Patent ID: 8653884
Filing Date: 2014-02-18
Classification: G05F,G06F

Abstract:
1. A semiconductor device comprising: a first power supply terminal configured to receive a main power supply voltage; a second power supply terminal configured to receive an auxiliary power supply voltage; a first switch coupled between the first power supply terminal and a power supply node; a second switch coupled between the second power supply terminal and the power supply node; a first internal circuit driven by the voltage of the first power supply terminal; a second internal circuit driven by the voltage of the power supply node; and a control circuit driven by the voltage of the power supply node, wherein the control circuit, when the voltage of the first power supply terminal is higher than a first reference voltage, is configured to turn on the first switch and turn off the second switch; and when the voltage of the power supply terminal is reduced to less than the first reference voltage, is configured to turn off the first switch, and turn on/off the second switch so that the voltage of the power supply node is gradually increased, wherein when the voltage of the first power supply terminal is lower than the first reference voltage, a first period when the second switch is turned on, and a second period when the second switch is turned off are alternately repeated, causing the first period to gradually increase.