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Component broke-up causing board failure

GioP
Intellectual 780 points
Part Number: INA239-Q1
Other Parts Discussed in Thread: INA239

I am using a INA239-Q1 in my design. The component was ordered as a preview from TI website, and I think it is worth reporting a failure, even if I cannot be sure if it was caused by the component itself or not.

The INA239 was used for monitoring a load connected to a 48 V output DCDC converter. There was a flash on the board and the component stopped working, signaling a malfunction with the \alert signal stuck low. I had no time to read the status register for reported failures, but even after many power cycles the component did not get back to operation, even though voltage levels around it were within the expected range.

Below a picture with all production details for the failed device

  • 0
    TI__Genius 17990 points

    Hello Giovanni,

    Thank you for using the TI forum. Can you please share some more details about the setup/fail event? How long had the device been working before this event? Also, what do you mean by a "flash" event? Did the device/setup get hit with ESD? Did two pins temporarily get shorted together? What was going on when this flash occurred? What is the value of the pull-up resistor on the ALERT pin? (Any other useful information would also be appreciated).

  • 0 in reply to Mitch M
    Intellectual 780 points

    The system was working since a couple of weeks, not continuously.

    It had been repeatedly used to power up the load using a 48-V DCDC converter. The current-monitoring shunt was 7.5E-3 ohm, measuring currents in the range between 10 and 30 A approximately.

    The "flash" was a short-duration flashlight originated from somewhere on the board. Unfortunately nobody was looking directly at the system when the event occurred. A voltage transient at DCDC output might have caused an overvoltage I guess, but as far as we have observed, DCDC output is quite stable.

  • 0 in reply to GioP
    TI__Mastermind 26445 points

    Hello Giovanni,

    Is there any way that there was a large over voltage  condition that was above the Absolute Maximum Rating of the INA239 pins.  This is most likely a condition that could have damaged the INA239.  Going below GND is one of the conditions most often overlooked.

  • 0 in reply to Javier Contreras4
    Intellectual 780 points

    We noticed large disturbances due to a disconnected ground line. It is likely that some destructive transient occurred because of that condition.

    I cannot provide much further details yet.

  • 0 in reply to GioP
    TI__Mastermind 26445 points

    Giovanni,

    Do you think you have found the root cause?  Have you tested another board with this item fixed and no more damages have occured?

  • 0 in reply to Javier Contreras4
    Intellectual 780 points

    Not yet Javier,

    but I am confident that revised wiring will prove effective once replaced  the damaged part.

  • 0 in reply to GioP
    TI__Mastermind 26445 points

    Giovanni,

    Thanks for the update.  I will close the post but please inform us if we need to follow up.