why can not Enter the shutdown mode?(BQ20Z75)

Libing Huang

Intellectual 285 points

Other Parts Discussed in Thread: BQ24103

Hi,

why Manufacturer Access enter 0010,device can not Enter the shutdown mode? Thanks!

over 6 years ago

0 Batt over 6 years ago

TI__Mastermind 42535 points

Once you send the shutdown command you must have the PACK pin voltage < Charger Present threshold. I can't see what your charger voltage is here. If your charger has been removed, the device automatically enters shutdown.

0 Libing Huang over 6 years ago in reply to Batt

Intellectual 285 points

our charger used the bq24103,and its suply voltage (12V) turned off ,but device still can not enter into shutdown mode

0 Batt over 6 years ago in reply to Libing Huang

TI__Mastermind 42535 points

I'm not familiar with the charger, but if your PACK pin voltage is there, with the shutdown command and no current, you will not shutdown.
As an alternative, you can try to check and see if the shutdown voltage in df is set higher than your BAT voltage, with no current does the gauge shutdown after 10s. If that works, it's your charger that's the issue.

0 Libing Huang over 6 years ago in reply to Batt

Intellectual 285 points

shutdown command is not effective if shutdown voltage set in df higher than BAT voltage? as i known,it not like that,just one of the three conditions is ok. Am I right?

0 Batt over 6 years ago in reply to Libing Huang

TI__Mastermind 42535 points

Yes, if one of three is met, it will shutdown.

0 Libing Huang over 6 years ago in reply to Batt

Intellectual 285 points

but why my device can not ? how can i check?

0 Batt over 6 years ago in reply to Libing Huang

TI__Mastermind 42535 points

Please refer to the TRM. If you're unable to shutdown, then you are probably violating some requirement or other.

This mode has been tested and verified to work.

0 Libing Huang over 6 years ago in reply to Batt

Intellectual 285 points

Hi Batt,
My device diagram is as below, In normal mode,DSG FET and CHG FET already on, voltage at pack pin equals to the BAT, at this time,I enter 0010 in Manufacturer Access,but ( voltage at pack pin< Charger Present threshold) did not meet. Is it the reason why device can not Enter the shutdown mode?tks

0 Batt over 6 years ago in reply to Libing Huang

TI__Mastermind 42535 points

Yes.

0 Libing Huang over 6 years ago in reply to Batt

Intellectual 285 points

1.Is there any other method can turn off CHG FET or DSG FET?can host software(mcu)write 0x46register with sbs cmd? thanks!

2.As I known,device(bq20z75) can enter into shutdown mode when write 0x0010 in Manufacturer Access.

but ,how can host(mcu) control device enter into shutdown mode with command ? we can read FullChargeCapacity(0x10) register with SBS Cmd,but how can access the Shutdown(0x0010)? Ican not find related instructions from TRM

0 Libing Huang over 6 years ago in reply to Batt

Intellectual 285 points

Hi Batt,
If I changed charger Present threshold,Is there any other problem for my device work normal?

0 Libing Huang over 6 years ago in reply to Batt

Intellectual 285 points

Hi,Batt:

As I known,device(bq20z75) can enter into shutdown mode when write 0x0010 in Manufacturer Access.
but ,how can host(MCU) control device enter into shutdown mode with command?
we can read FullChargeCapacity(0x10) register with SBS Cmd,but how can access the Shutdown(0x0010)?
Thanks!

0 Batt over 6 years ago in reply to Libing Huang

TI__Mastermind 42535 points

Shutdown is not an SBS command, you are confusing SBS with mfg access. Please refer to the TRM.

0 Batt over 6 years ago in reply to Libing Huang

TI__Mastermind 42535 points

No, your df will only be updated if voltage is > flash update OK voltage or pack V > Charger Present Threshold.

Because of the holidays, TI E2E™ design support forum responses will be delayed from Dec. 25 through Jan. 2. Thank you for your patience.

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why can not Enter the shutdown mode?(BQ20Z75)