A Base-Band Codec for Digital Cellular Telephony
12 October 1990
A base-band codec for digital cellular telephony has been designed in a 0.9 micron CMOS technology. This mixed analog-digital sub- system has two sigma-delta A/D converters, four D/A converters, two programmable gain amplifiers, two sets of decimators, high-pass equalizers, and d.c. offset correction logic on a 21 mm sup 2 chip.