BQ40Z80: Ra table

xiulan zhao

Part Number: BQ40Z80
Other Parts Discussed in Thread: BQSTUDIO

Hi,

We use 40Z80 fuel gauge. The technical reference mentions that before storage to Data Flash, the resistance values are normalized to 0°C as Ra[dod] =R[dod]/exp(Rb[dod]*T) where R is the measured resistance value at a given DOD.

Are the Ra values in gg file normalized to 0°C? Are the CompRes in the Bqstudio file normalized 0°C?

Is the CompRes the normalized resistance increment after low temperature compensation? Or is the normalized total resistance after compensation?

Best Regards,

Xiulan

over 3 years ago

+1 Wyatt Keller over 3 years ago

TI__Guru** 105590 points

Hello Xiulan,

I believe the application note on impedance track operation explains this in more detail: https://www.ti.com/lit/an/slua364b/slua364b.pdf?ts=1656006685031&ref_url=https%253A%252F%252Fwww.google.com%252F

CompRes should be the resistance calculated after the temperature compensation is applied with the Rb resistance values.

Sincerely,

Wyatt Keller

0 xiulan zhao over 3 years ago in reply to Wyatt Keller

Prodigy 160 points

Hi Wyatt Keller,

As you said,CompRes should be the resistance calculated after the temperature compensation is applied with the Rb resistance values. I want to know whether the temperature used for calculation is the current T_Sim or the predicted future T_Sim ?

Sincerely,

Xiulan

+1 Wyatt Keller over 3 years ago in reply to xiulan zhao

TI__Guru** 105590 points

Hello Xiulan,

What do you mean by future T_sim? The T_sim value is the Temperature() that the gauge used for the simulation at that specific point. When the simulation occurs it will use the present temperature for correction to CompRes.

Sincerely,

Wyatt Keller

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BQ40Z80: Ra table