High Efficiency 5V@1.5A Adapter (meets DOE-VI standard) using BJT Solution

This reference design demostrates a low cost single PCB board solution for 5V1.5A adapter. By using primary side regulation (PSR) mode chip UCC28720 which drives bipolar power device: average efficiency >80% @230Vac is achieved. Output ripple 4.32V with 0~0.5A load transient. The overall size is limited in 43mm(L)X28mm(W)x16mm(H) and no load power is less than 20mW.