F81866A
The following examples explain the differences for the stage auto mode and linear auto mode.
Stage auto mode
In this mode, the fan keeps in a same speed for each temperature interval. And there are two
types of fan speed setting: PWM Duty and RPM %.
A. Stage auto mode (PWM Duty)
Set the temperature limits as 70°C, 60°C, 50°C, 40°C and the duty as 100%, 90%, 80%, 70%, 60%
Fig 6-8 Stage mode fan control illustration
a.Once the temperature is under 40°C, the lowest fan speed keeps in the 60% PWM duty.
b.Once the temperature is over 40°C, 50°Cand 60°C, the fan speed will vary from 70%, 80% to 90%
PWM duty and increasing with the temperature level.
c.For the temperature higher than 70°C, the fan speed keeps in 100% PWM duty.
d.If set the hysteresis is 3°C (default 4°C), once the temperature becomes lower than 67°C, the fan
speed would reduce to 90% PWM duty.
B. Stage auto mode (RPM%)
Set the temperature as 70°C, 60°C, 50°C, 40°C and the corresponding fan speed is 6,000 RPM,
5,400 RPM, 4,800 RPM, 4,200 RPM, and 3,600 RPM (assume the Max Fan Speed is 6,000
RPM).
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Jan, 2012
V0. 12P