New Products: May 2013


iC-Haus iC-TW8

The iC-TW8 is a high-resolution signal processor designed to evaluate sine/cosine sensors. Its automatic functions help minimize angular errors and jitters. The processor can be used for initial, push-button calibration and to permanently adapt signal-path parameters during operation. The angular position is calculated at a programmable resolution of up to 65,536 increments per input cycle and output as an indexed incremental signal. A 32-bit word, which includes the counted cycles, is available through the SPI.

As an application-specific DSP, the iC-TW8 has two ADCs that simultaneously sample at a 250-ksps rate, fast CORDIC algorithms, special signal filters, and an analog front end with differential programmable gate amplifier (PGA) inputs that accepts typical magnetic sensor signals from 20 mVPP and up. Signal frequencies of up to 125 kHz enable high rotary and linear speeds for position measuring devices and are processed at a 24-µs constant latency period.

The device’s 12-bit measurement accuracy works with one button press. Measuring tools are not required. The iC-TW8 independently acquires information about the signal corrections needed for offset, amplitude, and phase errors and stores them in an external EEPROM.

The iC-TW8 has two configuration modes. Preset functions and interpolation factors can be retrieved through pins and the device can be calibrated with a button push. No programming is required for initial operation.

The device’s functions—including an AB output divider for fractional interpolation, an advanced signal filter to reduce jitter, a table to compensate for signal distortion, and configurable monitors for errors and signal quality—can be accessed when the serial interfaces are used. Typical applications include magnetic linear displacement measuring systems, optical linear scales, programmable magnetic/optical incremental encoders, high-resolution absolute/incremental angle sensors with on-axis, Hall scanning, and the general evaluation of sine/cosine signals (e.g., PC measuring cards for 1 VPP and 11 µAPP).

The iC-TW8 operates on a 3.1-to-5.5-V single-ended supply within a –40°C-to-125°C extended operating temperature range. It comes in a 48-pin QFN package that requires 7 mm × 7 mm of board space. A ready-to-operate demo board is  available for evaluation. An optional PC operating program, in other words, a GUI, can be connected with a USB adapter.

The iC-TW8 costs $7.69 in 1,000-unit quantities.

iC-Haus GmbH


Analog Devices AD9675

The AD9675 and the AD9674 are the latest additions to Analog Devices’s octal ultrasound receiver portfolio. The devices and are pin compatible with the AD9670/AD9671.

The AD9675 is an eight-channel ultrasound analog front end (AFE) with an on-chip radio frequency (RF) decimator and Analog Devices’s JESD204B serial interface. It is designed for mid- to high-end portable and cart-based medical and industrial ultrasound systems. The device integrates eight channels of a low-noise amplifier, a variable-gain amplifier, an anti-aliasing filter, and a 14-bit ADC with a 125-MSPS sample rate and a 75-dB signal-to-noise ratio (SNR) performance for enhanced ultrasound image quality. The on-chip RF decimator enables the ADC to be oversampled, providing increased SNR for improved image quality while maintaining lower data I/O rates. The 5-Gbps JESD204B serial interface reduces ultrasound system I/O data routing.

The AD9674 offers similar functionality, but includes a standard low-voltage differential signaling (LVDS) interface. Both devices are available in a 144-ball, 10-mm × 10-mm ball grid array (BGA) package.

The AD9674 and the AD9675 cost $62 and $68, respectively.

Analog Devices, Inc.


Melexis MLX92212

Melexis MLX92212

MLX92212 digital output Hall-effect sensors are AEC-Q100-qualified devices that deliver robust, automotive-level performance. The MLX92212LSE-AAA low-hysteresis bipolar latch and the MLX92212LSE-ABA high-hysteresis unipolar switch are optimized for 2.5-to-5.5-V operation. They pair well with many low-power microcontrollers in embedded systems. The sensor and specified microcontroller can share the same power rail. The sensors’ open-drain outputs enable simple connectivity with CMOS/TTL. They exhibit minimal magnetic switch point drift over temperature (up to 150°C) or lifetime and can withstand 8 kV electrostatic discharge.

