Improved modeling of sigma-delta modulator non-idealities in SIMULINK

The goal of this paper is to present an extension of the behavioral models, implemented in the Matlab/Simutink (TM) environment, previously presented in [1, 2] and available in [3]. This toolbox allows us to simulate at behavioral level most of the switched-capacitor (SC) sigma-delta (MA) modulator non-idealities, such as sampling jitter, kT/C noise and operational amplifier limitations (finite bandwidth, finite DC gain, slew rate and saturation). Although very effective in simulating wide-band, medium-resolution Sigma Delta converters the lack of a model for flicker noise and multi-bit quantizers makes this toolbox less attractive for simulating narrow band high resolution converters. The proposed extension not only fixes this limitation, but introduces a predictive model of the effect of capacitor mismatch in the internal multi-bit D/A converter.