ON Semiconductor was the first semiconductor company to provide an 80 PLUS open reference design for an ATX power supply in 2005 — a first-generation design. ON Semiconductor now introduces a second-generation reference design, which utilizes newer ICs from ON Semiconductor that enable it to exceed 80% efficiency, starting at 20% load across different line conditions with ample margin to spare. These results were made possible by the use of advanced new ON Semiconductor ICs, which not only speed up the development cycle, but also help achieve high efficiencies, while keeping a check on cost. This reference document provides the details behind this second-generation design, as well as a detailed list of the bill-of-materials (BOM).