On the Calculation and Simulation of Loop Gain in Feedback Circuits

We derive the expression of the loop gain in a circuit containing one or more feedback loops, where the transfer functions building the expression are found by means of a few AC analyses on the circuit. No approximations or assumptions on the nature of the loop or of the impedances therein contained are necessary. While hand calculations are certainly possible in the case of simpler circuits, the method is especially suitable for deployment in an analog circuit simulator environment.