集成放大器应用电路中的虚短和虚断概念

The Concept of Virtual Short and Virtual Open for Integrated Oparational Amplifier Circuit

本文为了更合理地解释集成运算放大器线性应用电路中虚短和虚断的概念,首先,从放大电路负反馈概念和原理开始分析,得到深度负反馈条件下输入量和反馈量近似相等的结果。然后,结合误差理论,以典型集成运算放大器线性应用电路进行论述,得出满足深度负反馈条件下集成运算放大器两个差分输入端近似虚短和虚断的结论。最后,简要介绍设计电路时需要注意的基本问题。

In order to give the more reasonable explanation for the concept of virtual short and virtual open, first the concept and principle of negative feedback amplifier circuit is analyzed and the approximately equal results of input quantity and feedback quantity are obtained in the depth degenerative conditions. Then, combining with error theory, by discussing the typical integrated operational amplifier linear application circuit, the conclusion, approximate virtual short and virtual open of two differential input for linear application of integrated operational amplifier, is obtained. Finally, some basic problems that need to be paid attention in the process of designing linear application circuit are briefly introduced.