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Original question:

FDC2214: sensor frequency

FDC2214: LC Tank Sense Frequency Optimisation for range and sensitivity

Dan1
Intellectual 865 points
Part Number: FDC2214

The FDC2214 datasheet shows how to calculate the frequency from the value of the parallel capacitor and inductor.

However, is there a way to calculate the optimal frequency we need so that we can choose the capacitor and inductor values around that frequency?
I assume this should depend on remote material being sensed and the materials that are in the way.

The sensing plates we are testing are significantly larger than the plates on the FDC2214EVM which may also make a difference.

  • 0
    Intellectual 865 points

    I'm struggling to find any research on how changing frequency affects a capacitive sensor, or more specifically, an LC tank sensor.

  • 0 in reply to Dan1
    TI__Mastermind 23810 points

    We have done more work on this for our inductive sensing portfolio. Inductive sensing uses metal targets, and it is possible to determine how thick the target needs to be for a given resonant frequency (or visa versa).

    For the FDC2214, the main thing is to make sure that you are operating within the design space of the device and that you are not operating too close to any interfering frequencies if there are nearby transmitters. We have found that the size of the sensor has a bigger impact than the frequency of operation.