i would like to know the input capacitance value (common) of the AD8601 amplifier.
If not known, do you have a method to estimate/measure it ?
I would like to put a follower in parallel of a capacitor to measure its voltage charge. But input capacitance of amplifier is measure as a parasitic parameter.
if you have any idea...
I have attached a slide on how to measure common-mode capacitance.
There is another way on how to measure it, which is described in this article by Glen Brisebois https://www.analog.com/en/technical-articles/signal-conditioning-for-high-impedance-sensors.html
You might also want to check this article https://www.analog.com/en/analog-dialogue/articles/direct-method-of-measuring-op-amp-input-differential-capacitance.html