mode switching from 1x to 1.5x operation during battery discharge. Combined with independent adaptive mode switching for each LED, this architecture improves efficiency by 12%, even with high LED forwardvoltage (VF) mismatching. These superior features make the MAX8647/MAX8648 ideal for cell phones, smartphones, portable media players, and other portable devices in which every milliamp-hour of battery life is crucial.

INPUT 2.7V TO 5.5V

LED 1

IN 1µF

SCL VDD

(Four LEDs, IF = 15mA, VF1 = 3.7V, VF2 = 3.6V, VF3 = 3.5V, VF4 = 3.4V) 100

LED 3

SDA

I2C CONTROL

EFFICIENCY vs. Li+ BATTERY VOLTAGE

LED 2

MAX8647 INTERFACE CONTROL

CURRENT REGULATORS AND SWITCHES

90 EFFICIENCY PLED/ PBATT (%)

Li+

LED 4

LED 5

93% PEAK EFFICIENCY

NEGATIVE CHARGE PUMP

MAX8647

80

AVG 81% AVG 69%

MORE BATTERY LIFE, NO ADDED COST

70 60

CONVENTIONAL POSITIVE CHARGE PUMP 50

LED 6

1µF NEG

DELIV HIGHER ERS 12% THAN C EFFICIENCY OMPET ITION

OUTPUT 0.1mA TO 24mA PER LED

40 4.20

3.90

3.85

3.80

3.75

3.70

3.65

3.60

3.55

3.50

3.40

3.00

Li+ BATTERY VOLTAGE (V, TIME WEIGHTED)

TQ 16- FN

♦ Adaptive, Independent Current Regulator for Each LED ♦ Drive Up to Six White or RGB LEDs ♦ ±0.4% Accurate Current Matching ♦ Low 70μA IQ ♦ 1MHz Fixed-Frequency Switching for Small Components

m x 3m

m

m

3

EACH LED DYNAMICALLY SWITCHES TO MINIMIZE LOSS

♦ Multizone Light Management for Up to 32 Brightness Levels or 32,768 Colors with RGB LEDs ♦ Ambient Temperature Derating Protects LEDs at High Temperatures ♦ Serial Pulse Dimming Interface (MAX8648) ♦ EV Kit Available ♦ Prices Start at $1.95† (MAX8647) and $1.70† (MAX8648)

†2.5k-up pricing provided is for design guidance and is FOB USA. International prices will differ due to local duties, taxes, and exchange rates. Not all packages are offered in 1k increments, and some may require minimum order quantities.

www.maxim-ic.com/MAX8647-info FREE Displays Design Guide—Sent Within 24 Hours!

CALL TOLL FREE 1-800-998-8800 (7:00 a.m.–5:00 p.m. PT) for a Design Guide or Free Sample

DIRECT

™

1-888-MAXIM-IC

1-800-777-2776

1-800-332-8638

Distributed by Maxim Direct, Arrow, Avnet Electronics Marketing, Digi-Key, and Newark.

The Maxim logo is a registered trademark of Maxim Integrated Products, Inc. © 2007 Maxim Integrated Products, Inc. All rights reserved.

news Microchip Launches Semiconductor Wiki

Microchip Technology Inc. has announced ICwiki (www.microchip.com/ICwiki)—a Web site that enables engineers, students and professors working with microelectronics to collaborate and share information related to semiconductor products, applications and best practices.

Using Wiki technology, participants can change content on the site and participate in Web log-

nd

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

ging (or “blogging”), voting and messaging. ICwiki is available in several different languages, including English, Spanish, Chinese, Japanese, French, German and Russian. ed Following recent trends toward online social networking, ICwiki was designed to help engineers share knowledge about designs and applications, and to help university students gain access to industry knowledge that can help bridge their transition from academia to companies providing solutions now industry.

Participants work together in eiexploration into products, technologies and companies. Whether your goal is to research the latest datasheet from a can company, mp to a company's technical page, the goal of Get Connected is to put you in touchther withpublic the right or resource.

Whichever private blogs level via of the site’s Group gy, Get Connected will help you connect with the companies and products you areDecision searching for.Support Systems (GDSS) feature. onnected Subject areas include vertical markets such as automotive, home appliances and robotics; function topics such as algorithms, oscillators, PCB layout best practices and signal conditioning; or product topics such as microcontrollers, Digital Signal Controllers (DSCs), analog and memory products.

ICwiki’s GDSS feature enables an author to start a new blog and invite selected members to join the group, while restricting access to others. In addition to blogging, ICwiki alGet Connected with companies mentioned in this article. lows voting or “polling,” where users can post www.portabledesign.com/getconnected a question and then view the responses online.

End of Article

10

PORTABLE DESIGN

Get Connected with companies mentioned in this article.

Its “messaging” feature allows users to communicate with each other, without disclosing e-mail addresses.

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

AMI Semiconductor Reports Earnings Up, Market Focus Shifting

In a conference call with editors and analysts, Dr. Ted Tewksbury, president and chief operating officer of AMI Semiconductor (AMI), expanded on the recently announced financial results for Q207.

AMI (NASDAQ: AMIS) announced second quarter revenues of $157.0 million, an increase of 4% both sequentially and year on year.

Gross margins were down slightly at 44.9%; operating margin was 6.1%, flat from Q1 but up slightly from Q206. GAAP operating margin was 6.1%; non-GAAP was 14.0%, the difference being due to acquisition and restructuring charges.According to an AMI statement, operational improvements that contributed to gross margins were “unfortunately offset by product mix.”

In Q2 07 AMI made 28% of its revenues ($45 million) from the automotive segment; 16% ($26 million) in the medical sector; 25% ($38 million) in industrial; 8% ($13 million)

in military/aerospace; and 7% ($12 million) in communications. Tewksbury attributed the hit on their operating margin to the medical sector. Three factors were responsible: the FDA tightening qualification standards for medical devices; Medicare tightening reimbursements for medical imaging procedures; and inventory buildup among AMI’s medical customers. Still, Tewksbury expects the medical segment— where, according to Gartner, AMI is the number one chip supplier—to be up year on year.

Tewksbury noted that AMI, which has long

run its own foundries in Europe and the U.S., intended to focus more on value added services and less on fabrication. “We used to be primarily a foundry/ASIC company,” said Tewksbury; “We have now migrated to a more market focused model rather than technology-based. We offer whatever skills and technologies customers need to solve their problems.” Whereas previously AMI’s primary differentiation had been process technologies, their new focus will be on adding more value. Process differentiation will be less critical. “Our foundry strategy will be: Use the lowest cost technology that will get the job done.”

AMI Semiconductor, Pocatello, ID. (208) 233-4690. [www.amis.com].

Software Defined Radio May Play Key Role in Emerging Broadband Wireless Access Market

According to a new study commissioned by the SDR Forum, software defined radio (SDR) stands poised to play a major role in delivering emerging triple-play services—voice, data/ Web and video—to portable devices.

The 52-page study—titled “Wi-Fi, WiMAX, and Beyond 3G/4G” and subtitled “Broadband Wireless Access (BWA)”—provides a comprehensive look at BWA market opportunities for the SDR community and the challenges it faces.

One such opportunity, the study says, is multiradio, whereby multiple radio standards (or waveforms) are included on a single mobile, portable or infrastructure platform. For example, a GSM cellular, a Wi-Fi and a GPS waveform could operate in parallel to provide wide-area, local-area and location services. As a result, SDR would need to address not only waveform selection—its traditional focus—but also simultaneous operations.

The SDR opportunities would be focused on reuse, portability, minimizing co-channel interference, optimizing RF links, beam-forming, multi-user detection, antenna sharing and power reduction.

The study concludes that virtually all stakeholders in the industry have indicated intentions for multiradio deployments that address Wi-Fi, WiMAX and beyond 3G waveforms on common platforms and for using SDR-centric

concepts and technologies to achieve the SDR platform benefits.

SDR Forum, Denver, CO. (303) 628-5461. [www.sdrforum.org].

NFC Forum Issues Specifications for Four Tag Types

The NFC Forum, a non-profit industry association that advances the use of near field communication (NFC) technology, has announced the publication of four tag type technical specifications. The specifications are available to the public for download at no charge from the NFC Forum Web site, www.nfc-forum.org/specs/.

NFC is a short-range, wireless connectivity technology that allows consumers to perform safe, contactless transactions, access digital content and connect electronic devices with the simplicity of a single touch. Consumers with NFC-enabled mobile phones may, for example, leave their wallets at home and use their phones to conduct contactless financial transactions, or to gain electronic access to public transportation.

Tags are integrated circuits that store data that can be read by NFC-enabled devices to support these applications. For example, a cin-

ema goer with an NFC-enabled mobile phone may touch the phone to a movie poster containing an embedded NFC tag to view a preview of the movie.

By standardizing the tag types and formats with the specifications announced today, the NFC Forum is promoting interoperability across the NFC market, enabling low-cost volume production, and clearing a path to a global, cost-effective mass market. More than one billion NFC-ready tags are already deployed worldwide for use in areas such as accessing public transportation, hotel rooms and offices.

NFC Forum, Wakefield, MA. (781) 876-8955. [www.nfc-forum.org].

Accellera Announces Election of Corporate Member Companies to Its Board

Accellera, the electronics industry organization focused on Electronic Design Automation (EDA) standards, has announced that its Board of Directors elected fourteen Corporate Member companies to its Board for the 2007/8 membership year. The election was held at the Accellera Board meeting at the Design Automation Conference.

Accellera Corporate Member companies for 2007/8 are: ARM Ltd., Cadence Design Systems, Denali Software Inc., Freescale Semiconductor, IBM, Intel Corporation, Magma Design Automation, Mentor Graphics, Nokia, Novas, Rockwell Collins, Sun Microsystems, Synopsys Inc. and Texas Instruments. The Accellera Board, comprised of these companies, includes representation from users and suppliers alike.

Bringing additional industry perspective to Accellera standards are: Aldec, Inc., Archpro Design Automation, Azuro, Inc., Certess Inc., Jasper Design Automation, OneSpin Solutions, Silvaco, SpringSoft, Inc., ST Microelectronics, Toshiba and Xilinx, which are represented in Accellera as Associate Members.

Accellera has developed nine standards that have been transferred to the IEEE. Seven have been ratified by the IEEE and the two newest ones are in active IEEE working groups now.

Accellera’s successes in advanced design and verification language standards include SystemVerilog and the Property Specification Language (PSL). Accellera recently completed the Unified Power Format (UPF) standard and is currently developing a Unified Coverage Interoperability (UCI) standard.

Accellera Organization Inc., Napa, CA. (707) 251-9977. [www.accellera.org].

Cirrus Logic Closes Transaction to Acquire Apex Microtechnology

Cirrus Logic Inc. has announced that it has closed on its agreement to acquire Apex Microtechnology, a leading provider of precision high-power analog amplifier products, for approximately $42 million in cash.

Founded in 1980 with headquarters in Tucson, Ariz., Apex Microtechnology is a leading innovator of integrated circuits, hybrids and AUGUST 2007

11

news Ericsson and Texas Instruments to Co-Develop 3G Solutions for Handset Manufacturers

modules used in a wide range of industrial and aerospace applications that require high-power precision analog products, such as PWM and power amplifiers. These precision amplifiers are used for driving motors, piezo electrics, programmable power supplies and other devices requiring high power and precision control.

Cirrus Logic intends to continue marketing the Apex hybrid products under the Apex precision Power brand and supporting Apex’s approximately 80 products and 1,200 customers worldwide.

Cirrus Logic, Austin, TX. (512) 851-4000. [www.cirruslogic.com].

Wolfson Acquires Sonaptic Limited

nd

Wolfson has announced that it has acquired Sonaptic Limited for an initial consideration of $24.8M. Wolfson extends its mixed-signal audio leadership with the acquisition of world class acoustic technology—enabling exciting new user experiences for consumer electronic ed devices.

Sonaptic Limited is a world leading provider of advanced micro-acoustic technologies based on more than 12 years of research

by Sonaptic’s founders. The acquisition will provide the third part of Wolfson’s AudioPlus companies providing solutions now growth strategy, is aimed at building on exploration into products, technologies and companies. Whether your goal is to research the latest datasheet which from a company, mp to a company's technical page, the goal of Get Connected is to put you in touchWolfson’s with the rightworld-class resource. Whichever level ofin high fidelity position gy, Get Connected will help you connect with the companies and products you areaudio searching for. semiconductors. onnected The acquisition will enable Wolfson to combine mixed-signal design and acoustic skills to offer advanced active noise cancellation, sound enhancement, 3D sound and acoustic echo cancellation in combination with its existing high-quality, low-power audio products for consumer electronic applications. These include Personal Media Players (PMP), mobile handsets, portable gaming consoles, Flat Panel TVs (FPTV), Portable Navigation Devices (PND) and automotive applications.

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Ericsson and Texas Instruments have announced that the companies will form a strategic technology engagement to develop custom solutions for new Open OS-enabled 3G devices.

