This engineering report describesa PFCpower supply utilizing a HiperPFS-3PFS7527H PFC controllerwith integrated power MOSFETand switching diode. This power supply is intended as a general purpose platform that operates from universal input line voltageand provides a regulated 385V DC output voltage and continuous output power of 275W.The DER-394 power supply is designed to operate with forced air cooling greater than 200 LFM for all input and load conditions up to the rated maximum ambient temperature of 50oC.Thisdocument contains the power supply specification, schematic, bill of materials, inductor documentation, printed circuit layout, and performance data.