基于传统的负反馈结构,提出一种改进的直流失调消除技术。分别采用密勒效应和线性区工作的MOS管,实现等效大电容和大电阻。采用此方法的失调消除技术易于实现片内集成。同时,使用补偿电路减小直流失调消除环路中高通截止频率随温度和工艺的变化。设计的电路高通截止频率为500Hz,芯片尺寸为740μm×780μm。 Based on the traditional negative feedback structure, an improved DC offset cancellation technique is proposed. Respectively, using the Miller effect and the linear region of the MOS tube, to achieve large equivalent capacitance and resistance. Offset cancellation techniques using this approach make it easy to implement on-chip integration. At the same time, the use of compensation circuit to reduce the DC offset cancellation loop high-pass cutoff frequency with temperature and process changes. The design of the circuit Qualcomm cut-off frequency of 500Hz, the chip size of 740μm × 780μm.