DS1231-35+ Dallas Semiconductor, DS1231-35+ Datasheet - Page 6

• Manufacturer Part Number: DS1231-35+
• Description: uP Supervisor, 4.75 or 4.5 V Monitor, DIP8
• Manufacturer: Dallas Semiconductor
• Type: Monitor Chipr

Specifications of DS1231-35+

• Current, Output: 2 mA (High), 3 mA (Low)
• Current, Supply: 0.5 mA
• Package Type: PDIP
• Temperature, Operating, Range: 0 to +70 °C
• Time, Fall: 300 μs
• Voltage, Input: 5 V
• Voltage, Output, High: 4.9 V
• Voltage, Output, Low: 0.4 V
• Voltage, Supply: 5 V
• Lead Free Status / Rohs Status: RoHS Compliant part Electrostatic Device

FEATURES
DESCRIPTION
The DS1231 Power Monitor Chip uses a precise tem-
perature-compensated reference circuit which provides
an orderly shutdown and an automatic restart of a pro-
cessor-based system. A signal warning of an impending
power failure is generated well before regulated DC
voltages go out of specification by monitoring high volt-
age inputs to the power supply regulators. If line isola-
tion is required a UL-approved opto-isolator can be di-
rectly interfaced to the DS1231. The time for processor
Warns processor of an impending power failure
Provides time for an orderly shutdown
Prevents processor from destroying nonvolatile
memory during power transients
Automatically restarts processor after power is
restored
Suitable for linear or switching power supplies
Adjusts to hold time of the power supply
Supplies necessary signals for processor interface
Accurate 5% or 10% V
Replaces power-up reset circuitry
No external capacitors required
Optional 16-pin SOIC surface mount package
CC
monitoring
PIN ASSIGNMENT
PIN DESCRIPTION
IN
MODE
TOL
GND
RST
RST
NMI
V
NC
shutdown is directly proportional to the available
hold-up time of the power supply. Just before the
hold-up time is exhausted, the Power Monitor uncondi-
tionally halts the processor to prevent spurious cycles
by enabling Reset as V
10 percent threshold. When power returns, the proces-
sor is held inactive until well after power conditions have
stabilized, safeguarding any nonvolatile memory in the
system from inadvertent data changes.
CC
MODE
MODE
GND
TOL
NC
NC
NC
GND
NC
IN
TOL
– Input
– Selects input pin characteristics
– Selects 5% or 10% V
– Ground
– Reset (Active High)
– Reset (Active Low, open drain)
– Non–Maskable Interrupt
– +5V Supply
– No Connections
IN
See Mech. Drawings
Power Monitor Chip
DS1231S 16–Pin SOIC
DS1231 8–Pin DIP
See Mech. Drawings
1
2
3
4
(300 MIL)
Section
1
2
3
4
5
6
7
8
CC
(300 MIL)
Section
falls below a selectable 5 or
14
13
12
11
16
15
10
9
8
7
6
5
VCC
NMI
RST
RST
RST
NC
VCC
NC
NMI
NC
RST
NC
DS1231/S
CC
detect
022698 1/9
DS1231/S