TelCom Semiconductor Inc TC1232EPA, TC1232EOE, TC1232EOA, TC1232CPA, TC1232COE Datasheet
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MICROPROCESSOR MONITOR
PRELIMINARY INFORMATION
1
TC1232
FEATURES
■ 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
APPLICATIONS
■ Computers
■ Controllers
■ Intelligent Instruments
■ Automotive Systems
■ Critical µP Power Monitoring
ORDERING INFORMATION
Part No. Package Temp. Range
TC1232COA 8-Pin SOIC 0°C to +70°C
TC1232COE 16-Pin SOIC (Wide) 0°C to +70°C
TC1232CPA 8-Pin PDIP 0°C to +70°C
TC1232EOA 8-Pin SOIC – 40°C to +85°C
TC1232EOE 16-Pin SOIC (Wide) – 40°C to +85°C
TC1232EPA 8-Pin PDIP – 40°C to +85°C
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
tolerance to ensure a stable system start-up.
Microprocessor sanity is monitored by the on-board
watchdog circuit. The microprocessor must provide a periodic 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 processor 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 pushbutton 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.
is within
CC
2
3
4
5
FUNCTIONAL BLOCK DIAGRAM
V
CC
5%/10%
TD
TOLERANCE
SELECT
DEBOUNCE
WATCHDOG
TIMEBASE
SELECT
TOL
PB RST
TELCOM SEMICONDUCTOR, INC.
REF
RST
+
–
+
RESET
GENERATOR
TC1232
RST
6
7
ST
GND
WATCHDOG
TIMER
8
TC1232-4 11/6/96
5-19
TC1232
MICROPROCESSOR MONITOR
ABSOLUTE MAXIMUM RATINGS*
Voltage on Any Pin (With Respect to GND)
Operating Temperature Range:
TC1232C .......................................... 0°C to +70°C
TC1232E ..................................... – 40°C to + 85°C
– 0.3V to +5.8V
*Stresses beyond those listed under "Absolute Maximum Ratings" may
cause permanent damage to the device. These are stress ratings only, and
functional operation of the device at these or any other conditions beyond
those indicated in the operational sections of the specifications is not
implied. Exposure to absolute maximum rating conditions for extended
periods may affect device reliability.
Storage Temperature Range ................– 65°C to +150°C
Lead Temperature (Soldering, 10 sec) .................+300°C
DC ELECTRICAL CHARACTERISTICS: T
A
= T
MIN
to T
MAX; VCC =
+4.5V to 5.5V, unless otherwise specified.
Symbol Parameter Test Conditions Min Typ Max Unit
V
V
V
I
L
I
OH
I
OL
I
CC
V
V
CC
IH
IL
CCTP
CCTP
Supply Voltage 4.5 5.0 5.5 V
ST and PB RST 2.0 — V
+0.3 V
CC
Input High Level Note 1
ST and PB RST – 0.3 — +0.8 V
Input Low Level
Input Leakage ST, TOL – 1.0 — +1.0 µA
Output Current RST V
Current RST, RST V
= 2.4V – 1.0 –12 — mA
OH
= 0.4V 2.0 10 — mA
OL
Operating Current Note 2 — 50 200 µA
VCC 5% Trip Point (Note 3) TOL = GND 4.50 4.62 4.74 V
V
10% Trip Point (Note 3) TOL = V
CC
CC
4.25 4.37 4.49 V
CAPACITANCE (Note 4): T
= +25°C
A
Symbol Parameters Test Conditions Min Typ Max Units
C
IN
C
OUT
AC ELECTRICAL CHARACTERISTICS: T
Input Capacitance ST, TOL — — 5 pF
Output Capacitance RST, RST
A
= T
MIN
to T
MAX; VCC =
+5V to +10%, unless otherwise specified.
——7pF
Symbol Parameters Test Conditions Min Typ Max Units
t
PB
t
PBD
t
RST
t
ST
t
TD
t
F
PB RST (Note 5) Figure 3 20 — — msec
PB RST Delay Figure 3 1 4 20 msec
Reset Active Time 250 610 1000 msec
ST Pulse Width Figure 4 75 — — nsec
ST Time-out Period Figure 4
TD Pin = 0V 62.5 150 250 msec
TD Pin = Open 250 600 1000 msec
TD Pin = V
V
Fall Time (Note 4) Figure 5 10 — — µsec
CC
CC
500 1200 2000 msec
5-20
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