Solutions from the technology created by the two companies will combine 3G modems from Ericsson Mobile Platforms with OMAP applications processors from TI. Solutions from the joint engagement will include OMAP, custom basebands and connectivity technologies and will be capable of supporting the major Open OS, which offers easy access to a rich array of applications and services. The result of this joint effort will enable all device manufacturers to offer advanced Open OS handsets for both the high-end and the rapidly growing mid-range market.

Ericsson’s access technology, current HSPAenabled platforms and future HSPA evolution and LTE technologies, combined with the multimedia performance enabled by TI’s OMAP 2, OMAP 3

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Wolfson Microelectronics, Inc., San Diego, CA. (858) 676 5090. [www.wolfsonmicro.com].

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and future generations of OMAP processors, are intended to push the performance boundaries of mobile devices and mobile entertainment features. By leveraging TI’s OMAP platform with Open OS support for Windows Mobile, Symbian S60, Symbian UIQ and Linux, these solutions will provide OEMs and operators with a robust and flexible architecture for applications and services deployment. This will enable handset manufacturers and mobile operators to differentiate their products through easy-to-use and customizable user interfaces, and through a robust and flexible application architecture.

Handsets based on these solutions are expected to be available on the market in the second half of 2008.

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

analysts’ pages New Influences Are Shaping User Expectations for Mobile Handsets

The global handset market could be about to undergo a major change during the next five years, providing handset vendors and component suppliers with opportunities to reshape consumers’ understanding of mobile devices, mobile computing and mobile connectivity, reports In-Stat. Four key factors that the high tech market research firm expects to shape handsets in the coming five years include the

table 1

In-Stat, Scottsdale, AZ. (480) 483-4440. [www.in-stat.com].

Q2 Rank

Company

Q2 ‘07 Revenue

Q2 Share

Q1 ‘07 Revenue

Sequential Q2 ‘06 Growth Revenue

Year to Year Growth

1

Samsung

2,083.8

28.4%

2,503

-16.7%

2,150.0

-3%

2

Hynix

1,518.0

20.7%

2,160

-29.7%

1,174.0

29%

3

Qimonda

988.0

13.5%

1,283

-23.0%

1,206.0

-18%

4

Elpida

885.0

12.1%

1,171

-24.4%

764.0

16%

5

Micron

741.8

10.1%

880

-15.7%

854.0

-13%

6

Nanya

347.0

4.7%

510

-32.0%

534.0

-35%

7

Powerchip

318.0

4.3%

527

-39.7%

342.0

-7%

8

ProMos

224.0

3.1%

393

-43.0%

260.0

-14%

9

Etron

94.0

1.3%

85

10.6%

57.0

65%

10

Winbond

38.0

0.5%

45

-15.6%

36.0

6%

Others

96.3

1.3%

101.0

-4.7%

109.0

-12%

iSuppli Total

7,333.8

100.0%

9,658

-24.1%

7,486.0

-2%

nd

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

ed

Preliminary DRAM Revenue Market Share in Q2, 2007 (Revenue in Millions of U.S. Dollars) Source: iSuppli Corp. July2007 companies providing solutions now

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 touchApple with theiPhone; right resource.

Whichever level of alternative networks, such as gy, Get Connected will help you connect with the companies and products you areWi-Fi searching for. and WiMAX; mobile video and televi-

onnected

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14

pected to drive development of dual-mode cellular/Wi-Fi handsets.

• Deployment of mobile broadcast networks (e.g., DVB-H and MediaFLO), as well as other sources of video for mobile devices, will require changes to handset applications, semiconductors and displays to provide the best viewing experience.

• WiMAX could lead to a new generation of devices that combine cellular and Internet functions.

sion; and more corporate-liable subscriptions.

“These influences will have a powerful effect on the design of mobile devices, as well as the semiconductors and applications used in them,” says David Chamberlain, In-Stat analyst.

Recent research by In-Stat found the following: • The iPhone introduced a number of technologies that were not yet common in mobile phones including touch screens and acceleration and proximity sensors.

• Both business and consumer users are ex-

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DRAM Disaster Sinks Suppliers in Q2

How bad were conditions in the DRAM market in the second quarter? According to iSuppli: • So bad that global DRAM revenue declined by 24.1 percent, falling to $7.3 billion, down from $9.7 billion in the first quarter.

• So bad that Samsung Electronics Co. Ltd. and Micron Technology Inc., which suffered 16.7 percent and 15.7 percent respective declines in revenue during the quarter, actually significantly outperformed the market and gained share.

• So bad that the DRAM per-megabit Average Selling Price (ASP) plunge of 39 percent was actually marginally good news, because it was slightly less than the 40 percent drop iSuppli Corp. had predicted.

Indeed, it was a terrible quarter for DRAM makers, with only one supplier among the Top10, Etron Technology Inc., managing to grow its revenue during the period.

A major culprit behind the poor market conditions was a rise in part availability, with megabit shipments increasing by 23 percent during the period. This was nearly 3 points higher than the increase predicted by iSuppli, indicating that the market oversupply in the second quarter was even more severe than anticipated.

The second quarter’s 23 percent sequential megabit growth was even higher than the 21 percent rise in the first quarter. The DRAM bit growth in the first half of 2007 increased by 89 percent compared to the first half of 2006. This over-

iSuppli Corporation, El Segundo, CA. (310) 524-4000. [www.isuppli.com].

Bluetooth Market Continues Growth, but Rate Is Slowing

Bluetooth had another successful year in 2006, and it will have continued success in 2007, led by its increasing penetration into mobile phones, reports In-Stat. However, market growth for Bluetooth products is beginning to slow, and it will see some complications arising from integration trends and new Bluetooth standards hitting the market, the high-tech market research firm says. The market for Bluetooth chips is also in flux.

“The Bluetooth silicon market is beginning to see some consolidation, as larger silicon vendors add new capabilities, such as Wi-Fi and GPS, to their chip portfolios, either by internal development or acquisition,” says Brian O’Rourke, In-Stat analyst. “The goal is to create combined radio silicon that is being demanded by mobile phone vendors.”

Recent research by In-Stat found the following: • Growth of Bluetooth devices will increase by 34% in 2007, slowing from the recent past.

• Wireless chip companies are seeking to offer integrated radio chips with Bluetooth, Wi-Fi, GPS and FM. • New low power and high data rate Bluetooth standards will emerge over the next two years.

• According to recently conducted In-Stat surveys; France, Germany and the UK have the highest percentages of those extremely or very familiar with Bluetooth. Korea and Japan had the lowest percentages, while the U.S. was in the middle.

Smartphones Headed for Mass Adoption in China

Driven by the continuous functional improvement of Smartphones, the introduction of middle-range models, better designs and the enrichment of third-party applications, 10.46 million Smartphones shipped in China in 2006, double from 2005, reports In-Stat. The explosive growth indicates that the Chinese Smartphone market will soon enter the mass adoption stage, the high-tech market research firm says. Entertainment functions are Chinese Smartphone owners’ primary favorites, rather than productivity functions, according to an In-Stat consumer survey.

“The most important three factors respondents would consider when purchasing their next Smartphone are function, brand and price,” says Raymond Yan, In-Stat analyst. “Security, Internet access and synchronization with PCs are the top three problems that existing Smartphone users thought needed improvement.”

Recent research by In-Stat found the following: • 97.9% of Smartphone users would purchase another Smartphone when their current phone needs replacement.

• More than half of Smartphone owners paid $25 or more every month for wireless services, 30% higher than that of non-Smartphone users.

• Most Smartphone users have no idea about the OS of the phone and do not care about it when purchasing Smartphones.

In-Stat, Scottsdale, AZ. (480) 483-4440. [www.in-stat.com].

Government Drives 3G Wireless Transition in China

China’s National Development & Reform Commission (NDRC) believes that a fundamental restructuring of the nation’s telecom industry is essential to promote the long-term growth of the country’s fixed and wireless core communications networks.

Because of this, the Chinese government is offering 3G licenses to the four state-owned telcos—China Mobile, China Unicom, China Telecom and China Netcom—as incentives if they are willing to accept reforms, according to iSuppli Corp. iSuppli believes that China’s core fixed and wireless networks all are transitioning to Internet Protocol (IP)-based Next-Generation Networks (NGNs). Furthermore, increasing numbers of media gateways and servers will allow China’s telecom networks to deploy advanced support services, video content distribution and online gaming. By offering this improved multimedia capacity, operators can more easily introduce new value-added services that in turn will generate more revenue for the state-operated companies. Mobile handsets in China also will have to incorporate more advanced multimedia capabilities and open operating systems. iSuppli forecasts that China’s TD-SCDMA 3G subscribers will jump to 28 million by 2011, up from 1.1 million subscribers in 2007. By 2008, 3G subscribers in China will reach 6.4 million. For each of these subscribers, a new mobile handset will be required,

iSuppli Figure: China’s 3G Value-Added Service Forecast (Millions of U.S. Dollars)

Millions of U.S. Dollars

supplied market condition contributed greatly to the drop in prices in the second quarter.

While the DRAM companies encountered varying fortunes in the second quarter, there were no real losers and winners. The industry as a whole experienced painful price drops amid an extremely oversupplied situation. The market clearly hit the bottom in the second quarter, and the suppliers’ profitability will be much better in the second half of the year, iSuppli predicts.

25,000

Others

20,000

Video Music

15,000

Games Pictures

10,000

Color Ring Back Tones 5,000 0

MMS SMS 2006

2007

2008

2009

2010

2011

In-Stat, Scottsdale, AZ. (480) 483-4440. [www.in-stat.com].

AUGUST 2007

15

analysts’ pages offering a new selling opportunity for many companies inside the wireless telecom industry in China.

However, iSuppli believes that a key revenue driver in China will come from the applications that will be enabled by 3G. Chinese consumers will be able to access the Internet, download music, stream Internet video, use mobile mailboxes, pay bills online and engage in mobile blogging and interactive 3D gaming—all through their mobile phones.

This expansion of the value-added services to the telecom industry in China will infuse the country with new revenues coming from domestic consumers. iSuppli believes most consumers will be naturally curious to explore the additional functions of their mobile handsets. iSuppli forecasts China’s 3G value-added services market will grow to $19.5 billion in revenue by 2011, maintaining a Compound Annual Growth Rate (CAGR) of 17.4 percent from $8.8 billion in 2006.

The table presents iSuppli’s revenue forecast for 3G value-added services in China for the period of 2006 through 2011.

Portable Devices Help Drive Rising Power-Management Chip Sales

iSuppli Corporation, El Segundo, CA. (310) 524-4000. [www.isuppli.com].

iSuppli Corporation, El Segundo, CA. (310) 524-4000. [www.isuppli.com].

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16

PORTABLE DESIGN

The global power-management semiconductor market will expand significantly during the next few years, driven in part by rising demand from makers of portable electronic equipment, iSuppli Corp. predicts.

Worldwide revenue from shipments of power-management semiconductors will rise to $39.9 billion in 2011, a 59.6 percent increase from $24.98 billion in 2006. Semiconductors in this segment include voltage regulators, powermanagement ASICs and Application-Specific Standard Products (ASSPs), rectifiers, thyristors and power transistors. “As sales of portable products like Portable Media Players (PMPs) and mobile handsets continue to rise, and the battery-life requirements for such devices continue to toughen, demand is rising for more sophisticated power-management solutions,� said Marijana Vukicevic, senior analyst for iSuppli. “This is a major factor behind the expected expansion of the power-semiconductor market over the next few years.�

cover feature embedded software

Integrated Static Analyzers: A New Breed New analysis tools enable you to catch more software bugs in less time.

by David N. Kleidermacher, CTO, Green Hills Software, Inc.

M

Many of the problems relating to loss of quality in software can be attributed to the growth of complexity that cannot be effectively managed.

Security flaws are one example of the downstream effect. According to Carnegie Mellon University’s Computer Emergency Response Team (CERT), the number of documented vulnerabilities has been increasing almost exponentially, from approximately 400 in 1999 to more than 4000 in 2002 and more than 8000 in 2006.

A number of studies over the years have shown that the cost of detecting and correcting a software flaw increases dramatically as a project moves through the development, integration, quality assurance and deployment cycle (Figure 1).

Increased complexity and cost of defect resolution strain traditional reliability techniques such as code reviews and functional testing, implying a growing necessity for automated static

18

PORTABLE DESIGN

analysis tools that can find more flaws, and find them early in the development process. A number of limitations, however, have prevented widespread adoption of static analyzers in everyday software development. A recent survey of software developers showed that less than 5% make regular use of these tools. Developers cited prohibitive execution time and lack of development environment integration as key inhibitors. A new breed of static analysis tool, called an Integrated Static Analyzer (ISA), uses a unique and innovative approach to address these barriers.

Static Analysis: How It Works

A static analyzer performs a full program analysis, finding bugs caused by complex interactions between pieces of software that may not even be in the same source file. The analyzer determines potential execution paths through the code, including paths into and across sub-

Analyzers often have knowledge about how standard run-time library functions behave.

For example, the analyzer knows that subroutines like free should be passed pointers to memory allocated by subroutines like malloc.

