US Patent 10135626 Power coupling circuits for single-pair ethernet with automotive applications

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.