A full switched-current S/sup 2/I second order sigma-delta modulator

Abstract

This paper presents a low pass sigma delta modulator for analog-to-digital conversion which uses the S/sup 2/I switched current technique. At circuit level, we propose a new differential pseudo bilinear integrator. Other building blocks such as the 1 bit digital to analogue converter and the quantizer are discussed as well. The whole modulator was implemented in a 0.6 /spl mu/m three-metal layers digital CMOS process with single 3.3 V power supply. The measured dynamic range is over 8 bits.