This 20-W multiple output, auxiliary power reference design supports AC/DC industrial power supplies with a wide input voltage range (100-425 VDC). The design achieves a peak efficiency of 85% by using discontinuous conduction mode (DCM) valley-switching of TI’s UCC28704 flyback controller with primary side regulation. The compact design uses a minimum number of components to help protect the system, including output overcurrent and output short circuit. The hardware is tested to meet Conducted Emission norm EN55022 Class A using an external EMI filter.
Features
- Peak power conversion efficiency of >85% at 400VDC full load
- Designed for wide operating input voltage range from 100- to 425-V DC
- Delivers full power of 20 W over the entire operating voltage range
- Configurable outputs: 15V (primary referred), 5V & 15V (isolated)
- Low stand-by power of <100mW
- Compact form-factor to achieve high power density solutions: 40mm × 40mm