A circuit comprises a switch, a driver circuit, and an open circuit detector. The switch has a first current electrode coupled to a power supply terminal, a second current electrode coupled to supply a current to a load, and a control electrode. The driver circuit has an input for receiving a control signal, and an output coupled to the control electrode of the switch. The open circuit detector has a first terminal coupled to receive a voltage from a bootstrap capacitor, a second terminal coupled to the power supply terminal, and a control terminal coupled to the driver circuit. The open circuit detector detects an open circuit, and in response, provides a signal at the control terminal for causing the driver circuit to open the switch.