Containing Lead (Pb) ......................................................+240°C
Stresses beyond those listed under “Absolute Maximum Ratings” may cause permanent damage to the device. These are stress ratings only, and functional operation of the device at these
or any other conditions beyond those indicated in the operational sections of the specifications is not implied. Exposure to absolute maximum rating conditions for extended periods may affect
device reliability.
Electrical Characteristics
(V
CC
= +2.5V to +5.5V, SET_ = V
CC
or GND, T
A
= -40°C to +125°C, unless otherwise noted. Typical values are at T
A
= +25°C and
V
CC
= +3V.) (Note 1)
PARAMETER
Operating Voltage Range
Supply Current
Input High Voltage
SYMBOL
V
CC
I
CC
V
IH
No load
T
A
= -40°C to +85°C
T
A
= -40°C to +125°C
0.8 x V
CC
0.8
0.6
V
0.6
0.4
0
±10
0.3
0.4
1
0.8 x V
CC
V
CC
- 1.5
nA
V
V
µA
V
CC
≥ 3.3V,
T
A
= -40°C to +85°C
WDI, SET0,
SET1, SET2
V
CC
≥ 3.3V,
T
A
= -40°C to +125°C
V
CC
≥ 2.5V,
T
A
= -40°C to +85°C
V
CC
≥ 2.5V,
T
A
= -40°C to +125°C
Logic Input Current (Note 2)
WDO
Output Low
Voltage
V
WDI
or V
SET_
= 0V or V
CC
V
OL
I
SINK
= 1.2mA, V
CC
> 2.7V, watchdog
output asserted
I
SINK
= 6mA, V
CC
> 4.5V, watchdog output
asserted
V
WDO
= 0 to +5.5V, output deasserted,
MAX6369/MAX6371/MAX6373
I
SOURCE
= 500µA, V
CC
> 2.7V,
watchdog output deasserted
I
SOURCE
= 800µA, V
CC
> 4.5V,
watchdog output deasserted
CONDITIONS
MIN
2.5
8
10
TYP
MAX
5.5
20
22
UNITS
V
µA
V
WDI, SET0, SET1, SET2
Input Low Voltage
V
IL
WDO
Leakage Current
I
LKG
WDO
Output High
Voltage
V
OH
V
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Maxim Integrated │
2
MAX6369–MAX6374
Pin-Selectable Watchdog Timers
Electrical Characteristics (continued)
(V
CC
= +2.5V to +5.5V, SET_ = V
CC
or GND, T
A
= -40°C to +125°C, unless otherwise noted. Typical values are at T
A
= +25°C and
V
CC
= +3V.) (Note 1)
PARAMETER
MAX6369/MAX6370
V
SET2
= 0V, V
SET1
= 0V, V
SET0
= 0V
V
SET2
= 0V, V
SET1
= 0,V SET0 = V
CC
V
SET2
= 0V, SET1 = V
CC
, V
SET0
= 0V
Startup Delay Period
t
DELAY
V
SET2
= 0V, SET1 = V
CC
, SET0 = V
CC
SET2 = V
CC
, V
SET1
= 0V, V
SET0
= 0V
SET2 = V
CC
, V
SET1
= 0V, SET0 = V
CC
SET2 = V
CC
, SET1 = V
CC
, V
SET0
= 0V
SET2 = V
CC
, SET1 = V
CC
, SET0 = V
CC
V
SET2
= 0V, V
SET1
= 0V, V
SET0
= 0V
V
SET2
= 0V, V
SET1
= 0V, SET0 = V
CC
V
SET2
= 0V, SET1 = V
CC
, V
SET0
= 0V
Watchdog Timeout
Period
t
WD
V
SET2
= 0V, SET1 = V
CC
, SET0 = V
CC
SET2 = V
CC
, V
SET1
= 0V, V
SET0
= 0V
SET2 = V
CC
, V
SET1
= 0V, SET0 = V
CC
SET2 = V
CC
, SET1 = V
CC
, V
SET0
= 0V
SET2 = V
CC
, SET1 = V
CC
, SET0 = V
CC
MAX6371/MAX6372
Startup Delay Period
t
DELAY
V
SET2
= 0V, SET1 = V
CC
, SET0 = V
CC
All other SET_ conditions
V
SET2
= 0V, V
SET1
= 0V, V
SET0
= 0V
V
SET2
= 0V, V
SET1
= 0V, SET0 = V
CC
V
SET2
= 0V, SET1 = V
CC
, V
SET0
= 0V
Watchdog Time-Out
Period
t
WD
V
SET2
= 0V, SET1 = V
CC
, SET0 = V
CC
SET2 = V
CC
, V
SET1
= 0V, V
SET0
= 0V
SET2 = V
CC
, V
SET1
= 0V, SET0 = V
CC
SET2 = V
CC
, SET1 = V
CC
, V
SET0
= 0V
SET2 = V
CC
, SET1 = V
CC
, SET0 = V
CC
MAX6373/MAX6374
V
SET2
= 0V, V
SET1
= 0V, V
SET0
= 0V
V
SET2
= 0V, V
SET1
= 0V, SET0 = V
CC
V
SET2
= 0V, SET1 = V
CC
, V
SET0
= 0V
Startup Delay Period
t
DELAY
SET2 = 0V, SET1 = V
CC
, SET0 = V
CC
SET2 = V
CC
, V
SET1
= 0V, VSET0 = 0V
SET2 = V
CC
, V
SET1
= 0V, SET0 = V
CC
SET2 = V
CC
, SET1 = V
CC
, V
SET0
= 0V
SET2 = V
CC
, SET1 = V
CC
, SET0 = V
CC
3
3
60
200
9
9
180
600
ms
s
