Fan Control Device with Hardware Monitoring and Acoustic Noise Reduction Features
Datasheet
3.3V
Tach
Output
from Fan
D1
IN4148
10k
TACH
Input
Note:
For fans controlled directly by a PWM, it is suggested to implement
the optional diode (D1) to protect the tachometer input from large voltage
spikes generated by the fan.
Figure B.3 Fan Tachometer Circuitry (Apply to Each Fan)
Remote Diode +
2.2nF
External Temperature
Sensing Diode
(MMBT3904)
Remote Diode -
Figure B.4 Remote Diode (Apply to Remote2 Lines)
Notes:
1. 2.2nF cap is optional and should be placed close to the EMC6D102 if used.
2. The voltage at PWM3 must be at least 2.0V to avoid triggering Address Enable.
3. The Remote Diode + and Remote Diode - tracks should be kept close together, in parallel with
grounded guard tracks on each side. Using wide tracks will help to minimize inductance and
reduce noise pickup. A 10 mil track minimum width and spacing is recommended. See Figure B.5,
.
GND
D+
D-
GND
10 mil.
10 mil.
10 mil.
10 mil.
10 mil.
10 mil.
10 mil.
Figure B.5 Suggested Minimum Track Width and Spacing
Revision 0.4 (06-15-06)
DATASHEET
86
SMSC EMC6D102
SMSC [ SMSC CORPORATION ]
