Primary-Side Regulated Flyback with 85-265VAC Input (12V @ 3W) Reference Design

The PMP8869 reference design uses the UCC28700 primary-side regulated flyback controller to generate a 12V/250mA output from a universal AC input. The valley switching of the UCC28700 allows this low-cost design to achieve a maximum load efficiency over 80%; no load losses are less than 30mW. This circuit fits onto a 23mm x 37mm PCB.