TPS3617-50 Datasheet, PDF (1/16 Pages) Texas Instruments – BATTERY-BACKUP SUPERVISOR FOR RAM RETENTION

TPS3617Ć50
BATTERYĆBACKUP SUPERVISOR
FOR RAM RETENTION
SLVS339B – DECEMBER 2000 – REVISED DECEMBER 2002
D Supply Current of 40 µA (Max)
D Battery Supply Current of 100 nA (Max)
D Precision 5-V Supply Voltage Monitor,
Other Voltage Options on Request
D Backup-Battery Voltage Can Exceed V_DD
D Watchdog Timer With 800-ms Time-Out
D Power-On Reset Generator With Fixed
100-ms Reset Delay Time
D Voltage Monitor for Power-Fail or
Low-Battery Monitoring
D Battery Freshness Seal
D 8-Pin MSOP Package
D Temperature Range . . . –40°C to 85°C
typical applications
D Fax Machines
D Set-Top Boxes
D Advanced Voice Mail Systems
D Portable Battery Powered Equipment
D Computer Equipment
D Advanced Modems
D Automotive Systems
D Portable Long-Time Monitoring Equipment
D Point of Sale Equipment
MSOP (DGK) Package
(TOP VIEW)
description
VOUT
VDD
The TPS3617-50 supervisory circuit monitors and
GND
PFI
controls processor activity by providing backup-
battery switchover for data retention of CMOS
RAM.
VBAT
RESET
WDI
PFO
ACTUAL SIZE
3,05 mm x 4,98 mm
During power on, RESET is asserted when the supply voltage (V_DD or V_BAT) becomes higher than 1.1 V.
Thereafter, the supply voltage supervisor monitors V_DD and keeps RESET output active as long as V_DD remains
below the threshold voltage (V_IT). An internal timer delays the return of the output to the inactive state (high)
to ensure proper system reset. The delay time starts after V_DD has risen above the threshold voltage (V_IT).
typical operating circuit
Power
Supply
0.1 µF
External
Source
Backup
Rx
VDD
VBAT
TPS3617
Battery
PFI
Ry
RESET
WDI
PFO
uC
RESET
I/O
I/O
VOUT
GND
Switchover
Capacitor
0.1 µF
VCC
GND
Please be aware that an important notice concerning availability, standard warranty, and use in critical applications of
Texas Instruments semiconductor products and disclaimers thereto appears at the end of this data sheet.
PRODUCTION DATA information is current as of publication date.
Products conform to specifications per the terms of Texas Instruments
standard warranty. Production processing does not necessarily include
testing of all parameters.
• POST OFFICE BOX 655303 DALLAS, TEXAS 75265
Copyright  2002, Texas Instruments Incorporated
1