Patent ID: 7388361

Claim:
A power control device, which is cooperated with a first power rail and a second power rail, wherein the first power rail and the second power rail are respectively coupled to a chip for providing a first voltage level to the chip through the first power rail and a second voltage level to the chip through the second power rail, the power control device comprising: a comparison unit, which electrically connects to the first power rail and the second power rail, respectively, and generates a comparing signal according to a reference voltage level, the first voltage level and the second voltage level; a control unit, which electrically connects to the comparison unit for receiving the comparing signal and generates a control signal based on the comparing signal; and a switch unit, which electrically connects to the control unit, and is turned on/off based on the control signal so as to connect/disconnect the first power rail and the second power rail, wherein the first voltage level equals to the second voltage level when both the first voltage level and the second voltage level do not reach the reference voltage level.