Fan Control Device with High Frequency PWM Support and Hardware Monitoring Features
Datasheet
Appendix B Example Fan Circuits
The following figures show examples of circuitry on the board for the PWM outputs, tachometer inputs,
and remote diodes. Figure B.1, "Fan Drive Circuitry (Apply to PWM Driving Two Fans)" shows how the
part can be used to control four fans by connecting two fans to one PWM output.
Note: These examples represent the minimum required components. Some designs may require
additional components.
12V
3.3V
3.3V
1k
2.2k
PWMx
MMBT3904
M
MMBT2222
MMBT2222
Fan1
M
Fan2
Figure B.1 Fan Drive Circuitry (Apply to PWM Driving Two Fans)
SMSC EMC6D103
Revision 0.4 (04-04-05)
DATA8S7HEET
SMSC [ SMSC CORPORATION ]
