K8055 , Analog input, Control Vref

I use some sensors and some converters. These converters put 3,3V when the temperature is MAX, and 0V When the temperature is MIN.
I want to have the best precision with th K8055, but in the moment, when i make readanalog, i recuperate 255 when there is 5V, and 0 when there is 0V. So i want to know if it’s possible to change the voltage reference, to have 255 when i put 3,3 V, and 0 when i put 0V.
Thank’s a lot.

You can simply adjust the gain of the input amplifiers in order to achieve max AD converter precision with 3.3V
Check manual of K8055, it explains how to change the gain.