SC1408 Semtech Corporation, SC1408 Datasheet - Page 6

• Manufacturer Part Number: SC1408
• Description: LOW VOLTAGE/ BOOST DC-DC CONTROLLER
• Manufacturer: Semtech Corporation

August 22, 2000
Fig. 3: Achieving output voltages greater than 16.5V
Fig. 4: Implementing shutdown with input/output isolation
© 2000 SEMTECH CORP.
SHORT = RUN
OPEN = SHUTDOWN
3.3V IN
C2
100uF
3.3V IN
+
D3
12V
D4
1N4148
J1
R5
5.1k
1
2
Q2
Si2301DS
C2
100uF
0.1uF
C4
0.1uF
C5
+
R6 470
2
4
5
7
0.1uF
C4
0.1uF
C5
SC1408IS
U1
BST
SHDN
REF
GND
LOW VOLTAGE, BOOST DC-DC
CONTROLLER
L1
2
4
5
7
ISENSE
AGND
U1
SC1408IS
22uH
GATE
BST
SHDN
REF
GND
FB
L1
ISENSE
1
8
3
6
AGND
22uH
GATE
652 MITCHELL ROAD NEWBURY PARK CA 91320
FB
1
8
3
6
Q1
IRL3103S
R2
0.05Ohm
D1
B130T
Q1
IRLL3303
200k
R2
0.05Ohm
R3
D1
B130T
90k
R3
R4
10.0k
R4
10.0k
+
C3
100uF
+
25V OUT
C3
100uF
12V OUT
+
SC1408
+
C8
100uF
C8
100uF
6