A Compact Switched-Capacitor Multi-Bit Quantizer for Low-Power High-Resolution Delta-Sigma ADCs

Abstract

This paper proposes a compact switched-capacitor (SC) multi-bit flash quantizer for low-power high-resolution delta-sigma modulators (ΔΣMs). First, a general power model for single-loop ΔΣMs is presented to show the importance of using multi-bit quantization when facing high-resolution specifications. In this context, a SC multi-bit quantizer circuit is proposed, which exhibits low-power operation, high modularity, single comparator design and compatibility with both multi-feedforward ΔΣM architectures and other SC low-power circuit techniques, like clocked comparators and switched OpAmps. A practical 50-kHz 16-bit ΔΣM design case is also presented.