Method for high voltage power feed on differential cable pairs from a network attached power sourcing device

A method operable to produce an Ethernet power signal within a power source equipment (PSE) network device, comprising:

• physically coupling a plurality of input nodes within the PSE network device to an isolated power supply;
• drawing currents from the plurality of input nodes through differential transistor pairs;
• sensing individual currents drawn through each transistor of the differential transistor pairs;
• comparing the individual currents drawn through each transistor of the differential transistor pairs;
• generating feedback signals based on the comparison of the individual currents drawn through each transistor of the differential transistor pairs;
• and
• applying the feedback signals to the differential transistor pairs;
• and
• supplying the currents drawn through the differential transistor pairs to a network attached power device (PD) via an Ethernet network.

A method operable to produce an Ethernet power signal within a power source equipment (PSE) Ethernet network device, comprising:

• physically coupling a plurality of input nodes within the PSE network device to an isolated power supply;
• drawing currents from the plurality of input nodes through differential transistor pairs;
• sensing individual currents drawn through each transistor of the differential transistor pairs;
• producing control signals for of each transistor within the differential transistor pair based on the individual currents drawn through each transistor of the differential transistor pairs;
• applying the control signal to a gate of each transistor, wherein the control signal forces the current passed by each transistor in a differential transistor pair to be equal;
• and
• supplying the currents drawn through the differential transistor pairs to a network attached power device (PD) via an Ethernet network.