POWER OVER DATA LINES SYSTEM WITH COMBINED DC COUPLING AND COMMON MODE TERMINATION CIRCUITRY

摘要

In a Power over Data Lines (PoDL) system that conducts differential data and DC power over the same wire pair, various DC coupling techniques are described that improve DC voltage coupling while attenuating AC common mode noise and avoiding mode conversion. A first CMC and AC coupling capacitors are connected in series between a PHY and a twisted wire pair. A DC power supply is DC coupled to the wires via a series connection of a DMC and either matched inductors or a second CMC. Coupled between the DMC and the inductors/CMC is an RC termination circuit comprising a first capacitor coupled to one leg and a matched second capacitor coupled to the other leg. The two capacitors are connected to the same resistor coupled to ground.