Datasheet Linear Technology LT4276AIUFD#PBF — Datenblatt

LT4276
LTPoE++/PoE+/PoE
PD Forward/Flyback Controller
Features Description IEEE802.3af/at and LTPoE++в„ў 90W Powered Device
(PD) with Forward/Flyback Controller
n LT4276A Supports All of the Following Standards:
nn LTPoE++ 38.7W, 52.7W, 70W and 90W
nn IEEE 802.3at 25.5W Compliant
nn 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 Operatio External Hot Swapв„ў 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 Г— 5mm QFN Package The LTВ®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. n Applications n n The LT4276A employs the LTPoE++ classification scheme,
receiving 38.7W, 52.7W, 70W or 90W of power at the PD …