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Fan-Failure Detector with Integrated
Power Switch
MAX6684
ABSOLUTE MAXIMUM RATINGS
Voltages Referenced to GND, Unless Otherwise Noted
V
CC
........................................................................-0.3V to +6.0V
FC+, FC-.....................................................-0.3V to (V
CC
+ 0.3V)
OFF, FAIL
..............................................................-0.3V to +6.0V
PGND ....................................................................-0.3V to +0.3V
SENSE to PGND ..................................................-0.3V to +28.0V
SENSE Current................................................................1400mA
Continuous Power Dissipation (T
A
= +70°C)
8-Pin SO (derate 5.9mW/°C above +70°C)..................470mW
Operating Temperature Range ...........................-40°C to +85°C
Storage Temperature Range .............................-65°C to +150°C
Junction Temperature ......................................................+150°C
Soldering Temperature (vapor phase, 60s).....................+215°C
Soldering Temperature (infrared, 15s).............................+220°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
= 3.0 to 5.5V,
OFF
= V
CC
, T
A
= -40°C to +85°C, unless otherwise noted. Typical values are at V
CC
= 3.3V, T
A
= +25°C.) (Note 1)
PARAMETER
Supply Voltage
Supply Current
V
CC
Shutdown Supply Current
SENSE-to-PGND Output
Low Voltage
SENSE-to-PGND Output
On-Resistance
SENSE Leakage Current
V
FAIL
Output Low Voltage
V
FAIL
Output Leakage Current
Average SENSE (Fan) Current
SENSE Current Shutdown
Thermal Shutdown of SENSE
Fan-Current Fluctuation
Frequency
V
FAIL
Output Delay After Fault
Minimum Fan-Current Fluctuation
Level (Note 2)
OFF
Input High Voltage
OFF
Input Low Voltage
OFF
Input Current
V
IH
V
IL
-10
0
t
FD
No fault detected
V
CC
= 3V
15°C hysteresis
No fault detected
25
0.3
15
0.7 x
V
CC
0.3 x
V
CC
1
1
35
R
DSON
V
SENSE
= 26V
I
FAIL
= 3mA
V
FAIL
= 5.5V
50
600
160
400
2.0
60
0.1
SYMBOL
V
CC
I
CC
I
SHDN
I
FAN
= 300mA
OFF
= GND
I
FAN
= 300mA
0.3
1
1
CONDITIONS
MIN
3.0
TYP
MAX
5.5
3.4
10
0.66
2.2
10
0.8
1
300
1200
UNITS
V
mA
µA
V
Ω
µA
V
µA
mA
mA
°C
Hz
s
mA
P-P
V
V
µA
Note 1:
Specifications to -40°C are guaranteed by design and not production tested.
Note 2:
The MAX6684 is guaranteed to register a fault when the fan current fluctuates less than the minimum; it is guaranteed not to
register a fault when the fan current is above the maximum.