ON Semiconductor was the first semiconductor company to provide an 80 PLUS-certified open reference design for an ATX power supply in 2005. A second generation 80 PLUS-certified open reference design with improved efficiency was then introduced in 2007. ON Semiconductor is now introducing its third generation 80 PLUS-certified open reference design with a drastic efficiency improvement. This is a 255 W multi-output power supply for the ATX form factor. Achieving a maximum efficiency of 90% at 50% load, and at 230 and 240 Vac, this third generation reference design achieves >88% efficiency at 50% load, and 100 and 115 Vac. All efficiency measurements were obtained at the end of a 41 cm (16 in.) cable, ensuring the design can be used ‘as is’ in all standard desktop PC configurations.

This reference document provides the details behind this third generation design. The design manual provides a detailed view of the performance achieved with this design in terms of efficiency, performance, thermals and other key parameters. In addition, a detailed list of the bill-of-materials(BOM) is also provided. ON Semiconductor will also be able to provide technical support to help our customers design and manufacture a similar ATX power supply customized to meet their specific requirements.