CIRCUITRY FOR CHARGING A BOOTSTRAP CAPACITOR

Charging circuitry for charging a bootstrap capacitor that provides a gate drive voltage to a high-side switch of switching circuitry, wherein a first terminal of the bootstrap capacitor receives a variable voltage, the charging circuitry comprising: current source circuitry configured to supply a charging current to the bootstrap capacitor; a charging switch for selectively coupling the current generator circuitry to the bootstrap capacitor to permit charging of the bootstrap capacitor by the current generator circuitry; and control circuitry configured to control operation of the charging switch to charge the bootstrap capacitor to at least a predefined target voltage, wherein the predefined target voltage is referenced to the variable voltage.