Silicon Investor (SI) -- The First Internet Community

STOCKTALK

We've detected that you're using an ad content blocking browser plug-in or feature. Ads provide a critical source of revenue to the continued operation of Silicon Investor. We ask that you disable ad blocking while on Silicon Investor in the best interests of our community. If you are not using an ad blocker but are still receiving this message, make sure your browser's tracking protection is set to the 'standard' level.

Technology Stocks : ADI: The SHARCs are circling! -- Ignore unavailable to you. Want to Upgrade?

To: Jim Oravetz who wrote (2856)	8/5/2005 2:21:12 PM
From: Jim Oravetz	Read Replies (1) \| Respond to of 2882

ARCHITECTURES: Data converters respond to shift in specs Stephan Ohr (08/01/2005 9:00 AM EDT) URL: eetimes.com San Francisco — Today's data converter applications reflect an entirely new mixture of specifications and part types. And that has changed how converter companies have architected their latest offerings. "It's not so much that the balance between standard linear building blocks and ASSPs [application-specific standard products] has changed," said Dick Meaney, vice president of Analog Devices Inc.'s precision data converters group. "The business mixture of standard-and-semicustom has been a consistent 60 percent to 40 percent since the mid-1990s," he said. Rather, the applications for ASSPs have themselves shifted and are now demanding entirely different specifications, technologies and engineering trade-offs, said Meaney. Where engineers were once balancing resolution and conversion speed (along with power consumption and cost), they are now homing in on concepts like spurious-free dynamic range (SFDR) and paying only for the effective number of bits (ENOB) they need for their particular application, even if that number turns out to be something like 9 ohms. New applications like ultrasound scanning, for example, demand not only high SNR and ENOB for strong image quality, but also overrange recovery, which has rarely been specified before, said Kevin Kattmann, the product-line director for high-speed converters. Ultrasound imagers are effectively radar processors. They use a phased-array antenna to bounce high-frequency signals (256 of them) off an object and then create an image based on the time it takes for each of these signals to bounce back to a sensor array at the antenna. Soft tissue will partially absorb and attenuate the signal and takes a longer moment to return it; hard tissue, like bone, will show a much stronger reflected signal. "The problem occurs when the scanner hits soft tissue right after encountering a solid object," Kattmann said. "The front-end gain amplifier must quickly reset, to grab the next set of samples. Otherwise, you'll have a blurred image." The front end of these converters needs as much as 50 percent overvoltage range protection, with the ability to bounce right back to the proper input range, Kattmann said. This attention to the fine details of data converter applications is nothing new to Analog Devices, which literally "wrote the book" on data conversion technology (see, for example, ADI's The Analog-Digital Conversion Handbook). The company has grown its market share from 30 to 45 percent since the mid-1990s. Some of this growth is attributable to standard products optimized for high resolution and speed. Some of it is attributable to market-specific products, though the 60-40 mix of products has remained roughly the same in this period, the company said. Analog Devices holds a 45 percent share of the $2.4 billion 2004 market, according to recent assessments by Gartner Dataquest. Maxim Integrated Products is No. 2, with a 15 percent share; Texas Instruments is No. 3, with a 14 percent share. National Semiconductor and Linear Technology continue to jockey for the fourth and fifth positions. Other examples of the specialized markets ADI and others now serve with more sophisticated data converters include cellular basestations, set-top boxes, digital still cameras and high-resolution TVs. Cellular basestations require high SFDR (up to 16 bits) to capture weak phone signals in the presence of strong ones, and an extremely high sampling rate (100 Msamples/second) to simplify the job of downconversion performed by receivers. Set-top box (STB) makers are now asking for 12-bit resolution where they were once content with 8 bits — though the human eye will barely sense the difference in pixel light intensity, Kattmann said. But a 12-bit resolution helps STB makers interpolate legacy video material onto newer high-resolution screens. Ac linearity — low noise, for example — serves CCD image processing in digital still cameras and camera phones. In addition, manufacturers want a high degree of integration to accommodate miniaturization and low power consumption to support longer battery life, ADI said. In such applications, multiple-chip packaging techniques such as stacked die help camera phone makers get data converters, image processors, zoom and autofocus drivers into one IC package, according to Meaney.