The analyzer uses this information to detect errors in code that calls or uses the result of a call to these functions. The analyzer can also be taught about properties of user-defined subroutines to enhance the efficacy and accuracy of the analysis. One common feature of quality static analyzers is an ability to limit

cover feature

the number of false positives so that developers can minimize time looking at them. If an analyzer generates too many false positives, it

figure 1 100 90 80 70 Unit of Cost

routine calls, and how the values of program objects (such as variables or aggregates) could change across these paths. The following is a list of some of the more common errors that the analyzer will detect: • Potential NULL pointer de-references • Access beyond an allocated area (e.g., array or dynamically allocated buffer); otherwise known as a buffer overflow • Writes to potentially read-only memory • Reads of potentially uninitialized objects • Resource leaks (e.g., memory leaks and file descriptor leaks) • Use of memory that has already been deallocated • Out of scope memory usage (e.g., returning the address of an automatic variable from a subroutine) • Failure to set a return value from a subroutine • Buffer and array underflows

60 50 40 30 20 10 0

Design

Code/UT

Integration

Beta Test

Post Release

Phase Cost of software flaws.

figure 2

Configuration can often be time consuming, requiring days of customization.

Web page flaw summary.

AUGUST 2007

19

cover feature

will become irrelevant because the output will be ignored by engineers.

Static analyzers commonly generate their results as a set of Web pages hosted by a Web server. The Web interface enables the user to browse high-level summaries of the different flaws found by the analyzer (Figure 2) and then click on hyperlinks to investigate specific problems. Within a specific problem display, the error is usually displayed inline with the surrounding code, making it easy to understand (Figure 3). Results are easily shared between members of the development team.

IDE Integration

Commercial static analyzers traditionally run as separate tools, distinct from the tool chain used to develop and build application software.

Thus, users must separately install, license and nd configure the analyzer. Configuration can often be time consuming, requiring days of customizaer exploration ether your goal tion in order to cajole the analyzer into processspeak directly ing the user’s particular dialect of source code. ical page, the ght resource.

A new type of analyzer, called an Integrated technology, Static Analyzer (ISA), performs static analysis es and products within the same compiler used to build softed ware. Green Hills Software’s DoubleCheck is one example of an ISA. The ISA approach brings with it the obvious advantage of reducing the time required to get useful results from the tool. In addition to the standard Web page reports, an ISA can generate its warnings or ercompanies providing solutions now rors other standard diagexploration into products, technologies and companies. Whether your goal is to research the interleaved latest datasheet with from a the company, mp to a company's technical page, the goal of Get Connected is to put you in touchnostics with the right resource. level of Furthermore, output

by Whichever the compiler. gy, Get Connected will help you connect with the companies and products you arecommon searching for.development environment integraonnected tions between the project builder and the editor augment the usability of the static analyzer: when a flaw is reported during the build process, the user can hyperlink from the builder’s output window back to the source code quickly, rectify the error, and then return to rebuilding the program (Figure 4).

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Commercial static analyzers typically require orders of magnitude more execution time than a regular compile. Large software projects may require hours or even days of analysis

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time. This execution cost presents a barrier to adoption. Static analysis, if used at all, may only be employed periodically or during test phases. Knowing that software development cost and time-to-market decrease when flaws are detected earlier in the project cycle, it follows that static analyzers would be more effective if execution time can be reduced to a level that encourages constant use. Developers can detect flaws while software is written and before it is ever committed to a configuration management system—certainly prior to quality assurance testing that may occur months after the software was first created.

Here again is where the ISA approach proves

figure 3

Context-sensitive flaw display.

beneficial. The ISA analysis engine takes advantage of efficient dataflow analysis, constant propagation and path pruning algorithms developed over many years to perform complex compiler optimizations. The result is that the ISA executes much faster than traditional analyzers.

Secondly, the total time to build and analyze software is reduced since the tool uses a single parsing pass of the code to perform both compilation and flaw analysis.

Finally, the integration with the development environment enables the analyzer to take advantage of the system’s existing distributed

cover feature build mechanism. The parsing pass for the project’s source code is distributed across available workstation bandwidth on the user’s network, dramatically reducing the total analysis time.

Case Study

According to apache.org, the Apache open source hypertext transfer protocol (HTTP) server is the most popular Web server in the world, powering more than 70% of the Web sites on the Internet. The Apache Web server consists of approximately 150,000 lines of code. DoubleCheck was used to search the shipping Apache source code base for flaws.

The analyzer reported 140 flaws, including potential invalid pointer references such as the following from line 120 in Apache source file scoreboard.c: ap_scoreboard_image = calloc(1, sizeof(scoreboard) + server_ limit * sizeof(worker_score *) + server_limit * lb_limit * sizeof(lb_score *)); Clearly, this allocation of memory could be substantial. It would be a good idea to make sure that the allocation succeeds before referencing the contents of ap_scoreboard_image.

However, soon after the allocation statement, we have this use: ap_score_board_image->global = (global_score *)more_storage; The de-reference is unguarded, making the application susceptible to a fatal crash. Another example can be found at line 765 in the file mod_auth_digest.c: entry = client_list->table[idx]; prev = NULL; while (entry->next){ /* find last entry */ prev = entry; entry = entry->next; ... }

Note that the variable entry is unconditionally de-referenced at the beginning of the loop.

This alone would not cause the analyzer to report an error. At this point in the execution path, the analyzer has no specific evidence or hint that entry could be NULL or otherwise invalid. However, the following statement occurs after the loop:

figure 4

if (entry) { ... } By checking for a NULL entry pointer, the programmer has indicated that entry could be NULL. Tracing backwards, the analyzer now sees that the previous de-reference to entry at the top of the loop is a possible NULL reference.

In addition to pointer problems, the analyzer discovered buffer overflows and reads of uninitialized variables.

Coverity, who markets a traditional static analyzer, recently published a study of its tool’s analysis of the same Apache code base, reporting an execution time of 10 minutes on a modern PC. Using the same hardware platform, the DoubleCheck Integrated Static Analyzer required less than two minutes. Using the ISA’s distributed build feature, analysis time dropped further to a mere 30 seconds.

Integration of static analysis with project builder.

Conclusion

Static analysis represents a major new weapon in the software developer’s arsenal for battling increasing complexity and its associated reliability, safety and security problems. The Integrated Static Analyzer approach makes it easy and efficient to incorporate automated static source code checking into the everyday software development process.

Green Hills Software, Inc. Santa Barbara, CA. (805) 965-6044. [www.ghs.com].

AUGUST 2007

21

cover feature embedded software

The Multimedia User Interface: A Look at Things to Come The success of any consumer electronic device depends to a high degree on having a flexible, intuitive user interface.

by Neil Henderson, General Manger and Geoff Kendall, Product Marketing Manager, Embedded Systems Division, Mentor Graphics Corporation

B

By now we all know about the Apple iPhone launch and the buzz it created. Why was demand so high for this particular product? One could argue it’s the mystique behind the Apple brand; or the anticipation of a device with so much functionality. Both of these explanations might be correct, but let’s add a third reason: The promise of a radically new user interface (UI).

The truth of the matter is the success of any consumer electronic device depends to a high degree on its UI—how appealing is the interface and how easy is it to use. Get the UI wrong and the product has little chance of success. In fact, studies have shown that an attractive UI design encourages users to explore the full range of features, creates the perception that a product is easy to use, and even makes users more tolerant of a product’s shortcomings.

So if the benefits of a great-looking, easy-touse UI are so clear, how come more products don’t have anything truly breakthrough to offer?

22

PORTABLE DESIGN

The answer lies in the fact that changing an embedded UI is not so easy. Even something as simple as migrating to a new screen size can cause major development headaches. To do something even more ambitious, say create a slick new interface that takes full advantage of the latest multimedia processor—is often not even a consideration.

It gets even worse as new features are introduced with each new product iteration. Timeto-market pressures mean that enhancements are often just “bolted on” to the UI rather than seamlessly integrated in an intuitive manner. Unsurprisingly, the result of such tactics is a market awash with products whose list of features might look convincing in a 30-second TV spot, but whose user experience ultimately fails to satisfy.

Finding an adequate solution to this problem demands that we take a fresh new look at the role the UI plays in modern consumer electronic devices. By identifying common UI

Creating UIs for Consumer Products Today

Most embedded application UIs today are constructed by laying out predefined controls on the screen, such as drop-down lists and check boxes. All of the UI logic—the “glue” that holds these controls together and makes them do useful things is generally implemented as part of the overall application code.

The upshot of this is that there is no clear separation between the UI (both its look and feel and its interactive behavior), and the underlying functionality it provides access to.

The code for both the UI and the underlying functionality tends to be highly interdependent.

It is this interdependency that makes it hard to modify a product’s UI. And the need to make such modifications is only increasing, as manufacturers strive to improve ease of use, deliver a better look and feel to differentiate from competitors, integrate new features into an updated product, meet the diverse brand requirements of multiple customers (e.g., mobile phone opera-

cover feature

functionality and implementing it in a reusable, customizable way, we can make it far easier for designers and software engineers to deliver visually engaging and easy-to-use products.

tors), support new screen sizes and languages, and exploit high-end hardware capabilities.

All such UI modifications are difficult today. Beyond the most basic visual adjustments (such as font color or background graphic), any change to the UI requires the application’s code to be modified, which can be time consuming and costly.

Clearly we need an alternative approach. If we could achieve a high degree of separation between a device’s UI and the functionality it relates to, we would be able to modify the UI freely with minimal complexity and risk.

An Alternative Approach

Much of what we do when we interact with a portable device can be boiled down to two things: browsing and selecting.

On a cell phone we might browse through the icons on our “home screen” and select the address book icon, and then browse through the list of contacts that appears to select the person we wish to call. Similar actions allow us to negotiate messages in an inbox, scroll channels in a TV program guide, or visit favorites in an embedded Web browser. Using an MP3 player we navigate our play-lists, tracks, or artists via a series of lists/menus until we find the music

figure 1

An application-centric UI (left), in which each application is responsible for its own interface, versus a menu-centric UI system (right), where all “browse and select” interactivity is delegated to one, unified, extensible menu system.

AUGUST 2007

23

figure 2

Rapid UI changes without modifying the underlying application code.

we want to play. Even while listening to a particular track we can control its playback (pause, rewind, etc.)

Even though these examples cover a range of functions and formfactors, what is happening at the interactive level is very similar. In each scenario, the user is being presented with (and asked to choose between) a number of options, which ultimately lead to a particular action being performed (e.g., a phone call is placed, an MP3 file is played).

All such activity could be managed by a single menu system, albeit an extremely flexible and generic one, capable of presenting a wide range of content in a wide range of ways from an equally wide range of sources.

By taking this menu-centric approach, it’s possible to think of all the functionality on a device as being accessed in a consistent and unified way. This is quite a departure from the application-centric interface model that dominates the desktop environment (Figure 1).

Advantages of a Menu-Centric UI

The real power of the menu-centric approach is that the concept of what constitutes a “menu” is highly abstract: it is really nothing more than a way to display one or more items that the user browses and selects. Lots of common UI constructs can be thought of in this way: a set of radio buttons is really just a menu in which only one item can be active; an “Are you sure?” message box is really just a menu with two selectable items, “Yes” or “No.” Note that this notion of a menu focuses only on what is being displayed.

It deliberately says nothing about how that information appears, or how the user interacts with it. We can exploit this degree of abstraction to 24

PORTABLE DESIGN

Multimedia Capabilities

Once a device’s UI layer is abstracted away from the underlying functionality it exposes, it becomes far easier to incorporate new types of content within an application’s screens. To support a new content type—such as video—all the UI technology needs to do is know how to display it. Once this capability is present any such content—in this case, individual video clips— may be embedded into any screen design as easily as a bitmap icon or a piece of text.

Inflexion Platform UI follows this approach, providing a plug-in API through which new “content players” may be hooked into the core engine. The Inflexion Platform Multimedia Feature Pack exploits this capability by providing audio and video player plug-ins that allow designers to drop rich, multimedia content into their interface designs.

Once integrated into a product, such a video

component may be used to replace static icons with animated alternatives. Specific use models might include incorporating live channel previews within a TV program guide, or offering pop-up “multimedia help” to offer assistance in using a particular product feature. Such enhancements, while requiring no application coding, can greatly enhance the overall user experience.

To ensure interoperability with a broad range of third-party audio/video codecs, the Inflexion Platform Feature Pack utilizes a Nucleus-based implementation of the OpenMAX standard specified by the Khronos Group (see sidebar “Free to Create”). OpenMAX defines a crossplatform API that facilitates the delivery of portable and efficient multimedia components (including codecs) across multiple operating systems and hardware. Although it is a new standard, major silicon vendors have already begun to embrace OpenMAX, one example being ARM who has announced support for the standard in its NEON product.

Conclusion

To maximize opportunities for success of consumer electronic products, it is essential that the manufacturer focus on delivering a great looking and easy-to-use UI experience.

Today’s embedded UI technologies demand that for all but the simplest UI modifications, the device’s software stack must be altered.

This is far from ideal, since such programming changes can be time-consuming, costly and introduce additional elements of risk when timeto-market pressures are already high.

This article describes one way in which the issue may be addressed; by re-thinking the role of the UI as it pertains specifically to consumer electronic devices and recasting it as a customizable, extensible menu system that can be utilized by underlying application code without being tied inextricably to it.

