Oversampling enhancement in sigma delta modulators

摘要

A method that virtually double the oversampling ration of a second order sigma-delta (ΣΔ) modulator is described. Accounting for a limited cost, the resolution increases by about 2-bit and power just increases by few percents. Therefore, the FoM diminishes by a factor close to 3.5. Simulation at the behavioral level of the proposed method verifies the operation. Circuit level schemes indicates that the architecture does not requires higher op-amp bandwidth. The method can be used with multi-bit quantizer without requiring additional efforts for the DEM.