PRELIMINARY INFORMATION
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TC1232
MICROPROCESSOR MONITOR
FEATURES
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Precision Voltage
Monitor ....................... Adjustable +4.5V or +4.75V
Reset Pulse Width ............................. 250msec Min
No External Components
Adjustable Watchdog
Timer ........................ 150msec, 600msec or 1.2sec
Debounced Manual Reset Input for External
Override
GENERAL DESCRIPTION
The TC1232 is a fully-integrated processor supervisor.
It provides three important functions to safeguard processor
sanity: precision power on/off reset control, watchdog timer
and external reset override.
On power-up, the TC1232 holds the processor in the
reset state for a minimum of 250msec after V
CC
is within
tolerance to ensure a stable system start-up.
Microprocessor sanity is monitored by the on-board
watchdog circuit. The microprocessor must provide a peri-
odic low-going signal on the ST input. Should the processor
fail to supply this signal within the selected time-out period
(150msec, 600msec or 1200msec), an out-of-control pro-
cessor is indicated and the TC1232 issues a processor reset
as a result.
The outputs of the TC1232 are immediately driven
active when the PB input is brought low by an external push-
button switch or other electronic signal. When connected to
a push-button switch, the TC1232 provides contact
debounce.
The TC1232 is packaged in a space-saving 8-pin plastic
DIP or SOIC package and requires no external components.
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APPLICATIONS
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Computers
Controllers
Intelligent Instruments
Automotive Systems
Critical
µ
P Power Monitoring
ORDERING INFORMATION
Part No.
TC1232COA
TC1232COE
TC1232CPA
TC1232EOA
TC1232EOE
TC1232EPA
Package
8-Pin SOIC
16-Pin SOIC (Wide)
8-Pin PDIP
8-Pin SOIC
16-Pin SOIC (Wide)
8-Pin PDIP
Temp. Range
0°C to +70°C
0°C to +70°C
0°C to +70°C
– 40°C to +85°C
– 40°C to +85°C
– 40°C to +85°C
FUNCTIONAL BLOCK DIAGRAM
V
CC
5%/10%
TOLERANCE
SELECT
REF
RST
+
–
+
TOL
RESET
GENERATOR
RST
PB RST
DEBOUNCE
TC1232
TD
WATCHDOG
TIMEBASE
SELECT
WATCHDOG
TIMER
ST
GND
8
TC1232-4
11/6/96
TELCOM SEMICONDUCTOR, INC.
5-19
TELCOM [ TELCOM SEMICONDUCTOR, INC ]