The MLX92212LSE-AAA is designed for use with multipole ring magnets or alternating magnetic fields. It is well suited for brushless DC electric motor commutation, speed sensing, and magnetic encoder applications. Typical automotive uses include anti-trap/anti-pinch window lift controls, automatic door/hatch systems, and automatic power seat positioning. The MLX92212LSE-ABA enables the use of generic/weak magnets or larger air gaps. It can be used in simple magnetic proximity sensing and interlocks in covers/hatches or ferrous-vane interrupt sensors for precise position and timing applications.

Both MLX92212 devices utilize chopper-stabilized amplifiers with switched capacitors. The CMOS technology makes this technique possible and contributes to the sensors’ low current consumption and small chip size.

The MLX92212 sensors cost $0.35 each in 5,000-unit quantities and $0.30 in 10,000-unit quantities.

Melexis Microelectronic Integrated Systems


Byte SPI Storm

Byte SPI Storm

The SPI Storm 50 and the SPI Storm 10 are the latest versions of Byte Paradigm’s SPI Storm serial protocol host adapter. The adapters support serial peripheral interface (SPI), Quad-SPI, and custom serial protocols in the same USB device.

The SPI Storm 50 and the SPI Storm 10 support serial protocols and master up to 50 and 10 MHz, respectively. The SPI Storm 10 features an 8-MB memory, while the higher-end devices are equipped with a 32-MB memory.

The SPI Storm adapters enable system engineers to access, communicate, and program their digital board and digital ICs, such as field-programmable gate array (FPGA), flash memories, application-specific integrated circuit (ASIC), and

system-on-a-chip (SoC). The SPI Storm 10 is well suited for engineering schools and universities because it is a flexible, all-around access device for hands-on digital electronics. The 50- and 100-MHz versions can be used in mid- and high-end testing and debugging for telecommunications, medical electronics, and digital imaging industries.

The SPI Storm 50 and the SPI Storm 10 cost $530 and $400, respectively.

Byte Paradigm


Microchip MCP19111

Microchip MCP19111

The MCP19111 digitally enhanced power analog controller is a new hybrid, digital and analog power-management device. In combination with the expanded MCP87xxx family of low-figure-of-merit (FOM) MOSFETs, it supports configurable, high-efficiency DC/DC power-conversion designs for many consumer and industrial applications.

The MCP19111 controller, which operates at 4.5 to 32 V, integrates an analog-based PWM controller with a fully functional flash-based microcontroller. This integration offers the flexibility of a digital solution with the speed, performance, and resolution of an analog-based controller.

The MCP19111 devices have integrated MOSFET drivers configured for synchronous, step-down applications. The MCP87018, MCP87030, MCP87090, and MCP87130 are 25-V-rated, 1.8-, 3-, 9-, and 13-mΩ logic-level MOSFETs that are specifically optimized for switched-mode-power-supply (SMPS) applications.

The MCP19111 evaluation board includes Microchip’s high-speed MOSFETs. This evaluation board includes standard firmware, which is user-configurable through an MPLAB X IDE graphical user interface (GUI) plug-in. The combined evaluation board, GUI, and firmware enable power-supply designers to configure and evaluate the MCP19111’s performance for their target applications.

The MCP19111 controllers cost $2.81 each and the MCP87018/030/090/130 MOSFETs cost $0.28 each, all in 5,000-unit quantities.

Microchip Technology, Inc.


Ironwood SG-QFE-7011

Ironwood SG-QFE-7011

The SG-QFE-7011 is a high-performance QFP socket for 0.4-mm pitch, 128-pin QFPs. The socket is designed for a

1.6-mm × 14-mm × 14-mm package size with a 16-mm × 16-mm lead tip to tip. It operates at bandwidths up to 10 GHz with less than 1 dB of insertion loss and has a typical 20 mΩ per I/O contact resistance. The socket connects all pins with 10-GHz bandwidth on all connections. The small-footprint socket is mounted with supplied hardware on the target PCB. No soldering is required. The small footprint enables inductors, resistors, and decoupling capacitors to be placed close to the device for impedance tuning.

The SG-QFE-7011’s swivel lid has a compression screw that enables ICs to be quickly changed out. The socket features a floating compression plate to force down the QFP leads on to elastomer. A hard-stop feature is built into the compression mechanism.

