LT4276

LT4276 LTPoE++/PoE+/PoE PD Forward/Flyback Controller Features n IEEE802.3af/at and LTPoE++™ 90W Powered Device (PD) with Forward/Flyback Controller n LT4276A Supports All of the Following Standards: n LTPoE++ 38.7W, 52.7W, 70W and 90W n IEEE 802.3at 25.5W Compliant n IEEE 802.3af up to 13W Compliant n LT4276B is IEEE 802.3at/af Compliant n LT4276C is IEEE 802.3af Compliant n Superior Surge Protection (100V Absolute Maximum) n Wide Junction Temperature Range (–40°C to 125°C) n Auxiliary Power Support as Low as 9V n No Opto-Isolator Required for Flyback Operation n External Hot Swap™ N-Channel MOSFET for Lowest Power Dissipation and Highest System Efficiency n >94% End-to-End Efficiency with LT4321 Ideal Bridge n Available in a 28-Lead 4mm × 5mm QFN Package Applications n High Power Wireless Data Systems n Outdoor Security Camera Equipment n Commercial and Public Information Displays n High Temperature Applications Description The LT®4276 is a pin-for-pin compatible family of IEEE 802.3 and LTPoE++ Powered Device (PD) controllers. It includes an isolated switching regulator controller capable of synchronous operation in both forward and flyback topologies with auxiliary power support. The LT4276A employs the LTPoE++ classification scheme, receiving 38.7W, 52.7W, 70W or 90W of power at the PD RJ45 connector, and is backwards compatible with IEEE 802.3. The LT4276B is a fully 802.3at compliant, 25.5W Type 2 (PoE+) PD. The LT4276C is a fully 802.3af compliant,...