Analog Hotspot

Okay, marketing is a dirty and nasty job, but somebody has to do it. Sometimes I put on my "marketing hat" and try to do some of it myself. But the best insight into that is the quote I have paraded before a couple thousand attendees at my recent linear seminars: "The only valid market survey is... a signed purchase order." Well over 2000 people attended these seminars, and nobody knew who said that. Answer below. Hint: He was one of the Fairchild Eight. Your chances of guessing the right...

Analog microcontrollers certainly aren't new. But they've advanced dramatically by getting smaller, more powerful, and less expensive. And their applications are far-ranging, from process and motor control to interfacing with the latest micromachines, such as 3D accelerometers. Despite the presence of analog microcontrollers, analog system design is still tough. Current analog-microcontroller options may not be as extensive as the number of op amps or comparators on the market,...

Speaking of new approaches to familiar products, bandgap voltage references have been around since the mid-1970s. Buried-zener references have been around since the early 1980s. Now Intersil has some new versions of its voltage references based on technology Xicor developed for depositing a precise charge on a floating gate. The most interesting is Intersil’s X60008-41, which provides a precise 4.096-V reference. It provides precise 1-mV resolution when used with a 12-bit...

Hi Bob: I think this may interest you. I repair electronics and had a guy bring me a TV/VCR. A month later he came back, and the belt I replaced was broken. It was one of those take-everythingapartto-get-to-the-belt kinds. This time, the belt looked like it was 20 years old—nothing but little, hard chunks of rubber. Yes, it was the same unit. He did not try to sneak in his friend's for repair. I started asking him what he could have in his house that could do this. It...

If somebody invents a wonderful new system with electromagnetic radiation and digital coding, it must be good. "Radio" is obsolete. "Wireless" is wonderful. Just this morning, I heard Disney head Michael Eisner say that before 1948, there were only three major movie studios, and no television, for entertainment. He seemed to have no inkling that there were several large (and lively) radio networks broadcasting music, news, drama, and entertainment all around this country (and...

The AD970x series of transmitpath digital-to-analog converters (DACs) for portables maintains compatibility with prior generations of Analog Devices' TxDAC series while reducing power dissipation and adding an on-chip voltage reference and RSET and RLOAD resistors. Clocking up to 175 Msamples/s, the series includes the 14-bit AD9707, the 12-bit AD9706, the 10-bit AD9705, and the 8-bit AD9704. Thin-scaled small-outline package (TSSOP) versions are pin-compatible with the previous...

What’s the difference between ac coupling and dc coupling in video and high-speed amps? Using capacitors on inputs and outputs, ac coupling simplifies circuit design by removing dc voltages on the transmission line and isolating ground connections between the transmit and receive systems. On the other hand, the presence of those capacitors compromises signal quality. Some systems can accommodate those compromises, while others cannot. Eliminating...

Automotive applications looking for a controller-area network (CAN) transceiver can hitch a ride with AMI Semiconductor's AMIS-42700. This low cost, low-component-count device provides an interface between two physical CAN lines for in-vehicle networking (IVN) needs, but it has industrial uses as well. CAN repeaters are used when standard buses in industrial applications have to cover longer physical distances. CAN also interconnects machines, process control units, and...

How fast is the current crop of high-speed analog-to-digital converters (ADCs)? The pipeline architecture and silicon-bipolar and CMOS process technologies dominate commercial high-speed converters below 300 Msamples/s. Typical resolutions range from 12 to 14 bits. There's a large speed gap between 300 Msamples/s and 1 Gsample/s. The relatively few converters available above 1 Gsample/s have 8- or 10-bit resolution and use flash or folding/interpolating architectures in...

Sensors are ubiquitous, providing the signals that feed our computer-centric world. The outputs for these sensors, though, must be signal-conditioned for computer use. This depends not only on the application involved, but also on the type of sensing technology employed. As a result, many OEMs turn to expensive ASICs and their embedded codes, which can take one to two years and cost $1 million to $2 million to develop. The cost factor becomes more noticeable with the spread of...

