INTERVIEW
EEWeb Issue 80
January 8, 2013
Brian Petted CTO, LS Research
SPECIAL FEATURE
MCU Wars 2.6 Comparison of Embedded Linux and an RTOS TECHNICAL ARTICLE
Education in Engineering: Hoover High
Electrical Engineering Community
Visit www.eeweb.com
1 eeweb.com
EEWeb PULSE
TABLE OF CONTENTS
4
Brian Petted LS RESEARCH Interview with Brian Petted - CTO
Featured Products
11
Education in Engineering: Hoover High Leads the Way
12
BY KAREN KOHTZ WITH EEWEB How an Alabama high school recognized for its academic excellence is preparing its students for college-level engineering courses.
MCU Wars 2.6 - OS Alternatives in the Embedded Space
16
Two experts in RTOS go into detail about the key differences between Embedded Linux and a real-time operating system.
Product Overview: RIGOL DS-2202 Digital Oscilloscope
22
RTZ - Return to Zero Comic
24
Visit www.eeweb.com
3
EEWeb PULSE
P 4
EEWeb | Electrical Engineering Community
INTERVIEW
Brian
Petted Visit www.eeweb.com
5
EEWeb PULSE How did you get into engineering? My father and grandfather were both mechanical engineers, so basically I became interested in it because my father left his old textbooks lying around in the attic. I would snoop around, open them up and thought it looked interesting. When I was in grade school, my interest was in drafting, so I did a lot of that – just making straight line drawings. As a teenager, I did the thing that most American kids did – played electric guitar and got into rock bands, which is actually how I got into electrical engineering. Everything involved with the equipment – signal processing for the guitars, amplifiers and sound reinforcement systems – really led me to pursuing electrical engineering instead of mechanical engineering, which was my initial influence. I had a teacher in high school that recommended the Milwaukee School of Engineering, which was nearby. I ended up going there and studied within the Electrical Engineering Technology program. Originally, four years seemed daunting so I went in with the intention of only going two years, graduating with an Associate’s degree and working as an electronics technician or maybe working at a recording studio or radio station. In my sophomore year, I discovered transmission lines, RF and microwave engineering and had a couple of great and influential teachers. I ended up staying for the four year Bachelor’s degree. At the end of the four years, I felt I still didn’t know enough about microwave engineering and electromagnetics, so I went to graduate school at Marquette University. One of the attractions of going to Marquette was working with Dr. Thomas Ishii, who is a fairly renowned expert
6
in microwave engineering. I had the pleasure of being able to study under him and earned my Master’s Degree. During my last years of college I worked some part-time jobs at various companies including, Curtis Industries which made power line filters, and Johnson Controls working in the corporate research department where I worked on the subject of my Master’s thesis – indoor spread spectrum communications. It was a research project on indoor communications for thermostats and wireless communications. This was in 1985, so there weren’t as many integrated parts as we have now, but I realized some experimental systems with the parts available at the time. After graduating from Marquette in 1987, I went to work for Harris Government Systems in Melbourne, Florida, which was my first full-time position in the RF and Microwave field. There, I was a senior engineer working on microwave integrated circuits and larger rack-based systems. Here, I started doing a lot of measurements on things that were already built, which included MMICs and a 20 GHz receiver. I worked in the RF and arrays department where we were focused on phased array antennas, realizing phase shifter/attenuators, complex weights, and any kind of component that could support phased array antennas. I spent two years in that department and was able to do some half-micron MMIC designs. After that, I wanted to move back to the Midwest and secured a position at Rockwell-Collins in Cedar Rapids, Iowa. There I continued along the same career track – working on RFIC and MMIC design. I was there for seven and a half years working on all different kinds of projects
EEWeb | Electrical Engineering Community
like a microwave landing system, a radar altimeter and airborne satellite terminals. The main focus of my work was the design of integrated circuits that helped reduce the size of those various systems. In 1995, I decided to move a little closer to Milwaukee and went to work at LS Research. At the time, LS Research was a fairly small company, operating as a sole proprietorship under Larry Schotz (which is where the LS comes from). I already knew of Larry because he was an alumnus of the Milwaukee School of Engineering and also on the board of regents there. He was a very influential person in the communications area as well. It was a great opportunity to work for Larry and also reconnect with one of my friends from graduate school. In fact 17 years later, my friend and I are still working together to this day. It was a difficult decision to move from a fairly large company – RockwellCollins – designing aviation and military equipment to a relatively small company with just around a dozen people that provided design services. It was a big change, but it was also a big opportunity to learn a lot of new things. Could you tell us a little more about LS Research and your role there? While LS Research started out as a design services company that later added an ISO 17025 accredited laboratory and testing expertise, we have since evolved as a global leader in enabling advanced wireless technologies spanning product development services, certification testing, and off-theshelf RF modules and wireless products. Whether our customers’ RF Design requirements call for
