I see a strange signal at ADC input which might cause the issue I am faced with.
I have attached the osci picture.
This signal looks like a sawtooth wave.
When I change the paramter SMPLTS then the area marked on the picture changes accordingly.
So I assume that when the ADC does "sample" the signal is forced to input level.
When the ADC does "hold" for internal sampling the signal follows a sawtooth wave.
I do not see this signal analysing the sample values. However the sampled signal does not match what I expect. Also I have
issue processing it.
The ADC input in connected with 1nF capacitor to ground.
Does anybody has n idea why this signal is so strange? What do I need to do here?
Thanks for your help
I found an Application Note
It seems that is the root cause ie the input impadance does not match.
I will check that
Could you please send the schematic and describe the ADC operation in more details?