LTC4270/LTC4271
31
42701fd
For more information www.linear.com/LTC4270
Information furnished by Linear Technology Corporation is believed to be accurate and reliable.
However, no responsibility is assumed for its use. Linear Technology Corporation makes no representa-
tion that the interconnection of its circuits as described herein will not infringe on existing patent rights.
REVISION HISTORY
REV DATE DESCRIPTION PAGE NUMBER
A 9/11 Updated Absolute Maximum Ratings.
Updated Electrical Characteristics.
Updated GATEn pin description.
Updated Inrush Control section.
Updated Power Supplies and Bypassing section.
Updated Typical Applications.
2
4, 5, 6, 7
13
21
25
28, 32
B 3/12 Removed temperature readback feature.
Changed LTPoE
++
power levels from 35W, 45W to 38.7W, 52.7W respectively.
Removed Lead Temperature.
Updated Electrical Characteristics (removed temperature dots).
Clarified AUTO Pin mode relationship to Reset Pin.
Modified Related Parts.
1, 5, 15, 23
1, 16, 17
2
5, 6
17-18
32
C 8/12 Removed temperature dot for V
DD
Undervoltage Lock-Out
Added 0.1µF label to capacitor on CAP2 pin
4
28, 32
D 06/15 Updated surge protection recommendations
Simplified Power over Ethernet system diagram
1, 26, 27, 28, 32
16
LTC4270/LTC4271
32
42701fd
For more information www.linear.com/LTC4270
LINEAR TECHNOLOGY CORPORATION 2011
LT 0615 REV D • PRINTED IN USA
Linear Technology Corporation
1630 McCarthy Blvd., Milpitas, CA 95035-7417
(408) 432-1900
FAX: (408) 434-0507
www.linear.com/LTC4270
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PART NUMBER DESCRIPTION COMMENTS
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CUT
/I
LIM
, 2-Event Classification, and Port Current and Voltage Monitoring
LTC4266A Quad LTPoE
++
PSE Controller Provides Up to 90W. Backwards Compatible with IEEE 802.3af and IEEE 802.3at PDs. With
Programmable I
CUT
/I
LIM
, 2-Event Classification, and Port Current and Voltage Monitoring
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2-Event Classification, Programmable Class, Synchronous Forward Controller, 100kHz to
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LTC4278 IEEE 802.3af PD Interface With Integrated
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LIM
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++
PSE Controller Provides Up to 90W. Backwards Compatible with IEEE 802.3af and IEEE 802.3at PDs. With
Programmable I
CUT
/I
LIM
, 2-Event Classification, and Port Current and Voltage Monitoring
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/I
LIM
, 1-Event Classification, and Port Current and Voltage Monitoring
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2
C Accelerator Improved I
2
C Rise Time, Ensures Data Integrity
TYPICAL APPLICATION
0.01µF
200V
0.01µF
200V
1
2
3
4
5
6
7
8
RJ45
CONNECTOR
3.3V –54V
100Ω
100Ω
T2
T3
3.3V –54V
ISOLATED
GND
–54V
100Ω
100Ω
GP0
GP1
MID
RESET
MSD
INT
AUTO
SCL
AD0
AD1
AD2
AD3
AD6
DGND
V
EE
VSSK
CAP1
CAP2
DND
DPD
CND
CPD
DNA
AGND
DPA
CNA
CPA
OUT12
OUT1
GATE1
SENSE1
GATE12
SENSE12
XIO0 XIO1
42701 F16
SDAIN
SDAOUT
LTC4271
LTC4270
V
DD33
3.3V 0.1µF F
1µF
SMCJ58A
+
>47µF
SYSTEM
BULK CAP
S1B
1
11
12
2
T1
0.25Ω, 1%
RS
0.22µF
100V
X7R
S1B
FDMC3612
0.01µF
200V
0.01µF
200V
0.01µF
200V
0.01µF
200V
75Ω75Ω
75Ω75Ω
1
2
3
4
5
6
7
8
RJ45
CONNECTOR
PHY
(NETWORK
PHYSICAL
LAYER
CHIP)
SMAJ58A
1µF
0.1µF
–54V
ISOLATED
2nF 2kV
1µF
100V
X7R
10Ω

LTC4270BIUKG#PBF

Mfr. #:
Manufacturer:
Analog Devices Inc.
Description:
Power Switch ICs - POE / LAN PoE+ 25.5W 12-Port PSE Controller (Ethernet interface)
Lifecycle:
New from this manufacturer.
Delivery:
DHL FedEx Ups TNT EMS
Payment:
T/T Paypal Visa MoneyGram Western Union