This fully-tested reference design is a high-efficiency: high-power-density: AC/DC adapter solution with a wide input voltage range (100- to 240-V AC) for laptop adapters and smartphone charger applications. This design consists of a front-end transition-mode (TM) power factor correction (PFC) circuit based on the UCC28056 device: followed by an active-clamp flyback for isolated DC/DC conversion based on the UCC28780 device.