Environmental Monitoring and Control Device
Datasheet
Chapter 3 Recommended Implementation
The following figures show the recommended circuitry on the board for the PWM outputs, tachometer
inputs, and remote diodes. FIGURE 3.1 shows how the part can be used to control additional fans by
connecting two fans to one PWM output.
12V
3.3V
3.3V
1k
2.2k
PWM3
MMBT3904
M
Fan1
10
MMBT2222
MMBT2222
Empty
Empty
M
10
Fan2
FIGURE 3.1 - FAN DRIVE CIRCUITRY (APPLY TO PWM DRIVING TWO FANS)
3.3V
12V
Fan
470
M
PWMx
0
MMBT2222
Empty
FIGURE 3.2 - FAN DRIVE CIRCUITRY (APPLY TO PWM DRIVING ONE FAN)
SMSC EMC6D100/EMC6D101
Page 12
Rev. 09-09-04
DATASHEET