The CHRG_EXTCHRG_ENZ of BQ24156 goes LOW when DEVOFF to TWL6030

WTMEC_FoneC

Intellectual 535 points

Other Parts Discussed in Thread: TWL6030

Dear Sirs,

The internal charger and external charger works fine when device is powered on.

When the device is powered off by the SW command to set the DEVOFF bits of MOD, CON, APP groups.

CHRG_EXTCHRG_ENZ will become HIGH automatically after above action.

This makes the BQ24156 not enabled so that all the internal and external charger are both not working.

My customer think this is not reasonable since the reference design is as below:

Any advice?

Thank you.

over 10 years ago

0 Kevin LaRosa over 10 years ago

TI__Genius 17380 points

Hey Fone,
Why are they disabling the PMIC during charging? TWL6030 should always be on while charging is taking place.
Thanks,Kevin LaRosa

0 WTMEC_FoneC over 10 years ago in reply to Kevin LaRosa

Intellectual 535 points

Hi Kevin,

1. They followed the reference design as the picture above in the datasheet.

2. chrg_extchrg_enz will goes HIGH automatically when DEVOFF.

This is normal right? Not much description about this pin when DEVOFF in Datasheet.

3. So pull LOW to let BQ24156 always alive?

Thank you.

0 Kevin LaRosa over 10 years ago in reply to WTMEC_FoneC

TI__Genius 17380 points

Hey Fone,

DEVOFF causes an ACTIVE to OFF transition as described in the Power State-Machine section of the datasheet (T3 transition to be particular).

It is normal for external charging to be gated when the PMIC is OFF. The PMIC is designed to manage the system power, disabling it will cause it to not be able to do this so it shuts the system down.

I guess they could pull the pin LOW externally if they really really want the Power Management IC to be OFF while the system is using an external charger, but I don't recommend it.

Thanks,

Kevin LaRosa

0 WTMEC_FoneC over 10 years ago in reply to Kevin LaRosa

Intellectual 535 points

Dear Kevin,

Got it.

Thank you.

Power management

Power management forum

The CHRG_EXTCHRG_ENZ of BQ24156 goes LOW when DEVOFF to TWL6030