Dual-Switch Quasi-Resonant Flyback Converter: Cost Effective Alternative to LLC Resonant Converters

This paper presents dual-switch Quasi-Resonant (QR) flyback topology as a cost effective and reliable alternative to the LLC resonant converter for energy efficiency regulation. The proposed topology shows excellent efficiency performance, while maintaining simple design of the conventional flyback converters. It offers higher efficiency than LLC resonant converter at medium and light load, resulting in higher average efficiency, which eventually allows compliance to energy efficiency regulations. It shows lower standby power consumption than LLC resonant converter. Being less sensitive to the transformer tolerance and gate drive timing, the proposed solution also enables more robust and reliable power supply design at lower cost. The validity of the proposed topology is verified with a 90W prototype power supply.