LTC4257CS8#PBF Datasheet PDF - Linear Technology

●The LTC4257CS8#PBF is an IEEE 802.3af® PD Power over Ethernet Interface Controller provides complete signature and power interface functions for a device operating in an IEEE 802.3af® power over Ethernet (PoE) system. The LTC4257 simplifies powered device (PD) design by incorporating the 25k signature resistor, the classification current source, input current limit with thermal foldback, under voltage lockout and power good signalling. By incorporating a high voltage power MOSFET on board, it provides the system designer with reduced cost while also saving board space. It can interface directly with a variety of linear technology DC/DC converter products to provide a cost effective power solution for IP phones, wireless access points and other PDs. Linear technology also provides solutions for power sourcing equipment (PSE) applications with quad network power controllers.

● Precision input current limit

● Onboard 25k Signature resistor

● Programmable classification current

● Undervoltage lockout

● Smart thermal protection

● Power good signal