DS1239 Datasheet, PDF (1/4 Pages) Dallas Semiconductor – MicroManager Chip

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DS1239
MicroManager Chip
FEATURES
Provides necessary control for start up and
shutdown of power supply from keyboard
Holds microprocessor in check during power
transients
Halts and restarts an out-of-control
microprocessor
Monitors push button for external override
Warns microprocessor of an impending power
failure
Converts CMOS SRAM into nonvolatile
memory
Unconditionally write-protects memory when
power supply is out of tolerance
Consumes less than 100 nA of battery current
Controls external power switch for high
current applications
Accurate 10% power supply monitoring
Optional 5% power supply monitoring
designated DS1239-5
Provides orderly shutdown in nonvolatile
microprocessor applications
Supplies necessary control for low-power
“stop mode” in battery operate hand-held
applications
Standard 16-pin DIP or space-saving 16-pin
SOIC
Optional industrial temperature range -40°C
to +85°C
PIN ASSIGNMENT
VBAT
1
16 PSO
VCCO
2
15 RST
VCC
3
14 PBRST
GND
4
PF
5
PF
6
WC/SC
7
PSI
8
13 CEI ^VBAT
VCCO
12
CEO _VCC
11 ST
GND
PF
10 NMI
PF
9
IN ^WC/SC
PSI
1 16
2 15
3 14
4 13
5 12
6 11
7 10
8
9
PSO
RST
PBRST
CEI
CEO
ST
NMI
IN
DS1239 16-Pin DIP (300-mil)
See Mech. Drawings Section
DS1239 16-Pin SOIC (300-mil)
See Mech. Drawings Section
PIN DESCRIPTION
V_BAT
V_CCO
V_CC
GND
- +3 Volt Battery Input
- Switched SRAM Supply Output
- +5 Volt Power Supply Input
- Ground
PF
- Power Fail (Active High)
PF
- Power Fail (Active Low)
WC/ SC
- Wake-Up Control (Sleep)
PSI
- Power Supply Control Input
IN
- Early Warning Input
NMI
- Non-Maskable Interrupt
ST
- Strobe Input
CEO
- Chip Enable Output
CEI
- Chip Enable Input
PBRST
- Pushbutton Reset Input
RST
- Reset Output (Active low)
PSO
- Power Supply Control Outputs
DESCRIPTION
The DS1239 MicroManager provides all the necessary functions for power supply control and
monitoring, reset control, and memory backup in microprocessor-based systems. Using the DS1239, an
AC power switch is no longer required for microprocessor-based systems. A keyboard control system for
power supply start up and shutdown is provided through the use of the Power Supply Control Input and
Output. In other respects, the DS1239 is functionally identical to a DS1236 in the NMOS mode. For a
complete description of the other DS1239 features, refer to the DS1236 data sheet. Pin-out of the
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