The sockets are constructed with high-performance, low-inductance gold-plated embedded wire on elastomer as interconnect material between a device and a PCB. They feature a –35°C-to-100°C temperature range, a 0.15-nH pin self inductance, a 0.025-nH mutual inductance, a 0.01-pF capacitance to ground, and a 2-A per pin current capacity.

The SG-QFE-7011 costs $474.

Ironwood Electronics

Issue 274: EQ Answers

The answers to the Circuit Cellar 274 Engineering Quotient are now available. The problems and answers are listed below.

Problem 1—What is wrong with the name “programmable unijunction transistor?”

Answer 1—Unlike the original unijunction transistor—which really does have just a single junction—the programmable unijunction transistor (PUT) is actually a four-layer device that has three junctions, much like a silicon-controlled rectifier (SCR).


Problem 2—Given a baseband channel with 3-kHz bandwidth and a 40-dB signal-to-noise ratio (SNR), what is the theoretical capacity of this channel in bits per second?

Answer 2—The impulse response of an ideal channel with exactly 3 kHz of bandwidth is a sinc (i.e., sin(x)/x) pulse in the time domain that has nulls that are 1/6,000 s apart. This means you could send a series of impulses through this channel at a 6,000 pulses per second rate. And, if you sampled at exactly the correct instants on the receiving end, you could recover the amplitudes of each of those pulses with no interference from the other pulses on either side of it.

However, a 40-dB signal-to-noise ratio implies that the noise power is 1/10,000 of the maximum signal power. In terms of distinguishing voltage or current levels, this means you can send at most sqrt(10,000) = 100 distinct levels through the channel before they start to overlap, making it impossible to separate one from another at the receiving end.

100 levels translates to log2100 = 6.64 binary bits of information. This means the total channel capacity is 3,9840 bits/s (i.e., 6,000 pulses/s × 6.64 bits/pulse).

This is the basis for the Shannon-Hartley channel capacity theorem.


Problem 3—In general, is it possible to determine whether a system is linear and time-invariant (LTI) by simply examining its input and output signals?

Answer 3—In general, given an input signal and an output signal, you might be able to definitively state that the system is not linear and time-invariant (LTI), but you’ll never be able to definitively state that it is, only that it might be.

The general technique is to use information in the input signal to see whether the output signal can be composed from the input features. Input signals (e.g., impulses and steps) are easist to analyze, but other signals can also be analyzed.


Problem 4—One particular system has this input signal:

Figure 1

The output is given by:

Figure 2

Is this system LTI?

Answer 4—In this example, the input is a rectangular pulse that can be analyzed as the superposition of two step functions that are separated in time, one positive-going and the other negative-going. This makes the analysis easy, since you can see the initial response to the first step function then determine whether the response following the second step is a linear combination of two copies of the first part of the response.

In this case, the response to the first step function at t = 0 is that the output starts rising linearly, also at t = 0. The second (negative) input step function occurs at t = 0.5, and if the system is LTI, you would expect the output to also change what it’s doing at that time. In fact, you would expect the output to level off at whatever value it had reached at that time, because the LTI response to the second step should be a negative-going linear ramp, which, when added to the original response, should cancel out.

However, this is not the output signal received, so this system is definitely not LTI.

Member Profile: John Peterson

John Peterson

John Peterson

Location: Menlo Park, CA

Education: BS and MS, University of Utah

Occupation: Software Developer

Member Status: John has been a subscriber since 2002.

Technical Interests: His interests include user interfaces for embedded systems, field-programmable gate array (FPGA) development, and embedded Internet development.

Most Recent Embedded Tech-Related Purchase: John recently purchased a power supply for one of his designs.

Current Projects: He is currently working on a custom light controller for strings of progammable LED lights.

Thoughts on the Future of Embedded Technology: John feels that smartphones have raised everybody’s expectations for how we interact with everyday things (e.g., cars, appliances, household control, etc.). “Either the phone becomes the interface (via the network) or the gadgets need touchscreen displays,” John said.

