运用负反馈模型分析实际运算放大器电路

Analysis of Operational Amplifiers Circuits with The Negative Feedback Model

对工作在深度负反馈状态的运算放大器电路,常采用虚短虚断技术得出的理想参数代替实际参数。这种方法忽略了理想模型与实际电路之间的误差。为了知道这个误差给实际运算放大器电路带来的影响,通过将运算放大器电路等效成对应的负反馈系统模型,并计算反馈系数,运用该模型的等效参数来更加近似的分析实际运算放大器电路闭环参数及其稳定性。

To the operational amplifiers circuits which works at deep negative feedback mode, we adopt ideal parameter deduced form ideal model instead of actual parameter usually. This method ignores the difference between the ideal model and actual model. For realizing the effect on the operational amplifiers circuits caused by the difference, this article founds a kind of equivalent negative feedback model on operational amplifiers circuits more accurately, and calculates the negative feedback coefficient. Then analyses the closed loop parameter and stability of the operational amplifiers circuits with the equivalent negative feedback model.