Universal AC Input 14V/2.4A Flyback With 88% Efficiency Reference Design

This reference design provides an isolated 14.5V/35W output from a universal 85-265VAC input. It uses the UCC28740 flyback controller to provide high efficiency and minimize light load losses. Maximum load efficiency is over 88%. The average efficiency (measured at 25%: 50%: 75%: and 100% load) is 87.9%. The UCC28740 also provides accurate current limiting which eliminates the need for a load protecting switch on the output.