Abstract: A circuit for power on data line (PoDL) injection includes a power source, a first and a second coupling component, and an interface. The power source provides one or more DC voltage levels. The first coupling component couples the power source to an interface for coupling to a transmission medium. An Ethernet device is coupled through the second coupling component to the interface. The first coupling component is a balanced component, and the Ethernet device is isolated from the power source via a pair of DC blocking capacitors connected between the first coupling component and the second coupling component.

Abstract: A circuit for power on data line (PoDL) injection includes a power source, a first and a second coupling component, and an interface. The power source provides one or more DC voltage levels. The first coupling component couples the power source to an interface for coupling to a transmission medium. An Ethernet device is coupled through the second coupling component to the interface. The first coupling component is a balanced component, and the Ethernet device is isolated from the power source via a pair of DC blocking capacitors connected between the first coupling component and the second coupling component.

Abstract: Systems and methods are provided for power control. In some implementations, a power control system includes a first transistor having a drain coupled to a first conductor (e.g., first pair of wires of an Ethernet cable), a second transistor having a drain coupled to a second conductor (e.g., second pair of wires of the Ethernet cable), a current sensor coupled to sources of the first and second transistors, and a current management circuit. The current management circuit may detect drain voltages of the first transistor and the second transistor, and adjust gate voltages of the first transistor and the second transistor to keep the drain voltages of the first transistor and the second transistor approximately equal. The current management circuit may detect a current through the current sensor, and adjust the gate voltages of the first transistor and the second transistor to limit the detected current to a current limit.

Abstract: Provided is a system and associated method for detecting a resistance of a cable. An example method may comprise applying power to a first end of a first and a second conductive pair of the cable, measuring a first voltage across the first end of the first and second conductive pairs of the cable, applying a current source across the first end of a third and a fourth conductive pair of the cable, measuring a second voltage across the current source, and determining a resistance of the cable using the measured first and second voltages. This method may be carried out in a physical arrangement where a second end of the first, second, third and fourth conductive pairs of the cable are connected to a first, a second, a third and a fourth input terminal of a powered device, respectively.

Abstract: Embodiments of the present disclosure provide systems and methods for reducing discovery time in a power over Ethernet (PoE) system where the nature of a load is known or can be safely assumed. By using prior knowledge of the nature of the load, the discovery procedure can be simplified. A power source device (PSE) controller measures a port voltage to determine if an open circuit exists or if a short circuit exists. If neither an open circuit or a short circuit exists, the system can be safely powered up.

Abstract: Systems and methods are provided for power control. In some implementations, a power control system includes a first transistor having a drain coupled to a first conductor (e.g., first pair of wires of an Ethernet cable), a second transistor having a drain coupled to a second conductor (e.g., second pair of wires of the Ethernet cable), a current sensor coupled to sources of the first and second transistors, and a current management circuit. The current management circuit may detect drain voltages of the first transistor and the second transistor, and adjust gate voltages of the first transistor and the second transistor to keep the drain voltages of the first transistor and the second transistor approximately equal. The current management circuit may detect a current through the current sensor, and adjust the gate voltages of the first transistor and the second transistor to limit the detected current to a current limit.

Abstract: Provided is a system and associated method for detecting a resistance of a cable. An example method may comprise applying power to a first end of a first and a second conductive pair of the cable, measuring a first voltage across the first end of the first and second conductive pairs of the cable, applying a current source across the first end of a third and a fourth conductive pair of the cable, measuring a second voltage across the current source, and determining a resistance of the cable using the measured first and second voltages. This method may be carried out in a physical arrangement where a second end of the first, second, third and fourth conductive pairs of the cable are connected to a first, a second, a third and a fourth input terminal of a powered device, respectively.