LT1425 Linear Technology, LT1425 Datasheet - Page 18

• Manufacturer Part Number: LT1425
• Description: Isolated Flyback Switching Regulator
• Manufacturer: Linear Technology

LT1425
TYPICAL APPLICATIONS
18
–36V TO
INPUT
5V TO
INPUT
COM
–72V
COM
15V
+
22 F
35V
3.3 F
0.1 F
0.1 F
1000pF
18.4k
3.01k
0.1%
1%
+
1N755
2N3906
R1
24k
7.5V
C1
27 F
35V
D1
Q2
U
1
2
3
4
5
6
7
8
R2
18
100k
GND
NC
R
V
R
SYNC
SGND
GND
C
FB
REF
BAV21
1000pF
30.1k
3.16k
LT1425
1%
1%
Q3
2N3904
2.4k
– 48V to 5V Isolated Telecom Supply
R
R
5k
OCOMP
CCOMP
SHDN
PGND
GND
GND
BAV21
V
V
SW
15V Isolated Power Supply
IN
1
2
3
4
5
6
7
8
16
15
14
13
12
11
10
9
GND
NC
R
V
R
SYNC
SGND
GND
10k
C
FB
REF
LT1425
PIN 7 TO 8, 6 TURNS QUADFILAR 29AWG
PIN 3 TO 4, 15 TURNS BIFILAR 31AWG
PIN 5 TO 6, 15 TURNS BIFILAR 33AWG
PIN 1 TO 2, 15 TURNS BIFILAR 31AWG
R
0.1 F
R
PIN 3 TO 4, 7 TURNS BIFILAR 34AWG
PIN 1 TO 2, 7 TURNS BIFILAR 34AWG
0.1 F
OCOMP
CCOMP
MBR0540LT1
SHDN
PGND
GND
GND
V
V
SW
IN
PIN 7 TO 8, 28 TURNS 40AWG
PIN 5 TO 6, 28 TURNS 40AWG
1N759
7.32k
1%
16
15
14
13
12
11
10
9
D2
7.5V
1N755
1425 TA06
T1
5
6
MUR120
10
75
220pF
510
150pF
1
4
2
3
*PHILIPS EFD-15-3F3 CORE
*PHILIPS EFD-15-3F3 CORE
T1*
0.12 INCH MARGIN TAPE
1
2
3
4
GAP FOR PRIMARY
GAP FOR PRIMARY
Q1
IRF620
8
7
6
5
T1*
L = 100 H
L = 40 H
8
7
MBRS1100T3
MBRS1100T3
150 F
MBR745
1 F
6.3V
130
18
+
330pF
+
+
15 F
35V
15 F
35V
470pF
+
1 LAYER 2 MIL
POLYESTER FILM
2 LAYERS 2 MIL
POLYESTER FILM
3 LAYERS 2 MIL
POLYESTER FILM
150 F
6.3V
1425 TA04
3k
3k
50
1W
15V
60mA
OUT
COM
–15V
60mA
5V
2A
OUT
COM