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BQ76940: ADC Measurement accuracy drift over time and ageing

Vishal Verma
Prodigy 40 points
Part Number: BQ76940

Hello,

I am using this IC for my application and I need to understand the trend and testing data of ADC measurement accuracy deviation of voltage, current and temperature sense over time due to ageing affect.

What are the main factors that contribute to it?

Regards,

Vishal Verma

  • 0
    TI__Expert 6085 points

    Hi Verma,

    Please detail your application environment.

    The bq769x0 d/s datasheet does not specify the drift or the aging information of the ADC accuracy. However, an accelerated temp(125C) to 700Hrs was conducted. For the ADC range "aging"can be summarized  as  ~

    CELL Voltage range(V) temp range device age Nominal worst case (ave +3 sigma)
    2V-5V 0-125C 80Hrs(note1) 9.79mV 19.87mV

    note 1: 80hrs @125C is equivalent to 1.54years at 45C.

    Typically, the range of interest and the desired temp range of the application will give different equivalency.

    hope this helps out.

  • 0 in reply to Vish Nadarajah
    Prodigy 40 points

    Hello Vish,

    Thanks for your reply.

    In our application we have the measurement range of 2 to 4.2V with approximate temperature range of 0 to 55degC.
    What would be the measured data as per your data captured.

    Also, Is Nominal data provided above the average of drift distribution with a 3sigma deviation centered around it?

    Regards,
    Vishal Verma

  • 0 in reply to Vishal Verma
    TI__Expert 6085 points
    In the range of the your application, refer to the d/s. ADC accuracy +/- 50mV is a conservative number to use. This number has taken into consideration of many variation and has +/- 4STD derivation.