运算放大器教学中的若干问题探析

Discussions on Several Issues in Operational Amplifier Teaching

针对“电路理论”课程中运算放大器(运放)的教学,对教学内容中的若干问题进行了讨论。辨析了不同运放模型符号之间的区别,厘清了虚短和虚断概念并给出了正确表述,说明了含运放电路含“地”的必要性,探讨了对含运放电路分析结果所必须进行的校核,指出了现有运放模型在反映放大倍数频率响应方面的局限性。讨论内容对“电路理论”课中运放相关教学内容的完善有积极意义。

For teaching operational amplifier(op-amp) in Circuit Theory course, several issues in op-amp teaching are discussed. This paper points out the advantages and disadvantages of different symbols of op-amps, clarifies the concept of virtual short-circuit and virtual open-circuit and gives their correct expressions, illustrates the necessity of “ground” in op-amp circuits, explores the verifications that need to be carried out on the op-amp circuit analysis results, and proposes the limitations of the existing op-amp ideal model in reflecting frequency response of its gain.The discussions are beneficial to improve the relevant teaching contents in the course of Circuit Theory.