Q&A: Clive “Max” Maxfield – Engineer, Author, Innovator

Clive “Max” Maxfield

Clive “Max” Maxfield is an engineer who has written more than a half-dozen engineering books, contributes to several blogs, and enjoys learning and relating information to others. Max and I recently discussed his journey from hardware design engineer to prolific book author and blogger, some of his ongoing projects, and his outlook on the future of embedded technology.—Nan Price, Associate Editor

NAN: Let’s start with some background information. Where are you located? Where and what did you study?

MAX: I’m originally from the city of Sheffield in the county of Yorkshire in England. (Yorkshire is God’s own county where all the men are handsome, all the women are beautiful, and all the kids are above average—similar to Lake Wobegon, MN, except that Yorkshire is real.) I moved to Huntsville, AL, in 1990 for the nightlife (that’s a little Alabama joke right there).

I studied at Sheffield Hallam University in South Yorkshire, England. My BSc is in Control Engineering, which involves a core of mathematics with “surrounding” subjects in electronics, mechanics, hydraulics, and fluidics.

NAN: When and how did you become interested in electronics?

MAX: I actually started in the playground when I was about 11 years old. One of my friends, Carl Clements, was really “clever beyond his years.” While the other boys (it was a boys’ grammar school) were kicking a soccer ball around or playing conkers or whatever, Carl and I would be crouched down in a corner somewhere, with him using his finger to draw circuit diagrams of things like one-transistor amplifiers and such in the dust.

NAN: Tell us about the first circuit with which you worked. What was the project? What did you learn from it?

MAX: I used to be an avid reader of electronics hobbyist magazines, including Practical Electronics and Practical Wireless. There was a series of articles in Practical Wireless called “Take 20” about projects that were 20 components or fewer costing 20 shillings or less (at that time there were 20 shillings in a UK pound). As I recall, the first circuit I built was a simple oscillator that warbled back and forth between two frequencies and sounded (a bit) like a police car. My mother loved it (not).

Building these projects, I learned to be really good at soldering. I also learned that, no matter how simple the project, something always went wrong. I can’t recall a single time that a project worked the first time I powered it up. So I also learned a lot about troubleshooting and tracking down shorts and opens and components I’d soldered in backwards.

NAN: Tell us about your current occupation.

MAX: Well, I still think of myself as being a hardware design engineer—in my time I’ve designed everything from silicon chips to circuit boards, and from brainwave amplifiers to steampunk “Display-O-Meters.” I’ve also been fortunate enough to be at the forefront of the Electronic Design Automation Consortium (EDA) for more than 20 years.

Having said this, I sort of drifted into writing—starting with magazine articles and presenting technical papers at conferences, and graduating into books. So now I don’t really do any engineering (apart from my hobby projects), I just talk about it a lot!

My current occupation is to act as editor for two EE Times websites: Programmable Logic Designline and Microcontroller Designline ( and, respectively) and as Editor-in-Chief for the All Programmable Planet (APP) community (

NAN: Tell us about APP, how you became involved, and what your role as Editor-in-Chief entails.

MAX: APP is, first and foremost, a knowledge-sharing website for programmable devices and technologies such as today’s state-of-the-art, all-programmable field-programmable gate arrays (FPGAs), 3-D integrated circuits (ICs), and system-on-chip (SoC) devices. But it’s more than that. It’s a community of really great guys and gals spanning the range from complete novices to absolute experts. It’s also full of interesting characters, such as The Mighty Hamster (a.k.a. Mike Field) from New Zealand, who is always performing interesting experiments in his lab and reporting them in his blogs on APP. Actually, we have so many interesting bloggers that it’s impossible to cover them here—your best bet is to bounce over to APP and see what’s going on.

I will say that we have some truly interesting projects on the go, such as the world’s (nay, the universe’s) first wireless mesh network to be utilized in propeller beanies ( This little beauty—in the form of 250 networked propeller beanies—was deployed at the DESIGN West 2013 Conference and Exhibition (

As to my role as Editor-in-Chief, have you ever heard the expression “herding cats?” That’s sort of what I do. I have a bunch of bloggers all going in different directions, and my role—in addition to penning my own incredibly interesting articles, of course—is to ensure that everything comes together at the right time.

