中图分类号： TN402文献标识码： ADOI：10.16157/j.issn.0258-7998.222743 中文引用格式： 何贵昆，马奎，杨发顺. 基于信号调理芯片的运算放大器设计[J].电子技术应用，2022，48(11)：67-73. 英文引用格式： He Guikun，Ma Kui，Yang Fashun. Design of operational amplifier based on signal conditioning chip[J]. Application of Electronic Technique，2022，48(11)：67-73.
Design of operational amplifier based on signal conditioning chip
He Guikun1，Ma Kui1，2，Yang Fashun1，2
1.College of Big Data and Information Engineering，Guizhou University，Guiyang 550025，China； 2.Key Laboratory of Micro-Nano-Electronics of Guizhou Province，Guiyang 550025，China
Abstract： Based on the domestic 40 V bipolar process, a fully differential operational amplifier is designed, which is applied to the driver module of the signal conditioning chip. The amplitude of the output signal of the operational amplifier can be adjusted by an external resistor. The overall circuit structure includes input stage, intermediate stage, output stage, bias circuit, feedback circuit and reference circuit. The input stage adopts a common base amplifier circuit, which has a wide operating frequency band; the intermediate stage adopts a common collector-common emitter circuit structure to improve the voltage gain; the power output stage constitutes a loop integrator and a resistor network that provides common mode feedback, so that the output common mode voltage is concentrated between the positive and negative power supplies, and the output signal amplitude can be adjusted by an external amplitude control resistor. When the power supply voltage is ±15 V, the test results are：the output voltage amplitude range is 1.488 V~18.57 V, the DC offset voltage is -169 mV, the output short-circuit current is 65 mA，and the total harmonic distortion is 41.2 dB.
Key words : operational amplifier；bipolar；all the difference；amplitude