A comparative study of small-signal average models for average current mode control

This paper presents a critical evaluation of four small-signal average models for average current mode control. The four models are divided into two groups. One group includes sampling effect in the model formulation that has been used successfully for peak current mode control, and the other does not include it. The models are evaluated against experimental data generated by using a Buck converter as a common test bed under various converter circuit and operating parameter changes. For practical design purposes, results are interpreted and explained by employing a simplified version of the second group of models to reveal more insight into average current model control. The study finds similarities and differences among these models as well as their limitations in predicting small-signal dynamics of average-current-mode-controlled DC-DC converters.