A 2.7-V CMOS single-chip baseband processor for CT2/CT2+ cordless telephones

Abstract

A low-voltage, low-power CMOS single-chip baseband processor for CT2 and CT2+ cordless telephones is presented. The chip integrates a complete voiceband codec, a tone generator, a G721 adaptive differential pulse code modulation coder/decoder, a burst-mode logic controller for CT2/CT2+ framings, and an I/Q baseband signal generator. The only external components are made of two quartz crystals. The chip is interfaced with standard microcontrollers through a parallel interface. With a 2.7 V minimum supply, it consumes normal and standby powers of 35 mW and 25 /spl mu/W, respectively. Maximum supply is 5.5 V, and temperature range is from -40 to 70/spl deg/C. Chip area (including scribe line) is 55.5 mm/sup 2/ in a 0.8 /spl mu/m N-well double-metal single-poly CMOS process with implanted capacitors.