General Description

The MAX6369–MAX6374 are pin-selectable watchdog

timers that supervise microprocessor (µP) activity and

signal when a system is operating improperly. During

normal operation, the microprocessor should repeated-

ly toggle the watchdog input (WDI) before the selected

watchdog timeout period elapses to demonstrate that

the system is processing code properly. If the µP does

not provide a valid watchdog input transition before the

timeout period expires, the supervisor asserts a watch-

dog (WDO) output to signal that the system is not exe-

cuting the desired instructions within the expected time

frame. The watchdog output pulse can be used to reset

the µP or interrupt the system to warn of processing

errors.

The MAX6369–MAX6374 are flexible watchdog timer

supervisors that can increase system reliability through

notification of code execution errors. The family offers

several pin-selectable watchdog timing options to

match a wide range of system timing applications:

• Watchdog startup delay: provides an initial delay

before the watchdog timer is started.

• Watchdog timeout period: normal operating watch-

dog timeout period after the initial startup delay.

• Watchdog output/timing options: open drain (100ms)

or push-pull (1ms).

The MAX6369–MAX6374 operate over a +2.5V to +5.5V

supply range and are available in miniature 8-pin

SOT23 packages.

________________________Applications

Embedded Control Systems

Industrial Controllers

Critical µP and Microcontroller (µC) Monitoring

Automotive

Telecommunications

Networking

Features

o Precision Watchdog Timer for Critical

µP Applications

o Pin-Selectable Watchdog Timeout Periods

o Pin-Selectable Watchdog Startup Delay Periods

o Ability to Change Watchdog Timing Characteristics

Without Power Cycling

o Open-Drain or Push-Pull Pulsed Active-Low

Watchdog Output

o Watchdog Timer Disable Feature

o +2.5V to +5.5V Operating Voltage

o 8µA Low Supply Current

o No External Components Required

o Miniature 8-Pin SOT23 Package

Pin-Selectable Watchdog Timers

________________________________________________________________

Maxim Integrated Products

1

19-1676; Rev 5; 1/11

PART

OUTPUT

WDO PULSE

WIDTH (ms)

MINIMUM STARTUP DELAY

MINIMUM WATCHDOG TIMEOUT

MAX6369

Open Drain

100

Selectable: 1ms to 60s

Selectable: 1ms to 60s

MAX6370

Push-Pull

1

Selectable: 1ms to 60s

Selectable: 1ms to 60s

MAX6371

Open Drain

100

60s

Selectable: 1ms to 60s

MAX6372

Push-Pull

1

60s

Selectable: 1ms to 60s

MAX6373

Open Drain

100

Selectable: 200µs to 60s or first edgeSelectable: 30µs to 10s

MAX6374

Push-Pull

1

Selectable: 200µs to 60s or first edgeSelectable: 30µs to 10s

Selector Guide

For pricing, delivery, and ordering information, please contact Maxim Direct at 1-888-629-4642,

or visit Maxim’s website at www.maxim-ic.com.

PART

TEMP

RANGE

PIN-

PACKAGE

TOP

MARK

MAX6369KA-T

-40

°C to +125°C 8 SOT23

AADC

MAX6369KA/V-T

-40

°C to +125°C 8 SOT23

AEQV

MAX6369KA/V+T

-40

°C to +125°C 8 SOT23

AEQV

MAX6370KA-T

-40

°C to +125°C 8 SOT23

AADD

MAX6371KA-T

-40

°C to +125°C 8 SOT23

AADE

MAX6372KA-T

-40

°C to +125°C 8 SOT23

AADF

MAX6373KA-T

-40

°C to +125°C 8 SOT23

AADG

MAX6374KA-T

-40

°C to +125°C 8 SOT23

AADH

Ordering Information

Pin Configuration appears at end of data sheet.

Note: All devices are available in tape-and-reel only. Required

order increment is 2,500 pieces.

/V denotes an automotive qualified part.

Devices are available in both leaded and lead-free packaging.

Specify lead-free by replacing “-T” with “+T” when ordering.