DC OFFSET CANCELLATION CIRCUIT AND DC OFFSET CANCELLATION METHOD

摘要

A DC offset cancellation circuit and a DC offset cancellation method. The DC offset cancellation circuit comprises a high-speed amplifier, a voltage comparator, a microprocessor, and a digital-to-analog converter. The high-speed amplifier comprises an input stage with a DC offset cancellation function, an amplification stage, and an output buffer stage. The voltage comparator is connected to the output buffer stage. The microprocessor is connected to the voltage comparator. The digital-to-analog converter is connected to the microprocessor. The digital-to-analog converter is connected to the output stage. The DC offset cancellation circuit provides a compensation signal for the input stage by means of a digital-analog hybrid control method to perform DC offset cancellation, can lock the compensation signal by means of the microprocessor to ensure the DC offset cancellation caused by the stable cancellation process, and can avoid the problem that the high-speed amplifier cannot work normally since the compensation signal does not correspondingly change with an input signal in time.