• State
  • Locked Locked
  • Replies 1 reply
  • Subscribers 63 subscribers
  • Views 88 views
  • Users 0 members are here
Support feedback
Options
Options
Related

This thread has been locked.

If you have a related question, please click the "Ask a related question" button in the top right corner. The newly created question will be automatically linked to this question.

BQ76942: fullscale digital range

Fabio Gou
Expert 4375 points
Part Number: BQ76942

" The effective fullscale digital range of the cell measurement is 5 × VREF1, and the effective fullscale digital
range of the ADCIN measurement is 1.667 × VREF1, although the voltages applied for these measurements
should be limited based on the device electrical specifications."

Why the fullscale is 5 × VREF1 and 1.667 × VREF1?

Is this because the internal design of the ADC/Amplifier circuit?

Could you pls help to describe this?

thanks

  • 0
    TI__Expert 4085 points

    Dear Fabio,

    In order to allow the user to have the most precision and accuracy for their measurements, the BQ76942 allows the gain to be set by the function of each pin rather than a universal gain value for all pins. The two values you mentioned are for measuring cell voltage and measuring the multipurpose GPIO pins voltage when they are configured as an ADC input. Each pin that probes cell voltage is rated up to 85V, while the GPIO pins are limited to ~2.1V when used as ADCs. Due to this it is best to have custom gains for the two situations. The 5VREF1 only applies to the cell voltage input while the 1.667VREF1 only applies to the GPIO input pin's gain. This is because they have different amplifier/ADC setups due to the larger voltages seen on power pins.

    Best,

    Asher Nederveld