Asymmetric half-bridge flyback converter and control method thereof

Abstract

Disclosed is an asymmetric half-bridge flyback converter and a control method, including: in an initial switching cycle of the asymmetric half-bridge flyback converter, obtaining a pre-turnoff time of the second switch transistor, and controlling the second switch transistor to be turned off after a delay which lasts for a first time and starts at the pre-turnoff time of the second switch transistor; in a non-initial switching cycle of the asymmetric half-bridge flyback converter, obtaining a judgment result by judging whether the first switch transistor is operated with zero-voltage switching in a current switching cycle, and adjusting a length of the first time based on the judgment result. The present disclosure can realize zero-voltage switching of the asymmetric half-bridge flyback converter, and at the same time, satisfy a requirement for achieving more ideal dead-time setting under a wider range of input voltage and a wider range of output voltage.