INTERVIEW a small consulting engagement or full turn-key development and manufacturing, we provide the solution. Each segment of our business is complimentary to the others, for example our design services segment of our business utilizes the compliance laboratory to test many of the new products being developed. In addition, the compliance group does independent contracting and testing spanning both radio related and EMC testing work. With that particular facility existing in your backyard, and as an RF designer, you look at it and say, “I have to get my designs through that.” It’s not an afterthought, it’s staring you right in the face. As a result, we have this thought process even before we put pen to paper. We work through how we are going to test and certify the device during the requirements capture and prior to the execution
“ Each segment of our business is complimentary to the others, for example our design services segment of our business utilizes the compliance laboratory to test many of the new products being developed. ”
Visit www.eeweb.com
7
EEWeb PULSE volume that, if grouped together can form the equivalent of a tier-1 customer in terms of volume. Since the semiconductor companies are not in a position to easily support a medium volume customer they will provide us with the proprietary information needed to support them and refer the customer to us for their product design. Much of our design services work comes from our relationships with semiconductor companies.
“
The off the-shelf modules have enhanced our design services offerings. We are able to offer the modules as a starting point, which results in reduced NRE costs for our customers to enter into the marketplace while at the same time reducing technical risk.
”
of the design. That was a big step for us – and a big investment – but it really pays off and helps us overall. I mentioned that moving to LSR was a huge learning experience for me. Over the years I’ve had the opportunity to learn how to do the testing for these devices and have performed many of the different emissions and immunity tests myself as part of pre-scanning initial prototypes. Now that I’m the Chief Technology Officer, that direct experience helps me in this role, as it lends the proper perspective to managing the process. Our work ranges from building componentlevel items, to radio sections that are integrated into our client’s baseband and application processing systems, to providing full turn-key solutions. We work extensively with 802.15.4 radios in the development of
8
products for industrial applications such as HVAC, 900 MHz solutions in utility meter reading and proprietary systems, and Bluetooth®, Bluetooth Low Energy and WLAN for medical, consumer, and industrial applications. Our extensive expertise has helped us build strong relationships with a number of different major semiconductor manufacturers such as Texas Instruments, Atmel, and Silicon Labs, to name a few. They call on us as a resource, mainly as an extension of their application engineering arm. Many other semiconductor companies, when they make an investment, invest in improving their processes, designs, and their applications engineering with a priority and focus on tier-1 customers. There are a lot of customers at a medium
EEWeb | Electrical Engineering Community
Our off-the-shelf RF modules and wireless product business segment has evolved over the last several years. We develop, certify, and control the design, and then manage the manufacturing process. Initially we started with ModFLEX™ 802.15.4 ZigBee, 6LoWPAN, and proprietary protocol ready modules to meet requirements for high performance, long range applications in both 2.4 GHz and 900MHz bands. We’ve since expanded to also providing the very popular TiWi™ 802.11 a/b/g/n, Bluetooth, and Bluetooth Low Energy selection of modules. This segment of our business solely focuses on product design, testing and maintaining the quality of these modules and accessory products. As mentioned previously, each of our business segments compliments the others. The off the-shelf modules have enhanced our design services offerings. We are able to offer the modules as a starting point, which results in reduced NRE costs for our customers to enter into the marketplace while at the same time reducing technical risk. For example, instead of designing a radio from the ground-up, the design can start with a placement of a precertified module. With availability of the compliance laboratory, we pre-certify the module products and customers can insert the module into their product or system and be
