Linear Technology DC1335A-A - LTC4269-1 | PoE Powered Device w/48V Isolated Auxiliary DC1335A-A DC1335A-A 数据表

LTC4269-1

1

42691fc

•

•

•

•

33mΩ

39k

10μF

30.9Ω

1.21k

38.3k

100k

12k

10nF

10μF

2.2μF

0.1μF

33pF

0.1μF

2.2nF

1μF

t

ON

SYNC

PGDLY

UVLO

PWRGD

SENSE

–

V

CMP

SENSE

+

R

CMP

V

NEG

SHDN

R

CLASS

V

PORTP

V

PORTN

ENDLY

OSC

LTC4269-1

GND

FB

V

CC

V

IN

SG

PG

C

CMP

10

μ

H

TO MICRO

CONTROLLER

•

47μF

0.18μH

5V
5A

100μF

+

+

3.01k

27.4k

T2P

14k

383k

54V FROM

DATA PAIR

54V FROM

SPARE PAIR

+
–

~
~

+
–

~
~

42691 TA01a

IEEE 802.3at PD with 

Synchronous No-Opto 

Flyback Controller

The LTC

®

4269-1 is an integrated Powered Device (PD) 

controller and switching regulator intended for high 
power IEEE 802.3at and 802.3af applications. The 
LTC4269-1 is targeted for high effi ciency, single and 
multioutput applications from 10W to 25W. By support-
ing both 1-event and 2-event classifi cations, as defi ned 
by the IEEE, the LTC4269-1 can be used in a wide range 
of product confi gurations.

The LTC4269-1 synchronous, current mode, fl yback con-
troller generates multiple supply rails in a single conversion 
step providing for the highest system effi ciency while main-
taining tight regulation across all outputs. The LTC4269-1 
includes Linear Technology’s patented No-Opto feedback 
topology to provide full IEEE 802.3 isolation without the 
need of an opto-isolator circuit. A true soft-start function 
allows graceful ramp-up of all output voltages. 

All Linear Technology PD solutions include a shutdown 
pin to provide fl exible auxiliary power options. The 
LTC4269-1 can accommodate adaptor voltages from 18V 
to 60V and supports both PoE or aux dominance options. 
The LTC4269-1 is available in a space saving 32-pin DFN 
package.

L, LT, LTC, LTM, Linear Technology and the Linear logo are registered trademarks of Linear 
Technology Corporation. Hot Swap is a trademark of Linear Technology Corporation. All other 
trademarks are the property of their respective owners. Protected by U.S. Patents, including 
5841643.

n

  25.5W IEEE 802.3at Compliant (Type 2) PD

n

  Integrated State-of-the-Art Synchronous Flyback 

n

  Flexible Integrated Auxiliary Power Support

n

  Superior EMI Performance

n

  Robust 100V 0.7Ω (Typ) Integrated Hot Swap MOSFET

n

 IEEE 802.3at 

High Power Available Indicator

n

  Integrated Signature Resistor and Programmable 

Class Current

n

  Undervoltage, Overvoltage and Thermal Protection

n

  Short-Circuit Protection with Auto-Restart

n

  Programmable Soft-Start and Switching Frequency

n

  Complementary Power Good Indicators

n

  Thermally Enhanced 7mm × 4mm DFN Package

n

  VoIP Phones with Advanced Display Options

n

  Dual-Radio Wireless Access Points

n

  PTZ Security Cameras

n

 RFID Readers

n

 Industrial Controls