A circuit includes a driver circuit having a high side switch device and a low side switch device coupled to a load voltage node and a motor winding output. A controller operates the high side switch device and the low side switch device. The controller operates in a normal mode to supply current to the motor winding output for driving a motor winding when an external power supply is available to supply the load voltage node. In response to detecting a loss of the external power supply, the controller operates the high side switch device and the low side switch device in a boost mode to utilize a back electromotive force (BEMF) voltage from the motor winding to supply current to the load voltage node.