LTC4265
22
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For more information www.linear.com/LTC4265
Linear Technology Corporation
1630 McCarthy Blvd., Milpitas, CA 95035-7417
(408) 432-1900
●
FAX: (408) 434-0507
●
www.linear.com
LINEAR TECHNOLOGY CORPORATION 2008
LT 0714 REV B • PRINTED IN USA
relaTeD parTs
PART NUMBER DESCRIPTION COMMENTS
LTC4257-1 IEEE 802.3af PD Interface Controller Internal 100V, 400mA Switch, Dual Current Limit, Programmable Class
LTC4263 Single IEEE 802.3af PSE Controller Internal FET Switch
LTC4266 Quad IEEE PoE/PoE
+
/LTPoE
++
PSE Controller With Programmable I
CUT
/I
LIM
, 2-Event Classification, Provides Up to 90W
LTC4267-3 IEEE 802.3af PD Interface with Integrated
Switching Regulator
Internal 100V, 400mA Switch, Programmable Class, 300kHz Constant
Frequency PWM
LTC4269 IEEE 802.3af PD Interface with Integrated
Switching Regulator
2-Event Classification, Programmable Class, Synchronous Flyback/Forward
Controller, Aux Support
LTC4270/LTC4271 12-Port PoE/PoE
+
/LTPoE
++
PSE Controller Transformer Isolation, Supports IEEE 802.3af, IEEE 802.3at and LTPoE
++
PDs
LTC4274 Single IEEE PoE/PoE
+
/LTPoE
++
PSE Controller With Programmable I
CUT
/I
LIM
, 2-Event Classification, Provides Up to 90W
LT4275 PoE/PoE
+
/LTPoE
++
PD Interface Controller External MOSFET, Up to 90W, –40°C to 125°C Operation
LTC4278 IEEE 802.3af PD Interface with Integrated Flyback
Switching Regulator
2-Event Classification, Programmable Class, Synchronous No-Opto Flyback
Controller, 50kHz to 250kHz, 12V Aux Support
LTC4290/LTC4271 8-Port PoE/PoE
+
/LTPoE
++
PSE Controller Transformer Isolation, Supports IEEE 802.3af, IEEE 802.3at and LTPoE
++
PDs
•
•
FDS2582
10.0k
33k
10µF
16V
237k
30.9Ω
B1100
82k 158k
332k
22.1k
1.2k
4.7nF
100pF
10µF
100V
0.1µF
100V
SMAJ58A
B1100 × 8 PLCS
2.2µF
100V
PA2431NL
4265 TA03a
PGND GND
SD_VSEC
OC
ISENSE
COMP
FB
VREF
SS_MAXDC
OUT
BLANK DELAY ROSC
LT1952
V
IN
V
CC
S
OUT
GND
R
CLASS
SHDN
LTC4265
T2PSE
V
IN
V
OUT
10µH
–54V
FROM
DATA
PAIR
–54V
FROM
SPARE
PAIR
•
5V
5A
220µF
6.3V
PSLVOJ227M(12)
FDS8880FDS8880
+
GND
GND 5V
2.2nF
2kV
BAS516
BAS516
10k
133Ω
0.1µF
1mH
DO1608C-105
IRF6217
4.7nF
250V
50mΩ
5.1Ω
158k
0.22µF
5.1Ω
1nF
5.1Ω
1nF
6.8µH
PG0702.682
2k
PS2801-1-L
PS22801-1-L
BC857BF
TLV431A
1.5k
33k 22k
0.1µF
10nF
11.3k
3.65k
51k 20k
T2P
(TO MICRO
CONTROLLER)
BAS516
BAS516
18V
PDZ18B
V
CC
PoE-Based Self-Driven Synchronous Forward Power Supply
Typical applicaTion
LOAD (A)
0.5
80
85
90
5
75
65
70
1.5 21
32.5
4 4.53.5
42V
50V
57V
Efficiency vs Load Current
