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BQ25896: BQ25896RTWR destroyed (on 2 boards) !!

Part Number: BQ25896

Trying to track down a problem involving 2 BQ25896RTWRs on two separate boards (out of 50-100 produced).


Both ICs have literally smoked, as shown in picture.

Prior to smoking, a "clicking" noise was heard coming from battery charge circuit, presumably the inductor.

At the time, the charge circuit was being used to charge an on board Li-Ion 5000mah battery ... as well as a Samsung S23 phone that was in a very dead state.

In fact, several phones had been charged from this dead state, one at a time.

When charging the 5th phone, a faint high pitched whining started.

Stopped the process for 2 days then started with charging the 6th phone and heard the clicking noise when connected. It persisted for about 5 minutes before smoke. 

Again, we have had this failure on one other board which we returned to our assembly house to have replaced.  After replacing it has worked fine, as far as I know.

Scratching my head on this one ...


  • It would seem likely that SOMETHING in this internal circuit is going bad …


    Could be on the SW circuit, but I don’t think so because both SYS and BATT are shorted to ground …





  • Hi Bill, 

    The provided image looks to clearly show the IC has been damaged. SYS/BAT being shorted to GND also indicates the buck converter has been damaged. 

    Did you happen to take any voltage or current measurements before the IC stopped functioning? It is hard to know exactly what caused the damage without any measurements or waveforms. 

    Can you also provide the charger portion of your schematic for us to review? Based on the information that the majority of boards work, I do not expect to find any glaring issue, but I would like to confirm just in case.

    Best Regards,


  • Hi Garrett !  Thanks for replying.

    Unfortunately, I don’t have any voltage/current measurements as the testing is taking place down in my manufacturing facility in FLA.

    And, it was just a charging (of Samsung phones connected to our product) test, so wasn’t testing for a failure.

    I will say that the charger is connected to a 5000MaH li-ion … and the input to the BQ is 9VDC.


    Here is the schematic …


  • Hi Bill, 

    Understood, no worries. I have reviewed the schematic and do not see any clear issues.

    Based on the fact that the majority of the boards work and you reported one of the failed boards works after the charger IC was replaced it makes me suspect the damage was due to a soldering issue. For example if some pin gets wrongly shorted it can lead to a very large current and damage the internal switching fet. 

    Best Regards,