A 90μW 15-bit ΔΣ ADC for digital audio

Abstract

Architecture, circuit design details and measurement results for a 15 bit audio continuous-time DeltaSigma modulator (CTDSM) are given. The converter, designed in a 0.18 mum CMOS technology, achieves a dynamic range of 93.5 dB in a 24 kHz bandwidth and dissipates 90 muW from a 1.8 V supply. It features a third order active-RC loop filter, a very low power 4-bit flash quantizer and an efficient excess delay compensation scheme to reduce power dissipation.