LTC4292/LTC4291
4-Port IEEE 802.3bt
PoE PSE Controller
FEATURES
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DESCRIPTION
The
LTC
®
4292/LTC4291
chipset is a 4-port power sourc-
ing equipment (PSE) controller designed for use in IEEE
802.3bt Type 3 and 4 compliant Power over Ethernet
(PoE) systems. The LTC4292/LTC4291 is designed to
power compliant 802.3af, 802.3at, and 802.3bt PDs.
The LTC4292/LTC4291 chipset delivers lowest-in-indus-
try heat dissipation by utilizing low-R
DS(ON)
external
MOSFETs and 0.15Ω sense resistance per power channel.
A transformer-isolated communication protocol replaces
expensive opto-couplers and complex isolated 3.3V sup-
ply, resulting in significant BOM cost savings.
Advanced power management features include per-
port 14-bit current monitoring, programmable current
limit, and versatile fast shut-down of preselected ports.
Advanced power management host software is available
under a no-cost license. PD detection uses a proprietary
multipoint detection mechanism ensuring excellent immu-
nity from false PD identification. Autoclass and 5-event
physical classification are supported. The LTC4292/
LTC4291 includes an I
2
C serial interface operable up to
1MHz. The LTC4292/LTC4291 is pin or I
2
C programmable
to negotiate PD delivered power up to 71.3W.
All registered trademarks and trademarks are the property of their respective owners.
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Four PSE Ports
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Two Power Channels Per Port
Fully Compliant IEEE 802.3bt Type 3 and 4 PSE
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Compliant Support for Type 1, 2, 3, and 4 PDs
Low Power Path Dissipation per Channel
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150mΩ Sense Resistance
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30mΩ or Lower MOSFET R
DS(ON)
Chipset Provides Electrical Isolation
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Eliminates Optos and Isolated 3.3V Supply
Very High Reliability Multipoint PD Detection
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Connection Check Distinguishes Single-
Signature and Dual-Signature PDs
Continuous, Dedicated Per-Port Power and Current
Monitoring
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Per-Port Power Policing
1MHz I
2
C Compatible Serial Control Interface
Pin or I
2
C Programmable PD Power Up to 71.3W
Available in a 40-Lead 6mm × 6mm (LTC4292) and
24-Lead 4mm × 4mm (LTC4291) QFN Package
APPLICATIONS
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PoE PSE Switches/Routers
PoE PSE Midspans
TYPICAL APPLICATION
10
0.1µF
3.3V
V
EE
ISOLATION
CPD
100
3.3V
100
CND
LTC4291
DPD
100
3.3V
100
DND
1µF
DGND
CAP1
2nF
2kV
0.1µF
CAP2
V
EE
V
EE
100
V
EE
100
DNA
100
V
EE
100
CNA
DPA
LTC4292
OUTnB
7
GATEnB
SENSEnB
VSSKn
0.22 F 100V
,
0.15Ω
AGNDP
VSSKn
S1B
0.15
VSSKn
V
EE
1000BASE-T
(1 OF 4 PORTS)
TX4
8
RJ45
429291
TA01a
AGNDP
1µF
100V
AGNDP
OUTnA
GATEnA
SENSEnA
AGNDP
0.22µF
100V
S1B
1
AGNDP
0.22µF
100V
S1B
TX1
2
3
S1B
0.15
VSSKn
V
EE
TX2
6
4
TX3
5
>47µF
GP0
GP1
4PVALID
(NO I
2
C
ISOLATION
