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Original question:

BQ35100: BQ35100 calibration

BQ35100: How to test BQ35100's accuracy after calibration for mass production?

user5874521
Intellectual 450 points
Part Number: BQ35100

In mass production, is there a simple method to test BQ35100's accuracy(current and charge accumulation) after doing calibration?

  • 0
    TI__Genius 10370 points

    Calibration is neede to be done in Accumulation Mode and charge accumulation is only done in ACC mode as well. So the easiest method is to apply a known current in this mode, send gauge start, and read [Current] to make sure it matches the value you are applying. 

    There is no shortcut for long term accumulation. 

  • 0 in reply to Vos
    Intellectual 450 points

    Hi Eric,

    Thank you for your reply.

    In the mass production, How to judge pass or fail? For example, the test stable current is 10.5mA. How to set the pass range? Or what is the typical accuracy in ACC mode? If BQ35100's measured value is 10mA, 11mA, or 12mA, do they pass the test?

  • 0 in reply to user5874521
    TI__Genius 10370 points

    This is not something i can say. It all depends on your acceptable error. i will say we normally deal with error in terms of ADC LSB's. The size of the senseR will determine how much current equates to a single LSB. The are other factors such as the senseR PPM temperature drift ect... I will say after you calibrate i would expect the current to be very accurate (+/- 1mA) at those same conditions, but i cannot determine your pass/fail criteria. 

    Thanks,

    Eric Vos

  • 0 in reply to Vos
    Intellectual 450 points

    Hi Eric,

    We use the same Rsense as BQ35100_EVM(demo board) (0.1R/1%/75ppm).

    BQ35100's coulomb ADC is 15bit. The resolution is about 38uA at 0.125V/0.1R.

    In 25℃, what is the accuracy of demo board? What is the typical error in different current flow?

  • 0 in reply to user5874521
    TI__Genius 10370 points

    Please see your other post. I expect In ACC mode your LSB error at 25C (If calibrated correctly to be) to be less than 2LSB of Error.