A DC-DC converter includes a control circuit for generating a pulse width modulated signal based on a voltage of an output node. A first switch is connected to conduct during pulses, and a second switch conducts between pulses. The first switch is connected to an internal power node and the second is connected to a current return node. There is a common node between the first switch and the second switch. The voltage of the common node is supplied to an output node. An input power switch supplies voltage to the internal power node. An over-voltage protection circuit is connected to receive an over-voltage fault signal from the control circuit, and it is connected to control a bias of the control terminal of the input power switch to cause the input power switch not to conduct during an event causing an over-voltage fault signal, whereby a load connected to the output node is protected.