NAN: You contribute to an EE Times blog, Max’s Cool Beans, with posts on topics ranging from personal supercomputers to embedded speech. Tell us about the types of projects you enjoy working on and blogging about.

Electronic Steampunk Suitcase

Electronic Steampunk Suitcase

MAX: As you say, my Max’s Cool Beans blog ( does tend to cover a lot of ground. One day I might be writing about life in a 1950s typing pool on the one hand and the latest and greatest technologies on the other. I also blog about my own personal projects, such as the “Electronic Steampunk Suitcase” ( I built as a prop to accompany one of the papers I presented at DESIGN West titled “Danger Will Robinson! How Radiation Can Affect Your Embedded Systems.”

Another ongoing project is my “Heath Robinson Rube Goldberg (HRRG) Mixed-Technology Computer.” The idea here is to have a collection of glass-fronted wooden cabinets mounted on the wall. The contents of each cabinet will be realized using a different implementation technology—relays in one, vacuum tubes in another, circuits built out of individual transistors in another, and so forth. Some cabinets will boast more esoteric technologies like pneumatic logic and magnetic logic. Combined, all of these cabinets will form a simple 4-bit computer.

Bebop to the Boolean Boogie

Bebop to the Boolean Boogie

NAN: You’ve written several books, including Bebop to the Boolean Boogie: An Unconventional Guide to Electronics, The Design Warrior’s Guide to FPGAs: Devices, Tools, and Flows, and Electrical Engineering: Know It All. How did you transition from being an engineer to writing about engineering?

MAX: A few years after starting work, I began to use a digital logic simulator that was owned by the company I worked for. I took to it like a duck to water, and it wasn’t long before my company asked me to give training courses to their customers, which meant I had to write the training materials. From there, I started writing articles on simulation for technical magazines, and things just started rolling along, picking up speed.

The great thing about writing for an engineering audience is that they really don’t care (or know) if I split an infinitive or leave a participle dangling in the wind.

NAN: Your book, How Computers Do Math (co-authored with Alvin Brown), includes the DIY Calculator (, which is an Assembly-based calculator program. Tell us why you created this tool.

MAX: When home computers first started to come out in the mid-1970s I really wanted one, but I simply couldn’t afford one. We’re talking about a single-board machine with an 8-bit microprocessor, like a 6502, only with 1 KB of ROM and 1 KB of RAM (if you were lucky), and a hexadecimal keypad. The strange thing is that, if you were into computers at that time, you tended to know an awful lot about how things worked at the “nitty-gritty” level.

By comparison, these days, everyone has an awesome amount of computing power at their fingertips, but very few people have a clue what goes on “under the hood.” Most of the non-academic computer-related books out there are along the lines of Learn to Use XXX Version 6.0 in 21 Days!” (I have a feeling that the reason they say “21 days” is because that’s when version 7.0 is going to hit the streets.)

Remembering how much I’d wanted a simple computer when I was a lad—something I could experiment with to really see what it was doing—I talked to my chum Alvin (we’d co-authored a couple of books by that time) and we decided to write a book that would really explain things in terms that anyone could understand.

As part of this, we created the DIY Calculator, which is a virtual machine that runs on your PC. The core of the DIY Calculator is a simple virtual microprocessor with an 8-bit data bus and a 16-bit address bus. This is then augmented by a virtual RAM, a virtual ROM, and a bunch of virtual I/O ports.

The virtual interface to this system looks like a calculator front panel. When you click this front panel’s On/Off button on your screen absolutely nothing happens. This is because there isn’t a program yet. What we do in the book is present a series of hands-on labs (each about 20 to 30 min.) in which the reader creates small programs in our (homegrown) Assembly language. First we display “Hello world” on the virtual LCD panel. Then we read buttons from the virtual keypad and display their values on the LCD, and we work our way up until the user has a four-function calculator (+, –, ×, /) up and running. And there are lots of extra keys for future development. We have readers as young as 11 and as old as 75 plus. One reader even created his own BASIC interpreter (in our Assembly language). Anyone can download the virtual DIY Calculator for free from the website.

