PWM regulators transfer-functions by exact time-variant network analysis

The paper shows how to obtain closed-form expressions for the main transfer functions of PWM regulators, i.e. open-loop-gain, input and output impedances, audio susceptibility, and output-to-input transmission. Results emerge through an exact time-variant dynamic model on the sole assumption of piecewise linear characteristics of the circuit elements. The given formulae make dynamic analysis of PWM DC/DC converters as easy as that of time-invariant networks.