Post Go back to editing

ADT7470 automatic mode and the PWM is incorrect

I use EVAL-ADT7470EBZ and use Automatic Fan Speed ​​Control Mode the following settings:
TMIN: 25
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?