Patent attributes
A low leakage power management system is provided. An external voltage domain is selectively coupled to the internal voltage domain of an integrated circuit according to demand for the functions provided by the integrated circuit. An external voltage VDD is connected to the internal supply voltage plane of the integrated circuit when the integrated circuit is active. The external supply voltage VDD is disconnected from the integrated circuit chip during idle periods. A plurality of switch cells may be provided for connecting the external voltage VDD to the integrated circuit. A multi-step sequence is provided for connecting the external supply voltage VDD to the chip's internal supply voltage plane to prevent excessive current from flowing through any individual switch cell.