F3/L4 ADC in Differential mode.

[Asantos]

Posted on May 30, 2017 at 17:44

Hi,

When  two inputs of ADC are in differential mode, can the ADCxINN input voltage be higher than the ADCxINP input voltage?

For Vref+ = 3.3V and Verf- = 0V.

Is the result value =  ((ADCxINP - ADCxINN)/3.3) * 2048 + 2048?

Ex. If ADCxINP = 1.0V and ADCxINN = 2.65V, is the result value = 1024?

Ari.

[Uwe Bonnes]

Posted on May 31, 2017 at 12:09

In my experience, conversion range in differential mode is -Vref to +Vref. I think this information is mssing from the datasheets.

[Asantos]

Posted on June 01, 2017 at 00:48

I tested the STM32L4 ADC in differential mode and it realy works as I supposed.

For Vref  = 3.3V.

 result value =  ((ADCxINP - ADCxINN)/3.3) * 2048 + 2048.

Ari.