BQ76PL455EVM: Cell sample calculation

Alexander Hernandez

Prodigy 90 points

Part Number: BQ76PL455EVM

Hello,

Why is the value .000076295 used to calculate cell sample, and how was this value calculated.

Thank you,

Alexander

over 5 years ago

0 David Wiest Jr over 5 years ago

TI__Genius 11480 points

Hi Alexander,

Please check section 7.3.3.4 of the datasheet (Vsense Input Channels) for details on how to get from a hex value to a voltage. All of the details you need are described there.

0 Alexander Hernandez over 5 years ago in reply to David Wiest Jr

Prodigy 90 points

Hello David,

In regards to Vref. I calculated it and saw it was equal to 2.5, is this correct? If so why is Vref set to this value?

Thank you,

Alexander Hernandez

0 David Wiest Jr over 5 years ago in reply to Alexander Hernandez

TI__Genius 11480 points

Hi Alex,

Yes, you are correct.

Vref is the actual reference voltage for the SAR ADC. 2.5V is a relatively common voltage to see for a bandgap reference, I believe (I could be mistaken, so take this with a grain of salt). I don't know if by design or by coincidence, but it also simplifies the math as well.

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BQ76PL455EVM: Cell sample calculation