NCP1232
Microprocessor Monitor
The NCP1232 is a fully-integrated processor supervisor. It provides
three important functions to safeguard processor functionality:
precision power on/off reset control, watchdog timer and external
reset override.
On power-up, the NCP1232 holds the processor in the reset state for
a minimum of 250 msec after VCC is within tolerance to ensure a
stable system start-up.
Microprocessor functionality 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 (150 msec, 600 msec or
1200 msec), an out- of- control processor is indicated and the
NCP1232 issues a processor reset as a result.
The outputs of the NCP1232 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
NCP1232 provides contact debounce.
The NCP1232 is packaged in a space-saving 8-pin plastic SOIC
package and requires no external components.
Features
• Precision Voltage Monitor
(Adjustable +4.5 V or +4.75 V)
• Reset Pulse Width (250 msec Min)
• No External Components
• Adjustable Watchdog Timer
(150 msec, 600 msec or 1.2 sec)
• Debounced Manual Reset Input for External Override
Applications
• Computers
• Controllers
• Intelligent Instruments
• Automotive Systems
• Critical mP Power Monitoring
http://onsemi.com
8
1
SO-8
D SUFFIX
CASE 751
MARKING
DIAGRAM
8
NCP
1232
YWWXZ
1
YY, Y
WW
X
Z
= Year
= Work Week
= Assembly ID Code
= Subcontractor ID Code
PIN CONNECTIONS
8-Pin SOIC
PB RST 1
TD 2
TOL 3
GND 4
8 VCC
7 ST
6 RST
5 RST
(Top View)
ORDERING INFORMATION
Device
Package
Shipping
NCP1232DR2
SO-8
2500 Tape & Reel
© Semiconductor Components Industries, LLC, 2003
1
February, 2003 - Rev. 1
Publication Order Number:
NCP1232/D