VAGND Pin [XMC4500 Relax Kit Lite]

[#1]

Hello all,

I have a quick questions, what Pin is the signal VAGND assigned to? Or is that connected to GND?

Cheers,
Ahmed

[#2]

Hi AEIGarem,

Unfortunately, I cannot give you a definitive answer at this point, however, I can do two things that might help you.

(1) Bump this thread up to the top of the list so some one else might answer it better than me 🙂

(2) Share what I have found before when working with ADC. VAGND is connected to AGND, which seems to be different from GND (see board schematics, such as this one here at the end of the document: http://www.infineon.com/dgdl/Board_Users_Manual_CPU_Board_XMC4400_General_Purpose_R1+0.pdf?fileId=db...). That being said, I suspect that this means that it is up to the user to define AGND and AREF levels such that they would suit the application (e.g. either utilise the full range from 0V to 3.3V or something smaller, like from 1V to 2V for better accuracy in that region). Try connecting VAGND to GND and there's a good chance that the ADC performance will be better.

Best regards,

Andrey

[#3]

Hello Andrey,

Thank you so much for your help! I thought of doing that but unfortunately there is no VAGND pin on the Relax Kit Lite :s So I just left it as it is and used two Pins, one would be my "GND" and the other as my output so that I can output values smaller than 0.3V and then used OpAmps to double my output so I can output values larger than 2.5V.
But thanks again for your answer!

Best regards,
Ahmed