Impala Linear Corporation
ILC1832
Preliminary
µP Supervisory Circuit
General Description
The ILC1832 is a multifunction circuit which monitors micro-
processor activity, external reset and power supplies in
microprocessor based systems. Ths 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
(2.55V or 2.88V). The RST pin will remain logic low with
V
CC
as low as 1.4V.
The Watchdog input (ST) monitors µP activity and will assert
RST if no µP activity has occurred within the watchdog time-
out period. The watchdog timeout period is selectable with
nominal periods of 150, 600, or 1200 milliseconds.
•
•
•
•
•
•
Features
Power OK/Reset Time Delay, 250ms min.
Watchdog Timer, 150 ms, 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 SOIC or DIP Package
Applications
•
•
•
•
•
Computers
Controllers
Critical Microprocessor Power Monitoring
Intelligent Instruments
Portable Equipment
Ordering Information
Part
ILC1832N
ILC1832M
Package
8-Lead PDIP
8-Lead SOIC
Temp. Range
-40°C to +85°C
-40°C to +85°C
Typical Circuit
V
CC
Pin-Package Configurations
Top View
PBRST
1
8
7
V
CC
TD
V
CC
µ
P
V
CC
ST
RST
RST
ILC1832
PBRST
ST
RST
TOL
GND
I/O
RESET
TD
2
ILC1832
TOL
3
6
5
GND
4
ETC1832N - 8 Lead Plastic DIP Package
ETC1832M - 8 Lead Plastic SOIC Package
Impala Linear Corporation
ILC1832 1.1
(408) 574-3939
www.impalalinear.com
October 1999
1
IMPALA [ Impala Linear Corporation ]
