LTC9101-x, LTC9102, & LTC9103 PoE 2 Controllers Analog Devices Inc. LTC9101-x, LTC9102, and LTC9103 PoE 2 Controllers are designed for use IEEE 802.3at Type 2, 802.3bt Type 3, and 4 compliant Power over Ethernet (PoE) systems. The LTC9101-1/-2, LTC9102, and LTC9103 implement up to 24 (71.3W) 4-pair or 48 (25.5W) 2-pair PSE ports in either an endpoint or midspan application. Virtually all necessary circuitry is included to implement an IEEE 802.3bt compliant PSE design, requiring a pair of external power MOSFETs and sense resistors per port. This integration minimizes power loss compared to alternative designs with onboard MOSFETs and increases system reliability.