The conduction-cooled PFH500F-28 ac/dc power modules are rated at 28 V 504 W, feature a compact 4-in x 2.4-in footprint and have optional read/write programming and communication through a PMBus interface. The series uses GaN semiconductors, bridgeless power factor correction, synchronous rectification and digital control, enabling efficiencies of up to 92%. Digital isolators have replaced opto-couplers for long-term reliability and stability. Accepting an 85- to 265-Vac input, the modules deliver 28-V at 18 A and can be adjusted from 22.4 to 33.6 V using the trim pin or PMBus interface. Baseplate cooling allows operation at temperatures ranging from -40 to 100 °C.