36V-72VDC Input Active Clamp Forward With Dual 12V/50W Outputs

This power supply design generates a 12V/100W isolated output from a standard 48V telecom input. An active clamp forward converter is controlled by the UCC2897A. The INA202 and an external PFET are used to provide a current limited 12V/4.5A output derived from the main 12V output of the forward converter. This power supply has a peak efficiency of over 94%.