An electronic device 2 has circuitry 4 which operates in a first voltage domain 6 supplied with a first voltage level VDD1 and a reference voltage level. A voltage regulator 14 generates the first voltage level VDD1 from a second voltage level VDD2 higher than the first voltage level VDD1. At least one power gate 20, 30 is provided for selectively coupling the circuitry 4 to one of the first voltage level VDD1 or the reference level. The control signal 22 for the power gate 20, 30 is generated in a second voltage domain supplied with a higher voltage level VDD2 or VDD3 derived from the second voltage level VDD2 supplied to the voltage regulator 14. Hence, an existing high voltage source within the device 2 can be reused for applying a boosted voltage to power gates to improve efficiency of power gating.