This reference design is a GaN-based 45-W active clamp flyback (ACF) providing auxiliary power in server and telecom power supply units (PSU). The UCC28782 ACF controller and LMG2610 GaN half-bridge drive a planar transformer with synchronous rectification using the UCC24612. This supply operates using the PFC bus voltage as an input, and generates an isolated 12-V, 3.7-A output, and a non-isolated 18-V, 400-mA output. The main 12-V output is protected by the TPS74800 ORing controller. Multiple PMP23146 units can be operated in parallel for higher power capability.