I use EVAL-ADT7470EBZ and use Automatic Fan Speed Control Mode the following settings:
PWM min: 20
PWM MAX: 100
According to the description of DataSheet, when the temperature reaches Tmin + 20 degrees, the PWM Duty will reach the value set by the PWM Max.
My Tmin is 25 degrees, theoretically when the temperatyre reaches 45 degrees, the PWM will be 100%
However, in reality when temperature reaches 45 degrees, the PWM Duty is only 83%, and when the temperature reaches 51 degrees, than he PWM Duty will be 100%.
Did I set a wrong?