Offset cancellation and 1/f noise suppression scheme for chopper amplifiers

This paper describes a scheme to suppress the modulated offset of chopper amplifier by using synchronous demodulation and subtraction. The operation is based on continuous time extraction of offset information from chopper output and generation of correction signal to be fed back to the auxiliary inputs of chopper opamp. Analytical and simulation results show that not only input referred offset is reduced but also 1/f noise is suppressed.