一种失调电压温度、负载高稳定性的运算放大器电路设计

A circuit design of operational amplifier with high temperature and load stability of offset voltage

基于互补双极工艺设计了一种失调电压温度、负载稳定性高的运算放大器,在传统的双转单电路基础上引入新型的双转单电路,该双转单电路采用了基极电流补偿技术、负载电流补偿技术,使运算放大器具有极低系统失调具有温度和负载高稳定性。该电路采用三级结构,输入级采用PNP差分对结构;中间级采用新型的双转单电路构架;输出级采用AB类输出结构。该电路基于40V互补双极工艺进行设计,后仿结果显示,失调电压随温度变化为36.24nV/℃,随负载电流变化为5.7nV/mA。

An operational amplifier circuit is designed based on the bipolar process in this paper.A new type of differential-in and single-ended output circuit with the compensation techniques of base current and the compensation techniques of load current,is introduced based on the traditional differential-in and single-ended output circuit.The system offset of operational amplifier is greatly reduced with high temperature and load stablilty.The circuit uses a three-stage structure,and the input stage uses a PNP differential pair structure,the intermediate stage uses a new type of differential-in and single-ended output circuit topology,the output stage uses a class AB output structure.The circuit is designed based on the 40V complementary bipolar process.The post layout simulation results show that the offset vlotage temperature drift is 36.24nV/℃and the offset vlotage load drift is 5.7nV/mA.