This offline flyback reference design uses the UCC28910 controller to generate 2 non-isolated outputs (6.5 V at 600 mA: 15 V at 67 mA) from a DC input (108 VDC - 411 VDC). The UCC28910 incorporate a 700-V power FET and a high-voltage current source for startup to achieve low stand-by power. 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.