US Patent 7940787 Low-power ethernet device

In accordance with the teachings of this disclosure, an Ethernet device is provided that draws current below a predetermined voltage, and as the voltage across the device exceeds the threshold, the device transforms into a high-impedance state, appearing as a high impedance device. Once in the high-impedance state, the discovery process proceeds normally as the current drawn through the high-impedance device is no more than normally occurs due to leakage or other typical conditions. Thus, the IEEE discovery now proceeds normally in the higher voltage ranges (6V to 9V) where the device of this disclosure is effectively out of the circuit, causing no interference.