When such an approach is taken, it becomes far easier to re-brand a product’s UI, to customize its interactive behavior, to modify its look and feel, and even to incorporate new types of content within it, such as video. Taking a menu-driven UI approach can improve the way consumer device UIs are created today, and can also make it easier for us to incorporate whatever new types of device features and content may appear in the future.

Mentor Graphics Corporation Wilsonville, OR. (503) 685-7000. [www.mentor.com].

cover feature

separate the UI description from the underlying functionality. This enables us to address a key requirement: the ability to completely change the look and feel and behavior of a UI without modifying the application code (Figure 2).

Apple’s iPod is an example of how a menucentric approach has been employed to deliver a product whose UI is perfectly attuned to the device’s purpose. There are many reasons why the iPod enjoys the market dominance it does, but the simplicity and aesthetic appeal of its UI is surely one of them.

If an application wishes to utilize the menu system to display some data, all it needs to do is specify what items to display, what properties each item possesses and what actions to trigger when each item is selected. On receiving this data, the menu system can decide how to display it by reference to a UI description defined elsewhere.

The Inflexion Platform UI product from Mentor Graphics takes just such a menu-centric approach. It enables the appearance and interactive behavior of any menu (or “screen”) to be defined in terms of a simple XML-based template.

Each template describes not only what items and properties (or “fields”) should be displayed, but also how the menu’s appearance should change in response to user actions. Inflexion Platform UI automates many of the common interactive behaviors required by a consumer device, including hierarchical browsing, display of rich content types, master/detail views and smooth scrolling so that highly sophisticated templates can be constructed rapidly without programming using only a PC-based design tool.

Free to Create We all use them, we all love them— our mobile phones, MP3 players, TV media centers, in-car entertainment centers, Web appliances of one type or another. They can deliver dynamic, interactive media to us wherever we go—the joys of listening to our favorite song on an MP3 player or seeing the face of a relative live on our phone screen. When implemented well, the sensory experience may seem effortless, but under the surface the delivery of multimedia content relies on enormous processing power and sophisticated software components.

At the heart of any multimedia device, you will find an increasingly complex infrastructure that is time-consuming and costly to develop and exploit. Silicon vendors are, with each generation of their chips, incorporating better multimedia processing capabilities. The number of multimedia standards for encoding audio, video and images continues to swell. Integrating support for MP3 audio, H.264 video, JPEG images, and an ever growing range of other media formats into a product is becoming increasingly difficult. The issue is compounded by the fact that every OS vendor typically has its own idea of what API a multimedia component should adhere to. Clearly, the task for every silicon vendor, device manufacturer and multimedia software provider is not getting any easier.

Enter OpenMAX, a royalty-free, crossplatform API that provides comprehensive streaming media codec and media application portability across operating systems and silicon platforms. OpenMAX specifications and conformance tests are produced by the Khronos Group, a member-funded industry consortium backed by many industry heavyweights.

OpenMAX has already been adopted by Sony in its PlayStation 3 game console, and looks set to become widely adopted across the whole industry.

AUGUST 2007

25

wireless communications wireless telemetry

PlatformIndependent Software Enables True Interoperability in ZigBee Networks Interoperable hardware-independent software has been a challenge in building a ZigBee-compliant product. This no longer needs to be the case.

by Srini Krishnamurthy, Vice President, Strategy and Business Development, Airbee Wireless, Inc.

T

The need for a new wireless network technology designed to meet the unique requirements of sensors and control devices led to the development of ZigBee. Standards such as Bluetooth and Wi-Fi were unsuitable for low-power applications because they deal with complex and power-hungry radio frequency integrated circuits (RFICs) and protocols. Thus, the ZigBee Alliance was born. This industry consortium— now over 200 companies strong—was formed to evaluate the short-range, low-power IEEE 802.15.4 standard for potential use in mesh networks made up of interoperable devices from different vendors. In 2004, years of work by the ZigBee Alliance finally paid off when they published the original ZigBee standard. Since then, numerous ZigBee devices have been developed for a range of cost-effective, reliable, low-power wireless applications.

To date, application developers have relied on custom coding and point solutions to create

26

PORTABLE DESIGN

one-off closed applications. Many of these older, wired technologies have limited scalability, are tied to specific vendors/products, and end up being very expensive to maintain. Deploying large complex wired networks involving thousands of nodes is prohibitive, almost unimaginable. ZigBee mesh sensor networks based on global standards open the door for developing cost-effective and innovative solutions that can scale to large networks and still be affordable.

The power of ad hoc mesh networking, coupled with low-cost battery-operated devices, creates opportunities for new real-time data-driven networked applications while enhancing operations and ongoing maintenance of existing wired solutions.

A low-cost microcontroller and an 802.15.4 radio are the main hardware components required for building a ZigBee device, apart from the physical sensors that control and capture real-time sensory information as shown in Fig-

Dream of Darkness,

Wasteman!

wireless communications

ure 1. While there are many providers of radios and controllers, interoperable hardware-independent software remains an overarching challenge in building a ZigBee-compliant product.

ZigBee Networking

Ad hoc wireless mesh sensor networks have no fixed structure. Nodes join and leave at will.

However, the intent to connect and communicate when announced creates a seamless mesh network using available nodes within range.

figure 1

ZigBee Network Module

Sensor Board

Sensors Analog or Digital Interface

Digital Interface

802.15.4 Radio + MCU + ZigBee Networking Stack

Radiocrafts Wireless Interface ZigBee Sensor Network

nd

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

ed

Sensors to ZigBee mesh networks.

This just-in-time networking (JITN) is a fascinating challenge that is squarely met by ZigBee, as illustrated in Figure 2. 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 theresulting right resource.

Whichever of The mesh sensorlevel networks are comgy, Get Connected will help you connect with the companies and products you areplex searching for. and yet simple in functionality. Networking onnected extends the data transmission range. Deployments become more affordable by eliminating wiring and installation costs. The potential monitoring and control applications for ZigBee within the commercial, consumer and industrial sectors are virtually limitless. ZigBee can meet the challenges that abound with interoperability, platform independence and network management solutions for large networks.

companies providing solutions now

End of Article Get Connected

with companies mentioned in this article. www.portabledesign.com/getconnected

28

Elements of ZigBee Networks

As seen in Figure 2, a ZigBee network is made up of three types of devices—a personal

PORTABLE DESIGN

Get Connected with companies mentioned in this article.

area network (PAN) coordinator; full function devices (FFDs), also known as routers; and reduced function devices (RFDs), also known as end devices. Each type of device plays a specific role in the network. Every device needs to be configured for its assigned role in the network through programmable options. The network stack provides a set of parameters for configuring the capability and other network operational characteristics. The configuration parameters for each of the devices are defined as part of network initialization. These parameters are programmable, either at the factory or in the field.

The PAN coordinator is responsible for forming the network. There can be only one PAN coordinator in a single ZigBee network.

Multiple ZigBee networks can be interconnected through gateway and bridge devices. A ZigBee network can operate in 2.4 GHz, 868 MHz or 915 MHz license-free bands, depending on the chosen 802.15.4 radio. The PAN coordinator device scans and selects an operational channel within its range of frequencies in the selected frequency band. Each PAN is assigned a unique identification number, known as the PAN identity (PAN ID). After starting as a PAN coordinator, it allows other devices to join with it, forming a ZigBee network. Devices join the PAN coordinator either as routers (FFD) or as end devices (RFD).

The router plays a vital role in extending the network diameter to cover a larger geographical area. Routers allow other routers and end devices to join with it, thereby extending the network. Routers also route data packets from other network devices to their intended destinations. Router do all the routing functions including maintaining routing table with active nodes, removing dead routes, flagging orphan nodes and dynamically switching to alternate routes when primary routes are unavailable.

The end device associates with a PAN coordinator or router as its parent in a ZigBee network. End devices cannot serve as a parent for other devices in the network; they are restricted to communicate only with/via their parent.

However, it can communicate data to other remote devices through its parent, a router or a PAN coordinator. End devices are typically functional elements of the network. For exam-

figure 2

The software adopts

Laptop

a layered architecture Cell Phone

model, where each

Back-Office Enterprise Networks

layer performs a specific set of services.

ple, a light switch is an end device in a lighting network application. The bulbs are routers in such a configuration.

Software Networking Architecture

The software architecture for true platformindependent interoperability is shown in Figure 3. The software adopts a layered architecture model, where each layer performs a specific set of services for its upper layer. Service access points (SAPs) provide the interface between layers. The upper layer accesses the data and management services of the lower layer through the respective SAPs. The lower layer uses these SAPs for sending confirmation and indication messages for the data and management services.

The SAPs support a number of service primitives to achieve a predefined functionality.

The software is architected such that the physical layer is abstracted with all the hardware-specific functions of the underlying radio as configurable parameters. In some cases, even the media access control (MAC) function is abstracted to accommodate for radios with built-in hardware MAC features. The upper layers (network and above) of the stack are designed to be oblivious to the existence of a specific hardware, enabling hardware independence and true interoperability in a multi-vendor ZigBee deployment.

PDA

Desktop

ZigBee Coordinator (FFD) ZigBee Router (FFD) ZigBee End Device (RFD or FFD) Mesh Link Star Link

Typical ZigBee network.

figure 3 Application Layer

Airbee-OS

Application Framework ZigBee Applications 1 to 240

User Applications

ZigBee Device Profile (ZDO)

ZDO SAP

APSDESAP

APSDESAP

Task Scheduler

APSMESAP

Application Part Support Sub-Layer NLDESAP Security Service Provider

Network Layer

ASPSAP

MLDE SAP

NWK Mailbox

MLMESAP

MAC Mailbox

MAC Layer

Application Support Package Layer

PLMESAP

PDSAP

DSPSAP Device Support Package Layer

APP Mailbox

NLMESAP

DSPSAP

PHY Layer RF-SAP RF-Transceiver

The Right Play

A pure-play software company with platform-independent ZigBee stacks, tools and

Platform-independent software networking architecture.

AUGUST 2007

29

wireless communications

ZigBee devices need to become platformindependent for true interoperability and vendor independence.

support is an excellent partner for building, deploying and maintaining a successful ZigBee network. Using platform-independent ZigBee software enables original equipment manufacturers (OEMs) and integrators to use any IEEE 802.15.4-compliant radio (from TI, Ember, Atmel, ZMD, Freescale or others), gives the freedom to choose any controller (from TI, Infineon, Atmel, Freescale, Renesas, Intel, Atmel or others), and allows the choice of any realtime operating system (RTOS) for building a ZigBee network.

ZigBee networking is software-intensive and requires networking experts in the customer domain as well. End-user engineers usually focus on their business application, while the ZigBee networking software providers focus on optimizing the myriad options in the ZigBee protocol to ensure the combination of hardware and software that is the most cost-effective and high performance for the application. Deploying complex ZigBee networks with hundreds and eventually thousands of nodes requires software tools and support. A network-management framework that can be customized to deploy, monitor, control and manage—essentially keep the network humming at all times—is one such essential tool. Ongoing software support is critical during the lifecycle of a ZigBee network and in particular during deployment, where unknowns abound in a crowded and often competing RF environment.

ZigBee devices need to become platform-independent for true interoperability and vendor independence. The opportunity is ripe for OEMs and integrators to bring compelling products to market quickly and at low cost—today. The first large-scale ZigBee deployments will be in energy management, followed by building automation, industrial plant monitoring and home control. The technology is proven, with many initial ZigBee pilots, test networks and initial deployments already underway. The year 2008 will be the year of the solution, when ZigBee implementations finally take off.

Airbee Wireless, Inc. Rockville, Maryland.

(301) 517-1860. [www.airbeewireless.com].

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PORTABLE DESIGN

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consumer electronics image sensors

Wide Dynamic Range Imaging Techniques A high-resolution image sensor is only the start of the story. How you process its output will ultimately determine image quality.

by V enkata Raghavan S., Product Applications Group Lead Memory and Imaging Division, Cypress Semiconductor

D

Digital imaging technology has progressed from digital still cameras into an array of portable applications such as cellular handsets, where it serves as a differentiating feature. In applications such as automotive sensors and medical equipment, digital imaging serves as the foundation of higher-order functionality such as machine vision, instrumentation, document scanning, motion analysis and scientific high-speed image analysis.

Image resolution is often seen as the most important factor determining the quality of an image. However, in all of these applications, from those that produce images for viewing or perform complex analysis of images, dynamic range plays a key role in determining how efficient and effective later imaging processing will be. Dynamic range directly affects final image quality as well as the effectiveness of any compression or analytics technologies.

The dynamic range of CMOS image sensors

32

PORTABLE DESIGN

is defined by their ability to capture dark as well as bright sections within an image while maintaining the highest fidelity. Real-life images have varying illumination levels throughout a scene. An image sensor must have wide dynamic range (WDR) in order to capture all the illumination levels (contrast) of an image.

The wider the dynamic range of the sensor, the more illumination levels that can be captured.

The key to achieving sufficient WDR is identifying the dark and bright portions of the image and controlling the integration of the pixels to avoid saturation. Pixels impinged with high illumination need saturation control, while pixels impinged within the dark portion of the image need longer integration times. In this way, the contrast of the scene can be restored by the imager. This article describes the definition of wide dynamic range and appropriate imaging techniques to use with CMOS image sensors.

