Small-signal modeling for digital predictive current mode control in CCM

Predictive current mode control is a promising digital current mode control technique. It has the advantages of fast transient response without knowledge of the exact value of the input voltage and inductance in the power converter. Control laws are based on an understanding of the inductor current waveform, thus providing flexibility in programming and implementation. However, only a few papers have been written about developing small-signal models for predictive current controllers. It is important to have a small-signal model to optimize the controller performance. In this paper, a small-signal s-domain model for predictive current mode control is proposed. This small-signal model is applied to two different predictive controller systems. The frequency response of the systems are compared with experimental measurements obtained with an AP300 network analyzer.