Equivalent Analytical Method for Negative-Feedback Amplifier Circuit
Zhang Zhi-qun · Journal of Electrical & Electronic Education · 2010
This paper proposes a new method of equivalence,solving equations and analysis. From the mother equivalent circuit of negative feedback amplifier, an open -loop gain and a feedback factor are defined. The closed-loop gain theorem is proved by the method, i.e. different inputs for each nod voltage and each branch current are applicable to closed-loop gain equation. From the theorem, closed-loop input and output resistance are derived.The calculation results are able to link the closed-loop properties with zero-controlled properties, ideal state properties, feedback depth and near factor, etc.