ILC1232 Datasheet, PDF (1/5 Pages) Impala Linear Corporation – mP Supervisory Circuit

Impala Linear Corporation
ILC1232
mP Supervisory Circuit
General Description
The ILC1232 is a multifunction circuit which monitors micro-
processor activity, external reset and power supplies in
microprocessor based systems. The circuit functions
include a watchdog timer, power supply monitor, micro-
processor reset, and manual pushbutton reset input.
The power supply line is monitored with a comparator and
an internal voltage reference. RST is forced low when an
out-of-tolerance condition exists and remains asserted for
at least 250ms after V_CC rises above the threshold voltage
(4.5V or 4.75V). The RST pin will remain logic low with V_CC
as low as 1.4V.
The Watchdog input (ST) monitors mP activity and will
assert RST if no mP activity has occurred within the watch-
dog timeout period. The watchdog timeout period is selec-
table with nominal periods of 150, 600, or 1200 milliseconds.
Features
• Power OK/Reset Time Delay, 250ms min.
• Watchdog Timer, 150ms, 600ms, or 1.2s typical
• Precision Supply Voltage Monitor, Select Between 5% or
10% of Supply Voltage
• 18µA Supply Current
• Debounced External Reset Input
• 8-Pin SO Package
Applications
• Computers
• Controllers
• Critical Microprocessor Power Monitoring
• Intelligent Instruments
• Portable Equipment
Ordering Information
Part
ILC1232N
ILC1232M
Package
8-Lead PDIP
8-Lead SOIC
Temp. Range
-40°C to +85°C
-40°C to +85°C
Typical Circuit
VCC
VCC
TD
ILC1232
PBRST
TOL
ST
RST
GND
VCC
µP
I/O
RESET
Pin Package Configurations
Top View
PBRST 1
TD 2
TOL 3
GND ⁴
ILC1232
8 VCC
7 _ST
6 _RST
5 RST
ETC1232N - 8 Lead Plastic DIP Package
ETC1232M - 8 Lead Plastic SOIC Package
Impala Linear Corporation
ILC1232 1.1
[phone] www.impalalinear.com
Sept 1999
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