Datasheet
LT1950
16
1950fa
Figure 11. 36V to 72V Input to 3.3V at 20A Synchronous Forward Converter
COMP
FB
R
OSC
SYNC
SLOPE
V
REF
SHDN
GND
V
SEC
V
IN
BOOST
PGND
GATE
V
IN2
I
SENSE
BLANK
LT1950
1
2
3
4
5
6
7
8
16
15
14
13
12
11
10
9
V
DD
CG
PGND
GND
OPTO
V
COMP
MARG
V
FB
=1.233V
FG
SYNC
V
AUX
I
COMP
+I
SNS
–I
SNS
P
WT
OK
OVP
LTC1698
1
2
3
4
5
6
7
8
16
15
14
13
12
11
10
9
R4, 18k
R17, 210k
R1
4.7k
C1
0.1µF
C3
10nF
+V
IN
+V
IN
+V
IN
–V
IN
COMP
UV
C
U1
1µF
R18
27k
C
S
10V
BIAS
10V
BIAS
10V
BIAS
COMP
U4
HCPL-M453
0.1µF
C6
4.7µF
D3
BAT760
R2
4.7k
100k
100k
R3
4.7k
UV
10V
BIAS
Q4
BC847BF
6
5
4
1
2
3
SYNC
FG
CG
7V
BIAS
+V
01
R14
1.2k
R16
2.8k
R15
4.7k
C9, 33nF
1µF
X5R
R13
270Ω
0.1µF
R9
470k
8
7
2
1
6
5
4
3
U2A
LTC1693-1
U2B
LTC1693-1
T1
STG-0313W
Q2
Si7380
2×
Q1
Si4490
FG
Q3
Si7380
2×
CG
L1
C.PI-1365-1R2
C
01
100µF
X5R
4×
+V
01
3.3V
20A
SYNC
220pF
560Ω
T2
R7
255Ω
D1
BAS516
C
S
R
S
0.015Ω
C4
1000pF
47Ω
D2
BAT760
C
IN
2.2µF
100V
X5R
36V
TO 72V
INPUT
R6
18k
R5
470k
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