High side power switch with charge pump and bootstrap capacitor

A power switching circuit comprising:

• a power semiconductor switching device;
• a charge pump circuit having a control input to control whether the charge pump is on or off and a charge pump output, the charge pump output being coupled to a control terminal of the power semiconductor switching device;
• a bootstrap power supply for supplying power to driver circuitry for the power semiconductor switching device, the bootstrap power supply comprising a bootstrap capacitor coupled to a charging current source;
• the bootstrap power supply providing power to the driver circuitry when the power semiconductor switching device is being switched by the driver circuitry in a pulsed mode;
• and
• the charge pump supplying a control voltage to turn on the power semiconductor switching device and maintain it on when the power switching device is to be maintained on continuously;
• and wherein a transistor switch of the driver circuitry is actively controlled to prevent the charge pump from charging the bootstrap capacitor.