Dynamic range is the ratio of the maximum signal output of the sensor to the smallest signal output of the sensor. The higher the dynamic range of the sensor, the greater the fidelity of the optical image transformation from the object scanned. The sensor generates its maximum output for brighter portions of the image and its minimum output for darker portions.

The maximum output of the sensor without saturation is limited by the well capacity of the photo diode, while the minimum detectable output is limited by the noise floor of the sensor. Figure 1 illustrates the noise floor in detail, where dynamic range (db) = 20 log (sensor’s maximum output / sensor’s minimum output).

A higher dynamic range results in a better transformation of the object to an image, accurately capturing the varying light intensities of a scene, from the brightest to the darkest parts, including shadows. Factors that affect dynamic range include: • Dark current of the sensor • Saturation of the pixels • Quantum efficiency/well capacity of the photo diode

Signal-to-Noise Ratio

The signal-to-noise ratio (SNR) is a measure of a captured image’s immunity to noise. SNR is the ratio of the peak light intensity without saturation to the scene background noise. A camera with a higher SNR typically produces low noise video in darker scenes. Photodiodes generally have better SNR when they are charged to more than half of their total capacity. However, they cannot be charged beyond saturation.

There are two basic noise sources in a CMOS image sensor: 1. Temporal noise caused by the photo diode and MOSFET, shot noise, thermal noise and 1/f noise as envisaged in electronic circuits.

2. Fixed pattern noise caused because of the pixel output variation for the same illumination. The source of fixed pattern noise are device and interconnect mismatches.

Figure 2 shows a three-transistor APD pixel circuit widely used in CMOS image sensors.

consumer electronics

Dynamic Range

figure 1

Sensor op

Maximum Signal Photon Noise Noise Floor

Dark/Read noise 10 Noise Signal

100

1,000 10,000 Photons Log Scale

Noise floor definition of the CMOS image sensor.

The first MOSFET is used to reset the photo diode to a known voltage by pulsing the gate (reset) signal. The photo diode’s stray capacitance is charged to a known voltage (reset voltage) and the photo diode is allowed to integrate the charge. Due to electron hole re-combination, the reset voltage is pulled down, depending upon the light intensity impinging on the photo diode.

If the pixel is saturated, the whole charge across the photodiode will be depleted completely. The second MOSFET is a source follower, while the third MOSFET switches the selected row/pixel to the bit line, which in turn is connected to the column amplifier. The actual voltage integrated

figure 2 Vdd Reset Vdd Barrier (Reset)

Row Select

Output (to CDS/ADC)

Three-Transistor pixel.

AUGUST 2007

33

consumer electronics

by the photo diode is the reset voltage minus the voltage across the diode after integration.

Hence the photo diode is operated with one reset for one integration cycle. This method is called linear integration (open loop with no control of saturation of the pixel). If the photo diode needs saturation, control multiple resets are ap-

system are: 1. Reset the photo diode with the maximum reset voltage VR1 allowed and allow integration time T1.

2. Reset the photo diode with smaller voltage VR2 (voltage less then VR1). With this reset voltage, the pixels saturated will have a

By choosing a suitable combination of barrier voltage and integration time, the desired wide dynamic range can be achieved.

plied with varying integration times optimally chosen for the end application to achieve a wide dynamic range. The first reset voltage would be the largest voltage level as per the design, and second, third and so on will be smaller voltage levels.

The steps involved in the multi-reset

figure 3

T2

B2 V B1

T1

T Integration (T=T1+T2)

Two-barrier reset timing.

34

PORTABLE DESIGN

Bright Response Medium Response Dark Response

source of the MOSFET less than the drain, and the MOSFET will conduct a voltage across the photo diode equal to the new reset voltage. If the pixel is not saturated, the source voltage will be less than VR2 and the MOSFET will not charge the photo diode to the new reset voltage. The photo diode will continue integration with time T2.

This pixel corresponds to the dark portion of the image and receives more integration time, which is desirable.

3. The resets are repeated until the last barrier (reset) voltage completes the integration.

Pixel Response with Multi-Barrier Operation

Pixels impinging with the brighter portion of the image are reset and pixels impinging with the darker portion receive more integration time to develop the charge. In this way, the saturation is controlled.

Parameters of control to achieve dynamic range: • Integration time • Barrier voltage (reset voltage is also called barrier voltage)

figure 4

a)

Achieving Wider Dynamic Range

Techniques to achieve wide dynamic range include: • Double shot exposure. To increase the dynamic range of an image, pixels are integrated two times, once with a shorter integration time to capture the brighter portion of the object scanned, and again with a longer integration time to capture the darkest portion of the object scanned. The final image is comprised of the two frames of data through signal processing.

• Multiple image detectors. Using this approach, multiple detectors capture the same scene at the same time using beam splitters to project multiple copies of the same image onto each detector at the same time. Each detector is preset for a predetermined exposure time (electronic control) or optical attenuators (optical control).

This method is suitable for generating high dynamic range images in real time.

Additionally, the camera or the scene can be moving during scanning.

• Saturation detection per pixel. Each pixel of the CMOS array has a saturation detection circuit, such as a comparator, to compare for a known voltage across the diode to detect and reset in case of saturation. This approach imposes the overhead of a saturation detection circuit per pixel, which is too expensive for large pixel arrays.

• Multi-reset with different integration times.

Pixels based on an APD as described in Figure 2 can be reset several times during the integration period. The minimum requirement is to have two barriers (reset

consumer electronics

By choosing a suitable combination of barrier voltage and integration time, the desired wide dynamic range can be achieved.

The three-transistor pixel (Figure 2) allows multiple resets and integration time control.

External circuits are required to detect the saturation and reset the pixel. Also required is a compression/transfer function table to decide the barrier voltage and integration times. In this way, the required dynamic range can be controlled and achieved based on the end application.

b) Images illustrating (a) linear and (b) multi-slope integration as captured by an IBIS-5 image sensor from Cypress Semiconductor.

voltages) with different integration times.

Again, the first barrier would be larger than the following barrier. The second barrier voltage can be selected based on the well capacity and the previous integration output (Figure 3).

Dynamic range is one of the important factors affecting the image quality of CMOS sensors. The wider the dynamic range, the better a digital imaging system will be able to accurately capture the varying light intensities of a scene. By varying the combination of barrier voltage and integration time, as well as applying different techniques to widen the dynamic range, developers can exercise more accurate control of image quality across a broad range of imaging applications.

Cypress Semiconductor, San Jose, CA. (408) 943-2600. [www.cypress.com].

AUGUST 2007

35

portable power powering displays & backlights

Powering Backlights in Portable Devices Advances in backlight technologies and techniques mean you can have more of your power budget to design with instead of write off.

by Tomi Koskela, Applications Engineer, Power Management Division, National Semiconductor Finland

M

Most portable electronic products such as mobile phones, PDAs and navigation systems have small-format LCD displays that need backlighting. Viewing high-resolution photos, video and Web pages has increased the utilization time of handset displays. The demand for high-quality displays is increasing in devices with media access. This creates challenges for backlight LEDs and also for the drivers. White backlight LEDs dominate the market, but the new RGB backlight will improve color saturation on displays.

The keypad backlighting and other cosmetic lights are commonly used for personalizing mobile phones. There are different requirements for the display backlighting and keypad backlighting, and this affects the way these LEDs are driven.

Changes in LED and Li-Ion battery technologies will affect the backlight driver design. Increases in LED count on portable devices cre-

36

PORTABLE DESIGN

ate challenges for the LED drivers. The most common challenges in driving backlights in portable devices are power efficiency, control interface/programmability, solution size, EMI and system cost.

Brightness Control

The brightness of backlight LEDs can be controlled by pulse width modulation (PWM) or by constant current controls. PWM brightness control needs a constant-current driver to drive the LED, but its on/off time is controlled to achieve the desired brightness. This makes PWM slightly more complex than direct constant-current control.

One good thing about the constant-current control is that there is no continuous switching, which results in low EMI. The down side is that the LED color spectrum shifts when brightness is adjusted. LED manufacturers group and bin the LED at certain grouping currents and then

portable power

guarantee the specifications with this so-called grouping current. When the current is moved outside the grouping current there will be more variation in the LED brightness than specified.

This is visible as a difference in brightness between backlight LEDs, especially when very low current is used.

With PWM control the brightness adjustment is linear through the whole range, and there is no color change when the brightness is adjusted. However, PWM switching can generate EMI and audible noise. Audible noise is caused by piezoelectric effect on the ceramic capacitors. X5R, X7R and similar capacitors have barium titanate dielectric, which is a piezoelectric material. To get rid of the audible noise, the PWM frequency has to be high enough that the human ear cannot hear it, for example 20 kHz. Another alternative is to use such a low frequency that the capacitors and the PCB in the application do not resonate; but the frequency must still be high enough that flickering is not visible (e.g. 250 Hz). EMI can be reduced by slowing down the rising/falling edges of the PWM control.

LED is to use low side driver outputs, where the LED output pin acts as a constant current sink. In this case the LED output and supply voltage need separate routing to the LED. With high side driver where the LED output pin is current source, only the LED pin needs routing, and the LED cathode is connected directly to the GND. Usually there is a GND plane in the PCB, so no separate routing is needed. Examples of different driving methods are shown in Figure 1.

figure 1

Backlight Driver Topologies

Driver topologies can be divided into parallel and serial types. Parallel driving is typically used when each LED requires individual control. In backlighting schemes where all LEDs must be the same brightness, there can be a slight mismatch between LED currents with parallel drivers. However, with the latest drivers the current mismatch is negligible because the typical LED brightness tolerance is much greater than the mismatch in output currents.

When the backlight LEDs are connected in series the same current flows through all LEDs, so the matching at LED currents is perfect. PCB routing is easier with serial driving, because there is no need for individual trace from the driver to each LED. The LED drive efficiency with serial driving can be considered to be slightly better than with parallel driving, because the driver output’s forward voltage is taken into account for several LEDs. Serial driving needs a high voltage boost converter (e.g. 20V) to get enough voltage from the LiIon battery to drive several LEDs in series.

The most common method for driving an

Examples of parallel high side and serial low side drivers.

White LEDs and Battery Technology

Portable devices are typically powered with a single cell Li-Ion battery, with voltage between 2.8-4.3V depending on its charge. White LED forward voltage is typically 3.5V. The single cell Li-Ion battery voltage therefore is not always enough to drive the LEDs and a step-up DC/DC converter is needed. A converter can be either capacitive (charge pump) or inductive (magnetic boost). A charge pump is typically used for parallel LED drivers because of its small solution size. A magnetic boost converter is used for high voltage serial LED drivers, since with charge pump technology it is difficult to achieve high enough output voltAUGUST 2007

37

portable power

figure 2 Voltage (V) 5.5 _

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Excess Voltage

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RGB LED Backlighting

Typically, a small panel LCD display backlight is implemented with a couple of white LEDs. The problem with white LEDs is that their spectrum is not ideal for photographic reproduction. This is caused by the fact that white LEDs are basically blue LEDs with yellow phosphor on top. The spectrum has two

VDRIVER<0.2V Today

age. Converter output voltage adjustment can be either automatic (adaptive) based on LED forward voltage sensing, or the user can set the constant voltage based on the LED forward voltage specification.

In the future, new Li-Ion battery and LED technology will bring new challenges to the LED driving. With new chemistry the battery voltage range will be about 2.3V-4.7V. The typical white LED forward voltage will drop to about 2.9V. At the same time output driver saturation voltage is going to drop as well. To drive 2.9V LEDs efficiently without burning too much power on the driver, it might become necessary to use buck-boost type converters to provide supply voltage for LEDs when parallel driving is used. Figure 2 shows the effects of the battery, driver and LED technology progress.

â&#x20AC;&#x153;Tomorrowâ&#x20AC;?

Battery and white LED forward voltage progress.

figure 3

+

1 Phosphor

Blue Chip 400

500

+

600

700nm

600

700nm

+

RGB Chips 400

500

Emission Wavelength Typical White LED vs. RGB LED spectrum.

38

PORTABLE DESIGN

portable power

peaks, one at blue and a second at yellow. Typical white LED versus RGB LED spectrum can be seen in Figure 3.

Pixels in LCD displays are divided into cells of three primary colors: red, green and blue.

Pixel color is defined by mixing the three primary colors. To filter the right color to each color cell, color filters are used. Color filters waste a big part of the optical power, and even after color filtering, the color spectrum passing through the LCD is not ideal. With white LED backlighting it is possible to produce up to 75% of National Television Standards Committee (NTSC) colors on an LCD display (the red end of the conventional LCD display is especially limited). When RGB LEDs are used for LCD display backlighting, the color reproduction can be adjusted to cover over 100% of the NTSC color gamut, which results in brighter colors and better picture quality. With optimized color filters, less power is wasted than in white LED backlighting. Structure of an LCD display can be seen in Figure 4.

With RGB backlighting the driver must correct the brightness balance between the primary colors (red, green and blue) when the LED temperature changes to avoid white point shifting.

