TIDUET3 February   2021

 

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1 System Description

This compact, high-efficiency AC/DC reference design has a 48-V DC, 500-W output at 230 VAC. The circuit consists of a front-end continuous conduction mode (CCM) power factor correction (PFC) circuit based on the UCC28180 device, followed by a robust LLC stage for an isolated DC/DC converter based on the UCC256403. For high-efficiency needs, synchronous rectification is done with the UCC24624. This design uses an auxiliary power supply flyback with the UCC28911 which has an internal high-voltage MOSFET (HV MOS). This design enables 94.5% peak efficiency and allows the system to work without forced cooling. This design has low THD, with 30% load at < 12%, 50% load at < 8%, 100% load at < 5.5%, and good load transient performance.