REQUIRED)
AUTO
RESET
MSD
INT
SCL
SDAIN
SDAOUT
AD0
AD1
AD2
AD3
V
DD
PWRMD0
PWRMD1
CPA
Rev 0
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For more information
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1
LTC4292/LTC4291
ABSOLUTE MAXIMUM RATINGS
(Notes 1, 4)
(Note 1)
LTC4292
Supply Voltages
AGNDP – V
EE
......................................... –0.3V to 80V
VSSK12, VSSK34 (Note 7) ... V
EE
– 0.3V to V
EE
+ 0.3V
Digital Pins
PWRMD0, PWRMD1 ........ V
EE
– 0.3V to CAP2 + 0.3V
Analog Pins
SENSEnM, GATEnM, OUTnM V
EE
– 0.3V to V
EE
+ 80V
CAP2 (Note 13) ...................... V
EE
– 0.3V to V
EE
+ 5V
CPA, CNA, DPA, DNA ..............V
EE
– 0.3V to V
EE
+ 0.3
Operating Ambient Temperature Range
LTC4292I .............................................–40°C to 85°C
Junction Temperature (Note 2) ............................ 125°C
Storage Temperature Range .................. –65°C to 150°C
LTC4291
Supply Voltages
V
DD
– DGND ......................................... –0.3V to 3.6V
Digital Pins
SCL, SDAIN, SDAOUT,
INT, RESET, MSD,
ADn, AUTO,
4PVALID,
GPn .................DGND – 0.3V to V
DD
+ 0.3V
Analog Pins
CAP1 (Note 13) ...........................–0.3V to DGND + 2V
CPD, CND, DPD, DND ......DGND – 0.3V to V
DD
+ 0.3V
Operating Ambient Temperature Range
LTC4291I .............................................–40°C to 85°C
Junction Temperature (Note 2) ............................ 125°C
Storage Temperature Range .................. –65°C to 150°C
PIN CONFIGURATION
LTC4292
CNA
CPA
V
EE
TOP VIEW
DNA
DPA
V
EE
V
EE
NC
NC
NC
LTC4291
TOP VIEW
CAP1
18 SCL
17 SDAIN
25
DGND
16 SDAOUT
15
INT
14
RESET
13 DNC
7
NC
8
CPD
9 10 11 12
CND
DPD
DND
V
DD
MSD
GP0
GP1
V
DD
30 GATE4B
29 OUT4B
28 GATE4A
27 OUT4A
41
V
EE
26 VSSK34
25 AGNDP
24 GATE3B
23 OUT3B
22 GATE3A
21 OUT3A
11 12 13 14 15 16 17 18 19 20
PWRMD0
SENSE1A
SENSE1B
SENSE2A
SENSE2B
SENSE3A
SENSE3B
SENSE4A
SENSE4B
PWRMD1
AD0 1
AD1 2
AD2 3
AD3 4
DGND 5
4PVALID
6
AUTO
40 39 38 37 36 35 34 33 32 31
GATE1A 1
OUT1A 2
GATE1B 3
OUT1B 4
VSSK12 5
CAP2 6
GATE2A 7
OUT2A 8
GATE2B 9
OUT2B 10
24 23 22 21 20 19
UJ PACKAGE
40-LEAD (6mm
×
6mm) PLASTIC QFN
T
JMAX
= 125°C,
θ
JC
= 2°C/W,
θ
JA
= 33°C/W
EXPOSED PAD (PIN 41) IS V
EE
, MUST BE SOLDERED TO PCB
UF PACKAGE
24-LEAD (4mm
×
4mm) PLASTIC QFN
T
JMAX
= 125°C,
θ
JC
= 4°C/W,
θ
JA
= 47°C/W
EXPOSED PAD (PIN 25) IS DGND, MUST BE SOLDERED TO PCB
Rev 0
2
For more information
www.analog.com
LTC4292/LTC4291
ORDER INFORMATION
LEAD FREE FINISH
LTC4291IUF#PBF
LTC4292IUJ#PBF
TAPE AND REEL
LTC4291IUF#TRPBF
LTC4292IUJ#TRPBF
http://www.linear.com/product/LTC4292#orderinfo
PART MARKING
4291
LTC4292UJ
PACKAGE DESCRIPTION
24-Lead (4mm × 4mm) Plastic QFN
40-Lead (6mm × 6mm) Plastic QFN
TEMPERATURE RANGE
–40°C to 85°C
–40°C to 85°C
Consult ADI Marketing for parts specified with wider operating temperature ranges.
For more information on lead free part marking, go to:
http://www.linear.com/leadfree/
For more information on tape and reel specifications, go to:
http://www.linear.com/tapeandreel/.
Some packages are available in 500 unit reels through
designated sales channels with #TRMPBF suffix.
