US Patent 7362647 Power control circuit

A power control circuit for an integrated circuit module includes at least one switch device coupled between a supply voltage and a node of the integrated circuit module; and a switch control module having a first terminal coupled to the switch device and a second terminal coupled to the node of the integrated circuit module for controlling the switch device to pass the supply voltage to the node with or without a substantial voltage drop depending on an operation mode of the integrated circuit module, the switch control module having at least one capacitor for selectively discharging the node, thereby creating the substantial voltage drop for the supply voltage across the switch device.