REV. 0

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a

Microprocessor

Supervisory Circuits

ADM8698/ADM8699

FUNCTIONAL BLOCK DIAGRAM

RESET

GENERATOR

4.65V

V

CC

WATCHDOG

INPUT

WDI

*

ADM8698/

ADM8699

RESET

WATCHDOG

OUTPUT

RESET

*

RESET (SOIC ONLY)

WDO (ADM8699 SOIC ONLY)

WATCHDOG

TRANSITION DETECTOR

(1 sec)

TYPICAL APPLICATION CIRCUIT

+5V

V

CC

WDI

*

GND

ADM8698/

ADM8699

RESET

µP POWER

µP SYSTEM

I/O LINE

µP RESET

FEATURES

Superior Upgrade for ADM698/ADM699, MAX698/MAX699

Guaranteed

Low 70

A Supply Current

Precision 4.65 V Voltage Monitor

Power OK/Reset Time Delay

Watchdog Timer

Minimum Component Count

Performance Specified over Temperature

APPLICATIONS

Microprocessor Systems

Computers

Controllers

Intelligent Instruments

Automotive Systems

Critical

P Power Monitoring

GENERAL DESCRIPTION

The ADM8698/ADM8699 supervisory circuits provide power

supply monitoring and watchdog timing for microprocessor

systems.

ates a

RESET pulse during power up, power down and during

low voltage “Brown Out” conditions. The

RESET output is

The ADM8699 features an identical monitoring circuit as in the

ADM8698, plus an additional watchdog timer input to monitor

microprocessor activity. The

RESET output is forced low if the

watchdog input is not toggled within the 1 second watchdog

timeout period.

Both parts are available in 8-pin plastic DIP/SOIC and 16-lead

SOIC packages. The 16-lead SOIC contains additional out-

puts

RESET (without inversion) and Watchdog Output WDO

(ADM8699 only).

One Technology Way, P.O. Box 9106, Norwood, MA 02062-9106, U.S.A.

Tel: 617/329-4700

World Wide Web Site: http://www.analog.com

Fax: 617/326-8703

© Analog Devices, Inc., 1997