The driver must also keep the light intensity adjusted correctly at any operating temperature.

Compensation can be either closed-loop or open-loop. With closed-loop compensation an optical sensor is used for measuring the white point and intensity. With open-loop compensation the temperature is measured, and predefined compensation curves are used to adjust the brightness balance.

An example of a RGB backlight driver is National’s LP5520, which is an open-loop compensated LED driver. The principle of open-loop color compensation is illustrated in Figure 5. The temperature compensation curves are measured for the actual RGB LED type used in the application, and these curves are programmed to the chip’s internal EEPROM memory. The chip is integrated into the LCD display module, and the module manufacturer programs compensation curves in production.

A RGB LED backlight optimized color filter is used as well.

Keypad Backlighting and Other Cosmetic Lights

Keypad backlighting has some specific requirements compared to display backlighting.

The color wanted in keypad backlighting is not necessarily white; it can be basically any color.

The trend is today that the keypad backlighting

figure 4 Polarizer Color Filter Substrate Color Filter Cell (red, green, or blue)

Black Matrix

L i q u i d

Transparent Common Electrode

C r y s t a l Capacitor

TFT

Transparent Pixel Electrode

Thin Film Transistor Array Substrate Polarizer Polychromatic Backlight Structure of an LCD Display.

and other cosmetics lights in portable devices are used to produce some light effects. Display backlight control is usually the on/off type with possible smooth fade in/out, but cosmetic light control is more complex. By using RGB LEDs for keypad backlighting it is possible to change the color and the whole appearance of the device by simply changing the brightness balance between the red, green and blue LEDs. This gives interesting possibilities for personalizing handsets and other portable devices with software control.

For complex lighting sequences such as smooth transition between different colors, a sophisticated control method is required besides a simple enable control pin. An I²C control bus is widely used in many portable devices as it provides great flexibility for controlling an LED driver via only two wires. Usually there are other components, for example a camera AUGUST 2007

39

portable power

module, using the same bus. Therefore, LED control should not use all of the I²C bandwidth.

Controlling the LED brightness in real time creates considerable I²C traffic.

New LED drivers such as National’s LP5521 allow minimum real-time control by incorporating internal memory and an execution engine for lighting sequences. Lighting sequences are written to an internal memory after power-up,

figure 5

Conclusion

Brightness Control (I2C/SPI or external PWM)

Temperature Sensor

PWM Logic

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Integrated To One Chip

ed Principle of the open-loop color compensation.

and then an external trigger pin or I²C write is used to start the sequences. When the sequence is the running, processor control is not required. exploration into products, technologies and companies. Whether your goal is to research latest datasheet from a company, mp to a company's technical page, the goal of Get Connected is to put you in touchWhen with thethe rightphone resource. levelmode, of is Whichever in standby the appligy, Get Connected will help you connect with the companies and products you arecation searching for. processor can be put in sleep mode, and onnected the LEDs can be still running complex lighting sequences. Sequences can include time delays, ramps, blinking, loops and sending/receiving of trigger signals.

To further decrease power consumption the latest LED drivers have automatic powersave-mode operation. The DC/DC converter is started only when the Li-Ion battery voltage is not sufficient to supply the LEDs. The driver also shuts down any unused functions when the LEDs are not active and while the sequence is Get Connected with companies mentioned in this article. running internally. This significantly decreases www.portabledesign.com/getconnected average current consumption.

companies providing solutions now

End of Article

40

PORTABLE DESIGN

Get Connected with companies mentioned in this article.

With small LED driver solution size, it is possible to create a localized, rather than centralized, lighting solution, meaning that the LED drivers are located near the LEDs. This way the PCB routing is a lot easier, and the EMI is reduced. Drivers that are designed for a localized solution have external control pins, which are used for synchronizing several drivers, making it possible to achieve very interesting lighting effects.

There are several possible driver topologies for driving backlight LEDs. Choosing the right one depends highly on the application. The upcoming new Li-Ion battery technology together with lower forward voltage white LEDs create new challenges to the drivers.

RGB LEDs can be used for LCD display backlighting on high-end phones and other portable devices where high display image quality and color reproduction is essential. With RGB backlighting it is also possible to reduce power compared to white LED backlighting when the right kind of driver, LEDs and color filters are used on the display module.

Programmability is the key feature in the latest keypad backlight drivers. It provides easier control, and also enables power savings when application processor control is not needed during lighting sequences. Programmable LED drivers also create interesting possibilities for personalizing handsets.

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

Pump Up Your ARM ® Powered Design!

October 2-4 2007 Santa Clara Convention Center

ARM Developers’ Conference and Design Pavilion

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Plus: through the combination of track sessions, presentations and company design centers you will be fully immersed in leading strategies and methodologies for building complex designs with the ARM architecture.

And Finally-- Conference Delegates who pre-register before September 10 receive the conference proceedings on a 4 GB iPod Nano to take home!

Register early and save!

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Co-Located with the Portable Design Conference & Exhibition

product feature Configurable Video Subsystem Targets Portable Devices

by John Donovan, Editor-in-Chief Last year ARC threw its hat in the mobile phone ring when it introduced the AV 401, a lowpower multimedia subsystem that could decode standard-definition (SD) video and a variety of audio formats. This month ARC upped the ante, introducing five new subsystems targeting multi-standard video-capable devices in applications ranging from low-resolution image sensor modules to high-end cell phones, set-top boxes and DVRs, including high-quality H.264 encode and decode. ARC claims its high-end AV 417V subsystem is the smallest programmable SD solution on the market.

Based on the recently introduced VRaptor Multicore Architecture, each is programmable; encodes and decodes a wide range of popular video standards; and comes with optimized media processing elements including: a configurable ARC 700 core; up to two 128-bit SIMD Media Processors; a dual-channel media-optimized DMA engine; separate multi-standard encoding and decoding accelerators; programmable motion estimation accelerator; and SoC development tools. ARC

figure Integrated Software

SIMD MP #1 128-bit SIMD MP #2 128-bit

Entropy Decode (ED)

ARC 700 CPU Instruction Cache

Data Cache

Local Scratchpad Memory (SDMI)

Hardware Platform

Entropy Encode (EE)

Motion Estimation (ME)

Video Optimized DMA Engine

Standard Definition Encode H.264 BP Encode under 200MHz H.263 MPEG-4 SP/ASP Encode JPEG Encode Standard Definition Decode H.264 BP Decode under 160MHz VC-I Decode MPEG-4 (ASP, SP) Decode MPEG-2 Decode, MJPEG, JPEG, GIF, PNG, TIFF Decoders

Channel

System Bus I/F

Audio Coding MP3, WMA, AAC, aacPlus v2, AC3, Dolby Digital Plus

includes a full range of optimized audio and video codecs that can encode and decode pretty much every format that isn’t moribund or defunct.

The VRaptor architecture is a scalable heterogeneous processor design that puts a lot of horsepower in a small piece of silicon. VRaptor provides three distinct classes of ARC core modules.

The first is a configurable 700 family core and a

range of specialized SIMD multimedia processors optimized for functions such as low-pass de-blocking filters and pixel transforms. The second class includes accelerators, such as entropy encoders and decoders and motion estimators; these perform multimedia processing tasks more efficiently than general-purpose, programmable cores. The third class includes high-speed DMA controllers

42

PORTABLE DESIGN

to relieve the CPU from complex data movement often found in multimedia codecs.

Since they are both configurable and programmable—enabling design differentiation and reuse—ARC is positioning its subsystems as the logical alternative between fixed function blocks on the one hand and general-purpose DSPs on the other.

Still, why should designers care about doing H.264 encoding—a seriously power-hungry process—on a cell phone? ARC’s answer is, “YouTube.” What good is a high-resolution image sensor if the output is only encoded to display on a tiny CIF screen? If you want to share your videos with Aunt Alice in Atlanta via email—or on your couch via your HD-TV—you need to do high-quality video encoding. ARC claims to do 30 fps low-power H.264 encoding, normally a powerhungry process. One power saving technique is dynamic encoding, which continuously evaluates system resources and adaptively applies different processing resources to achieve the optimum result. For example, dynamic encoding allows the designer to adjust the encoding process in a phone with a fully charged battery versus one running close to empty.

Despite its “low-power” claims, ARC is reluctant to release power figures for its new processor family. This is frustrating to reviewers, though understandable to anyone who is familiar with the amount of “specmanship” in the IP industry. Still, how do you evaluate their claims? A good indirect estimate comes from the size of the module— 10.27 mm² in a 130 nm TSMC G process using Virage libraries. ARC claims its modules can do H.264 BP encoding of D1 video, processing a 10 Mbit/s bitstream at 30 fps at under 200 MHz; it can decode the same bitstream at 1.5 Mbits/s at under 160 MHz. If they can claim low power at 130 nm, what happens when you go to 90 or 65 nm?

For comparison’s sake, ARM’s Coretex-A8, designed for “power-optimized mobile devices needing operation in less than 300 mW,” needs to run at 350 MHz to decode H.264 video at 30 fps.

And the A8 is built for a TSMC 65 nm LP process using Artisan libraries; a speed-optimized CoretexA8 capable of running at 650 MHz results in a “<4 mm²” core (area with cache). If you assume that active power is roughly halved if you reduce chip area by 2x—by moving from 130 nm to 65 nm, for example—and if you further assume that running a chip at half speed will reduce the active power by half—the ARC subsystem would seem to compete well with the A8 in terms of both power and performance. Core area, frequency range and power consumption are of course dependent on processes, libraries and optimizations; and lacking spec sheets, we’re clearly in no position to make a definitive comparison between these two chips. But right now one editor’s educated guess is that ARC may just have a winner on its hands.

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products for designers Low-Power Wireless USB Chip Integrates PHY, MAC Wisair is sampling its new WSR601, a single-die CMOS chip for both host and device Wireless USB applications. The production-ready chip, based on WiMedia and Certified Wireless USB standards, integrates UWB PHY (including RF), MAC and Wireless USB subsystems. The WSR601 combines high performance and low power consumption to offer a costeffective solution for a wide range of Wireless USB applications, including battery-powered, portable devices.

Implemented in digital CMOS process, the WSR601 supports HWA, DWA and Native device protocols, and features SDIO and USB interfaces, isochronous data transfer and cable and numeric association models.

With unique PHY capabilities, the single chip delivers full-room coverage with connectivity ranges of 8 meters at 480 Mbits/s and over 20 meters at 200 Mbits/s.

For mobile devices where battery life is key, the WSR601 provides power-save modes and an average power consumption of 385 mW at 100 Mbit/s throughput.

A two-wire coexistence scheme allows the WSR601 to coexist in close proximity to other radios such as Bluetooth and 802.11. The chip’s low out-of-band emission, below -70 dBm/MHz, provides the flexibility to support Japan regulatory requirements without the need for a dedicated external filter. Additionally, integrated Detect & Avoid technology enables the WSR601 to coexist with other wireless technologies sharing the same spectrum, such as WiMAX. The WSR601 is currently sampling, with production volumes expected in Q4 2007. BOM costs for an HWA are expected to be below $15 in production quantities. For additional chip information please refer to www. wisair.com/products/chipset/wsr601/.

Wisair, Campbell, CA. (408) 370-4727. [www.wisair.com].

High-Performance NAND Controllers for Mobile Storage Applications SST (Silicon Storage Technology, Inc.) has announced that it is expanding its NAND controller offerings with two new NAND controllers, the ATA Flash Disk Controller (SST55VD020) and the CompactFlash Card Controller (SST55LC200). Featuring an advanced error correction code (ECC) engine, these high-performance controllers are designed for managing current and future high-density NAND flash requirements.

SST SuperFlash-based embedded firmware allows for firmware updates before, during and after manufacturing. Firmware update functions eliminate the need to redesign or re-qualify new controllers to meet the requirements of new NAND flash technology introduced after the system has been put into production. This allows system manufacturers to optimize NAND costs, availability and performance requirements in the face of fast-changing NAND technologies.

With an Ultra-DMA host interface and intelligent NAND flash interface, the new NAND controllers can operate up to 30 Mbytes/s for both sustained write and read operations. Both controllers also directly support up to eight chip-enables for NAND devices. In addition, the SST55VD020 ATA Flash Disk Controller can support up to 64 chip-enables for NAND devices with external decoding logic and drivers.

Ideal for products with size constraints such as music players, portable multimedia players and camcorders, the SST55VD020 is offered in a very small 6 mm x 6 mm x 0.85 mm 85-ball VFBGA package. Both the ATA Flash Disk Controller and the CompactFlash Card Controller are also available in a 100-pin TQFP package. The ATA Flash Disk Controller is also compliant to industry standards ATA-4 supporting PIO-4, MWDMA-4 and UDMA-4. The CompactFlash Card Controller is compliant to CFA 3.0 supporting PIO-6, MWDMA-4 and UDMA-4.

Samples of the SST55VD020 and the SST55LC200 controllers are available now. Pricing starts at $3.12 in 100K unit quantities.

Silicon Storage Technology, Inc. (SST), Sunnyvale, CA. (408) 735-9110. [www.sst.com].

