A 5 MHz Nyquist rate continuous-time sigma-delta modulator for wideband wireless communication

A 3 V continuous-time sigma-delta A/D converter is presented to optimize high speed baseband channels of radio receivers in wideband spread-spectrum communication. A second-order continuous-time sigma-delta ADC is proposed to simplify high-speed baseband design with the inherent characteristics of lowpass filtering and A/D conversion. In 1.2 /spl mu/m CMOS technology, the sigma-delta ADC has a 2.5 MHz bandwidth and 65 dB (/spl ges/10 bits) dynamic range with 80 MHz oversampling clock and 12 mW power dissipation.