Analog Hotspot

Enter “motion control” or “motor control” into your favorite search engine, and you’ll be rewarded with links to an ad-hoc encyclopedia of solid design information. Freescale’s site (www.freescale.com/webapp/sps/site/overview.jsp?nodeId=02M0zpbnQXGM0zpqCKS2&tid=tMCdr) is broad, deep, and far more than a product selection guide—which it...

Cars are exciting, and appliances are boring, right? That depends. While you can’t take an air conditioner for test drives on a frozen lake to evaluate its dynamic response to regenerative braking in slippery conditions, as Greg Solberg did with the Tesla Roadster, there can still be challenges. For example, cultural and economic differences in regional markets for white goods influence motor-control design. On the cultural side, to cite one case, China and Japan present a...

When most designers think of DFM, they think of deep-submicron SoCs and digital design. But more often, DFM is a factor in analog/mixed-signal flows for RFICs as well. “There’s no such thing as a pure RFIC anymore,” says Marc Peterson, director of RFIC product planning at Agilent EEsof. “All RFICs are mixed-signal chips these days, and they’re moving to the smaller process nodes where process variability is a much bigger problem.” A key part of mixed-signal...

SchmartBoard has announced that patent 7,511,228 has been granted for the company’s “EZ” technology for hand-soldering surface-mount technology (SMT) electronic components (see the figure). This brought to mind a SchmartBoard demo I once participated in at an EDS trade show. The company was betting that anyone could solder a tiny chip to a board in a matter of seconds with its new technique. I’m...

“Noise” can have different meanings. It could be the common phenomenon of, say, a buzz in an audio system. Other times it may refer to something less acoustic, perhaps a limit on the precision of measurements. As an example of the way the latter has become more problematic for designers, consider the analog portion of one channel in an industrial control or automotive system. As IC and sensor supply voltages keep shrinking, that kind of noise has...

I was helping some engineers working on a strain-gauge preamp not too long ago. We had it functioning, but there seemed to be some bad linearity problems. We even set up a little calibrator and tried to get it linear, yet we kept getting odd errors, using the conventional amplifier setup per Figure 1. The guys said, “We don’t have to worry about precision or calibration because we’re calibrating it in ...

HI BOB, Regarding quad op amps (“Cdesign.com/ArtICles/ArtICleID/20895/20895.html">What’s All This ‘Free Amplifier’ Stuff, Anyhow?”), I thought I’d pass on this tidbit from my early days in the late 1970s. I was working at an industrial controls company on the east coast named Leeds & Northrup Co. (now defunct). (Yeah, I have collaborated...

To commemorate our second annual Top 101 Components report, I read through some of the hundreds of e-mails I get on a daily basis for information related to the kinds of components we typically cover in the Electronic Design Products section, which appears every other issue. Let’s start with resistors. Vishay recently introduced streaming video comparisons of different types of resistors on its Web site....

Once upon a time when I was about four years old, my father went up the road to buy a couple of piglets, and he took me along. We brought them home to our little farm in a burlap bag in the back of our pickup truck. I guess I must have thought this was quite exciting, because my mother thought I was overstimulated. She sent me in to the living room to take a nap, even though it was only 11 a.m. So, I lay quietly on the couch and tried to get to...

My last column showed how a single-stage delta-sigma modulator (DSM) produces an output that is a sum of the low pass-filtered input signal and the high pass-filtered quantization noise (see “Part 4,” Jan. 29, p. 18; ED Online 20485). The primary difference between a filter and a DSM is that a filter feeds back its output while the DSM feeds back its quantized output. If ...

BOB, I’ve got 35 years as an electronics design engineer doing microprocessors, hardware, and quite a bit of analog. In the late 1970s, I was involved with two different slewrate- limited applications. One was control of the throttle and pitch of the props on patrol boats. The bridge could signal full ahead, and this condition would cause engine stalls. So, a slew-rate control was needed to bring the engine to full power and adjust the prop...

FFrom its inception, the holy grail for the design automation industry has been in the analog realm. Digital logic, with its relatively straightforward structures and topologies, has long been the chief beneficiary of the EDA industry’s efforts. Yet compared to the digital domain, automation of analog and mixed-signal design remains lacking. There are some obvious factors at work. Chief among them is the painstakingly hands-on, custom nature of analog design work. ...

One RFIC maker with an interesting set of EDA challenges is WiSpry, which relies on RF-MEMS (microelectromechanical systems) technology to create its chips, components, and modules. The issues a design house faces in incorporating MEMS technology is one that more companies will face as MEMS make their way into a growing array of consumer electronics. There would be no Nintendo Wii game system without them. “We have the classic problem of having two separate tool chains to...

Measuring key characteristics of high-speed pulses such as frequency, amplitude, and pulse width for simultaneous pulses that overlap in time has long been an issue in design. To solve that problem, engineers developed and refined the monobit receiver. The system includes RF signal shaping and filtering functions, a latched comparator (which is a single-bit analog-to-digital converter, or ADC), a demultiplexer to interface the high-speed digital...

If a signal is sampled, the spectrum is replicated at every harmonic of the sampling frequency (see the figure). For example, if the spectrum is sampled at 9.2 GHz, the spectrum will repeat at 9.2-GHz intervals, out to plus and minus infinity. As a consequence, the frequency at 4 GHz is indistinguishable from the signal at +13.2 GHz, +22.4 GHz, etc. The opposite is also true—signals at +13.2 GHz and +22.4 GHz, sampled at 9.2...

One of my friends was working on a story. She observed correctly that an “ideal” op amp would have infinite gain and common-mode rejection ratio (CMRR)—and zero IB and VOS— and zero price. She conceded she would never get rich selling those op amps! But there is a zero-price op amp, and I have been using them for many years—over 40. Maybe you have too. Let’s assume I have used three-fourths of an LM324 for three tasks, and that is working...

Power delivered to sensitive analog circuitry must be treated differently than power for digital circuitry. All circuits are affected by noise delivered through the power supply, yet analog loads tend to be more sensitive. The actual type of circuitry and application will determine the tolerable noise limits. Powering digital circuitry today is a fairly straightforward task and can be handled with available power design tools, such as ...

Last night, I was attacking a thorny problem and thought about the time domain. I think about circuits, as an engineer, in the time domain. When something happens, or changes, then something else can happen—or may start to happen. Is that something that I like? Or is it something I don’t like? I have used this analysis many times, as in “What’s All This Fuzzy-Logic Stuff, Anyhow? (Part 4)” (Nov. 6, 2000; ...

The MAX19505, MAX19506, and MAX19507 8-bit, dual-channel analog-to-digital converters (ADCs) from Maxim Integrated Products provide a 49.8-dBFS signal-to-noise ratio (SNR) and 69-dBc spurious-free dynamic range (SFDR) at 70 MHz (see the figure). Available in speed ranges from 65 to 130 Msamples/s, they target cellular basestations and point-to-point microwave receivers, set-top boxes, or...

Hello to Mr. Bob Pease! In the datasheet for the LM135/LM235/ LM335, there is no mention of capacitive bypass (minimum acceptable, maximum acceptable). This publication also did not say anything: www.national.com/appinfo/tempsensors/files/temphb2.pdf. (I apologize for this omission. You are right. This info should have been...