Patent ID: 6891425
Filing Date: 2005-05-10
Classification: H03K

Abstract:
1. A method of allowing current flow in a forward direction and reducing or preventing current flow in a reverse direction in multiple power supply, single load system, in a single power supply, multiple load system, or in a multiple power supply, multiple load system, comprising: providing a first transistor and a diode; coupling a first power supply, to a first terminal of the first transistor and coupling a second terminal of the first transistor to the load, and coupling a body to one of the first and second terminals of the first transistor so that one of the pn junctions acts as a body diode that will be biased toward conduction when the voltage on the first terminal of the first transistor exceeds the voltage on the second terminal of the first transistor; coupling the first transistor and the diode in parallel between a source of power and a load so that the diode will be biased toward conduction when biased in the forward direction; sensing the current through the parallel combination of the first transistor and the diode; controlling the first transistor to turn the first transistor on when the current through the parallel combination in the forward direction is above a first threshold; and, controlling the first transistor to turn the first transistor off when the current through the parallel combination in the forward direction is below a second threshold, the first threshold being greater than the second threshold.