A High-resolution Δ-Modulator ADC with Oversampling and Noise-shaping for IoT

Abstract

This paper proposes a novel high-resolution delta-modulator with oversampling and noise-shaping suitable for industrial IoT systems. “Inspired by” a SAR ADC, this architecture uses an integrator in the digital domain, instead of the usual SAR logic. Combining adaptive-step delta-modulation with the adopted low/medium-resolution DAC scheme, an energy efficient A/D converter architecture is proposed, presenting encouraging results in comparison with the reported SAR algorithms. Behavioral simulations demonstrate a dynamic performance of 88 dB of SNDR, corresponding to an ENOB of 14.3 bits, for a 1 MHz input signal bandwidth and using an oversampling-ratio of 64.