LT4276
26
4276fa
For more information www.linear.com/LT4276
LINEAR TECHNOLOGY CORPORATION 2015
LT 1215 REV A • PRINTED IN USA
Linear Technology Corporation
1630 McCarthy Blvd., Milpitas, CA 95035-7417
(408) 432-1900
●
FAX: (408) 434-0507
●
www.linear.com/LT4276
relaTeD parTs
Typical applicaTion
PART NUMBER DESCRIPTION COMMENTS
LTC4267/
LTC4267-1/
LTC4267-3
IEEE 802.3af PD Interface With Integrated
Switching Regulator
Internal 100V, 400mA Switch, Programmable Class, 200/300kHz Constant Frequency
PWM
LTC4269-1 IEEE 802.3af PD Interface With Integrated
Flyback Switching Regulator
2-Event Classification, Programmable Class, Synchronous No-Opto Flyback Controller,
50kHz to 250kHz, Aux Support
LTC4269-2 IEEE 802.3af PD Interface With Integrated
Forward Switching Regulator
2-Event Classification, Programmable Class, Synchronous Forward Controller, 100kHz to
500kHz, Aux Support
LT4275A/B/C LTPoE
++
/PoE
+
/PoE PD Controller External Switch, LTPoE
++
Support
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
LT4320/LT4320-1 Ideal Diode Bridge Controller 9V-72V ,DC to 600Hz Input. Controls 4-NMOSFETs, Voltage Rectification without Diode Drops
LT4321 PoE Ideal Diode Bridge Controller Controls 8-NMOSFETs for IEEE-required PD Voltage Rectification without Diode Drops
25.5W (Type 2) PoE
+
Power Supply in Flyback Mode with 12V, 1.9A Output
Efficiency vs Load Current Output Regulation vs Load Current
+
V
OUT
12V AT 1.9A
–V
OUT
Q1
C5: 22µF, 16V, PANASONIC 16SVP22M
C7: 2.2µF, 100V, MURATA GRM32ER72A225KA35
T1: WÜRTH, 750310742 OR PCA EPC3410G
Q1-Q9: PSMN075-100MSE
T2: PCA EPA4271GE OR PULSE PE-68386NL
L2
10µH
L1
180nH
L4
100µH
10µF
100V
10nF
100V
3.3k
24V
8.2Ω
10µF
10V
HSSRC
SWVCC FB31
PG
SG
T2P
ITHBROSCSFSTFFSDLYRCLASSGND
VPORT
LT4276B
HSGATE
ISEN
+
ISEN
–
V
IN
V
CC
C7
2.2µF
BSZ520N15NS3G
BAT54WS
BAT46WS
MOC207M
V
OUT
TO MICROPROCESSOR
4276 TA11
FDMC86160
MMBT3906 MMBT3904
T1
470pF
1µF
6.49k
2.00kΩ
150V
1/4W
13Ω
1/4W
40mΩ
1/4W
15Ω
100Ω
1µF
220pF
0.1µF
107k5.23k35.7Ω
PTVS58VP1UTP
3.3nF
2.2nF
2KV
26.1k
10k
2.2nF
C2
10µF
C5
22µF
47pF
630V
47nF
100V
2.2nF
2kV
BG36
LT4321
BG12TG12 TG36
TG78TG45BG45 BG78
OUTP
OUTN
EN
EN
IN12
T2
Q2 Q3
Q4 Q5
Q6 Q7
Q8 Q9
1
DATA
PAIRS
SPARE
PAIRS
2
3
6
4
5
7
8
IN36
IN45
IN78
47nF
100V
L1: COILCRAFT, DO1813P-181HC
L2: COILCRAFT, DO1608C-103
L4: COILCRAFT, DO1608C-104
C2: 10µF, 16V, MURATA GRM31CR61C106KA88
BAV19WS
10k
47k
20Ω
••
•
•
•
FMMT723
LOAD CURRENT (A)
0.2
70
EFFICIENCY (%)
90
88
86
84
82
80
78
76
74
72
92
1.2 1.6 1.81.4 2.01.00.80.60.4
4276 TA11a
VPORT = 57V
VPORT = 50V
VPORT = 42.5V
LOAD CURRENT (A)
0.2
11.5
V
OUT
(V)
12.3
12.2
12.1
12.0
11.9
11.8
11.7
11.6
12.5
12.4
1.2 1.6 1.81.4 2.01.00.80.60.4
4276 TA11b
VPORT = 57V
VPORT = 50V
VPORT = 42.5V
