Interface circuit for providing a computer logic circuit with first and second voltages and an associated method

Abstract

A universal interface circuit and an associated method are provided that can supply a computer logic circuit, such as the components mounted upon an adapter card, with first and second inputs having first and second predetermined voltage levels, respectively, based upon power drawn from both first and second supply voltages. The interface circuit typically includes a first power supply circuit for providing the first input having the first predetermined voltage level in response to the first supply voltage. Additionally, the interface surface includes a regulator for generating an output having the second predetermined voltage level in response to the first supply voltage. The interface circuit further includes a second power supply circuit for providing an output that also has the second predetermined voltage level, albeit in response to the second supply voltage. In order to divide the anticipated load between the first and second supply voltages, the regulator and the second power supply circuit cooperate to provide the second input having the second predetermined voltage level in instances in which the second supply voltage is present. The interface circuit provides for the universal operation of the computer logic circuit, however, in that the regulator will provide the second input having the second predetermined voltage level in a manner independent of the second power supply circuit in instances in which the second supply voltage is unavailable.