A design approach for server power supplies for networking applications

Present specifications for computer power supplies for networking applications call for designs with dual inputs: the universal AC-line input and the 48-V nominal DC input. In this paper, a design and evaluation of the DC-input version of a 900-W server power supply is presented. The AC-input version of this power supply is leveraged from the AC-input version by using the same output stage, and by replacing the AC front-end in the AC-input version with a DC front end which provides the same input voltage to the output stage. By adopting this design approach, it is possible to achieve design modularity, design standardization, minimize the design time, optimize utilization of resources, and minimize the cost. The DC-input version uses a cascade connection of two DC boost converters because of its superior performance compared with other topologies.