A 10 /spl mu/V-offset 8 kHz bandwidth 4/sup th/-order chopped /spl Sigma//spl Delta/ A/D converter for battery management

Abstract

A chopped 4/sup th-/order continuous-time 1 bit /spl Sigma//spl Delta/ A/D converter with 10 /spl mu/V offset and 8 kHz bandwidth has been designed for battery current measurement. Chopping at 16 kHz, the circuit has a 0.1 V input range, a 68 dB SNR, and a 1 MHz output bit rate. Area is 0.45x0.4 mm in 0.35 /spl mu/m CMOS. Current consumption is 30 /spl mu/A at 2.5-4 V.