This reference design generates a 3.3V/100W output from a standard 48V telecom input and allows for a pre-biased output. The UCC2897A controls operation of the active clamp power stage. The drive signal for the synchronous rectifiers is sent to the secondary side through an ISO7220 digital isolator. This drive signal is blanked out during startup to allow for a pre-biased output. This design achieves efficiencies over 92% and is built on a standard ¼ brick footprint.