BQ28Z610 Sense Resistor Selection

B-A

Other Parts Discussed in Thread: BQ28Z610, BQSTUDIO

Hello,

Regarding the sense resistor, the datasheet for the BQ28Z610 IC mentions that the sense resistor may be chosen in the range of 1-3mOhms. On the demo board, a 1mOhm resistor is used. If I desired to change this to a 3mOhm resistor, does the gauge automatically adjust for this, or is calibration necessary using the "Current: CC Gain" parameter in the gas gauge settings?

Thank you for your time.

Blake

over 8 years ago

0 Benjamin Lough over 8 years ago

TI__Mastermind 26695 points

Hi Blake,

You would need to perform current calibration on your device to adjust for the 3mOhm sense resistor. I would suggest changing the sense resistor on the EVM, use bqstudio to perform current calibration and export a .srec file. You can use the .srec to program other gauges as necessary.

Best Regards,
Ben Lough

0 B-A over 8 years ago in reply to Benjamin Lough

Intellectual 720 points

Ben,

Thank you for clarifying that. As a follow up question, I noticed that the TRM states that calibration is not necessary due to hardware improvements and should only be used if a CC offset is observed. Would you recommend a calibration regardless?

Thanks,
Blake

0 Benjamin Lough over 8 years ago in reply to B-A

TI__Mastermind 26695 points

Hi Blake,

Majority of cases you will not need to calibrate current, only if you see an offset. However, if you increase the sense resistance, it increases the voltage input to the coulomb counter on the gauge so calibration would be necessary.

Best Regards,
Ben Lough

0 B-A over 8 years ago in reply to Benjamin Lough

Intellectual 720 points

Ok, thank you much.

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BQ28Z610 Sense Resistor Selection