EQADC Interesting Problem on MPC5777C

[berat24]

Hello everyone,

I am reading analog datas from two different eQADC channels(ANA0,ANA1) connected to first ADC module in eQADCA. Although ANA1 pin is not connected to any signal, it follows ANA0 when I examine both of them in free master.

I could not find any logical reason when I checked reference manuel. What could be reason leading to this situation?

I attached a photo from Free Master below.

Note : A sinus signal from signal generator is connected to ANA0 pin. 

Sincerely.

[davidtosenovjan · Accepted solution]

If second input is unterminated i.e. Hi-Z, it is understandable you are measuring cross-talk for first channel. Pull this input to GND and or other low impedance voltage level and you will see valid conversions.