F71869A
hysteresis setting (0 ~ 15°C) could also be found in register 0x98.
The Manual Mode and Auto Mode could be selected by register 0x96h.
There are two kinds of auto mode: stage auto mode and linear auto mode. The “FAN1_
INTERPOLATION_EN” in register 0xAFh is used for linear auto mode enable. The following
examples explain the differences for 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%
Figure 8 Stage mode fan control illustration-2
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,
29
Oct., 2011
V0.19P
FINTEK [ FEATURE INTEGRATION TECHNOLOGY INC. ]
