Henry Samueli's keynote address was undoubtedly a bellwether. In rapid fire, the Broadcom founder and chief technology officer described the kind of data converters-the analog signal-capturing elements-that will support satellite, cable and Gigabit Ethernet communications circuits. Digital subscriber-line transceivers, for example, will use 10-bit, 60-MHz sampling A/D and D/A converters for signal capture. Cable modems, functioning two-way in 2001, according to Samueli, would need 10-bit, 200-MHz D/As to push 5-to-65-MHz analog signals up the hose.

Samueli described Fast Ethernet terminals with as many as ten 100-Mbit/second physical-layer devices on one chip. And he called attention to Broadcom designer Klaus Bult's recommendations for doing this in submicron CMOS.

Sure enough, 1,500 to 1,600 engineers showed up to listen to Bult's presentation on A/Ds for RF front ends. Indeed, the audience spilled out into the hallway, where passersby stopped to see what was causing the excitement.

Bult described a 100-Msample/s A/D implemented in 0.5-micron CMOS with a 2.5-V supply voltage-no mean feat when you have a dependent relationship between speed and supply voltage. But his real message was: You digital guys, listen up! This stuff doesn't scale.

While shrinking CMOS geometries will always benefit the digital designer with higher levels of circuit integration and faster performance, this always penalizes the analog designer. Lower voltages make it harder to bias linear circuits, and this kills speed and accuracy-as well as creating current concentrations and heat problems on a CMOS device.

If analog know-how is golden, conference attendees can catch as much as they can from the experts. It was great to see so many interested in analog at ISSCC. If this keeps up, we'll see a similar interest at the EE Times Conference on Analog and Mixed Signal Applications later this year.