INTERVIEW exempt from the transmit radiator tests, which is an advantage in terms of time-to-market and implementation risk. As a CTO, it’s been nice to have been down in the trenches in our three different areas and now that we have been able to build a staff around these areas I can act in a leadership role working with the various people and processes. I think it goes a long way to have the respect of your peers in the sense that they know you’ve already worked directly with details in their area, you’re not just managing people, you’ve been there, and you can empathize and help them solve problems. How would you describe the culture in the company? When I came to the company, it was pretty much a family business. The environment was very free – we were still responsible to our customers and had a lot of pressure on us to get new design contracts. That really hasn’t changed. The culture on a larger scale, I’d say, is to try and make it a fun and interesting place to work, but still be effective in satisfying the business objectives and objectives of our customers and product groups. As we’ve grown, we’ve had to add more management functions to the company which makes it hard to maintain a small company feel. I think people have grown to learn that we have so many things going on that it’s nice to have management people who can focus on the customers and take care of the logistical things which allows engineering to concentrate on the technical execution of projects. While we’re getting larger and have had to shift to a somewhat more “corporate” culture while maintaining our agility, we have
“ The culture on a larger scale, I’d say, is to try and make it a fun and interesting place to work, but still be effective in satisfying the business objectives and objectives of our customers and product groups. ” certainly not forgotten our roots of entrepreneurial spirit, which has and will continue to permeate our mentality and approach to what we do. How many people are at the company now? Our corporate headquarters are located in Cedarburg, Wisconsin and consists of about 50 people. In Cedarburg, our services segment consists of an RF/Analog engineering group including antenna design capabilities, a software group, and we’ve recently added industrial design and mechanical engineering expertise as well. This is also where the EMC laboratory staff, product group staff, management and administrative personnel are located. There are another ten people in a second engineering group located in Madison, Wisconsin. The second group is more software-oriented, however, there is also a considerable amount of hardware, communications and wireless experience within that group. We also have a few additional folks that work remotely to cover different regions.
Do you have any hobbies outside of work? One of the things I have been doing for the last eight years in the evenings is teaching part-time at Milwaukee School of Engineering as an associate professor. I teach classes on signals, electromagnetic fields, and transmission lines—mainly to junior and senior level students. It makes for a couple long days, but it’s always inspiring. Getting students involved and inspired by engineering keeps me inspired and it keeps my enthusiasm level high. It’s nice to go off and immerse yourself in pure engineering theory and practice and at the same time, give back to the community. ■
For more information about LS Research, visit their website at:
www.lsr.com
Visit www.eeweb.com
9
Technology You Can Trust
Avago Technologies Optocouplers
Safety Certified Protection... Worldwide! IEC 60747-5-5 Certified
Optocouplers are the only isolation devices that meet or exceed the IEC 60747-5-5 International Safety Standard for insulation and isolation. Stringent evaluation tests show Avago’s
optocouplers deliver outstanding performance on essential safety and deliver exceptional High Voltage protection for your equipment. Alternative isolation technologies such as ADI’s magnetic or TI’s capacitive isolators do not deliver anywhere near the high voltage insulation protection or noise isolation capabilities that optocouplers deliver. For more details on this subject, read our white paper at: www.avagoresponsecenter.com/672
FEATURED PRODUCTS Low Noise 36-V Single Supply Op-Amp The OPA170 is a 36-V, single-supply, low-noise operational amplifier that features a micro package with the ability to operate on supplies ranging from +2.7V (±1.35V) to +36V (±18V). It offers good offset, drift, and bandwidth with low quiescent current. Unlike most op amps, which are specified at only one supply voltage, the OPA170 is specified from +2.7V to +36V. Input signals beyond the supply rails do not cause phase reversal. The OPA170 is stable with capacitive loads up to 300pF. The input can operate 100mV below the negative rail and within 2V of the positive rail for normal operation. For more information, click here.
IR Thermometer with Thermal Imaging Fluke Corporation introduces the Fluke VT02 Visual IR Thermometer, a troubleshooting camera with an infrared heat map. Until now, electricians and industrial, HVAC, and automotive technicians have had to choose between single-point infrared thermometers and highresolution thermal imagers (infrared or “IR” cameras). The Fluke VT02 Visual IR Thermometer fills the gap, for when a single-spot temperature reading isn’t enough and a high-resolution thermal image is more than users need. One tool combines the visual insight of a thermal imager, the visual images of a digital camera, and the point-and-shoot convenience of an IR (infrared) thermometer. For more information, please click here.
