AnsweredAssumed Answered

AD7746 capacitance range vs. excitation voltage

Question asked by trschneider1 on Mar 2, 2016
Latest reply on Mar 11, 2016 by Wa$iM

I am interfacing to a sensor with 30pF nominal capacitance and total change of +/-1pF.  Also, the breakdown voltage of the sensor is approx 2V, so I'd like to keep the excitation voltage around 1V or below, using a VDD of 3.3V.  I know the maximum CAPDAC setting is approx. 17pF, but I've seen some other posts on this forum indicating that this may be dependant on excitation voltage.  I don't see this characterized anywhere in the datasheet.  Is there a linear relationship between excitation voltage and CAPDAC range?  For that matter, is there a relationship between excitation voltage and dynamic range of the converter?