Resonation-based cascade ΣΔ modulator for broadband low-voltage A/D conversion

A novel cascade SigmaDelta modulator architecture is presented that employs inter-stage resonation to increase its effective resolution compared to traditional cascades while presenting very relaxed output swing requirements and, subsequently, high robustness to nonlinearities 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 architecture very suited to wideband A/D conversion.