Multiple-Input Buck Boost Power Converter

A power converter circuit to convert multiple direct current (dc) inputs to one or more dc outputs. This dc-dc power converter allows its load to be powered by multiple, different sources of various voltage and current levels (such as solar panels, batteries, fuel cells, etc.). This converter has both buck and boost capability.

This circuit can simultaneously draw power from several dc electrical energy sources of different kinds (such as solar panels, batteries, fuel cells, etc.). The circuit topology is capable of an arbitrary number of input sources of different voltage/current/power levels. There is a single output voltage that can directly supply a load, or can supply another power converter. The default circuit uses an inductor, but it may be substituted with a transformer to provide electrical isolation or multiple output as well. The power flow from each source can be controlled separately in order to optimize the power flow characteristics for cost, environmental protection, or any other performance objective. Low power applications regulate source switching with a control circuit. High power applications regulate and optimize flow characteristics with a digital signal processor (DSP). This circuit contains a minimum number of components which reduce overall complexity and cost when compared to other implementations. In addition, due to efficiency in design, this circuit can be scaled to work across a multitude of power ranges.


This technology can be used in any application which uses multiple dc energy sources and in situations where backup or simultaneous alternative energy sources are used. Such sources include solar cells, fuel cells, batteries, and thermoelectric sources. 


  • Simple: Designed with minimal parts, allowing for reduced complexity in design and higher reliability.
  • Low Cost: Requires fewer inductors and transistors when compared to equivalent dc-dc converters, therefore manufacturing costs are reduced.
  • Efficient: Less loss and higher conversion efficiency due to the minimal design parts.
  • Adaptable: Easily integrated into existing systems and combined with other converters (i.e. ac-dc).

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