BQ40Z80: BQ40Z80 Precharge problem

habibe arslan

Part Number: BQ40Z80
Other Parts Discussed in Thread: BQSTUDIO

Hello,

I can't get out of the BQ40Z80 precharge mode and I can't start charging with the precharge current I set. I have added the bqstudio display and pre-charging settings.

Thanks,

8 months ago

0 Anthony 8 months ago

TI__Genius 16530 points

Hello,

Can you please tell me what the purpose of the DSG FET being active while PCHG is active?

Can you also please send the .gg and log file of this situation occurring?

Regards,

Anthony Baldino

0 habibe arslan 8 months ago in reply to Anthony

Prodigy 65 points

Hello,

DSG FET is automatically activated when FET EN is used. I don't know why. 150823.gg.csv

0 Anthony 8 months ago in reply to habibe arslan

TI__Genius 16530 points

Hello,

If you are turning on the PCHG and CHG FET manually via the toggle commands, please try using these commands with the FET_EN = 0.

Regards,

Anthony Baldino

0 Nate Martin 8 months ago in reply to Anthony

Prodigy 220 points

Im not sure what your setup is, but if you don't have PCHG_COMM = 1 in the FET Options the BQ40Z80 will use the PCHG fet output as the precharge fet rather then the CHG fet and will wait for PACK to be equal to BAT.

If you do not have a dedicated precharge circuit attached to the PCHG pin, then you need to set PCHG_COMM = 1.

Be careful, this will result in high inrush current if you are charging a capacitive load.

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BQ40Z80: BQ40Z80 Precharge problem