FDC2214EVM: Least count that can be measured

Vedansh Sharma

Part Number: FDC2214EVM
Other Parts Discussed in Thread: FDC2214, LDC1614

Hello,

I wanted to know that what is the least count of "FDC2214EVM: FDC2214 with Two Capacitive Sensors Evaluation Module" capacitance measurement without the use of external circuit.
Is it ~0.5fF, as I came across these values in datasheet but wasn't sure.

Also there is another query regarding the inbuilt sensor, can they both be used as co-planar capacitance and if yes do you have any results available with you.

Regards,
Vedansh Sharma
vedansh@nebulaa.in

over 6 years ago

0 Clancy Soehren over 6 years ago

TI__Mastermind 23810 points

What do you mean by "least count"? Are you referring to the resolution?

By coplanar, are you trying to measure the capacitance between two plates? You can see possible sensor implementations in this app note:

www.ti.com/.../snoa927

0 Vedansh Sharma over 6 years ago in reply to Clancy Soehren

Prodigy 80 points

Yes I am referring to the resolution (e.g : C2 - C1 = 0.2pF, so to measure this change ).

Can it be measured by FDC2214EVM ?

Regarding co-planar capacitor please refer to this document. ( )

0 Clancy Soehren over 6 years ago in reply to Vedansh Sharma

TI__Mastermind 23810 points

Co-planar is no problem (as you can see, the EVM uses this type of sensor).

Resolution is not a completely straight forward answer and depends on multiple factors (such as your needed sampling rate). This app note discusses resolution for the LDC parts, but the FDC2214 has very similar performance as the LDC1614. In particular, look at graph 5 to see the frequency resolution.

www.ti.com/.../snoa944.pdf

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FDC2214EVM: Least count that can be measured