LTC4265

1

4265f

TYPICAL APPLICATION

DESCRIPTION

IEEE 802.3at High Power PD

Interface Controller with

2-Event Classification Recognition

Interface controller intended for IEEE 802.3at high power

Power-over-Ethernet (PoE) applications up to 25.5W. By

supporting 1-event and 2-event classification signaling as

defined by IEEE 802.3, the LTC4265 can be used in a wide

range of product configurations. A 100V MOSFET isolates

the DC/DC converter during detection and classification,

and provides 100mA inrush current for a smooth power-

up transition. The LTC4265 also includes complementary

power good outputs, an on-board signature resistor,

undervoltage/overvoltage lockout and comprehensive

thermal protection. All Linear Technology PD solutions

include a shutdown pin with signature corrupt to provide

flexible auxiliary power options.

The LTC4265 PD interface controller can be used along

with a variety of DC/DC converter products to provide a

complete, cost effective power solution for high power

PD applications.

The LTC4265 is available in the space-saving low profile

(4mm

× 3mm) DFN package and is drop-in compatible

with the LTC4264.

Turn-On vs Time

L, LT, LTC and LTM are registered trademarks of Linear Technology Corporation.

All other trademarks are the property of their respective owners.

FEATURES

APPLICATIONS

Current Limit.

× 3mm DFN Package

GND

SHDN

54V FROM

DATA PAIR

54V FROM

SPARE PAIR

0.1μF

PWRGD

PWRGD

LTC4265

T2PSE

RUN

5μF

MIN

3.3V

TO LOGIC

RTN

SWITCHING

POWER

SUPPLY

4265 TA01a

+

–

+

~

~

+

–

~

~

+

–

TO LOGIC

TO AUX

50V/DIV

50V/DIV

50V/DIV

100mA/DIV

TIME

25ms/DIV

4265 TA01b