Module for Thermal Applications AAEON released the new NanoCOM-CV Rev.A COM Express Type 1 module with low power BGA type Intel® Atom N2600 1.6GHz Dual Core processor. Complimented by the low power Intel® NM10 chipset, the NanoCOM-CV Rev.A module boasts wider temperature tolerance and good performance, making it suitable for small form factor designs in thermal critical applications such as parking systems and home automation or computing intensive applications for medical, gaming and industrial automation. For more information, please click here.
Low Power Nonvolatile Memory Cypress Semiconductor Corp. announced that it has integrated Ramtron International’s ferroelectric random access memory (F-RAM) products into its portfolio, offering the market’s widest range of densities for fast-write nonvolatile memories. F-RAM is the industry’s lowestpower nonvolatile memory, complementing Cypress’s nonvolatile static random access memories (nvSRAMs), which are the world’s fastest. This new combination serves a broad range of applications that require data to be retained when power is lost. Combined, over a billion units of Cypress nvSRAM and Ramtron F-RAM products have been shipped worldwide. For more information, please click here.
Visit www.eeweb.com
11
EEWeb PULSE
Education in Engin
Hoover Hig Leads the Way Karen Kohtz
Assistant Editor, EEWeb
12
EEWeb | Electrical Engineering Community
TECH ARTICLE
neering:
gh P
resident Obama famously said that, “improving education in math and science is about producing engineers and researchers and scientists and innovators who are going to help transform our economy and our lives for the better.” The President went on to make the claim that “American 15year olds now rank 21st in science and 25th in math when compared to their peers around the world.” I talked to Mark Conner, Director of The Engineering Academy at Hoover High School, about how his program is stepping up to prepare more students for careers in engineering, while they’re still in high school. Hoover High School is a public school in Hoover, Alabama, recognized for academic success. The Engineering Academy, which began in 2004, is a 4 year program in which students take college-preparatory science, math, and engineering courses, ending with Calculus, Calculus-based Physics, and Engineering Design & Entrepreneurship in their fourth year.
The Engineering Academy has been a success, Conner says; students are often surprised by how much they can learn in a 48 minute class. “Statistically,” Conner points out, “many, if not most, students who transfer out of engineering in college actually transfer out of Calculus and Physics courses, before they have taken anything beyond introductory engineering courses.” The program at Hoover High aims to prepare students for college engineering courses by teaching math and science in traditional classroom settings and in the context of engineering electives. Students learn and apply critical math and science concepts as they tackle openended design problems in each of the four engineering electives. The program also aims to help students develop competencies in a variety of engineering tools, including Microsoft Excel, SolidWorks, MATLAB, and LabVIEW, while simultaneously honing the necessary “soft skills” of speaking, writing, and working in groups. According to Conner, students in the Engineering Visit www.eeweb.com
13
EEWeb PULSE
Academy often report that their work in other courses, such as English, improves because of their coursework in the Engineering Academy and its emphasis on these “soft skills.” Students who’ve gone on to study at universities have reported to Conner that their high school coursework prepared them for the presentations and speeches required in college. I asked Conner if there have been any challenges implementing and funding the engineering curriculum at Hoover High School. He responded that the administration at Hoover High has been supportive and worked with the program. Funding has not been a problem, partly because the program was started at a school that had solid infrastructure to begin with. Dr. Conner is one of 6 engineers (5 fulltime and 1 part-time) who split time between teaching in The Engineering Academy and the Science Department at Hoover. Each of the faculty members brings industry and/ or academic research experience to the classroom. Given the engineering faculty, the infrastructure, and the funds, required for the program’s success, I asked Conner whether he thought that similar programs might be possible at other schools around the country. His response was a confident “yes,” and he pointed out the internet as a powerful tool for teaching engineering to high school students, a tool that is already being used at Hoover High. Conner explained that Hoover High is in the second year of a pilot program, called The Online Engineering Academy, through which The Engineering Academy curriculum is being offered to schools around the country. In this model, called a “blended classroom,” “We provide content and the engineers to teach the content, while math or science teachers at partner schools facilitate class discussions, communicate with us, and make sure that a schedule is maintained,” Conner said. “We train the facilitating teachers but they are not responsible for the primary teaching of the engineering content.”