Power-Efficient DSP Platform FPGAs Xilinx, Inc. has announced the addition of power-efficient Spartan-3A DSP devices to its XtremeDSP portfolio of solutions for signal processing applications. The new devices, which are in production today, deliver high-performance DSP capabilities in a low-power FPGA for applications such as tactical radios for military communications, wireless access points and portable medical equipment.

Spartan-3A DSP low-power (LP) devices deliver a 50% static power savings, and a 70% savings while in suspend mode, compared to the standard devices. The lower power complements the dynamic power advantage inherent in the Spartan-DSP series due to the integration of dedicated DSP circuitry. The Spartan-3A DSP 3400A LP devices have a 25% power efficiency advantage over competing FPGAs by delivering 4.06 GMACs/ mW at a speed of 250 MHz in the lowest-cost speed grade.

The Spartan-3A DSP FPGA platform’s ability to perform signal processing functions without the need to consume logic resources enables designers to meet their performance and cost goals while enabling better power efficiency. The XtremeDSP DSP48A slices that make up the dedicated DSP circuitry include dedicated 18 x 18 multipliers along with 18-bit pre-adder and 48-bit post-adder/accumulator to deliver superior performance of DSP functions at a low cost.

The Spartan-3A DSP LP devices can be used in applications such as ultra portable ultrasound equipment, where digital beamforming is a key DSP application and channel counts vary from 16 to 128 depending on system requirements. The suspend mode capabilities of the Spartan-3A DSP FPGA platform also help to extend battery life in these applications. Other applications that can benefit from the industry’s lowest-power/high-performance FPGA platform include MILCOM portable and mobile tactical radios, and portable night vision equipment.

The XC3SD1800A-4LI (low power, industrial temperature grade) device is priced at $34.80 and the XC3SD3400A-4LI device is priced at $50.00 Pricing is for 25,000 units in volume production, end 2008.

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

44

PORTABLE DESIGN

Fairchild Semiconductor’s FPF214X and FPF216X series of IntelliMAX advanced load switches feature superior thermal performance and full system protection for portable applications operating between 1.8V and 5.5V. Available in a 2 mm x 2 mm green-compliant MicroFET MLP package, this new series offers 45 percent enhanced thermal performance compared to traditional SOT-23 packages. These highly integrated advanced load switches simplify design, reduce component count and minimize board space by integrating a 0.11 ohm currentlimited P-channel MOSFET with protection and control features, including thermal shutdown, controlled turn on, reverse-current blocking and under-voltage lockout (UVLO).

Key features of the FPF214X and FPF216X series include: • Ultra-compact and thermally efficient 2 mm x 2 mm MLP packaging that improves thermal dissipation by 45 percent.

• Power “Good” signal to indicate stable output power signal for software management in power-sequencing applications.

• Integrated current limiting with fast limiting response time (5 µs for nominal over current conditions) with fixed (up to 400 mA) and adjustable current-limit options (up to 1500 mA).

• Additional reverse-current function to protect against reverse-current flow conditions in accessory or battery-powered applications.

Samples are available now. Pricing is $0.72-.78 in 1,000-lot quantities.

Fairchild Semiconductor Corporation, South Portland, ME. (207) 775-8100. [www.fairchildsemi.com].

Mobile TV SoC for ISDB-T Newport Media is sampling the world’s first complete single-chip solution for the mobile version of Japan’s Integrated Services Digital Broadcasting-Terrestrial (ISDB-T) digital television standard. The NMI320 Sundance J mobile digital TV receiver integrates an RF tuner, demodulator and all required memory in a single monolithic CMOS device that will enable designers to deliver today’s smallest, most power-efficient handset products.

Key features of the NMI320 solution include up to 120 dB of variable gain, 50 dB of image rejection and greater than 55 dB of adjacent channel selectivity. The device consumes only 70 mW of power, yet still combines an extremely low 3.0 dB noise figure with a very high +20 dBm IP3. The monolithic chip includes a dual-band radio, an ISDB-T One-Seg and Three-Seg demodulator, plus all necessary memory in a very small footprint. No other external memory, baluns or loop filters are required to create a complete solution with a very low bill of materials.

The London-based market research firm Screen Digest reported in June 2007 that the Japan Electronics and Information Technology Industries Association (JEITA) estimates that mobile TV handset shipments almost doubled during the first quarter of 2007 to a total of 7.3 million handsets, just under a year after first commercial deployment of the ISDB-T-based technology known as One-Seg. JEITA said that the strongest growth was recorded in March 2007, with more than 1.6 million shipments. One-Seg service is accessible without charge, and the associated handsets are available from all Japanese operators.

Newport Media’s Sundance Series for DVB-H, mobile DVB-T and ISDB-T will also serve as the foundation for future solutions aimed at other popular air interface standards including, but not limited to, Terrestrial-Digital Multimedia Broadcasting (T-DMB) and MediaFLO. The Sundance J NMI320 is available in sample quantities and priced at $8.00 per unit in OEM quantities of 10,000.

Volume production is scheduled to commence in Q407.

Newport Media Inc., Lake Forest, CA. (949) 340-6169. [www.newportmediainc.com].

TaNFilm Discrete Chips Meet Military S-Level Requirements TT electronics IRC Advanced Film has further expanded its military product capabilities. In addition to offering a broad range of military-specific products including precision chips and resistor networks, IRC has received approvals for 16 DSCC drawings. IRC is one of the few manufacturers in the industry to offer TaNFilm discrete chips at S level (0.001% allowable failure) requirements.

IRC’s military-qualified products include MIL-Chip Series, PFC Military Series and TMC Military Series precision chip resistors; 1900 Series TaNFilm precision DIP resistor networks; 4700 Series TaNFilm precision SIP resistor networks; CCN Series TaNFilm precision chip carrier resistor networks; FP Series TaNFilm precision flat pack resistor networks; and SON Series TaNFilm precision leadless resistor networks.

IRC meets the following military qualifications: MIL-PRF-55342; MIL-PRF-83401; MIL-PRF-83401/13 & 14; and MIL-PRF-83401–H. IRC’s approved DSCC drawings include: DSCC 87012; DSCC 87013; DSCC 87014; DSCC 87015; DSCC 87016; DSCC 87017; DSCC 87018; DSCC 87025; DSCC 87033; DSCC 87064; DSCC 88016; DSCC 88020; DSCC 94015; DSCC 94016; DSCC 01033; and DSCC 02010.

TT electronics IRC Advanced Film Division, Corpus Christi, TX. (361) 992-7900. [www.irctt.com].

AUGUST 2007

45

products for designers

Load Switches Offer Improved Thermal Dissipation in Portables

products for designers

Debug Tools for Infineon’s XC2300 MCU Family Infineon Technologies has unveiled its new scalable XC2300 microcontroller (MCU) family specifically designed for use in vehicle safety applications. pls Programmierbare Logik & Systeme today announced—as the first manufacturer—a complete set of optimized debug tools specifically tailored to support the unique features of these 16/32 bit MCUs. Both the UDE 2.0.12 and the UAD2 hardware from pls provide unlimited support for all internal debug resources and peripheral units of Infineon’s new XC2300 MCUs. For example, dependent on the requirements of the application, different pins of the XC2300 devices can be configured as JTAG debug interfaces. The UDE 2.0.12 is usable with all conceivable combinations.

By use of a special mode, the connection between debugger and chip is retained even after a hardware reset.

Furthermore, the integrated Flash/OTP programming function of the UDE 2.0.12 provides exceptionally high speeds in the entire cycle: erase/download/program/verify. This support does not just apply for the on-chip flash, but also for external peripheral devices from: AMD, Atmel, Intel and other JEDEC-compatible flash memories.

JTAG, CANbus and serial interfaces are available to the user as a communication channel to the target. A special feature of the UDE 2.0.12 is its capability to support direct access to the MCU via bootstrap loader.

In this mode of operation, the XC2300 MCU in the target system can be started under direct control of the debugger. This is particularly beneficial for initial start-up and subsequent service tasks, because it allows very fast and simple flash updates. pls Development Tools, San Jose, CA. (408) 451-8408. [www.pls-mc.com].

Tricolor LED Driver for LCD Backlighting in Portable Devices ON Semiconductor has introduced the NCP5623, a high-efficiency, tripleoutput LED driver with I²C interface and built-in gradual dimming. The device is specifically designed to drive tricolor RGB (red, green, blue) LEDs for fun lighting or enhanced LCD backlighting in portable applications such as cell phones and MP3 players.

Offered in the compact LLGA-12 package, the NCP5623 is the smallest RGB LED charge pump driver housed in a nonbump plastic package on the market today.

The NCP5623 LED driver performs autonomous operations upon the command of the processor via its I²C interface. Its three independently controlled current outputs—with +/- 0.5 percent typical matching tolerance and 32 current levels—allow the display of more than 32,000 colors with a tricolor RGB LED. The device features an integrated gradual dimming feature, which progressively increases or decreases output current to produce a theatrical fade-in/fade-out effect. The use of a logarithmic current profile ensures the light and color changes appear smooth and linear to human eyes.

To help maximize battery life, the NCP5623 achieves 94 percent peak efficiency with less than 1 micro ampere (µA) standby current over the operating range of a Lithium-based battery. Despite the small IC package, the device requires only four passive components to operate in a typical application. The device also features short-circuit and overvoltage protection, which protects the system in case of LED failure.

The NCP5623 is housed in the lead-free (Pb-free) 2.0 mm x 2.0 mm x 0.55 mm LLGA-12 package and is priced at $0.55 per unit for 3,000 unit quantities.

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

Dual Output Synchronous DC/DC Controller Draws only 30 μA in Automotive Systems Linear Technology Corporation has introduced the LTC3826/-1, an ultra-low quiescent current, 2-phase dual output synchronous step-down DC/DC controller. The LTC3826/-1 draws only 30 μA when one output is active and only 50 μA when both outputs are active, making it ideal for automotive applications, such as navigation systems, where one or both supplies remain active while the engine is off. With both outputs shut down, the LTC3826/-1 draws a mere 4 μA. The LTC3826/-1’s input supply range of 4V to 36V is wide enough both to protect against high input voltage transients and to continue operation during automotive cold crank. The LTC3826/-1 features a tight +/-1% reference voltage tolerance over the operating temperature range of -40°C to 85°C and can provide output voltages from 0.8V up to 10V, suitable for powering audio systems, analog tuners and CD/DVD players in automobiles. Each output can deliver up to 20A of current at efficiencies as high as 95%.

The LTC3826/-1’s constant frequency, current mode architecture provides excellent line and load regulation, and its 2-phase operation reduces input capacitance requirements. The LTC3826/1 smoothly ramps each output voltage during start-up using separate adjustable soft-start and tracking pins. It operates at a selectable frequency between 250 kHz and 550 kHz, and can be synchronized to an external clock from 140 kHz to 650 kHz using its phased-locked loop (PLL). In addition, the user can select from Burst Mode Operation, pulse skipping and continuous operation at light loads. There are two versions offered: the LTC3826 is the fully featured part with additional functions that include a clock out, phase modulation, two separate power good signals and a current limit foldback disable capability.

The LTC3826 is offered in 32-lead 5 mm x 5 mm QFN package, whereas the LTC3826-1 is housed in the 28-pin SSOP. Pricing for both parts in 1,000-piece quantities starts at $5.38 each.

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

46

PORTABLE DESIGN

Texas Instruments (TI) has introduced a family of highly programmable, one to four phaselock loop (PLL) clock generator devices with the ability to generate up to nine output clock sources from a single input frequency. Each output can be programmed in-system for any clock frequency up to 230 MHz. These features provide a number of system benefits such as reduced power consumption, shorter lead time and the flexibility to easily upgrade the clock without redesigning the system. These benefits ultimately reduce cost for a broad range of consumer applications such as IP set-top boxes or phones, digital media systems such as digital televisions, streaming media and printers, navigation systems and portable devices.

The new CDCE9xx and CDCEL9xx family of clock generators ranges from one to four PLLs with very low jitter at 60 picoseconds typical. The CDCE9xx devices provide either 2.5V or 3.3V outputs, and the CDCEL9xx provide 1.8V outputs, enabling the low-power capability needed for portable devices. Each PLL supports spread-spectrum clocking (SSC) to reduce electromagnetic interference (EMI) to enable compliance with EMC regulations.

The family provides a variety of programmability options including the ability to program and customize the devices in-system through I²C and EEPROM. By offering footprint compatibility across the family, designers can adapt the system design easily without changing hardware, which reduces cost and enables the designer to simply increase or decrease the number of clock outputs. The new family of devices further simplifies system design by replacing a number of components in the system including crystals, oscillators, buffers and PLLs. The CDCE949 is available now in 24-pin TSSOP package for $2.20 in 1K lots. The remaining devices in the family will be available throughout 2007 in 20-pin, 16-pin and 14-pin TSSOP packages. In addition, evaluation modules (EVMs) to evaluate the performance of the family are available.

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

Eval Kit for Freescale MPC5516

0402 Multi-Layer Ceramic Capacitor

iSYSTEM AG, a manufacturer of emulation and test tools for use in the development of embedded applications, has introduced a new lowcost evaluation kit with everything needed to begin embedded development on the new PowerPC 5516 microcontroller from Freescale.

