System and method for dissipating energy on the primary side of a bi-directional switching power supply

A switching power supply, comprising:

• a switching power output stage coupled to a primary power supply side and a secondary power supply side, the switching power output stage configured to operate in quadrant one and in quadrant two;
• and
• a current sinking circuit coupled to the primary power supply side, the current sinking circuit configured to dissipate energy when the switching power supply is operating in quadrant two.

A method for dissipating energy in a power supply, comprising:

• detecting energy on a secondary side of a power output stage, the detecting comprising sensing a voltage across a resistance associated with the primary side of the power output stage;
• and
• dissipating the energy from the secondary side of the power output stage to a primary side of the power output stage, the dissipating comprising activating a control element associated with the primary side of the power output stage to conduct the energy through the primary side of the power output stage.