Chopper Stabilized Amplifier 101

A chopper stabilized amplifier is an electronic circuit that employs a modulation technique to reduce or eliminate dc offset and low-frequency noise in op amps. Modern chopper-stabilized op amps utilize a variety of techniques to accomplish this purpose, but all have in common a chopper amplifier that works in conjunction with the main amplifier. The chopping amplifier utilizes switches to chop or modulate the input signal. The output of the chopper amplifier is then filtered, summed and fed back to the inputs of the main and chopper amplifiers in an effort to remove low-frequency errors from the circuit.