An integrated circuit, method of controlling power supplied to semiconductor devices, a method of designing an integrated circuit and a computer program product are disclosed. The integrated circuit comprises: a semiconductor device for handling data; a power source for powering said semiconductor device, said power source comprising a high voltage source for supplying a high voltage level and a low voltage source for supplying a low voltage level; a plurality of switching devices arranged between at least one of the high or low voltage sources and the semiconductor device. There is also a control device for controlling a first set of the plurality of switching devices to connect one of the high or low voltage sources to the semiconductor device and for controlling a second set of the plurality of switching devices to connect the one of the high or low voltage sources to the semiconductor device. At least some of the first set of the plurality of switching devices have a higher resistance when closed and providing a connection than at least some of the second set of the plurality of switching devices such that when the first set of the plurality of switching devices connect the semiconductor device to the one of the voltage sources the semiconductor device operates with a lower performance than when the second set of the plurality of switching devices connect the semiconductor device to the one of said voltage sources.