A delta-sigma modulator for 1-bit digital switching amplifier audio power amplifier

摘要

A delta-sigma modulator for a 1-bit digital switching amplifier is presented. To achieve high SNR and a large input range, a 7/sup th/ order single-loop single-bit modulator using a feedback comparator was designed. The chip was implemented in a 0.35 /spl mu/m CMOS process with optional 5 V transistors. The measured SNR is 111 dB and the distortion (THD+N) is 0.0015 %. The normalized maximum allowable input range is 0.89. The chip area is 12.6 mm/sup 2/ and it draws 60 mA from a 5 V supply.