Patent ID: 6765416
Filing Date: 2004-07-20
Classification: G06F

Abstract:
A device for recognizing a power source for a chip, wherein said power source can be a native power or a cable power, wherein the native power ranges from a voltage V1 a voltage V2 with V1>V2, and the chip can tolerate a maximum input voltage Vm and has a threshold voltage Vt, the device for recognizing the power source comprising:a first voltage-dividing device coupled to the native power for providing a first partial voltage, wherein said first voltage-dividing device comprises a plurality of resistors determined by a ratio of the maximum input voltage Vm to the voltage V1; and a second voltage-dividing device coupled to the native power for providing a second partial voltage to a second pad of the chip, wherein said second voltage-dividing device comprises a plurality of resistors determined by the ratio of the maximum input voltage Vm to the voltage V1; wherein said first voltage-dividing device is coupled to a first pad on said chip and said first pad is designed in response to the voltage V2 and said ratio, so the device for recognizing the power source can recognize the power source according to the first partial voltage.