This reference design is a 40-W dual-output offline converter using UCC28742: a secondary side regulator. A 5-V rail is regulated to within ±1% precision and cross regulation of 12-V rail is within -8%~+14% at 25% to 100% load. The design adopts a single-layer PCB for cost optimization. The peak efficiency is 82.68% at 115 V/60 Hz and 84.03% at 230 V/50 Hz. Power consumption at standby mode is 32.7 mW at 115 V/60 Hz and 57.51 mW at 230 V/50 Hz.