DSPs can make some fairly precise notch or bandpass filters. But with all the surrounding components (A/Ds and D/As), the thing might cost around $30-and take some programming effort to get it working right. A clever analog engineering guru-like National Semiconductor's Bob Pease or Linear Technology's Jim Williams-could probably string together a pretty good filter with a fistful of op amps and passive components for, say, $1.38.

Yet DSP prices have fallen precipitously, and the devices now come with drop-in software functions. Moreover, the filter functions required by traditionally analog applications-modems, cell-phone voice coding and RF signal modulation, disk-drive read channels, audio and video signal processing-are so complex that DSP waveshaping is the only way to handle them.

Consequently, a lot of the new cleverness in analog design involves rendering analog functions (like peak detection) with digital logic that can be reproduced cheaply in foundry CMOS. This is true for the most attention-getting applications of mixed-signal technology: ADSL, cellular telephony, digital TV and home theater, DVD and audio playback-even PC audio and car stereo.

This concern for processing analog signals as ones and zeros makes me wonder if "analog and mixed signal" is a good description for what we do. Thus, you'll see a different name attached to the annual meeting of the faithful: Forget Analog and Mixed Signal Applications; this year's event (Oct.5-7 at the Westin Hotel in Santa Clara, Calif.) will be called EE Times' Special Seminar Series on Communications and Multimedia Systems. We will be looking at the technologies that make these applications tick-dedicated DSPs, analog and mixed-signal building blocks. For EEs with a need to know, the series promises to be at least as informative as a Holiday Inn-vs.-Ramada debate.