Some electronic systems need positive or negative power from the same terminal and ability to adjust the voltage level, smoothly transitioning output from one voltage level to another and from one polarity to opposite. This article presents such a solution describing power supply generating ±10V to same terminal and able to sink current from the output terminals functioning as load.

Figure: Thermal image of a 4-quadrant converter power train in load (reverse current) mode.

Bipolar, Bidirectional Power Supply Circuit

Most electronics rely on a power system with two voltage terminal rails that are positive and negative. But there are a few applications that require individual rails that can be both positive or negative. Furthermore, some applications in the automotive industry (such as regenerative braking) require power supplies which function as a source and sinking current from the output terminals.

Single terminal bipolar power supplies are well documented. But this paper will provide solutions that can operate during input voltage drops, such as cold crank conditions while continuing to provide bidirectional functionality.