A new optimization approach for the automatic design of Sigma Delta-modulators

In this paper, a new methodology for the automated design of one-bit internal quantizer Sigma Delta-modulators is presented. The core of the method is an NTF prototype generation in the DT-domain based on the quasilinear quantizer modeling, that maximizes the maximum stable amplitude (MSA) of the modulator while achieving a certain minimum peak SNDR. For CT-modulators, this is followed by a DT-CT mapping of the loop filter in state-space. The improved MSA allows for higher circuit noise and thus greatly relaxes the area and power consumption constraints of the design. Simulation results at the end of the paper verify the validity of the method.