The small-signal input-to-output frequency response of switching converters

An exact analytical method for the computation of the input-to-output frequency response of DC-to-DC switching converters is introduced. Because of the time-varying nature of such converters, the result is not very useful in gaining an insight into their dynamics. An analytical method that is based on the small-signal frequency response theory and the measurement approach is introduced to overcome this problem. The key idea is to use a signal which is formed by passing a continuous sinusoidal signal through a sample-and-hold circuit as the injected signal instead of the traditional continuous sinusoidal signal. Only the case in which the sampling frequency of the sample-and-hold circuit equals the switching frequency of the converter circuit is discussed.