Watchdog Disabled
60
1
3
10
100
300
3
60
180
3
9
30
300
900
9
180
ms
s
1
10
30
100
1
10
60
1
10
30
100
1
10
60
3
30
90
300
3
30
180
3
30
90
300
3
30
180
s
ms
ms
s
ms
ms
SYMBOL
CONDITIONS
MIN
TYP
MAX
UNITS
Watchdog Disabled
Watchdog Disabled
Watchdog Disabled
ms
s
Watchdog Disabled
µs
First Edge (Note 3)
First Edge (Note 3)
60
180
s
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Maxim Integrated │
3
MAX6369–MAX6374
Pin-Selectable Watchdog Timers
Electrical Characteristics (continued)
(V
CC
= +2.5V to +5.5V, SET_ = V
CC
or GND, T
A
= -40°C to +125°C, unless otherwise noted. Typical values are at T
A
= +25°C and
V
CC
= +3V.) (Note 1)
PARAMETER
SYMBOL
CONDITIONS
V
SET2
= 0V, V
SET1
= 0V, V
SET0
= 0V
V
SET2
= 0V, V
SET1
= 0V, SET0 = V
CC
V
SET2
= 0V, SET1 = V
CC
, V
SET0
= 0V
Watchdog Timeout
Period
t
WD
V
SET2
= 0V, SET1 = V
CC
, SET0 = V
CC
SET2 = V
CC
, V
SET1
= 0V, V
SET0
= 0V
SET2 = V
CC
, V
SET1
= 0V, SET0 = V
CC
SET2 = V
CC
, SET1 = V
CC
, V
SET0
= 0V
SET2 = V
CC
, SET1 = V
CC
, SET0 = V
CC
Watchdog Input Pulse Width
(Note 2)
Watchdog Output Pulse Width
Internal Setup Time
(Note 4)
t
WDI
t
WDO
t
SETUP
After
WDO
deasserted
MAX6369/MAX6371/MAX6373
MAX6370/MAX6372/MAX6374
After
WDO
deasserted
MIN
3
3
1
30
1
10
10
100
100
1
300
3
300
TYP
MAX
9
9
3
90
3
30
30
ns
ms
ms
µs
s
UNITS
ms
s
Watchdog Disabled
µs
Note 1:
Production tested at T
A
= +25°C. Guaranteed by design over temperature limits.
Note 2:
Guaranteed by design.
Note 3:
In this setting the watchdog timer is inactive and startup delay ends when WDI sees its first level transition. See the
Selecting Device Timing
section for more information.
Note 4:
After power-up, or a setting change, there is an internal setup time during which WDI is ignored.
Typical Operating Characteristics
(Circuit of Functional Diagram, T
A
= +25°C, unless otherwise noted.)
SUPPLY CURRENT
vs. TEMPERATURE
MAX6369/74-01
NORMALIZED WATCHDOG TIMEOUT PERIOD
SUPPLY CURRENT (µA)
12
10
8
6
4
V
CC
= +5.5V
1.002
1.001
1.000
0.999
0.998
0.997
V
CC
= +2.5V
-40
-15
10
35
60
85
-40
-15
10
35
60
85
TEMPERATURE (°C)
TEMPERATURE (°C)
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Maxim Integrated │
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MAX6369/74-02
14
WATCHDOG TIMEOUT PERIOD
vs. TEMPERATURE
1.003
MAX6369–MAX6374
Pin-Selectable Watchdog Timers
Pin Configuration
TOP VIEW
WDI 1
GND 2
N.C.
3
8
7
6
5
V
CC
WDO
SET2
SET1
SET0 4
MAX6369
MAX6370
MAX6371
MAX6372
MAX6373
MAX6374
SOT23
Pin Description
PIN
1
2
3
4
5
6
7
8
NAME
WDI
GND
N.C.
SET0
SET1
SET2
WDO
V
CC
FUNCTION
Watchdog Input. If WDI remains either high or low for the duration of the watchdog timeout period (t
WD
),
WDO
triggers a pulse. The internal watchdog timer clears whenever a
WDO
is asserted or whenever
WDI sees a rising or falling edge.
Ground
Not Connected. Do not make any connection to this pin.
Set Zero. Logic input for selecting startup delay and watchdog timeout periods. See Table 1 for timing details.
Set One. Logic input for selecting startup delay and watchdog timeout periods. See Table 1 for timing details.
Set Two. Logic input for selecting startup delay and watchdog timeout periods. See Table 1 for timing details.
Watchdog Output. Pulses low for the watchdog output pulse width, t
WDO
, when the internal watchdog
times out. The MAX6369/MAX6371/MAX6373 have open-drain outputs and require a pull-up resistor.
The MAX6370/MAX6372/MAX6374 outputs are push-pull.