Linear Technology LTC4265 IEEE802.3at PD Controller DC1415A DC1415A Ficha De Dados
Códigos do produto
DC1415A
LTC4265
1
4265fa
TYPICAL APPLICATION
DESCRIPTION
IEEE 802.3at High Power PD
Interface Controller with
2-Event Classifi cation Recognition
The LTC
®
4265 is a 3rd generation Powered Device (PD)
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 classifi cation signaling as
defi ned by IEEE 802.3, the LTC4265 can be used in a wide
range of product confi gurations. A 100V MOSFET isolates
the DC/DC converter during detection and classifi cation,
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
fl exible auxiliary power options.
Power-over-Ethernet (PoE) applications up to 25.5W. By
supporting 1-event and 2-event classifi cation signaling as
defi ned by IEEE 802.3, the LTC4265 can be used in a wide
range of product confi gurations. A 100V MOSFET isolates
the DC/DC converter during detection and classifi cation,
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
fl exible 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.
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 profi le
(4mm
(4mm
× 3mm) DFN package and is drop-in compatible
with the LTC4264.
Turn-On vs Time
L, LT, LTC, LTM, Linear Technology and the Linear logo are registered trademarks of Linear
Technology Corporation. All other trademarks are the property of their respective owners.
Technology Corporation. All other trademarks are the property of their respective owners.
FEATURES
APPLICATIONS
n
IEEE 802.3af/at Powered Device (PD) Controller
n
IEEE 802.3at 2-event Classifi cation Signaling
n
Programmable Classifi cation Current
n
Flexible Auxiliary Power Support Using SHDN Pin
n
Rugged 100V Onboard MOSFET with 100mA Inrush
Current Limit.
n
Complementary Power Good Outputs
n
Onboard Signature Resistor
n
Comprehensive Thermal Protection
n
Undervoltage and Overvoltage Lockout
n
12-Lead, 4mm
× 3mm DFN Package
n
802.11n Access Points
n
High Power VoIP Video Phones
n
RFID Reader Systems
n
PTZ Security Cameras and Surveillance Equipment
GND
R
CLASS
SHDN
R
CLASS
54V FROM
DATA PAIR
54V FROM
SPARE PAIR
0.1μF
PWRGD
PWRGD
LTC4265
T2PSE
V
+
RUN
5μF
MIN
3.3V
TO LOGIC
RTN
SWITCHING
POWER
SUPPLY
SUPPLY
V
IN
V
OUT
4265 TA01a
+
–
+
~
~
+
–
~
~
+
–
TO LOGIC
TO AUX
GND – V
IN
50V/DIV
GND – V
OUT
50V/DIV
PWRGD – V
OUT
50V/DIV
I
PD
100mA/DIV
TIME
25ms/DIV
4265 TA01b
C
LOAD
= 100μF