HN1232
HN1232
Microprocessor Monitor
DESCRIPTION
The HN1232 microprocessor (µP) supervisory circuit provides “housekeeping” and power supervision functions. The
HN1232 enhances circuit reliability in µP systems by monitoring the power supply, monitoring software execution, and
providing a debounced manual reset input.
First, a precision temperature–compensated reference and comparator circuit monitors the status of V
CC
. When an
out–of–tolerance condition occurs, an internal power fail signal is generated which forces reset to the active state.
When V
CC
returns to an in–tolerance condition, the reset signals are kept in the active state for a minimum of 250 ms to
allow the power supply and system microprocessor to stabilize. The trip point tolerance signal, TOL, selects the trip
level tolerance to be either 5- or 10-percent.
The second function the HN1232 performs is manual reset control. A debounced manual reset input activates the reset
outputs for a minimum period of 250 ms.
The third function is a watchdog timer. The HN1232 has an internal timer that forces the reset signals to the active state
if the strobe input is not driven low prior to time–out. The watchdog timer function can be set to operate on time–out
settings of approximately 150 ms, 600 ms, and 1.2 seconds.
Devices are available in 8-pin DIP, 8/16-pin SO and compact 8-pin MicroSO packages, and requires no external
components.
FEATURES
Precision voltage monitor - adjustable +4.5V or
+4.75V
Halts
and
restarts
an
out–of–control
microprocessor
Holds microprocessor in check during power
transients
Automatically restarts microprocessor after power
failure
Reset pulse width – 250ms min.
Debounced manual reset input for external override
Adjustable watchdog timer – 150ms, 600ms, or
1.2sec
Precision
temperature-compensated
voltage
reference and comparator
No external components
The HN1232 is a plug-in replacement of the
Max1232, DS1232, IMP1232, etc.
APPLICATIONS
Microprocessor Systems
Portable Equipment
Computers
Controllers
Intelligent Instruments
Automotive Systems
Critical µP Power Monitoring
ORDERING INFORMATION
PART NO.
HN1232CN
HN1232CM
HN1232CU
HN1232CWM
HN1232CX
HN1232EN
HN1232EM
HN1232EU
HN1232EWM
TEMP. RANGE (°C)
0 – 70 °C
0 – 70 °C
0 – 70 °C
0 – 70 °C
0 – 70 °C
-40 – 85 °C
-40 – 85 °C
-40 – 85 °C
-40 – 85 °C
PACKAGE
8-Pin DIP
8-Pin SO
8-Pin MicroSO
16-Pin Wide SO
Dice
8-Pin DIP
8-Pin SO
8-Pin MicroSO
16-Pin Wide SO
地址: 南京市珠江路
88
号，新世界中心
B
座
4004
室, 邮编:210008
ADD.: RM. 4004,
BLOCK B,
NEW WORLD CENTRE,
电话(TEL.):
(86)-25-68853600
NANJING 210008,
CHINA
传真(FAX):
(86)-25-68853600-810
WEB-SITE: WWW.HN-ELEC.COM
NO. 88 ZHUJIANG ROAD,
1
HN [ NANJING HONANO ELECTRONIC CO., LTD. ]
