System-level design of single-bit sigma-delta modulators based on MSA and SNR data graphics

Abstract

This paper presents a more comprehensive approach for the design of single-bit single-loop sigma-delta modulators, either in continuous or discrete-time domain. The approach is based on SNR and MSA data graphics generated for second-, third- and fourth-order modulators. The simulated data is obtained within a Matlab/Simulink® environment and is valid for a particular topology. The data graphics help the designer to exploit the performance of the topology as they provide insight of how the SNR and MSA are affected when more aggressive noise transfer functions are synthesized. A case study that compares second- and third-order modulators, designed for a given application, is analyzed to find the more efficient architecture in terms of circuit complexity and robustness against non-idealities.