A New Multiple-Frequency Small-Signal Model for High-Bandwidth Computer V-Core Voltage Regulator Applications

A new multi-frequency small-signal model for high bandwidth constant-frequency voltage-mode (CFVM) DC voltage regulator is proposed in this dissertation. Describing function (DF) approach is taken to model the duty-cycle modulator, incorporating the effects of not only the modulating frequency fm, the switching frequency fs, but also the two sideband frequencies fs-fm and fs+fm. The new model is significantly more accurate than the two existing small-signal models, the average model and the two-frequency model, especially when the ratio of control bandwidth to switching frequency is high. The model is verified by computer simulations and hardware experiments. Discussions of practical implications of the model are also given. The model provides an essential tool for designing the feedback system for DC power converters for the latest and the future generations of computer V-Core voltage regulator applications. Furthermore, it can be used for tolerance analysis in a mass-production situation.