TPS3617
TPS3618
www.ti.com
SLVS339C–DECEMBER 2000–REVISED NOVEMBER 2004
BATTERY-BACKUP SUPERVISOR FOR RAM RETENTION
FEATURES
DESCRIPTION
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Supply Current of 40 µA (Max)
The TPS3617 and TPS3618 are battery-backup
supervisors that monitor 5 V supplies. They provide a
battery-backup function ideal for applications that
require data retention of CMOS RAM during fault
conditions. When the voltage at VDD drops below a
preset threshold (VIT), the active low push-pull
RESET output asserts, and VOUT switches from VDD
to VBAT. When VDD rises above the trip threshold,
Battery Supply Current of 100 nA (Max)
Precision 5-V Supply Voltage Monitor, Other
Voltage Options on Request
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Backup-Battery Voltage Can Exceed VDD
Watchdog Timer With 800-ms Time-Out
Power-On Reset Generator With Fixed 100-ms
Reset Delay Time
VOUT switches immediately from VBAT to VDD
.
The RESET output remains low until the delay time
(td) expires. During power on, RESET is asserted
when the supply voltage (VDD or VBAT) goes higher
than 1.1 V.
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Voltage Monitor for Power-Fail or Low-Battery
Monitoring
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Battery Freshness Seal (TPS3617 Only)
8-Pin MSOP Package
The PFI and PFO pins are provided if additional
voltage monitoring is needed. If the voltage at PFI is
less than 1.15 V, the push-pull PFO pin will assert
low. When the voltage at PFI exceeds the threshold
voltage, PFO will go high.
Temperature Range: -40°C to 85°C
APPLICATIONS
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Fax Machines
Set-Top Boxes
Advanced Voice Mail Systems
Portable Battery Powered Equipment
Computer Equipment
Advanced Modems
Automotive Systems
Portable Long-Time Monitoring Equipment
Point-of-Sale Equipment
These devices also feature a watchdog timer pin
(WDI) that monitors processor activity and asserts
RESET if the the processor is inactive longer than the
watchdog timeout period. If the watchdog timer is not
used, the WDI pin should be left floating.
The TPS3617 and TPS3618 are available in an 8-pin
MSOP package and are characterized for operation
over a temperature range of -40°C to 85°C.
Power
Supply
TPS3617
TPS3618
Microcontroller
or
Microprocessor
MSOP (DGK) Package
Backup
Battery
0.1 µF
(TOP VIEW)
V
V
BAT
DD
V
V
V
BAT
RESET
WDI
OUT
External
Source
DD
GND
PFI
RESET
I/O
RESET
WDI
PFO
R
R
x
PFI
I/O
PFO
Switchover
Capacitor
y
ACTUAL SIZE
3,05 mm x 4,98 mm
V
OUT
V
CC
0.1 µF
GND
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 the Texas
Instruments standard warranty. Production processing does not
necessarily include testing of all parameters.
Copyright © 2000–2004, Texas Instruments Incorporated