EMC6D103 Datasheet, PDF (88/89 Pages) SMSC Corporation – FAN CONTROL DEVICE WITH HIGH FREQUENCY PWM

Fan Control Device with High Frequency PWM Support and Hardware Monitoring Features
Datasheet
3.3V
470
PWMx
MMBT2222
12V
Fan
M
Figure B.2 Fan Drive Circuitry (Apply to PWM Driving One Fan)
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)
Revision 0.4 (04-04-05)
88
DATASHEET
SMSC EMC6D103