F81866A Datasheet, PDF (40/210 Pages) Feature Integration Technology Inc. – 6 UARTs Super IO With 128 Bytes FIFO and Power

F81866A
Fig 6-9 Stage mode fan control illustration
a.Once the temperature is lower than 40°C, the lowest fan speed keeps in 3,600 RPM (60% of full
speed).
b.Once the temperature is higher than 40°C, 50°C and 60°C, the fan speed will vary from 4,200
RPM to 5,400 RPM and increasing with the temperature level.
c.For the temperature higher than 70°C, the fan speed keeps in the full speed 6,000 RPM.
d.If the hysteresis is set as 3°C (default 4°C), once temperature gets lower than 67°C, the fan speed
would reduce to 5,400 RPM.
Linear auto mode
Furthermore, F81866A also supports linear auto mode. The fan speed would increase or decrease
linearly with the temperature. There are also PWM Duty and RPM% modes for it.
A. Linear auto mode (PWM Duty I)
Set the temperature as 70°C, 60°C, 50°C and 40°C and the duty is 100%, 80%, 70%, 60% and
50%.
40
Jan, 2012
V0. 12P