Cascade ΣΔ modulator for low-voltage wideband applications

Abstract

A new cascade ΣΔ modulator architecture with unity signal transfer function is presented, which avoids the need for digital filtering in the error cancellation logic. The combination of these two aspects makes it highly tolerant to noise leakages, very robust to nonlinearities of the circuitry and especially suited for low-voltage implementations at low oversampling. Behavioural simulations are presented that demonstrate the higher efficiency of the proposed topology compared to existing cascades intended for wideband applications.