This paper presents a comparative study of high-frequency chopping and low-frequency chopping. Several key parameters of a chopper-stabilized amplifier are analyzed in detail. To verify the effect of chopping frequency, a general-purpose chopper-stabilized amplifier is designed and implemented with a 0.18-µm CMOS process. Simulations show that the input biasing current, thermal noise level, and input offset voltage are all related to the chopping frequency.