Resonation-based Cascade ΣΔ Modulators for High-Linearity Broadband A/D Conversion

Abstract

This paper presents two new architectures of cascade ΣΔ modulators that, based on the use of resonation, allow to increase the effective resolution compared to previously reported topologies whereas keeping relaxed output swing and high robustness to non-linearities of the amplifiers. In addition, the use of loop filters based on Forward-Euler integrators, instead of Backward- Euler integrators as proposed in earlier approaches, simplifies the switched-capacitor implementation and makes the proposed architectures very suited for the implementation of highly-linear broadband A/D conversion†.