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FDC2114EVM: Not able to measure capacitances of a standard 200nF capacitor

Part Number: FDC2114EVM

Dear Sir,

I have been trying to use the FDC2114EVM for measuring capacitance changes in my sensor. The sensor however could not be measured properly using the module. As a cross check I went ahead to measure certain standard capacitors starting from low value capacitors like 47pF, upto 2000pF which are read fairly well. However as I start measuring higher values like 10nF, the output drops down showing few pF. I even tried changing the 18uH with a 1mH inductor to increase the range of the device but that did not help. Capacitors in nF ranges are not measured truthfully. Are there any other settings I have to execute.

Regards,

Vijay

  • Hello Vijay,

    Please check the sensor amplitude with the 200nF capacitance. It is likely that the sensor Rp had dropped out of the recommended operating amplitude of 1.2Vp to 1.8Vp. Adjust the channel's IDRIVE setting to increase the sensor amplitude and also the device deglitch filter setting to match the sensor frequency.

    Regards.

    Chris O