Power conversion circuit and control method thereof

Abstract

A power conversion circuit includes a transformer, a resonant capacitor, a high-side transistor, a low-side transistor and a control circuit. The transformer includes a primary coil and a secondary coil, where the primary coil is coupled between the switch node and the resonant node. The resonant capacitor is coupled between the resonant node and the ground. The high-side transistor provides an input voltage to the switch node based on a high-side driving signal. The low-side transistor couples the switch node to the ground based on a low-side driving signal. The control circuit operates in a normal mode to generate the high-side driving signal and the low-side driving signal, so that the secondary coil generates an output voltage. When the control circuit operates in a discharge mode, the control circuit discharges the resonant capacitor with a discharge current using the low-side transistor.

Images