Chopper-stabilized sigma-delta modulator

A new architecture of the sigma-dela modulators using a chopper-stabilized configuration is described. It is shown that using this new architecture and without any other circuit techniques, a sigma-delta modulator becomes immune from the contamination of the inherent low-frequency noise, such as offset noise, flicker noise, and clock feedthrough noise. The new architecture can be easily designed from the existing architectures without any stability problems. As an example, a second-order sigma-delta modulator is designed by using the new architecture. The simulation results show excellent immunity from the low-frequency noise