stm32f303re wrong adc value reading

[TB5BYO]

I am using stm32f303re nucleo board, I apply a voltage of 3.3 volts directly to the adc2_in2 analog pin of the stm32f303 microcontroller. My adc resolution rate is 12 bits and the value I read is around 3975. this causes me to get wrong results, why does it do this? Why can't I read properly with the 446re but not the 303?

[waclawek.jan]

Did you perform ADC calibration as outlined in the RM?

JW

[TB5BYO]

How do i calibrate?

[AScha.3 · Accepted solution]

call ->

is this :

[TB5BYO]

it is work. thank you so much.