In summary, the LT3798 is a follow-on part to the LT3799 LED driver which operates from the AC main and incorporates an active PFC in a single-stage flyback converter. Both devices are capable of providing up to 100W of output power. With efficiencies of greater than 86% at output power levels up to 100 W, an LT3798 based design can easily comply with emissions specifications. The input voltage range, 90VAC to 307VAC, is dependent on the choice of external components and can be scaled higher or lower. The LT3798 can also be designed for high input voltage DC applications. Current Energy Star guidelines for computers call for a power factor of ≥0.9 at 100% of rated output and less than a 0.5W power draw when unloaded. With active PFC, an LT3798 based design meets both of these requirements.