Patent ID: 7723867
Filing Date: 2010-05-25
Classification: H03K

Abstract:
1. A control device for controlling power supplied to circuitry, said circuitry comprising a plurality of portions, each of said plurality of circuit portions being arranged between a first voltage level source and a second voltage level source, said first and second voltage level sources being adapted to output different voltage levels; said control device being adapted to control power supplied to each of said plurality of circuit portions, said control device comprising: a plurality of power switching devices corresponding to said plurality of circuit portions, each power switching device being arranged between said first voltage level source and a corresponding circuit portion such that when one of said plurality of power switching devices is switched on a voltage level close to a voltage level output by said first voltage level source is supplied to said corresponding circuit portion and said corresponding circuit portion is powered up and when switched off said corresponding circuit portion is isolated from said first voltage level source and said corresponding circuit portion is powered down; and at least one voltage equalisation switching device arranged between at least two of said power switching devices to provide a low resistance path between said at least two of said power switching devices when they are both turned on and to isolate said at least two of said power switching devices from each other when either is turned off.