Patent ID: 8922247

Claim:
A power control integrated circuit cell comprising: a voltage switching device having a voltage supply input and a voltage supply output and wherein said voltage supply output is switchably coupled to said voltage supply input in response to a power control input signal such that in a power on configuration of said voltage switching device said voltage supply output is coupled to said voltage supply input; a retention switching device coupled to said voltage switching device and configured to switchably couple said voltage supply output said voltage supply input in response to a retention enable signal such that in a retention enabled configuration of said retention switching device said voltage supply output corresponds to a retention voltage reduced relative to said voltage supply input; wherein said retention switching device has a further voltage input from an overdrive voltage supply such that in said retention enabled configuration, said retention switching device is switched on more strongly relative to being both coupled to said voltage supply input signal and driven from said voltage supply input signal and wherein in a power off configuration of said voltage switching device said voltage supply output is determined by said retention switching device.