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LAUNCHXL-F28379D: LAUNCHXL-F28379D + DRV8305: Does ADC offset correction required for every different setup?

Ananthkumar Selvaraj
Prodigy 120 points
Part Number: LAUNCHXL-F28379D
Other Parts Discussed in Thread: DRV8305

I am using LAUNCHXL-F28379D launch pad and DRV8305 and Teknic PMSM motor.

Do I need to do ADC offset correction for each of current sensor channel before start my application?

When I changed launch pad or DRV board, Do I need to re-calibrate ADC offset correction for each of the measurement channels?

Please recommend me the good practice.

Thanks

  • 0
    TI__Mastermind 34405 points

    Hi Ananth,

    During the boot process, the ADC offset correction is automatically populated to the offset trim registers and the values of the offsets are determined during TIs production process.  For general applications, these factory measured offsets work well with TIs LAUNCHXL-F28379D and DRV8305 HW designs in correcting the offsets and there is no need to perform offset correction each time as long as there is no ADC module reset invoked as this clears the offset correction.

    The only instances where you may need to perform ADC offset correction is when you have a new HW design where reference lines and ADC inputs are not optimally routed maybe due design constraints.

    Let me know if you have any other questions on this topic.

    Regards,

    Joseph 

  • 0 in reply to Joseph Casuga
    Prodigy 120 points
    Hi Joseph,

    I am using Launchxl-F28379D both V1 and V2 and trying to execute code for sensorless FOC for PMSM (DRV8305).
    Code for V1 not able to drive the PMSM motor in V2. Motor stalls and draws more current. After adjusting the ADC offset correction values in V2, we found PMSM motor was running for the same code. So based on our testing with V1 and V2 versions of launchxl-F28379D, we found ADC offset correction values is required for different board.
    FY I, ADC offset correction value for V1 is 2322 and V2 is 2286.

    Our understanding is different from your reply.
    We found ADC calibration results different behavior, please comment.
  • 0 in reply to Ananthkumar Selvaraj
    TI__Genius 17175 points

    A typical scenario when ADC offset recalibration is used is when different boards run the same motor. Another example is when the same board has been running for a long period of time and the hardware components for the voltage and current feedback might have changed in value due to ambient conditions or component tolerances. In this last example it is recommended to run the offsets recalibration as needed depending on the quality of the hardware components used in a particular board.

    Sean