Patent ID: 6327635
Filing Date: 2001-12-04
Classification: G06F

Abstract:
For use within a computer system having an expansion slot connected to a bus, the bus having a first supply line for supplying a first predetermined voltage, and having a second supply line for supplying a second predetermined voltage which is higher than the first predetermined voltage, an add-on card which is adapted to operate properly regardless of whether the respective predetermined voltages are supplied on (1) the first supply line only, (2) the second supply line only, or (3) both supply lines, the card comprising:a selection circuit which connects to the first and second supply lines, and which detects the presence of the first predetermined voltage on the first supply line and selects between the first and second supply lines as a power source for at least one integrated circuit of the card, the selection circuit selecting the first supply line as the power source when the detection circuit detects the first predetermined voltage on the first power supply line; anda step-down circuit which steps down a voltage provided on the second supply line when the second power supply line is selected as the power source.