Analog-circuit designs have fundamentally different architectures from those of processor, FPGA, and PLD designs. Once you implement the circuit topology and parameters, the circuit’s signal-processing function is relatively fixed. Sure, some functional blocks exist, such as filters, in which you can digitally adjust cutoff frequency, roll-off, and other factors by varying the clock (for switched-capacitor designs) or adjusting circuit factors via DACs, but these examples are the exceptions. Most designs are fixed in their functions and nearly fixed in their performance. Read the rest of this entry »

If you think that developing new designs for the conventional analog plain-old-telephone-service (POTS) line is like designing for dinosaurs, think again. The Consumer Electronics Association (www.ce.org) estimates that manufacturers last year sold about 16.8 million desktop and laptop PCs, and nearly every one of them had a V.90/56-kbps modem as a standard feature. In addition, vendors shipped millions of relatively invisible embedded modems within devices such as set-top boxes and home-based controllers plus about 5 million retrofit modems for PCs. Read the rest of this entry »

You’ve heard endless predictions about the new millennium, and some of these predictions will even come true. But there’s one low-risk prediction that you can make: Electronic systems will increasingly require point-to-point serial links at the 1-Gbps-and-higher rate between pc boards, chassis, and subsystems. This requirement means that the demands on the physical link will increase, and, if you don’t prepare properly, the physical link will become the slowest and thus the weakest link in your signal-path chain. Read the rest of this entry »