A high speed isolation interface which can be used to enable high speed communications between the isolated side and the wire side in a PoE system is provided. The high speed isolation interface may implement an Ethernet or non-Ethernet based signaling scheme. The high speed isolation interface can be used within both PSE (endspan or midspan) and PD systems, including single port and multi-port PSE and PD systems. Further, the high speed isolation interface is usable within pre-standard PoE, 802.3af PoE, and 802.3at PoE systems. The high speed isolation interface may also be used within 2-pair PoE (Alternative A) and 4-pair PoE (Alternative B) systems.