LT4276
21
4276fa
For more information www.linear.com/LT4276
Typical applicaTions
25.5W (Type 2) PoE
+
and 9V-57V Auxiliary Input 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
L1: COILCRAFT, DO1813P-561ML
L2: WÜRTH, 7443330820
L3: MURATA, LQM31PN2R2M00L
L4: COILCRAFT, DO1813H-223
C2, C3: 10µF, 16V, MURATA GRM31CR61C106KA88
C5: 33µF, 20V, KEMET, T494V336M020AS
C7, C8: 3.3µF, 100V, TDK C3225X7S2A335M
T1: PCA EPC3601G OR WÜRTH 750315422
Q1: PSMN075-100MSE
Q1-Q9:PSMN075-100MSE
T2: PCA EPA4271GE OR PULSE PE-68386NL
L2
8.2µH
L3
2.2µH
1µF
680µF
63V
L1
560nH
L4
22µH
10µF
100V
68nF
100V
0.1µF
3.3k
158k
931k
24V
47nF
100V
8.2Ω
22µF
10V
PMEG10010ELR
HSSRC
SWVCC FB31
PG
SG
T2P
ITHBROSCSFSTFFSDLYRCLASSGND
VPORT
AUX
LT4276B
HSGATE
ISEN
+
ISEN
–
V
IN
V
CC
C7, C8
3.3µF
FDMC86160
BAT54WS
BAT46WS
TO MICROPROCESSOR
4276 TA08
BSZ900NF20NS3
CMLT7820G CMLT3820G
T1
220pF
1µF
4.75k
2.00k
62Ω
1/4W
82Ω||82Ω
1/4W
15mΩ
1/4W
15Ω
100Ω
1µF
220pF
0.1µF
107k9.31k
RLDCMP
51k35.7Ω
PTVS58VP1UTP
4.7nF
2.2nF
2KV
43k
10k
2.2nF
C2, C3
10µF
||
10µF
C5
33µF
100pF
100V
47nF
100V
2.2nF
2kV
OPTO
BG36
LT4321
BG12TG12 TG36
TG78TG45BG45 BG78
OUTP
OUTN
EN
EN
IN12
TG2
TG1
OUTP
OUTN
IN1
IN2
BG2
BG1
T2
Q2 Q3
Q4 Q5
Q6 Q7
Q8 Q9
1
DATA
PAIRS
SPARE
PAIRS
2
3
6
4
5
7
8
IN36
IN45
IN78
LT4320
BSZ110N06NS3 x4
MMSD4148 x3
V
AUX
9V TO 57VDC
OR 24VAC
1Ω
••
•
•
•
+
FMMT723
LOAD CURRENT (A)
0.2
70
EFFICIENCY (%)
92
90
88
86
84
82
80
78
76
74
72
94
1.2 1.6 1.81.4 2.01.00.80.60.4
4276 TA08a
V
AUX
= 57V
V
AUX
= 42.5V
V
AUX
= 24V
V
AUX
= 9V
LOAD CURRENT (A)
0.2
11.5
V
OUT
(V)
12.4
12.3
12.2
12.1
12.0
11.9
11.8
11.7
11.6
12.5
1.2 1.6 1.81.4 2.01.00.80.60.4
4276 TA08b
V
AUX
= 57V
V
AUX
= 42.5V
V
AUX
= 24V
V
AUX
= 9V
