LT4275
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LTPoE /PoE /PoE
PD Controller
Fea T Descrip T
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IEEE 802.3af/at and LTPoE Powered Device The LT 4275 is a pin-for-pin compatible family of IEEE
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(PD) Controller 802.3 and LTPoE powered device (PD) controllers.
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LTPoE Supports Power Levels Up to 90W
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The LT4275A employs a proprietary LTPoE classification
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LT4275A Supports All of the Following Standards:
scheme, delivering 38.7W, 52.7W, 70W or 90W of power
n
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LTPoE 38.7W, 52.7W, 70W and 90W
at the PD RJ45 connector. The LT4275A is fully compat-
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IEEE 802.3at 25.5W Compliant
ible with IEEE 802.3. The LT4275B is an IEEE 802.3at
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IEEE 802.3af Up to 13W Compliant
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compliant, Type 2 (PoE ) PD delivering up to 25.5W. The
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LT4275B is IEEE 802.3at/af Compliant
LT4275C is an IEEE 802.3af compliant, Type 1 (PoE) PD
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LT4275C is IEEE 802.3af Compliant
delivering up to 13W.
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100V Absolute Maximum Input Voltage
The LT4275 internal charge pump provides an N-channel
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Wide Junction Temperature Range (40C to 125C)
MOSFET solution, eliminating a larger and more costly
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Overtemperature Protection
P-channel MOSFET. A low R MOSFET also maxi-
n DS(ON)
Integrated Signature Resistor
mizes power delivery and efficiency, reduces power and
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External Hot Swap N-Channel MOSFET for Lowest
heat dissipation, and eases thermal design. Startup inrush
Power Dissipation and Highest System Efficiency
current is adjustable with an external capacitor. The LT4275
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Programmable Aux Power Support as Low as 9V
also includes a power good output, on-board signature
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Optional Support of Non-Standard Low Voltage PoE
resistor, undervoltage lockout, and thermal protection. The
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Available in 10-Lead MSOP and 3mm 3mm DFN
LT4275A/LT4275B drives a single opto-coupler to indicate
Packages
the power level of the attached PSE. Pin-selectable sup-
port for non-standard low voltage operation is provided.
a T
Auxiliary power override is supported with the AUX pin.
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High Power Wireless Data Systems
The LT4275A can be configured to support all possible
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Outdoor Security Camera Equipment
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LTPoE , 802.3at and 802.3af power levels with external
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Commercial and Public Information Displays
component changes.
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High Temperature Industrial Applications
L, LT, LTC, LTM, Linear Technology and the Linear logo are registered trademarks and
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LTPoE and Hot Swap are trademarks of Linear Technology Corporation. All other trademarks
are the property of their respective owners.
Typical a T
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LTPoE 90W Powered Device Interface
V (9V TO 60V)
AUX LT4275 Family
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C
PORT
LT4275 GRADE
FDMC86102
MAX DELIVERED
~ +
DATA C POWER A B C
PD
V
PORT
PAIR 0.1F
3.3k
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~
LTPoE 90W l
V
47nF IN
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LTPoE 70W l
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ISOLATED
+
SPARE
POWER
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l
PAIR VPORT HSGATE HSSRC LTPoE 52.7W
V
SUPPLY OUT
~
AUX PWRGD RUN
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LTPoE 38.7W l
LT4275A
l l
25.5W
RCLASS
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RCLASS
PSE TYPE
T2P OPTO 13W l l l
(TO P)
GND IEEEUVLO
R R
CLS CLS++
4275 TA01a
4275f
1
ion pplica
ions pplica
ion uresLT4275
a T e Maxi Mu M r a T
(Notes 1, 3)
VPORT, HSSRC Voltages ......................... 0.3V to 100V Operating Junction Temperature Range (Note 4)
HSGATE Current.................................................. 20mA LT4275AI/LT4275BI/LT4275CI ..............40C to 85C
IEEEUVLO, RCLASS, LT4275AH/LT4275BH/LT4275CH ....... 40C to 125C
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RCLASS Voltages ....... 0.3V to 8V (and VPORT) Storage Temperature Range .................. 65C to 150C
AUX Current ........................................................ 1.4mA Lead Temperature (Soldering, 10 sec.) ..................300C
T2P, PWRGD Voltage ............................... 0.3V to 100V
T2P, PWRGD Current ...............................................5mA
p c F T
TOP VIEW
TOP VIEW
IEEEUVLO 1 10 VPORT
IEEEUVLO 1 10 VPORT
AUX 2 9 HSGATE
AUX 2 9 HSGATE
11
RCLASS 3 8 HSSRC
RCLASS 3 8 HSSRC
GND
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RCLASS /NC* 4 7 PWRGD RCLASS /NC* 4 7 PWRGD
GND 5 6 T2P/NC*
GND 5 6 T2P/NC*
MS PACKAGE
10-LEAD PLASTIC MSOP
DD PACKAGE
10-LEAD (3mm 3mm) PLASTIC DFN
T = 150C, = 45C/W
JMAX JC
T = 150C, = 5C/W
JMAX JC
EXPOSED PAD (PIN 11) IS GND, MUST BE SOLDERED TO PCB GND
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* RCLASS is not connected in the LT4275B/C versions. T2P is not connected in the LT4275C version.
o r D i n F Ma T
MAX PD
LEAD FREE FINISH TAPE AND REEL PART MARKING* POWER PACKAGE DESCRIPTION TEMPERATURE RANGE
LT4275AIDD#PBF LT4275AIDD#TRPBF LGBS 90W 10-Lead (3mm 3mm) Plastic DFN 40C to 85C
LT4275AHDD#PBF LT4275AHDD#TRPBF LGBS 90W 10-Lead (3mm 3mm) Plastic DFN 40C to 125C
LT4275AIMS#PBF LT4275AIMS#TRPBF LTGBT 90W 10-Lead Plastic MSOP 40C to 85C
LT4275AHMS#PBF LT4275AHMS#TRPBF LTGBT 90W 10-Lead Plastic MSOP 40C to 125C
LT4275BIDD#PBF LT4275BIDD#TRPBF LGBV 25.5W 40C to 85C
10-Lead (3mm 3mm) Plastic DFN
LT4275BHDD#PBF LT4275BHDD#TRPBF LGBV 25.5W 10-Lead (3mm 3mm) Plastic DFN 40C to 125C
LT4275BIMS#PBF LT4275BIMS#TRPBF LTGBW 25.5W 10-Lead Plastic MSOP 40C to 85C
LT4275BHMS#PBF LT4275BHMS#TRPBF LTGBW 25.5W 10-Lead Plastic MSOP 40C to 125C
LT4275CIDD#PBF LT4275CIDD#TRPBF LGBX 13W 10-Lead (3mm 3mm) Plastic DFN 40C to 85C
LT4275CHDD#PBF LT4275CHDD#TRPBF LGBX 13W 40C to 125C
10-Lead (3mm 3mm) Plastic DFN
LT4275CIMS#PBF LT4275CIMS#TRPBF LTGBY 13W 10-Lead Plastic MSOP 40C to 85C
LT4275CHMS#PBF LT4275CHMS#TRPBF LTGBY 13W 10-Lead Plastic MSOP 40C to 125C
Consult LTC Marketing for parts specified with wider operating temperature ranges. *The temperature grade is identified by a label on the shipping container.
Consult LTC Marketing for information on nonstandard lead based finish parts.
For more information on lead free part marking, go to: