DER-114: 5V @ 4A, 15V @ 67mA, 85 ~ 265 VAC in

This engineering report describes a universal input 5 V, 4 A power supply designed around a TNY280P device from the TinySwitch-III family of ICs. Although designed as an auxiliary or bias supply for a personal computer (PC) power supply, this design can also be used as a general-purpose evaluation platform for TinySwitch-III devices.

Typically, PC power supplies have a power factor corrected (PFC) input stage. However, since the bias supply must operate before the PFC stage is active, this supply has been designed for universal input operation.

Input rectification and input storage capacitance have been included, for evaluation purposes. This stage and the EMI filter components would normally be part of the main PC supply, in an actual application.

This report contains the power supply specification, the circuit diagram, a complete bill of materials (BOM), the PI Xls transformer spreadsheet design results, complete transformer documentation, the printed circuit board (PCB) layout and relevant performance data.