“I definitely don’t think you should eliminate the teacher-student dynamic,” Conner responded, “but the Internet can help a great teacher in one location positively impact students in many locations.”
Conner pointed out that, while Hoover High is
14
EEWeb | Electrical Engineering Community
fortunate because of its large student population, course offerings at many other schools around the country are limited by smaller student and faculty populations. Often a school must have 20 students enrolled in order to offer a class, but with online programs, this critical mass for offering a course could be reduced to a single student. Given The Engineering Academy’s use of the internet in their “blended classroom” approach, I asked Conner what he thinks about the recent focus in education on online learning. “I definitely don’t think you should eliminate the teacherstudent dynamic,” Conner responded, “but the internet
TECH ARTICLE
can help a great teacher in one location positively impact students in many locations.” Finally, I asked Conner about some of the challenges facing educators wishing to encourage the study of engineering. He responded that the greatest challenge has been garnering significant support from the engineering industry, although he pointed out that some organizations, such as the IEEE, have helped fund part of the development of online academy programs. “More engineering companies are venturing into K-12 outreach activities, but if these activities do not affect the courses that students are taking in high school – courses that will adequately prepare them for college – then the outreach activities will do little to change the number of students pursuing engineering in college.” “Reaching corporate decision-makers with the message that a portable, scalable, and cost-effective collegepreparatory engineering is available,” Conner said, “is critical to the growth and success of programs like The Online Engineering Academy.” “Companies could start to build relationships with these students while they are still in high school,” Conner said. “The co-op field (where college students work at a company while earning their degree) is getting more and more competitive. Many of our students walk out of the 9th grade with marketable skills. We would love to see partnerships where companies provide scholarships for students to participate in the online academy and begin building relationships with their future workforce.” After my talk with Conner, it seemed clear that if government groups and private engineering companies look to Hoover High (and programs like it) for direction, they may be able to better develop high school engineering education across the country. The Engineering Academy at Hoover High is continuing to work with other schools to expand its online engineering program. You can view the website for The Online Engineering Academy at http://www. theonlineengineeringacademy.com ■
Visit www.eeweb.com
15
EEWeb PULSE
Episode 2.6
OS Alternatives in the Embedde Space 16
EEWeb | Electrical Engineering Community
s ed
SPECIAL FEATURE
In this episode of MCU Wars, Jean Labrosse of Micrium and Richard Barry of FreeRTOS go into detail about the key differences between Embedded Linux and an RTOS. This series was filmed at DevCon 2012 by Renesas in Anaheim, California. DevCon provides an environment for valuable technical information exchange and access to Renesas’ technology experts and partenrs from around the world. Visit www.eeweb.com
17
EEWeb PULSE
Can you explain the difference between other operating systems—like Embedded Linux—and an RTOS? This is a very good question. It’s one of those things that I hate when Richard people come up to me and say, “FreeRTOS—is that like Linux?” I can answer that in one word: No. It’s nothing like Linux. Linux is not real-time, first of all. My product is specifically designed to be real-time and deterministic, however you want to define that, and Linux isn’t any of these. My product is designed to run on microcontrollers from the very start. It runs around 8-bit all the way up to the large 32-bit, but that is its core market. Linux is way outside that and much more complex. Mine is specifically designed for a specific job; to keep everything small and deterministic. Linux is in a completely different space and isn’t a competitor at all.
Featured Above: (From left) Cody Miller of EEWeb, Richard B
I like to use an analogy when I talk about the real-time Kernels versus Jean Linux. Real-time Kernels for us is like driving your car to work, which is normal. Linux is like an 18-wheel truck—you wouldn’t want to drive an 18-wheel truck to work everyday. Linux is good for certain things like when you have to move a lot of furniture and do a lot of things, but when you have to drive to work everyday, it’s really not the same thing. So, for us, real-time Kernels are designed for embedded systems from the get-go—it was never designed to be in a large operating system. The real-time Kernel, in our case, is anywhere between 4 or 5k all the way to about 25k if you enable all of the features. From an operating system point of view, if you want to have an equivalent, our software services fits in a megabyte of code space. Clearly not even close to what Linux requires.
