Decimation Lowpass Filters for SIGMA-DELTA Modulators - A Comparative Study

This thesis explores various filter topologies for decimating sigma-delta modulated digital signals, focusing on optimizing filter architectures for efficient VLSI implementation. It examines a fifth-order 1-bit sigma-delta modulator employing local feedback as the front-end A/D converter. The digital filter designed subsequently reduces the sampling rate by a factor of 32 while ensuring a narrow transition band between 0.5 and 0.55, with a required stopband attenuation of 100dB, highlighting the technical intricacies of signal processing.