This offline flyback reference design uses the UCC28722 controller to generate 2 isolated outputs (5 V at 400 mA: 24 V at 300 mA) from an AC input (85 VAC - 480 VAC). The UCC28722 output drive interfaces to a bipolar transistor power switch: enabling a more efficient design than a typical design. The valley-switching technique reduces switching losses and keeps the efficiency high. The controller provides constant-voltage and constant-current regulation without the use of an optical-coupler.