A 1.8 mW 2 MHz signal bandwidth continuous-time sigma-delta modulator

Abstract

A fully differential feedback third-order continuous-time sigma-delta modulator suitable for Mega Hertz wireless communication is presented. Some design optimizations mainly regarding power consumption are demonstrated. The proposed single-bit modulator clocked at 128 MHz achieves 2 MHz signal bandwidth, 11 bits of resolution, 68 dB signal-to-noise ratio and 66 dB dynamic range. Designed in 0.18 µm CMOS process, the sigma-delta modulator consumes 1.8 mW from a 1.8 V single supply, occupying a 0.16 mm2 chip area.