I plan to use AD7689 and have some trouble to clearly understand the data
My plan is to use 3 inputs as bipolar differential with their “ground” at the
level of Vref/2 either at the corresponding negativ input (eg. IN1, IN3, IN5)
or at COM, I did not decide about this yet (Any hints on advantages and
disadvantages are welcome) and two other inputs as unipolar single ended with
their ground at Gnd.
Can I do this from the electrical point of view or do I violate any specs?
How do I switch between channels and how long, how many conversions will it
take till I get the valid result?
Am I free to chosse input pins, which is differential and which single ended or are there rules to be followed?
Just looked at EVAL-AD76MUXEDZ schematics and there is a filter or "charge reservoir" with 22 ohms and 2700pF in front of each analog input. I couldn't find anything about this in the data sheet. Do I need it or can I simply connect the analog inputs to an op amp output?
Thanks a lot for any help
Nachricht geändert durch Martin Mensch