Patent ID: 6995599

Claim:
A power selection circuit for use with a plurality of voltage sources, comprising: a comparator configured to compare a first voltage provided by a first voltage source with a second voltage provided by a second voltage source; control circuitry including cross-coupled logic circuits having only a first and second logic level each having a fixed voltage level having first and second outputs, the cross-coupled logic circuits being configured, in the event the first voltage is greater than the second voltage, to provide said first logic level at the first output and said second logic level at the second output, and, in the event the second voltage is greater than the first voltage, to provide the second logic level at the first output and the first logic level at the second output, the second logic level being opposite to the first logic level; and first and second switching elements, the first switching element being configured to provide the first voltage as an output voltage when the first logic level is provided at the first output, and the second switching element being configured to provide the second voltage as the output voltage when the first logic level is provided at the second output.