bq25890 / Clear BATFET_DIS bit during shipping mode

S.Satoshi

Other Parts Discussed in Thread: BQ25890, BQ25895

Hi,

Please let me ask about exiting shipping mode. My customer consider to clear BATFET_DIS bit to exit shipping mode, then can we clear it via I2C communication during shipping mode? I mean that I'd like to know if I2C module in bq25890 is activated during shipping mode.

Please let me know how to clear the bit if I2C module is not activated during shipping mode.

Best Regards,

Sonoki / Japan Disty

over 9 years ago

0 Jeff F over 9 years ago

TI__Guru**** 166896 points

Use the /QON pin BATFET enable/reset control input. When BATFET is in ship mode, a logic low of tSHIPMODE (typical 1sec) duration turns on BATFET to exit shipping mode.

0 S.Satoshi over 9 years ago in reply to Jeff F

Guru 21685 points

Hi Jeff,

I know that it can be exited by using /QON. I'm asking how to clear BATFET_DIS bit because there are four way to exit shipping mode in datasheet.

Please give your comment for my question.

Best Regards,

Sonoki

0 Jeff F over 9 years ago in reply to S.Satoshi

TI__Guru**** 166896 points

/QON clears the bit.

0 S.Satoshi over 9 years ago in reply to Jeff F

Guru 21685 points

Hi Jeff,

Is I2C communication not activated during ship mode?

Best Regard,
Sonoki

0 Jeff F over 9 years ago in reply to S.Satoshi

TI__Guru**** 166896 points

I2C communication is not active.

0 S.Satoshi over 9 years ago in reply to Jeff F

Guru 21685 points

Hi Jeff,

I confirmed that the I2C communication is active and BATFET_DIS bis can be cleared at ship mode when VBUS is connected. So I understand that you meant that I2C communication is not active at ship mode without VBUS. Is my understand correct?

Best Regards,

Sonoki

0 S.Satoshi over 9 years ago in reply to S.Satoshi

Guru 21685 points

Hi Jeff,

Can you give your comment for this question?

Best Regards,
Sonoki

0 Jeff F over 9 years ago in reply to S.Satoshi

TI__Guru**** 166896 points

correct, I2C communication is not active without VBUS and in ship mode.

0 Julhio over 9 years ago

Intellectual 310 points

Hi Satoshi.

I have the same doubt about the /QON and the shipping mode (in BQ25895).

In datasheet there are few information about it and the support is not helping so much...

I'm beginning to think that the best way to microcontroller force exit shipping mode is using a mosfet N or NPN on /QON to tie it to GND.

If you have some advance or additional information, please share.

Best regards,

Julhio.

0 Brian Uznanski26 over 8 years ago in reply to Jeff F

Prodigy 20 points

I am also unclear on the operation of the /QON pin.

I have this pin tied to ground on by board.

Are there any consequences to having this pin always grounded?

Thanks,

Brian Uznanski

0 Jeff F over 8 years ago in reply to Brian Uznanski26

TI__Guru**** 166896 points

Hi Brian,

/QON is internally pulled high. When the BATFET between BAT and SYS is turned off via I2C (i.e. in ship mode for lowest BAT ), pulling /QON low for tSHIPMODE (typical 1sec) duration turns on the BATFET, allowing the battery to supply SYS and/or be charged, if VBUS is plugged in. When VBUS is not plugged-in, pulling /QON low for tQON_RST (typical 15sec) duration turns off the BATFET for tBATFET_RST (typical 0.3sec) and then re-enables the BATFET. Since VBUS is not plugged in, the system is only powered by SYS and this provides a full system power reset.

Since /QON is internally pulled high through a resistor, there is no need to GND it is not being used. In fact, grounding it will waste power.

0 Jeff F over 8 years ago in reply to Jeff F

TI__Guru**** 166896 points

Hi Brian,

Moreover if you leave /QON ground, you will need to disable its system capability using REG09b2 BATFET_RST_EN. So I suggest not grounding it.

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bq25890 / Clear BATFET_DIS bit during shipping mode