BQ24031: chip consuming high current without any load

Mathias Breuss21

Part Number: BQ24031

Hi Team,

we have been using the BQ24031RHLR for a previous project and it worked fine on many 100k units.

Now with our new design we experienced on some boards that the power manager got damaged after production. The chip consumes around 230mA without any battery or load attached. In this case the chip is supplied with 5V from AC pin. The chip still provides 5V at the output pins but gets really hot. The /ACPG pin which is a open drain output remains at 200mV with a pull-up of 100k to 3.3V.

The package marking says:

BZJ

TI 33k

C6E5

From the datasheet I could not tell what the second and third line means and how to translate it to a batch number or production week/year.

After having replaced the chip with a new sample everything worked fine.
The USB and the LDO pin are the only pins that are not connected on the board and theoretically the chip could have been damaged by ESD but this is only a theory.
Was wondering if you have a similar case with any other customer? Could it be related to this specific production batch?

thank you in advance

/Mathias

over 5 years ago

0 Raheem over 5 years ago

TI__Mastermind 21590 points

Hello Mathias,
If you're powering the device through AC, /ACPG should be low though i expect it to be lower than 200mV. Try powering up through USB and see if the voltage on /ACPG stays the same. Also check all the other pins for unexpected voltages.

0 Mathias Breuss21 over 5 years ago in reply to Raheem

Prodigy 50 points

Hi and thanks for the quick reply.

Powering from USB input works fine, the chip works as expected and the open drain output /USBPG goes low down to 10mV with 100k pull-up.

It seems as only the AC channel is damaged as it works fine with USB or battery input power source.

What could have caused this damage on the AC channel? Overvoltage? Overcurrent? ESD?

kind regards

/Mathias

0 Raheem over 5 years ago in reply to Mathias Breuss21

TI__Mastermind 21590 points

Mathias,
This could be ESD damage. That much current with no load and no bat is not expected. Before we proceed to do a failure analysis, have you replaced the IC on the same board with another unit to ensure there aren't any problems with the board?

0 Mathias Breuss21 over 5 years ago in reply to Raheem

Prodigy 50 points

Hi,

yes I did replace the chip on one board and it worked fine after that. The power path manager remains cold and the current consumption drops to almost 0mA without load and the regular current consumption with load.

In total I got 3 boards with this type of error. Our concern is that we could get bad yield in production if the problem is not ESD related. If it is ESD related it won't be a problem for series production.

0 Raheem over 5 years ago in reply to Mathias Breuss21

TI__Mastermind 21590 points

Hello Mathias,

Can you submit the unit to your local field application engineer for Failure Analysis?

Regards,

Raheem

0 Mathias Breuss21 over 5 years ago in reply to Raheem

Prodigy 50 points

Hi Raheem,

I got in touch with our local TI support and he agreed to your suggestion. I will send the board and leave this service case open until I got further information as it can be of help to others in the future as well.

Kind regards

/Mathias

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BQ24031: chip consuming high current without any load