Patent ID: 8330294
Filing Date: 2012-12-11
Classification: G06F

Abstract:
1. A semiconductor device to select a power supply providing a voltage from first and second external power supply, comprising: a first power node receiving a voltage from said first external power supply; a second power node receiving a voltage from said second external power supply; an output node coupled between said first power node or said second power node; a first switch, a one end of said first switch coupled between said first external power supply and said output node; a second switch, one end of said second switch coupled between said second external power supply and said output node; and a switch control circuit controlling said first and second switches, wherein said first and second switch are controlled by an output voltage of said switch control circuit when said first external power supply or said second external power supply provides a voltage to said output node, complementarily, wherein said first switch is turned off when said second external power supply provides a voltage to said output node, and wherein said second switch is turned off when said first external power supply provides a voltage to said output node.