DS1314
3V Nonvolatile Controller with Lithium
Battery Monitor
www.dalsemi.com
FEATURES
Converts CMOS SRAM into nonvolatile
memory
Unconditionally write-protects SRAM when
V
CC
is out of tolerance
Automatically switches to battery backup
supply when V
CC
power failure occurs
Monitors voltage of a lithium cell and
provides advanced warning of impending
battery failure
Signals low-battery condition on active low
Battery Warning output signal
Automatic V
CC
power-fail detection for 3.0V
or 3.3V power supplies
Space-saving 8-pin DIP and SOIC packages
Optional 16-pin SOIC and 20-pin TSSOP
versions reset processor when power failure
occurs and hold processor in reset during
system power-up
Industrial temperature range of -40掳C to
+85掳C
V
CCO
V
BAT
TOL
GND
PIN ASSIGNMENT
1
2
3
4
8
7
6
5
V
CCI
BW
CEO
CEI
V
CCO
V
BAT
TOL
GND
1
2
3
4
8
7
6
5
V
CCI
BW
CEO
CEI
DS1314 8-Pin DIP
(300-mil)
NC
V
CCO
NC
V
BAT
NC
TOL
NC
GND
1
2
3
4
5
6
7
8
16
15
14
13
12
11
10
9
NC
V
CCI
RST
NC
BW
CEO
NC
CEI
DS1314S-2 8-Pin SOIC
(150-mil)
NC
V
CCO
NC
V
BAT
NC
NC
TOL
NC
NC
GND
1
2
3
4
5
6
7
8
9
10
20
19
18
17
16
15
14
13
12
11
NC
V
CCI
RST
NC
NC
BW
NC
CEO
NC
CEI
DS1314S 16-Pin SOIC
(300-mil)
DS1314E 20-Pin TSSOP
PIN DESCRIPTION
V
CCI
V
CCO
V
BAT
CEI
CEO
TOL
BW
RST
GND
NC
- Power Supply Input
- SRAM Power Supply Output
- Backup Battery Input
- Chip Enable Input
- Chip Enable Output
- V
CC
Tolerance Select
- Battery Warning Output
(Open Drain)
- Reset Output (Open Drain)
- Ground
- No Connection
DESCRIPTION
The DS1314 Nonvolatile Controller with Battery Monitor is a CMOS circuit which solves the application
problem of converting CMOS RAM into nonvolatile memory. Incoming power is monitored for an out-
of-tolerance condition. When such a condition is detected, chip enable is inhibited to accomplish write
protection and the battery is switched on to supply the RAM with uninterrupted power. Special circuitry
uses a low-leakage CMOS process which affords precise voltage detection at extremely low battery
consumption.
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