18
EEWeb | Electrical Engineering Community
“
Linux is like an 18-whee want to drive an 18-wh eryday. Linux is good when you have to m and do a lot of things to drive to work every same thing.
SPECIAL FEATURE
That’s not to say that Linux is not a good product, you should say it’s all Richard about choosing the right tool for the job that you’re doing. The market that I provide a tool for is completely different from the Linux market. ■
EEWeb would like to thank Richard Barry and Jean Labrosse for participating in MCU Wars. To find out more information about FreeRTOS and Micrium, visit their websites linked below:
Barry of FreeRTOS and Jean Labrosse of Micrium
el truck—you wouldn’t heel truck to work evfor certain things like move a lot of furniture s, but when you have yday, it’s really not the
”
To view this episode of MCU Wars and other EEWeb videos:
Click Here
Visit www.eeweb.com
19
World’s lowest power capacitive sensors with auto-calibration NXP is a leader in low power capacitance touch sensors, which work based on the fact that the human body can serve as one of the capacitive plates in parallel to the second plate, connected to the input of the NXP capacitive sensor device. Thanks to a patented auto-calibration technology, the capacitive sensors can detect changes in capacitance and continually adjust to the environment. Things such as dirt, humidity, freezing temperatures, or damage to the electrode do not affect the device function. The rise of touch sensors in modern electronics has become a worldwide phenomenon, and with NXP’s low power capacitive sensors it’s never been easier to create the future.
Learn more at: touch.interfacechips.com
Get the Datasheet and Order Samples http://www.intersil.com
Low Voltage ORing FET Controller ISL6146
Features
The ISL6146 represents a family of ORing MOSFET controllers capable of ORing voltages from 1V to 18V. Together with suitably sized N-channel power MOSFETs, the ISL6146 increases power distribution efficiency when replacing a power ORing diode in high current applications. It provides gate drive voltage for the MOSFET(s) with a fully integrated charge pump.
• ORing Down to 1V and Up to 20V with ISL6146A, ISL6146B, ISL6146D and ISL6146E
The ISL6146 allows users to adjust with external resistor(s) the VOUT - VIN trip point, which adjusts the control sensitivity to system power supply noise. An open drain FAULT pin will indicate if a conditional or FET fault has occurred. The ISL6146A and ISL6146B are optimized for very low voltage operation, down to 1V with an additional independent bias of 3V or greater. The ISL6146C provides a voltage compliant mode of operation down to 3V with programmable Undervoltage Lock Out and Overvoltage Protection threshold levels The ISL6146D and ISL6146E are like the ISL6146A and ISL6146B respectively but do not have conduction state reporting via the fault output. TABLE 1. KEY DIFFERENCES BETWEEN PARTS IN FAMILY PART NUMBER
KEY DIFFERENCES
ISL6146A
Separate BIAS and VIN with Active High Enable
ISL6146B
Separate BIAS and VIN with Active Low Enable
ISL6146C
VIN with OVP/UVLO Inputs
ISL6146D
ISL6146A wo Conduction Monitor & Reporting
ISL6146E
ISL6146B wo Conduction Monitor & Reporting
+
VOLTAGE DC/DC (3V - 20V)
VIN GATE VOUT BIAS ADJ ISL6146B FLT GND
EN
Q2 +
VOLTAGE DC/DC (3V - 20V)
VIN GATE VOUT VOUT BIAS ADJ ISL6146B FLT GND
EN
-
FIGURE 1. TYPICAL APPLICATION
October 5, 2012 FN7667.3
• VIN Hot Swap Transient Protection Rating to +24V • High Speed Comparator Provides Fast <0.3µs Turn-off in Response to Shorts on Sourcing Supply • Fastest Reverse Current Fault Isolation with 6A Turn-off Current • Very Smooth Switching Transition • Internal Charge Pump to Drive N-channel MOSFET • User Programmable VIN - VOUT Vth for Noise Immunity • Open Drain FAULT Output with Delay - Short between any two of the ORing FET Terminals - GATE Voltage and Excessive FET VDS - Power-Good Indicator (ISL6146C) • MSOP and DFN Package Options
Applications • N+1 Industrial and Telecom Power Distribution Systems • Uninterruptable Power Supplies • Low Voltage Processor and Memory • Storage and Datacom Systems
+
Q1
• Programmable Voltage Compliant Operation with ISL6146C
C O M M O N P O W E R
GATE FAST OFF, ~200ns FALL TIME ~70ns FROM 20V TO 12.6V ACROSS 57nF GATE OUTPUT SINKING ~ 6A
B U S +C O M M O N P O W E R B U S
FIGURE 2. ISL6146 GATE HIGH CURRENT PULL-DOWN
Intersil (and design) is a registered trademark of Intersil Americas Inc. Copyright Intersil Americas Inc. 2011, 2012 All Rights Reserved. All other trademarks mentioned are the property of their respective owners.
