Comparative evaluation of delta-sigma modulator structures used in the oversampling A/D converters

The authors focus on computer simulations of delta-sigma (/spl Deltaspl Sigma/) modulators for oversampling analog-to-digital (AD) converters. They question the efficacy of traditional additive white noise techniques for modeling and analyzing the asymptotic statistical properties of quantization errors that arise in single and multistage oversampling /spl Deltaspl Sigma/ modulators. The potential of the Comdisco Signal Processing Work System (SPW) on the SunSPARC1 platform has been utilized for estimating gain error commonly used for data acquisition AD converters. It is shown that the cascaded structure works much better than the common second-order modulator. The simulation results obtained have exhibited that the cascaded structure with differential first-order modulators has the potential of 20-b amplitude resolution within the acoustic signal bandwidth.