A Triple-mode Reconfigurable Incremental SigmaDelta ADC with SAR-based Zooming and Extended Counting

Abstract

This paper proposes a triple-mode discrete-time incremental sigma-delta ADC employing SAR-based zooming and extended counting for programmable resolutions. A SAR-based zooming structure allows the sigma-delta modulator to have better linearity and resolution, and also additional activation of extended counting function gives additional resolution. A prototype ADC is fabricated in a 180 nm CMOS process, and it achieves 111.9 dB, 106.6 dB, and 73.3 dB dynamic range for the triple mode consuming 1.60 mW, 1.26 mW, and 0.31 mW respectively.