Small signal modeling of hysteretic current mode control using the PWM switch model

In this paper, based on the small signal analysis of switching power converters under a hysteretic current mode control, a unified PWM switch model is derived. The model is easy to handle because all manipulations are performed on a circuit diagram which includes simply-described function blocks indicating the physically intuitive relationships among the model parameters. This paper presents two kinds of small signal model of hysteretic current mode control such as critical current mode (CRM) variable frequency control and fixed-band current mode control methods. From the results of the PWM switch modeling, the dynamic characteristics of the hysteretic mode control scheme and that of the peak current mode (PCM) control are compared and summarized. Finally, both of the hysteretic current mode control models are verified by the experimental results