US Patent 7385435 Programmable power gating circuit

In general, in one aspect, the disclosure describes a programmable power gating circuit that includes a reference voltage generator to generate a reference voltage and a voltage selector, coupled between a voltage source and active circuitry, to gate application of the voltage source to the active circuitry and provide a certain voltage to the active circuitry when the active circuitry is in a reduced capacity mode. The certain voltage is based on the reference voltage.