![](http://datasheet.mmic.net.cn/370000/MAX6370KA-T_datasheet_16714161/MAX6370KA-T_1.png)
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
M
Pin-Selectable Watchdog Timers
________________________________________________________________
Maxim Integrated Products
For pricing, delivery, and ordering information, please contact Maxim/Dallas Direct! at
1-888-629-4642, or visit Maxim’s website at www.maxim-ic.com.
1
PART
TEMP
RANGE
-40
°
C to +85
°
C
-40
°
C to +85
°
C
-40
°
C to +85
°
C
-40
°
C to +85
°
C
-40
°
C to +85
°
C
-40
°
C to +85
°
C
PIN-
PACKAGE
8 SOT23-8
8 SOT23-8
8 SOT23-8
8 SOT23-8
8 SOT23-8
8 SOT23-8
TOP
MARKS
AADC
AADD
AADE
AADF
AADG
AADH
MAX6369
KA-T
MAX6370
KA-T
MAX6371
KA-T
MAX6372
KA-T
MAX6373
KA-T
MAX6374
KA-T
19-1676; Rev 2; 2/03
Ordering Information
PART
OUTPUT
WDO PULSE
WIDTH (ms)
MINIMUM STARTUP DELAY
MINIMUM WATCHDOG TIMEOUT
MAX6369
MAX6370
MAX6371
MAX6372
MAX6373
MAX6374
Open Drain
Push-Pull
Open Drain
Push-Pull
Open Drain
Push-Pull
100
1
100
1
100
1
Selectable: 1ms to 60s
Selectable: 1ms to 60s
60s
60s
S el ectab e: 200μs to 60s or fi st ed g e
S el ectab e: 200μs to 60s or fi st ed g e
S el ectab e: 1ms to 60s
S el ectab e: 1ms to 60s
S el ectab e: 1ms to 60s
S el ectab e: 1ms to 60s
S el ectab e: 30μs to 10s
S el ectab e: 30μs to 10s
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.
Selector Guide