Stability Analysis of Continuous Time Sigma Delta Modulators

Abstract

Several methods have been developed for predicting the stability of continuous time sigma delta modulators (CT ΣΔMs). In this paper, an analytical root locus method is used to determine the stability criteria for CT ΣΔMs that include exponential functions in their signal transfer functions and noise transfer functions. This method can be used to determine the minimum quantizer gains that keep a CT ΣΔM stable. Using the minimum quantizer gains, a CT ΣΔM's maximum input amplitude that guarantees stability can be determined. © Springer International Publishing Switzerland 2015.