Datasheet

(V
CC
= +5V, T
A
= +25°C, unless otherwise noted.)
PIN NAME FUNCTION
1 WDO
Active-Low Watchdog Output. Pulses low for 140ms (min) when the watchdog timer exceeds the watchdog
timeout period. WDO is low when V
CC
is below the UVLO threshold and remains low for 140ms (min) after
V
CC
exceeds the UVLO threshold.
2 GND Ground
3 N.C. No Connection. Leave unconnected or connect to V
CC
.
4 WDI
Watchdog Input. If WDI remains either high or low for longer than the watchdog timeout period, the internal
watchdog timer runs out and a watchdog pulse period is triggered. The internal watchdog timer clears
whenever a watchdog pulse period is asserted, or whenever WDI sees a rising or falling edge. If WDI is left
unconnected or is connected to a three-stated buffer output, the watchdog is disabled.
5 V
CC
Supply Voltage
2.0
1.0
-40
-20 40 100
WATCHDOG TIMEOUT PERIOD
vs. TEMPERATURE
1.2
1.1
1.3
1.8
1.9
MAX6814 toc03
TEMPERATURE (°C)
WATCHDOG TIMEOUT PERIOD (s)
0 20 8060
1.6
1.7
1.4
1.5
250
150
-40 -20 40 100
WDO PULSE PERIOD
vs. TEMPERATURE
170
160
180
230
240
MAX6814 toc02
TEMPERATURE (°C)
WDO PULSE PERIOD (ms)
0 20 8060
210
220
190
200
1
3
2
6
5
4
8
7
9
-40 20 40-20 0 60 80 100 120
MAX6814 toc01
TEMPERATURE (°C)
SUPPLY CURRENT (mA)
V
CC
SUPPLY CURRENT
vs. TEMPERATURE
MAX6814 5-Pin Watchdog Timer Circuit
Maxim Integrated │ 3
www.maximintegrated.com
Pin Description
Typical Operating Characteristics