Datasheet

7
LTC1157
Information furnished by Linear Technology Corporation is believed to be accurate and reliable.
However, no responsibility is assumed for its use. Linear Technology Corporation makes no represen-
tation that the interconnection of its circuits as described herein will not infringe on existing patent rights.
TYPICAL APPLICATIO S
U
Ultra Low Voltage Drop Battery Switch with Reverse Battery
Protection, Ramped Output and 3µA Standby Current
Generating 3.3V and 5V from a 3.3V or 5V Source
(Automatic Switching)
1
2
3
4
7,8
2
5,6
4
3
1
5,6
7,8
5V/150mA
3.3V/150mA
Si9956DY
Si9956DY
+
MBRS12OT3
+
V
IN
GND
FB
SW2
SET
AO
LT1111
I
LIM
SW1
2N7002
*20µH
120µF/10V
*20µH
100µF
6V
140k
1%
174k
1%
105k
1%
ZTX869-M1
47Ω
39Ω
1M
123
4
8
5
6
7
430k
+
180µF
6V
2N7002
1M 1M
3.3V OR 5V
V
S
GND
G2
G1
IN2
IN1
LTC1157
*CTX20-3 COILTRONICS
LTC1157 • TA07
V
S
GND
G2
G1
IN2
IN1
LTC1157
CONTROL
LOGIC
OR µP
0.47µF
LTC1157 • TA06
+
3 TO 4
CELL 
BATTERY 
PACK
300Ω
0.1µF
1k100k
1
24
3
5,6,7,8
Si9956DY
+
100µF
6.3V
SWITCHED (RAMPED)
BATTERY