BookshelfNAN: What do you enjoy most about writing? Do you plan to write any future books?

MAX: Generally speaking, I don’t like a lot of technical or science books because they are so dry and boring. I like books that are fun to read and teach me all sorts of new things, such as Reinventing Gravity: A Physicist Goes Beyond Einstein Reinventing Gravity by John Moffat (physics), The Disappearing Spoon: And Other True Tales of Madness, Love, and the History of the World from the Periodic Table of the Elements by Sam Kean (chemistry), and Wetware: A Computer in Every Living Cell by Dennis Bray (biology). I love discovering nuggets of knowledge and tidbits of trivia, so that’s the way I try to write my books.

What I really like is receiving e-mails from readers saying how much they’ve enjoyed reading something I’ve written, and how they didn’t understand it before but they do now. Once, as I was giving a course based on Bebop to the Boolean Boogie, while I was explaining something using a diagram, a loud (and happy) voice from the audience said, “So that’s what that means!”

With regard to the future, I have a lot of ideas for books explaining science and technology for younger readers—say boys and girls around 12 to 16. I always think of myself as writing for myself at that age, if you see what I mean. Like, if I could take my books and use a time machine to send them back to myself when I was 14.

One book I’m working on at the moment is a book on “how to write for engineers” sort of thing. This is not trying to explain everything to do with grammar and spelling and such, just the main things. Like I always say, if someone sends me an e-mail saying “Your an idiot” (using “your” instead of “you’re”), then they are not conveying the message they had hoped for.

NAN: What do you consider to be the “next big thing” in the embedded design industry?

MAX: You are joking! There are so many “next big things” that I wouldn’t know where to start. Two obvious areas are embedded vision and embedded voice. These technologies are poised to start appearing in all sorts of products in the very near future. For example, imagine a cat door that isn’t triggered by a magnet on your cats’ collars, but instead uses embedded vision to actually recognize your cats and grant them entry. Or imagine climbing into bed and saying, “Clock, please wake me up at 6:30 AM tomorrow,” and your clock responding, “You’ve asked to be woken at 6:30 AM for the last three days, do you want me to set that as the default in the week?”

But the thing to watch out for is the technologies and end-user applications that we haven’t even thought of yet. Look at how fast things are changing. As we moved into the new millennium (circa 2000, which is only 13 years ago), we couldn’t imagine smartphones boasting speech recognition, the ability to take photos and videos, and inbuilt GPS. Now we take them from granted. The first iPad was released on April 3, 2010, which is only three years ago, but now it seems like they’ve been around forever. I certainly don’t know what I’d do without my iPad.

All I can say is that I am 100% confident that the future is going to be much more wonderful, stranger, and scarier (in some ways) than most of us can imagine. I can’t wait! I love this stuff!

Electrical Engineer Crossword (Issue 274)

The answers to Circuit Cellar’s May electronics engineering crossword puzzle are now available.Across

1.            MOSIPROTOCOL—Adds a state indicating ownership [two words]

3.            SPECTROMETER—Measures wavelengths

8.            SHELL—Protects an operating system’s kernel

10.          CHARGE—Q

12.          ASSIGN—A FORTRAN control statement

13.          HALL—American physicist (1855–1938) who had an “effect” [two words]

15.          FIELDPROGRAMMABLE—Configurable after purchase [two words]

17.          MOUNTPOINT—In a Linux system, create this first to access the queue [two words]

19.          CORDIC—Calculate digit by digit

20.          MEISSNEREFFECT—Flux jumping [two words]



2.            INTERPROCESSCOMMUNICATION—Data exchanging method [two words]

4.            SQUIRRELCAGE—Commonly used in asynchronous motors [two words]

5.            DEGLITCHER—Type of delay circuit, serves as a pulse generator

6.            MERCURYARC—Emits  bright bluish-green light [two words]

7.            BALLGRIDARRAY—Packages ICs [three words]

9.            THREADEDCODE—A compiler technique [two words]

11.          DARAF—Unit of elastance

14.          AMPEREHOUR—3,600 coulombs [two words]

16.          RIPPLE—Unwanted undulation

18.          NIXIE—Used for numeric display