The ITMPC5516 package consists of a board populated with the Freescale MPC5516 CPU, JTAG and Nexus debug connectors, as well as two serial interfaces and an onboard integrated iSYSTEM debugger.

It ships with a power supply, USB cable and winIDEA IDE/debugger software. The software runs unlimited for 90 days, after which it is limited to a 32 Kbyte download file. Upgrades to a complete unlimited version of winIDEA are available. A complete GNU C compiler for the PowerPC and sample applications are also included.

A simple jumper selects whether the onboard iSYSTEM USB-JTAG debugger is used or an external debug tool is connected via JTAG or the 38-pin mictor interface. The latter enables the user to have full on-chip Nexus trace access. A trace is the basis for professional testing and the detection of major defects and bugs.

Program execution and time stamps are recorded and displayed by a trace debug system. Profiling and code coverage analysis are additional capabilities enabled by such a Nexus trace tool.

Taiyo Yuden (U.S.A.), Inc. has announced the mass production availability of its new AMK105BJ475MV multi-layer ceramic capacitor (MLCC) for decoupling power-line circuits in highperformance ICs used in cell phones, digital still cameras and other battery-powered portable electronics.

The AMK105BJ is the first MLCC to achieve a capacitance rating of 4.7 μF in the 1.0 × 0.5 × 0.5 mm (EIA 0402) case size. The AMK105BJ allows designers to obtain the desired capacitance value from a single 0402-size device, where two 2.2 µF-rated 0402 capacitors were previously required. This saves cost and simplifies manufacturability by reducing parts count by 50 percent for this application. Moreover, the AMK105BJ allows designers to downsize from 0603size components (1.6 × 0.8 × 0.8 mm) to the more compact 0402 size, resulting in space savings of 76 percent (volume) and 61 percent (area) without sacrificing device performance.

The AMK105BJ475MV (4.7µF, 0402) is available now for $0.15 each in OEM quantities.

iSYSTEM USA, San Diego, CA. (858) 385-9100. [www.isystem.com].

Taiyo Yuden (U.S.A.), Inc., Schaumburg, IL. (847) 925-0888. [www.yuden.us].

AUGUST 2007

47

products for designers

Flexible 3.3V, 2.5V and 1.8V Clock Generator Family

design idea

Semiconductor Partners

Single-Cell Charger Serves Multicell Applications Philip Simpson and Robert Stimach, Maxim Integrated Products, Inc. U1 of Figure 1 is a battery monitor and charge controller useful for charging and gas-gauging applications. Though the IC (DS2770) is normally restricted to single-cell applications, it can operate in multicell applications after you add a few extra components to the standard application circuit.

U3 is a linear regulator used to drop the battery-pack voltage to a value suitable for normal operation of the DS2770. Low supply current (<4.5 μA) and a high input-voltage range (>12V) enable this device (MAX1726) to be

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Expert Analysis Customer Defined Services End-Market Based Unit Demand Driven

figure 1 PACK+

Q2 PNP

R3 100R

Quantitative & Qualitative Analysis On:

U3 MAX1726EUK5 IN OUT

R7 2M2

NPN Q3

R5 150R

C2 100nF

PACK-

Q4 NPN

GND GND SHDN

R11 1K R10 1K U4

U1 DS2770 1 16 UV Vdd 2 15 CC VIN 3 14 VCH DQ 4 13 SNS Vss 5 12 SNS Vss 6 11 SNS Vss 7 10 N/C N/C 8 9 IS2 IS1 C1

+ BAT1 9V

MAX4240

R9 2M2

R1 150R

C4 1uF

C3 1uF

U2 PROTECTOR

100nF R2 RES DATA

The external circuitry shown enables this single-cell battery monitor and charge controller (U1) to charge multiple-cell batteries.

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used in lithium-battery packs containing at least three cells. The low current draw extends battery life.

Because the battery voltage in this application is too high, a divider (R7/ R9) has been added to reduce the voltage level at U1’s voltage-measuring input. Resistor values should be high to maximize battery life, so the circuit requires a buffer (op amp U4) to preserve accuracy. The op figure 2 amp shown (MAX4240) is Charge Current vs Voltage chosen for its rail-to-rail input, large common-mode input-volt2.5 age range and low supply current. For divider strings totaling 1 MΩ or less you can reduce 2 costs by removing U4, but IMAX=2.0A only at the expense of some accuracy and battery life.

1.5 Transistors Q3 and Q4 operate in the common-base IMAX=1.5A configuration as level transla1 tors. They have the full supply voltage across their collectorIMAX=1A emitter junctions, but collector 0.5 currents are low. Their current gain (Hfe) is not critical, so any suitably rated NPN signal tran0 sistor is suitable. The choice 5.5 6 6.5 7 7.5 8 8.5 9 of Q1 is governed mainly by Battery Voltage (V) the required charge current, so high gain and a suitable The Figure 1 circuit produces these collector-current rating are the charge-voltage profiles for the levels main considerations. For the of charging current shown. less-critical Q2, a general-purpose PNP signal transistor is Battery Charge Current (A)

Services:

PORTABLE DESIGN

R4 100R

CHARGE SOURCE

Technology Issues Market Sizes Technical Roadmaps Manufacturing Processes Due Dilligence Strategic Planning

Untitled-3 481

R6 360R

Q1 PNP

Maxim Integrated Products, Inc., Sunnyvale, CA. (408) 737-7600. [www.maxim-ic.com].

Thermal Management for Handheld Thermal Printers â&#x20AC;&#x201C; A Programmable Solution

by Brady McMacken, Marketing Engineer Lattice Semiconductor Corporation Thermal management is critical to ensure high-quality printing from handheld thermal printers. At the same time, the ever-increasing demand for smaller, lower-cost products with increased functionality presents daunting challenges for design engineers. Integrating thermal and power management ICs into a single-chip programmable solution allows design engineers to reduce overall system cost, complexity and board space and increase system reliability and performance.

Thermal print head temperature is proportional to printing speed. If the temperature is too hot, the ink will smudge. On the other hand, when the temperature is too cool the ink may become illegible. Consequently, a controller adjusts the printing speed to maintain the temperature within these two thresholds.

To facilitate low-cost design, thermal print head electronics provide an

figure 1

algorithm solutions require specific firmware to control each unique print head. The arduous task of changing firmware adds an extra level of complexity, and therefore difficulty, to hardware changes.

But this need not be the case. A single programmable power management IC, such as Lattice Semiconductorâ&#x20AC;&#x2122;s POWR607, can provide multiple threshold comparators to monitor print head temperature. In addition, other power management functions for the handheld thermal printer can be integrated within the programmable device. A proposed block diagram for a handheld thermal printer is shown in Figure 1.

When the print head temperature exceeds its safe operating range, the power management device signals the microprocessor to reduce printing speed. When the operating temperature is back within a safe range, the power management IC signals the microprocessor to resume normal operation. The logic is performed entirely within the programmable device.

Hardware changes, such as new print heads, require only simple reprogramming of the voltage thresholds; complex firmware updates become a thing of the past.

Other power management functions in handheld thermal printers are often performed by a set of discrete components. The same power management device used for thermal management can also perform all the key power management functions, from power up through normal operation. The power management device not only replaces the ADC, but also the reset generator IC, voltage supervisor ICs, mechanical power switch and LED controllers.

While the system is starting up, the programmable device monitors the voltage of the power supplies and, through a simple logic equation and a programmed voltage threshold, sends the CPU reset signal to the microprocessor. Power supply voltages are continuously monitored while the printer operates. The power management device also features a power-down mode, where it draws 10 microamperes, making it ideal for power-sensitive handheld applications.

For less than the price of a single ADC, a power management IC such as the POWR607 can be implemented to handle all thermal and power management functions in a handheld thermal printer. This programmable solution reduces system cost and implements hardware changes with simple software updates.

Lattice Semiconductor, Hillsboro, OR. (503) 268-8000. [www.latticesemi.com].

On/Off Control

CPU_Reset

Temp Hi/Lo

Microprocessor

Voltage Monitor

Temp_ Mon

Thermal Print Head

POWR607 LED Control

Input Supply

System Supply

Handheld Thermal Printer Block Diagram analog voltage proportional to the print headâ&#x20AC;&#x2122;s temperature. Most controllers use a microprocessor and an Analog to Digital Converter IC (ADC) to convert the voltage to a digital code. A software algorithm, implemented in the microprocessor, regularly compares the digital code to internally stored thresholds and adjusts the printer speed accordingly.

However, print heads from different vendors have different thresholds and therefore require different monitoring rates. ADC-based software

AUGUST 2007

49

design idea

acceptable. Maximum charging voltage depends on the charging current (Figure 2).

The ratio of R7 to R9 depends on the number of cells to be charged, and the sum of these resistor values should be as large as practical to reduce cell discharge. The circuit shown is suitable for charging two cells. For three cells, R7 should be twice the value of R9.

R2, the shunt for current measurement and gas gauging, should be selected according to the application. (Consult the DS2770 data sheet for more details.) Some variants of U1 include an internal shunt suitable for this purpose. Note that BAT1 and U2, which protect the battery being charged against overvoltage, undervoltage, overcharge current and overdischarge current, are usually integral to that battery. Note also that satisfactory operation of this circuit depends on the use of an external-current limited supply with the correct output voltage.

event calendar 09/11/07

Real-Time & Embedded Computing Conference Ottawa, ON www.rtecc.com/ottawa 09/13/07

Real-Time & Embedded Computing Conference Pointe-Claire, QC www.rtecc.com/montreal 09/17/-20/07

AUTOTESTCON Baltimore, MD www.autotestcon.com 09/18-21/07

Embedded Systems Conference Boston, MA www.esconline.com/boston 09/25/07

Real-Time & Embedded Computing Conference San Diego, CA www.rtecc.com/sandiego 09/27/07

Real-Time & Embedded Computing Conference Long Beach, CA www.rtecc.com/longbeach 10/02-04/07

ARM Developers’ Conference & Design Pavilions Santa Clara, CA www.rtcgroup.com/arm/2007

advertiser index Actel Corporation www.actel.com

51

Amphenol Mobile Consumer Products/T&M Antennas 17 www.ampphenol-tm.com ARM Developers Conference www.arm.com

41

Atmel www.atmel.com

27

Cirrus Logic www.cirrus.com

2, 16

EDA Tech Forum www.edatechforum.com

16

Embedded Systems Conference www.embedded.com/esc/

13

Empower Technologies www.empowertechnologies.com

30

Intersil Corporation www.intersil.com

5, 7

Linx Technologies, Inc www.linxtechnologies.com

4

Maxim Integrated Products www.maxim-ic.com

9

Mouser Electronic www.mouser.com

31

Santa Clara, CA www.portabledesignconference.com

National Semiconductor www.national.com

52

10/11/07

Portable Design Conference www.portabledesign.com

43

Tyson’s Corner, VA www.rtecc.com/tysons

Semico Research www.semico.com

48

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

Tesilica www.tensilica.com

24

10/03-04/07

Portable Design Conference & Exhibition (PDCE)

Real-Time & Embedded Computing Conference

50

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RGB LED Driver Generates Highly Efficient “True White” Backlighting LP5520 Provides Innovative, Easy-to-Use, Instant Color Gamut Improvement for Small Format Displays Typical Application Diagram D1

2.9 - 5.5V

+

C VDDA

C VDDD

C IN

5 - 20V

COUT

-

C VLDO

VDDA

VLDO S1_IN S2_IN

ADC

VDDD

Calibration Memory

SCK/SCL SI/A0 SO IFSEL VDDIO

CVDDIO

PWMR PWMG PWMB BRC

100 nF

BOOST

FB V LDO

LP5520

NRST SS/SDA

MCU with I2C or SPI

SW

SPI/I 2 C

Interface

LM 20

LP55XX

Color and Brightness PWM Logic

LED Drivers

ROUT GOUT BOUT

GND

Key Features • Temperature compensated LED intensity and color • 100% NTSC color gamut, brighter color, better picture quality • Individual calibration coefficients for each color • User programmability for effects, aging, dimming Color accuracy ΔX and ΔY ≤ 0.003 • • PWM control inputs for each color Product

Description

Packaging

NEW! LP5520

RGB Backlighting LED driver with integrated white balance compensation

microSMD-25

NEW! LP5521

Programmable, low power, 3-channel LED driver

microSMD-20, LLP-24

NEW! LP5522

Autonomous single LED controller with one wire interface

microSMD-6

LP5526

Lighting Management Unit with high voltage boost converter with up to 150 mA serial flash LED driver

microSMD-25

LP5527

LED driver for camera flash and 4 LEDs with I2C programmability, LED connectivity, test, and audio synchronization

microSMD-30

13 channel LED driver with audio sync, LED connectivity test and independent PWMS/PWMS blinking cycles

microSMD-36

NEW! LP55281

Ideal for navigation systems, mobile phones, medical devices, and other portable devices For FREE samples, datasheets, and more information on the LP5520, contact us today at: led.national.com Or call: 1-800-272-9959 National Semiconductor Corporation, 2007. National Semiconductor and

are registered trademarks of National Semiconductor Corporation. All rights reserved.