Modeling Average-Current-Mode-Controlled multi-phase buck converters

A new small signal model of average current mode control (ACMC) for multi-phase Buck converters is presented in this paper. The model is an approximation of an existing model with all its parameters expressed explicitly with converter circuit parameters. Because of this, the model reveals valuable insight into the profound influence of current feedback on the converter small signal dynamics. Similarities and differences between the peak current mode control (PCMC) and ACMC can also be distinctly identified with the new model. The model has the advantage of simplicity, yet it is accurate enough to represent the small signal dynamic behavior of the ACMC Buck converters. Experimental results are given to validate the new model.