EEWeb PULSE
Overview of the
RIGOL DS-2202 Digital Oscilloscope EEWeb Tech Lab
22
EEWeb | Electrical Engineering Community
PRODUCT OVERVIEW
Overview
Recording a Signal
The DS-2202 is a 200MHz, 2GSa/s, 2 Channel oscilloscope with 56 Mpts memory.
This oscilloscope has a large display and dedicated knobs for all of your position and scaling adjustments, both for your vertical and horizontal axis. It also has a dedicated knob for trigger adjustments, on the bottom right of the oscilloscope. The channels and their corresponding knobs are all color-coded.
If you have a signal that’s a little more exciting than a plain sine wave, you can actually record your signal by pressing the record button on the far right hand side of the oscilloscope. You will be able to confirm that it’s recording on the display screen. When it’s finished, you can playback that signal by pressing the play/pause button to the left of the record button. This recording function allows you to capture a complicated signal moving around in time, such as a communication signal, and then play it back to see exactly what the wave form is doing.
Measuring with the DS-2202
Triggering Modes
In order to take measurements with the DS-2202, you can begin by clearing a channel, such as channel two. You can then bring channel one back to the zero position very easily, by pressing the position adjustment button.
The DS-2202 also offers various triggering modes, which you can select using the menu button from the Trigger menu on the bottom right hand of the oscilloscope. The default is the standard edge, but if you need something custom, you can use the menu on the right of the display screen and the intensity knob to select pattern, and program in your own pattern of highs and lows. If you’re using a standard communication interface, such as RS 232 I2C ISP or USB, those are all built in trigger types.
It features an 8 inch screen, and USB and Ethernet for connectivity. It sells for just over $1626.
Another feature of the DS-2202 is the measurement function. To measure a wave, such as a 1Mhz sine wave, you bring up the measurement menu, which is easy to access by using the soft key to the left of the display screen. Select the frequency soft key, and will see the frequency measurement pop up at the bottom of the chart. If you’d like to measure voltages, you can click over to the vertical menu, and measure your Vmin, Vmax, using the associated soft keys. The measurements will populate along the bottom of the screen. If you want to see the min, max, and average of those measurements, rather than just the current value, you can go over to the measurement menu (which is located at the top of the oscilloscope on the right-hand side of the display screen) and turn on the statistic function using the soft keys by the display screen. All the measurements are represented on the bottom of the screen with their logo, min, max, and average values. If the built-in measurement functions aren’t enough, you can bring up your cursors (from the soft keys on the right-hand side of the screen) select the cursor that you’d like to adjust, and adjust the cursor using the small “intensity” knob at the top of the oscilloscope by the right hand measurement menu. Using this knob, you can dial in the voltage you need. If you need to change the voltage, you simply change the type to voltage (using the third button down on the measurement menu) and then you can again adjust your cursors up and down.
Conclusion The DS-2202 has many of the same features as the DS-4054, but with fewer channels and less bandwidth, which allows the price to be lower.
To watch this review and others from EEWeb Tech Lab:
Click Here Visit www.eeweb.com
23
Lunchtime - Part 4
Tasty Settlement- Part 5
Jack-O-Lantern