TC1232_13 Datasheet, PDF (1/20 Pages) Microchip Technology – Microprocessor Monitor

TC1232
Microprocessor Monitor
Features
• Precision Voltage Monitor
- Adjustable +4.5V or +4.75V
• Reset Pulse Width – 250 msec minimum
• No External Components
• Adjustable Watchdog Timer
- 150 msec, 600 msec or 1.2 sec
• Operating Voltage 4.0V to 5.5V
• Debounced Manual Reset Input for External
Override
Block Diagram
V_CC
Tolerance
Select
TOL (5% or 10%) +
+
–
+
V_R–EF
RST
RST
PB RST Debounce
Reset
Generator
TD
Watchdog
Timebase
Select
Watchdog
Timer
ST
General Description
The TC1232 is a fully-integrated processor supervisor
that 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 250 msec after V_CC is
within tolerance to ensure a stable system start-up.
Microprocessor sanity is monitored by the onboard
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 (150 msec, 600 msec or 1200 msec),
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
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 PDIP
or SOIC package, a 16-Pin SOIC (wide) package and
requires no external components.
Package Types
8-Pin PDIP
PB RST 1
TD 2
TOL 3
GND 4
TC1232
8 V_CC
7 ST
6 RST
5 RST
PB RST
TD
TOL
GND
8-Pin SOIC
16-Pin SOIC (Wide)
1
8 V_CC
NC 1
2
7 ST ^{PB RST 2}
TCC11223322
NC 3
3
6 RST
TD 4
4
5 RST
NC 5
TOL 6
NC 7
GND 8
TC1232
16 NC
15 VCC
14 NC
13 ST
12 NC
11 RST
10 NC
9 RST
Device Features
Device
RST pin
Type
Pull-up Active
Resistor Level
RST pin
Trip Points
Type
Active _(Max)
Level
Minimum
Reset
Active Time
(ms)
WDI Input
Typical
Timeouts (ms)
MR
Input
TC1232 Open-drain External Low Push-pull High 4.75V
250
150, 600 or Yes
or 4.5V
1200
 2002-2012 Microchip Technology Inc.
Preliminary
DS21370D-page 1