A 1.1mW 87dB Dynamic Range Audio AX Modulator in 0.18μm CMOS

摘要

A 1.1mW 87dB dynamic range 3rd order △∑ modulator is implemented in 0.18μm CMOS technology for the audio applications. By adopting a feed-forward multi-bit topology, the signal swing at the output of the first integrator can be suppressed and only one simple current mirror single-stage OTA with 34dB DC gain is used in the first integrator. The prototype modulator achieves 87dB DR and 83.8dB peak SNDR across the bandwidth from 100Hz to 24KHz with 3KHz input signal.