First and second FETs of a half-bridge are series connected between first and second terminals and are gate driven, respectively, by first and second drivers. An inductance is connected to the intermediate node of the half-bridge. Power supply for the second driver circuit is a supply voltage generated by a voltage regulator as a function of the voltage between the first and the second terminal. Power supply for the first driver circuit is a supply voltage generated by a bootstrap capacitor having a first terminal connected via a first switch to receive the supply voltage output from the voltage regulator and a second terminal connected to the intermediate node. The first terminal of the bootstrap capacitor is further connected by a second switch to receive a second supply voltage. A control circuit generates control signals for the first and second driver circuits and the first and second switches.