Dear Bob: This is a general question about TO-220 packages. I am finding MOSFETs available in TO-220AB packages that claim to have continuous ratings of 120 A. I can believe the die can take it if heatsinked well. But can those skinny 0.044-in.2 wires take that kind of current? (I think they are tin plated copper lead frames unless they are some kind of superconducting alloy.) The copper wires in my house are 14 gauge and are only rated for 15 A, and they are bigger. And what...

Today's megagate FPGA densities permit full digital system implementations. Still, many of these systems also require a reasonable amount of analog capability to complete the full system solution. These systems typically need a handful of analog components, like op amps, comparators, and analog-to-digital and digital-to-analog converters. The Fusion mixed-signal FPGA architecture from Actel eliminates those components so designers can implement a true single-chip system....

Many new homes and office buildings come prewired with more CAT5 wiring (Ethernet cable containing four unshielded twisted pairs) than present tenants need. Architects and planners have been asking: Why not use this infrastructure to distribute analog video? After all, CAT5 is much less expensive than coax. Also, video digital-to-analog converters readily provide RGB or component video that can be sent over three of the CAT5's twisted pairs. Analog video driver and...

The iP2003A from International Rectifier suits low-voltage power rails in servers, desktops, and data-communication systems. This 40-A (continuous up to 100°C case temperature) building block for multiphase, synchronous buck converters integrates most of the necessary silicon and passive components into a single 9- by 11- by 2.2-mm land grid array (LGA) package. The chip's silicon components comprise a synchronous gate driver, high-side and low-side power MOSFETs,...

In industrial-control applications, many sensors and actuators must operate at tens of volts, while control-logic voltages have continued to shrink in step with successive generations of digital process geometries. For engineers who design industrial control systems, the voltage divide has typically meant the need to add ever more external signal conditioning and biasing circuits. Late last year, though, Analog Devices released the first products in its iCMOS 36-V,...

The LTC2480 delta-sigma analog-to-digital converters (ADCs) from Linear Technology feature a front-end design that can be driven directly from bridges, resistance-temperature detectors (RTDs), thermocouples, and other high-impedance sensors. This eliminates the drawbacks of on-chip buffering. The company's Easy Drive technology yields zero average differential input current, simplifying the design of front-end signal conditioning circuits. Traditional delta-sigma ADCs...

Dear Bob: I'm running into a head-scratcher. I am working on a 2-µA current source (pnp transistor plus sense resistor in the emitter lead, and an op amp to control the pnp's base so the voltage across the sense resistor is constant) with as much compliance to use as much of the 5 V as I have available. (Constancy of current is important but I don't care too much whether it's exactly 2µA as long as it doesn't have much tempco/drift.) But I've only...

Decades of development and high-volume production generated mature amplifier technologies that satisfy the requirements of many market segments. Class A designs address more demanding high-end applications, while Class B and AB amplifiers serve the consumer market with cost, power, and performance tradeoffs. Class D technology, however, has changed the balance. With Class D, the power efficiency of audio amplifiers-once constrained to a range roughly between 30% and 50%-has...

For most of the industry, lead-free means home free. At least for a while. You have likely heard by now that the European Union (EU) adopted a new directive called Restrictions on Hazardous Substances (RoHS). It eliminates or significantly reduces the use of certain substances from electronic products beginning July 1, 2006. If you haven't already done so, now might be a good time to remove most of the lead (Pb), cadmium (Cd), mercury (Hg), hexavalent chromium (Cr VI), and all...

This year I'm going to start off with magazines: It is well known that huge (astronomical!) quantities of magazines—especially National Geographic—have been stored in a million attics across the U.S. This raises the center of gravity of the house and the Polar Moment of Inertia of the whole Earth. Physicists have predicted that the Earth will wobble excessively, its rotation will slow down to a critical speed, and then the Earth will fall out of its orbit...