Design of a Dual-Ended Quasi Resonant Flyback Converter

A new Dual Switch Flyback (DSFB) topology which operates in quasi resonant mode is proposed to meet various challenge of current power supply design ranging from 75Watt to 250Watt. Current design challenge of a power supply is multifold and it continues to pursue higher efficiency, higher power density, lower standby power consumption and lower BOM cost. Among all available topology and solutions, it is not easy to find a solution to meet all requirements. DSFB could possibly achieve higher than 92% average efficiency and meet 2013 ErP lot 6 standby power requirement of less than 0.5Watt input power when the load is 0.25Watt. The operation principle and solution benefit are illustrated in this paper and some design examples are shown to demonstrate the capability of this solution.