Two novel cascade ΣΔ modulators for broadband low-voltage A/D conversion

This paper presents two new architectures of cascade SigmaDelta modulators that, based on the use of resonation, increase their effective resolutions compared to previously reported topologies while presenting high robustness to non-linearities of the amplifiers and very relaxed output swing requirements. 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 highly-linear broadband A/D conversion.