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FDC1004: Environmental change

Part Number: FDC1004

Hi Team,

My customers are suffering from measurement fluctuations due to changes in the environment.
As an experiment, My customer disconnected the sensor part of FDC1004EVM board and opened CH1 - CH4.
As a result of measuring the temperature and humidity, the detected value shifted.
Is there a lower limit of the capacity for detection?

I understand that the humidity change is not affected, but the temperature change has a change in the tcG characteristic.
As a customer's request, it is a constraint to acquire 1 Ch at a high speed.
I would like to know how to not affect the change of temperature and humidity.

Best Regards,
Kenji

  • Hi Kenji,

    The full-scale range of the input capacitance is +/-15pF, and the maximum offset capacitance is 100pF.

    The best way to compensate for capacitive drift due to environmental changes is to use a reference sensor. I would suggest using a differential measurement between the original sensor and the reference sensor. You can read more about differential measurements in section 8.4.2 of the datasheet.

    Regards,