This application note describes a relatively novel and simple way to produce an off-line, power factor corrected 15 Vdc and higher output power supply using an isolated, single stage conversion topology. The power topology is essentially a buck-boost derived flyback converter operating in continuous conduction mode (CCM) and utilizing ON Semiconductor’s NCP1652A controller which was designed specifically for this implementation. The power supply described in this application note is a 48 Vdc, 2 A supply with universal AC input and is intended for general purpose supplies, telecom distributed power “front-ends” and constant voltage LED drivers such as those used in area lighting and distributed lighting applications such as refrigerator case lighting and cove lighting. Efficiencies approaching 90% were achieved with a power factor exceeding 0.95 for most typical loads. The supply includes overcurrent protection, overvoltage protection, brownout detection, and an input EMI filter.