Datasheet

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