BQ20Z90-V150: Common Calibration Current Offset

Mark Ackerson

Part Number: BQ20Z90-V150
Other Parts Discussed in Thread: BQ20Z90

Customer wants to use a common calibration for BQ20Z90 based production battery packs.

Current and voltage spread is reasonable, but they need to know more about the current offset.

Is there any internal functionality in the IC which ‘auto-adjusts’ or similar?

The reason I ask this is that we put 50 samples through with NO calibration (just using defaults in the GG), and initially saw a spread around +/- 4mA. However, an hour or so later these offsets had become zero - which is unexpected.

Please advise.

Thanks,
Mark

over 3 years ago

0 Wyatt Keller over 3 years ago

TI__Guru** 102355 points

Hello Mark,

The bq20z90 performs an auto calibration when there are no communication and within the temperature range.

Were all the parameters the same for the test? Temperature can play a role if the gauge isn't calibrated. Did the same thing occur to the calibrated boards?

Sincerely,

Wyatt Keller

0 Mark Ackerson over 3 years ago in reply to Wyatt Keller

TI__Genius 10190 points

Hi Wyatt,

Yes, all of the boards were at the same temperature.

Regards,
Mark

0 Wyatt Keller over 3 years ago in reply to Mark Ackerson

TI__Guru** 102355 points

Hello Mark,

Then the gauge probably did auto calibration to set the offset for the most accurate gauging.

Sincerely,

Wyatt Keller

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BQ20Z90-V150: Common Calibration Current Offset