LT4321IUF#PBF

The LT4321IUF#PBF is a dual Ideal Diode Bridge Controller that enables a power over Ethernet (PoE) powered device (PD) to receive power in either voltage polarity from RJ-45 data pairs, spare pairs or both. The LT4321 and eight N-channel MOSFETs replace the eight diodes in a passive PoE rectifier bridge. The LT4321 eases thermal design and increases delivered power. An internal charge pump allows an all-NMOS bridge eliminating larger and more costly PMOS switches. High impedance input sense pins prevent reverse current on unused pairs. If the power source fails or is shorted, a fast turn-OFF minimizes reverse current transients. Unlike discrete ideal bridge solutions, the LT4321 will operate through transients without enabling the MOSFETs on unpowered pairs.