DRV8343-Q1: Offset voltage calibration questions

Part Number: DRV8343-Q1

Tool/software:

Hi,

My customer has three questions regarding offset voltage calibration:

A. Where are the values of the autocalibration which is carried out during the start-up stored?
B. How can these values be used (which unit do the values have)?
C. What error for gain and offset voltage do I have to consider in my tolerance calculation after calibration?

Best regards

  • Hi,

    Thank you for reaching out. I will get back to you by the end of the week.

    Best,

    Allison F.

  • Hi,

    The values of the autocalibration are stored within the device logic and cannot be directly accessed. Both SPI and H/W options allow you to perform calibration through the use of the CAL pin. For the SPI option, autocalibration can be performed again by enabling the AUTO_CAL register setting. You can then rerun autocalibration with the CSA_CAL_X register. Figure 35 demonstrates how calibration is executed by shorting the shunt resistor. 

    Your gain will range from 4.85V/V to 40.8V/V depending on certain conditions. I have included the table for you to reference. The error for offset voltage can range from -4mV to 4mV when your gain is equal to 10, 20, or 40 V/V. It could also range from -5mV to 5mV when the value for gain is 5 V/V.

    Best,

    Allison F.

  • Thank you very much Allison!