Hi,
I'm now searching for a way to perform capacitive conversions of really small capacitors (20 fF - 50 fF) and I have two questions regarding the FDC1004 chip.
1) Why is the resolution 0.5 fF in the best cases? Theoretically, if the maximum value is 16 pF and we have 23 bits for the conversion (one is the sign bit so it does not count) the resolution should be 16 / (2^23) = 0.019 fF, pretty smaller than teh one in the datasheet.
2) For capacitance changes as the mentioned before (around 30 fF), is it recommended to your this chip? In case that yes, which considerations/recommendations would you give for obtaining the best performance? Afterall, parasitic capacities will be affecting the system...
Best regards.