NCP1232 Datasheet, PDF (1/8 Pages) ON Semiconductor – Microprocessor Monitor

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 µP 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, 2000
1
May, 2000 – Rev. 0
Publication Order Number:
NCP1232/D