A converter, for feeding a load via an inductor, includes a switch to permit or prevent the feeding of current towards inductor, and a current sensor with a resistor coupled to the converter output, adapted to sense the current through said inductor when switch is off. A further switch is provided which is conductive when said switch is turned off; moreover, a drive circuitry is provided which is coupled to current sensor to turn said switch on as a function of the detected current. Drive circuitry is fed by a bootstrap circuit which includes: a bootstrap capacitor to accumulate a feeding charge for drive circuitry and coupled to the converter output and to a bootstrap diode, a coupling capacitor interposed between said further switch and bootstrap diode, as well as a bootstrap resistor interposed between a power supply source and bootstrap diode to charge coupling capacitor therefrom.