ltc1751 Linear Technology Corporation, ltc1751 Datasheet - Page 11

• Manufacturer Part Number: ltc1751
• Description: Micropower, Regulated Charge Pump Dc/dc Converters
• Manufacturer: Linear Technology Corporation

TYPICAL APPLICATIO S
USB Port to Regulated 5V Power Supply with Soft-Start
10 F
1
V
IN
= 5V
10 F
1nF
3
7
8
V
SHDN
SS
IN
C
LTC1751-5
–
5
Low Power Battery Backup with Auto Switchover and No Reverse Current
GND
1 F
475k
1.43M
PGOOD
4
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.
IN4148
V
C
OUT
+
6
U
2
1
75k
OFF
10 F
V
IN
10 F
BATTERY
ON
1751 TA04
3-CELL
NiCd
Boosted Constant Current Source
100k
3
7
8
V
PGOOD
V
SHDN
SS
OUT
IN
C
–
LTC1751
+
5
+
+
= 5V
330pF
GND
10 F
1 F
4
V
C
10k
1M
OUT
+
6
FB
LTC1751/LTC1751-3.3/LTC1751-5
6
3
8
4
3
5
2
1
BAT54C
HYST
V
SS
IN
C
LTC1751-5
–
10 F
5
+
–
GND
NiCd OR
1 F
2-CELL
LTC1540
LOAD
2-Cell NiCd or NiMH to 3.3V with Low Standby Current
NiMH
PGOOD
4
7
2
SHDN
V
C
OUT
+
R
6
X
1
I
V
L
OUT
= 1.205V
2
1
7
8
OFF
+
+
1751 TA07
R
X
2 V
ON
IN
10 F
Si4435DY
10 F
1nF
3
7
8
V
SHDN
SS
IN
LTC1751-3.3
C
–
100k
5
1751 TA05
GND
HIGH = BACKUP MODE
1 F
V
I
OUT
OUT
PGOOD
4
V
C
OUT
= 5V
+
6
100mA
2
1
10 F
1751 TA06
100k
3.3V
40mA
PGOOD
11