A 1.1mW 87dB dynamic range audio ΔΣ modulator in 0.18µm CMOS

A 1.1 mW 87 dB dynamic range 3rd order ΔΣ modulator is implemented in 0.18 μm 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 34 dB DC gain is used in the first integrator. The prototype modulator achieves 87 dB DR and 83.8 dB peak SNDR across the bandwidth from 100 Hz to 24 KHz with 3 KHz input signal.