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.
Features
- 180-VAC - 264-VAC input to 3 isolated outputs
- Primary-side regulation eleminates the need for an optical-coupler
- Valley-switching operation keeps the efficiency high
- Dynamic BJT drive enables lower cost converter design