A 119-dBA Dynamic Range, 3.3-mW Audio CTDSM With a Class-B Resistor DAC and Continuous-Time Quantizer

Applications requiring far-field voice/audio recording have increased the need for low-power, high dynamic range (DR) audio analog to digital converter (ADC). In these applications, the DR specification determines the maximum distance at which a low-cost microphone can obtain a good quality recording. The continuous-time delta-sigma modulator (CTDSM) architecture is typically chosen for audio applications due to its inherent antialiasing property and resistive input. This work presents a high-performance audio CTDSM designed in a 130-nm process. The ADC achieves a DR of 119-dB A-weighted (117-dB unweighted) over a 20-Hz-20-kHz bandwidth while consuming only 3.3 mW.