A novel converter topology for multiple individually regulated outputs

Power supply voltages in digital systems have reduced considerably in recent years, and often digital components requiring different voltages are present on the same board. This has increased the demand for multiple output power distribution systems with tight individual load voltage regulation. This paper presents a power distribution system having a central power supply that acts as a controlled current source whose output is connected to individual loads on a time shared basis. All the magnetics are concentrated in the converter acting as the current source. The current source can be realized by a current controlled buck, buck-boost, or single-ended primary inductance converter (SEPIC). First, a comparative analysis of buck, buck-boost, and SEPIC based implementation of the current source is carried out. Next, a buck-based current source implementation with constant frequency pulse-width modulation control for the output voltages is described. Detailed component and control design, simulations, and experimental results for a 100-W prototype are presented.