We are trying to modify the input stage of an already manufactured board by replacing AD7793 by AD7684 in order to measure up to 1KHz signals. I have attached a simplified schema of our input stage and two waveforms we have obtained from the AD7684 output.
We are only getting good performance when we connect our oscilloscope to IN+ and IN-, furthermore, we get good results when connecting just the GND of the oscilloscope wherever IN+ or IN-.
We need to measure in both scenarios IN+ > IN- and IN- > IN+, that is why we selected this AD7684 truly differential instead of AD7693
Could you provide some solutions, similar experience... any hint could help!
Best regards and thank you in advance,