IEEE 802.3bt PD Interface with Forward/Flyback Controller Features: IEEE 802.3af/at/bt Powered Device (PD) with Forward/Flyback Controller Supports Up to 71.3W PDs 5-Event Classification Sensing Superior Surge Protection (100V Absolute Maximum) Wide Junction Temperature Range (–40°C to 125°C) >94% End-to-End Efficiency with LT4321 Ideal Bridge External Hot Swap N-Channel MOSFET for Lowest Power Dissipation and Highest System Efficiency No-Opto Flyback Operation Auxiliary Power Support as Low as 9V Easy Migration of LTPoE++® PDs to IEEE 802.3bt PDs Pin Compatible with LT4276A/B/C 28-Lead 4mm × 5mm QFN Package