LTC1517-3.3
TYPICAL APPLICATION
Low Power Battery Backup Supply with Autoswitchover and No Reverse Current
MAIN
SUPPLY
5V
3 LT1521-3.3 1
1µF
2
BAT54
TRICKLE CHARGE
75k AND LTC1517-3.3
IDD
0.1µF
5
4
1 LTC1517-3.3 3
2-CELL
NiCd
3.3µF
2
1.5µF
SILICONIX
Si2301DS
3.3µF
VOUT = 3.3V,
IOUT = 300mA
(IOUT = 8mA IN
BACKUP MODE)
1.1M
3.9VTRIP
470k
7
3
+
8
4
–
5
6 LTC1540
21
LOGIC LOW = BACKUP MODE
1517-3.3 TA03
RELATED PARTS
PART NUMBER
LTC1514-X
LTC1515
LTC1516
LTC1517-5
LTC1522
DESCRIPTION
Step-Up/Step-Down Switched-Capacitor DC/DC Converter with
Low Battery Comparator
Step-Up/Step-Down Switched-Capacitor DC/DC Converter with POR
Micropower Regulated 5V Charge Pump DC/DC Converter
Micropower Regulated 5V Charge Pump in a 5-Pin SOT-23 Package
Micropower Regulated 5V Charge Pump DC/DC Converter
COMMENTS
3.3V or 5V Output up to 50mA
Fixed or Adjustable Output up to 50mA
20mA for VIN ≥ 2V, 50mA for VIN ≥ 3V
IOUT up to 20mA
Same as LTC1517-5 with Shutdown
8
Linear Technology Corporation
1630 McCarthy Blvd., Milpitas, CA 95035-7417
(408)432-1900 q FAX:(408)434-0507 q www.linear-tech.com
15173fs, sn15173 LT/TP 0998 4K • PRINTED IN USA
© LINEAR TECHNOLOGY CORPORATION 1998