Characterization of asymmetrical half bridge flyback converter

Flyback derived converters are attractive because of their simple capacitive output filter when compared with other converters used in multiple-output or cost-sensitive applications. This paper analyzes the detailed circuit behavior of the asymmetrical half bridge flyback converter. Several practical issues, including the specific relationships between the duty cycle and the different types of energy in the energy-storage elements, and the zero voltage switching (ZVS) conditions of the power switches have been thoroughly examined. Mathematical equations have also been given. A 5V/20A prototype has been built to verify the analytical results.