How to Calibrate the ADC AD7718

Hi,

          I am working with the ADC AD7718 and interfacing it to 8051 microcontroller, i am able to drive the adc and receiving the converted data. Now I want to write the Auto calibration routine for the same please any one help me in this case.

Thank you,

Sharath Pandith

  • 0
    •  Analog Employees 
    on Oct 13, 2011 4:51 PM

    Hi Sharath,

    Depending on the mode you are using the AD7718 in you may not need to perform a calibration. The AD7718 has factory calibrated gain coefficients and if chopping is enabled then there is no need for offset calibration. The factory calibration is done at 25 degrees C and so unless you operate at a significantly different temperature or if you change the range (gain) then this does not need to be changed.

    If you are not using chopping then you should perform either a System or Internal Zero-Scale Calibration. This will update the offset coefficient. If it is the case that you have changed the gain or are operating at a significantly different temperature then you will need to perform either a System or Internal Full-Scale Calibration. This will update the gain coefficients. System calibrations are used to take the entire circuit offset and gain errors into account and internal calibration only take the ADC errors into account.

    For more information on this please see page 40 of Rev.0 of the AD7718 datasheet http://www.analog.com/static/imported-files/data_sheets/AD7708_7718.pdf

    Regards,

    Rob