DAQ-CN0350 Solution Input Charge

We are designing a new DAQ for measuring output from Hemispherical Resonator Gyroscope sensor.DAQ should meet the requirement of measuring charge of order 0.001pC at 5KHZ frequency.
Could you please confirm the solution based on CN0350 evaluation kit meets our requirement of measuring charge in order of femto coloumb.

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  • 0
    •  Analog Employees 
    on Jul 21, 2020 4:11 PM 7 months ago

    Hi,

    What is the range of input charge that you will be measuring? The total system error of the CN0350 after calibration is at 0.25% FSR. To be able to attain accurate measurements of 1 fC, capacitor C2 should be changed such that the input charge range is much less than 400 fC. A good design rule is to make it less than half of this range if you want to detect 1 fC changes and less than a tenth of this range if you want to accurately measure 0.001 fC.

    Below is the equation used to calculate C2 for a sensitivity of 1 pC/g and 1000g range making the input charge range to 1000pC.

    Regards,

    Nikko

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  • 0
    •  Analog Employees 
    on Jul 21, 2020 4:11 PM 7 months ago

    Hi,

    What is the range of input charge that you will be measuring? The total system error of the CN0350 after calibration is at 0.25% FSR. To be able to attain accurate measurements of 1 fC, capacitor C2 should be changed such that the input charge range is much less than 400 fC. A good design rule is to make it less than half of this range if you want to detect 1 fC changes and less than a tenth of this range if you want to accurately measure 0.001 fC.

    Below is the equation used to calculate C2 for a sensitivity of 1 pC/g and 1000g range making the input charge range to 1000pC.

    Regards,

    Nikko

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