Rev 0
For more information
www.analog.com
3
LTC4292/LTC4291
TYPICAL APPLICATION
Figure 34. IEEE 802.3bt Type 3 or Type 4 PSE, Alternative A (MDI-X) and Alternative B(S), 1000BASE-T, 1 of 4 Ports Shown
QnA, QnB: PSMN040-100MSE
D1: SMCJ58A
D2: SMAJ58A
0.1µF
3.3V
V
EE
10
D1
>47µF
D2
AGNDP
1µF
100V
1
AGNDP
0.22µF
100V
S1B
TX1
2
3
S1B
VSSKn
AGNDP
LTC4292
OUTnB
GATEnB
SENSEnB
VSSKn
0.22 F 100V
,
0.15Ω
AGNDP
VSSKn
QnB
0.15
VSSKn
7
S1B
V
EE
1000BASE-T
(1 OF 4 PORTS)
TX4
8
RJ45
429291
F34
GP0
GP1
4PVALID
(NO I
2
C
ISOLATION
REQUIRED)
AUTO
RESET
MSD
INT
SCL
SDAIN
SDAOUT
AD0
AD1
AD2
AD3
V
DD
ISOLATION
PWRMD0
PWRMD1
AGNDP
OUTnA
GATEnA
SENSEnA
CPD
100
3.3V
100
CND
LTC4291
DPD
100
3.3V
100
DND
1µF
DGND
CAP1
2nF
2kV
0.1µF
100
V
EE
100
100
V
EE
100
CPA
QnA
0.15
TX2
V
EE
6
4
TX3
CNA
DPA
0.22µF
100V
S1B
5
DNA
CAP2
V
EE
V
EE
RELATED PARTS
PART NUMBER
LT4294
LT4295
DESCRIPTION
LTPoE++/PoE+/PoE PD Controller
IEEE 802.3bt PD with Forward/Flyback
Switching Regulator Controller
IEEE 802.3af PD Interface Controller
Single IEEE 802.3af PSE Controller
IEEE 802.3at PD Interface Controller
Quad IEEE 802.3at PoE PSE Controller
IEEE 802.3af PD Interface with Integrated
Switching Regulator
IEEE 802.3at PD Interface with Integrated
Flyback Switching Regulator
COMMENTS
External Switch, IEEE 802.3bt Support Configurable Class
External Switch, IEEE 802.3bt Support, Configurable Class, Forward or No-Opto Flyback
Operation, Frequency, PG/SG Delays, Soft-Start, and Aux Support as Low as 9V, Including
Housekeeping Buck, Slope Compensation
Internal 100V, 400mA Switch, Dual Current Limit, Programmable Class
Internal FET Switch
Internal 100V, 1A Switch, 2-Event Classification Recognition
With Programmable I
CUT
/I
LIM
, 2-Event Classification, and Port Current and Voltage Monitoring
Internal 100V, 400mA Switch, Dual Inrush Current, Programmable Class
2-Event Classification, Programmable Class, Synchronous No-Opto Flyback Controller,
50kHz to 250kHz, Aux Support
LTC4257-1
LTC4263
LTC4265
LTC4266
LTC4267
LTC4269-1
LTC4269-2
LTC4270/
LTC4271
LTC4278
LTC4279
LTC4290/
LTC4271
IEEE 802.3at PD Interface with Integrated
2-Event Classification, Programmable Class, Synchronous Forward Controller, 100kHz to
Forward Switching Regulator
500kHz, Aux Support
12-Port PoE/PoE+/LTPoE++
®
PSE Controller Transformer Isolation, Supports Type 1, Type 2 and LTPoE++ PDs
IEEE 802.3at PD Interface with Integrated
Flyback Switching Regulator
Single PoE/PoE+/LTPoE++ PSE Controller
8-Port PoE/PoE+/LTPoE++ PSE Controller
2-Event Classification, Programmable Class, Synchronous No-Opto Flyback Controller,
50kHz to 250kHz, 12V Aux Support
Supports IEEE 802.3af, IEEE 802.3at, LTPoE++ and Proprietary PDs
Transformer Isolation, Supports IEEE 802.3af, IEEE 802.3at and LTPoE++ PDs
Rev 0
4
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For more information
www.analog.com
D16832-0-4/18(0)
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