BQ20Z95: Software Board Offset Calibration bqEVSW problem

Daniel Shlomo

Part Number: BQ20Z95

Hello,
I'm trying to generate a golden image file to bq20z95 battery pack and every time at the Calibration part (according to SLUA409A) when I'm doing the "CC Board Offset calibration" DSG and CHG FET STATUS go to '0'
its mean fets are close and don't have chg\dsg current.

Also, in each APP NOTE write something different about the Calibration part.
Is there an unequivocal answer to do or not to do Calibration with the cells-attached or not attached in mass production?

Thanks for the helpers.

over 3 years ago

0 Kang Kang over 3 years ago

TI__Mastermind 24870 points

Hello Daniel,

I don't think it should go to zero. Can you try this with an EVM?

0 Shirish over 3 years ago

TI__Guru 57747 points

Hi Daniel,

Calibration should be performed before cells are attached.

0 Daniel Shlomo over 3 years ago in reply to Shirish

Prodigy 85 points

The calibration was performed before the cells were attached.
Every time that I'm doing "Software Board Offset Calibration" the FETS STATUS goes to '0' with and without cells, before and after attaching cells, every time. All the combinations.
Maybe I should send Manufacturer Access Command 0021?
Because at SLUA409A in "Calibration if cells are attached" it's said at the end to send Manufacturer Access Command 0021, but in "Calibration of the board if cells are not attached" there is no step like that.

0 Shirish over 3 years ago in reply to Daniel Shlomo

TI__Guru 57747 points

Board offset calibration requires current to be zero. Therefore the FET gets turned off.

See section B.2 FETControl(0x46) of Technical reference manual for manual control of FETs

Power management

Power management forum

BQ20Z95: Software Board Offset Calibration bqEVSW problem