Analog Hotspot

For the latest and greatest, take a look at what's coming up at this year's International Solid-State Circuits Conference (ISSCC), scheduled for Feb. 4-8 in San Francisco. As noted above, the delta-sigma architecture is enjoying a rennaisance, at remarkably high input signal frequencies. Xignal will disclose the details of its continuous-time, delta-sigma converter in a paper titled ?A 14b 20 mW 640MHz CMOS Continuous-Time ΣΔ ADC with 20-MHz Signal Bandwidth and ENOB of...

Just as in the ASIC world, cell libraries and logic-synthesis tools help designers quickly turn designs completed with high-level design languages into circuits. But many functions don't easily or efficiently convert from HDL code to logic. To achieve the desired performance, a lot of logic and/or layout hand-tweaking may be necessary. Or if you don't have the expertise to design the block or are under time-to-market constraints, an expedient approach is to license a block of...

In designing wireless sensor network (WSN) machine monitoring and vibration analysis, the physical size of the sensor end-point modules must be minimized. To meet that goal, Quickfilter offers a monolithic four-channel alternative to using a DSP and supporting components for the edge-of-network filtering function. The QF4A512 provides software-configurable input voltage ranges and gain settings for each channel. Its software-configurable anti-aliasing filters then handle signals...

This year has seen all kinds of impressive sensor advances, whether they involve the applications they serve, the processes that make them, or even their packaging. Combined with wireless technology, sensors have become powerful tools. What does it all mean? It means a narrowing of the gap between our world of analog variables and the digital power of the computer, giving us a better understanding of our surroundings. Many of these sensors take advantage of microelectromechanical...

This year's most engaging news came from a briefing by Julian Hayes of Wolfson Microelectronics, Edinburgh, Scotland, in September. Walking through the company's-plant, I saw a flat-screen TV disassembledon an engineer's bench. Wolfson was helping a Chinese customer optimize its use of some of the company's audio chips. The number of subassemblies in the design surprised me. "This doesn't look like a low-margin product designed to sell on price alone at discount outlets," I said. "There's...

Dear Bob: I had to laugh at your recent column.* I experienced similar product destruction with my (brand x) air cleaner. Let's see, I lost: all belts and wheels in two high-end (industrial) VCRs—and one a second time. Also, belts in three audio CD players, in a DVD player, three computer CD drives and one DVD drive, plus a belt in a vacuum cleaner—three times. (Ouch!! That's painful!! /rap) The air cleaner seems to be two appliances in one. It has an...

THE ELEKTRA ELK200-EA-XT PC/104 single-board computer (SBC) from Diamond Systems combines analog and digital data acquision with extensive communication support. It includes four serial ports and 10/100-BaseT Ethernet, as well as USB 1.1 support. The analog complement includes a 100-KHz analog-to-digital converter with a 512-sample time-stamped FIFO. There also is a quad-channel 12-bit digital-to-analog converter. The board has 24 programmable digital I/O lines and two...

The IC versus VBE of modern transistors has some excellent log characteristics, as we have discussed.* If you ground a transistor's base and compensate for its VBE with a matching VBE, you can do some good logging over a wide range, from 1 mA to 1 pA, and really quite accurate from 100 pA to 100 µA. That's six decades where the limitation of REE' on the high end is the major limitation. Input leakage...

In the last 15 years, high-speed piezo electric actuators have become less expensive to manufacture. Consequently, they find themselves as a favorite design choice for a growing number of applications. Piezoelectric actuators made their initial entry in medical devices, including surgical tools and ultrasonic testing in the late 1980s. It was for good reason. Piezoelectric actuators are the fastestresponding positioning element available with microsecond time constants....

The open-source Power Management Bus (PMBus) communication protocol is gaining ground. With Astec's DTX digital dc converter, designers will be able to prepare and evaluate a range of PMBus-compliant converters (see the figure). They also will be able to choose from an array of preprogrammed modules that emulate existing industry-standard converter types with or without a menu of additional features. The control...

The INA159 interfaces ±10-V signals from sensors in industrial applications to singlesupply analog-to-digital converters (ADCs). Developed by Texas Instruments, this levelshifting difference amplifier presents an economical alternative to using complicated and expensive precision resistor networks and a high-performance operational amplifier with a dual-supply ADC. It's especially suited for driving up to 14-bit ADCs. A split reference connection simplifies biasing at...

While some established chipmakers are developing new proprietary process technologies for mixed-signal and analog devices (see "'Sample Wars' And Silicon Energize ADCs," p. 47), other companies are using clever chip design to enhance the performance of established architectures on well-stabilized, mature process technologies. One of these companies, Linear Technology, has eliminated most of the problems of switched-capacitor inputs in delta-sigma analog-to-digital...

Focusing on chip design to improve performance, Texas Instruments put its HPA07 process technology to work in the ADS1610 delta-sigma analogtodigital converter (ADC), which provides 16-bit resolution at 10 Msamples/s. This discretetime device operates from a 5-V analog and a 3-V digital supply. It also achieves an 86-dBFS signal-to-noise ratio (SNR) in a 5-MHz signal bandwidth with a 95-dB spurious-free dynamic range (SFDR) and a ?94-dB total harmonic distortion (THD) (...

Hi Bob: I've been an avid fan of yours for many years, and I'm writing now to plumb the depths of your arcane knowledge. We've got a design that needs a little bit of insulation, and I told the engineer to use fish paper to do the job. She asked me a question that's got me stumped: "What's the origin of the term fish paper (and how did it come to be associated with vulcanized fiber)?" A search on the Internet left me still scratching my head. Any ideas? Matthew L....

Not many off-the-shelf ADCs use continuous-time delta-sigma technology. So to get a clearer understanding of the technology, we'll compare it to discrete-time delta-sigma. The major difference between discrete and continuous sampling in a delta-sigma lies in the loop filter. Discrete sampling employs a switched-capacitor filter, which demands fast settling circuits and requires an input buffer to eliminate sample glitches. A number of other disadvantages hinder switched-capacitor...

Some big chipmakers have been looking to maintain an edge in the frenetic pace of the electronics industry partly by upgrading their online development tools beyond simple parametric device selectors. This has led to the creation of more comprehensive tools that link all design parts. In addition to these tool upgrades, they have begun moving from their own custom tool toward standardizing on National Instruments' LabVIEW as a common interface and engine. National Semiconductor's...

If it moves, jumps, rotates, or vibrates, it usually contains a motor. Electric motors come in all types of devices, from tiny hard-disk drives to hybrid vehicles to locomotives. Intelligent motor control can be employed over this wide range of devices, delivering improved efficiency, longer life, and better fault control compared to simply applying power to a motor. Key to greater use of intelligent motor-control systems are low-cost microcontrollers and digital-signal-processing chips...

What do the United Nations Educational, Scientific and Cultural Organization (UNESCO), Star Wars, and the San Francisco Opera have in common? The answer is simple—Ray Dolby, inventor of the technology that eliminates the hiss from analog tape sound. His company, Dolby Laboratories, has helped define the sound of everything from audio cassettes and movies to DVDs and digital TV. In 1963, a two-year United Nations appointment to India led Dolby to...

When electrical engineers hear the name "Nyquist," they think of what Harry Nyquist is best known for: his Sampling Theorem. Evidence of its importance is everywhere. Products like cell phones, audio CDs, and iPods are all based on the broad-shouldered foundation of the theorem, and that alone is enough to place Nyquist among the industry's greats. But Harry Nyquist had many other, lesser known accomplishments, a number of which resonate strongly today. Harry...