Ripple effects on small signal models in average current mode control

Abstract

The effects of switching frequency ripple on the behavior of average current mode PWM DC/DC converters are studied. Ripple estimation and superposition methods are applied to derive new frequency-dependent averaged models that take into account these effects. Small-signal analysis of the new model reveals several important characteristics of average current mode control, especially under large ripple conditions, that previous models were unable to predict. Discussions on the small-signal models for PWM DC/DC converters are demonstrated.