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DRV8301: The output suddenly drops from 5V to 0V

Annie Liu
Genius 10295 points
Part Number: DRV8301

Hi Team,

The customer uses DRV8301 to drive the drive motor. When suddenly loaded, the 5V output by DRV8301 will drop to 1V, causing 3.3V to drop and MCU reset. Customer would like to know how to resolve this issue?

Thanks,

Annie

  • 0
    TI__Intellectual 2345 points

    Hey Annie,

    Could you clarify what you mean by "suddenly loaded"? is this just referring to turning on one of the high side gates so current flows through the motor?

    I'm guessing the 5V output you are referring to is AVDD. In this device, AVDD is generated internally by PVDD1 (power supply pin). This means that if the voltage on PVDD1 disappears then so will the output on AVDD.

    Can you probe PVDD1 to see if the power supply voltage drops when you add the load?

    Regards,

    Paul

  • 0 in reply to Paul Parrot
    TI__Intellectual 2345 points

    Hey Annie,

    Do you have any update on the status of this issue?

    If not, I'll go ahead and close this thread.

    Regards,

    Paul

  • 0 in reply to Paul Parrot
    TI__Genius 10295 points

    Hi Paul,

    I just got customer feedback.

    PVDD1 dropped from 48V to 44V. Will 44V cause the AVDD output to disappear?

    Thanks,

    Annie

  • 0 in reply to Annie Liu
    TI__Mastermind 18900 points

    Hello Annie,

    No, assuming the 48V to 44V transient was verified by an oscilloscope (and not by looking at the power supplies' voltage monitor), the drop will not cause the AVDD the drop out. We explicitly look for the UVLO condition (PVDD1 < 5.9V) to be met for AVDD to drop out.

    Unless there was some assembly issues on the capacitor on AVDD (which could cause it to drop more readily as the output would be sensitive to instability) or the layout is bad enough to cause the PGND to bounce during this high loading condition, the PVDD will be the more likely answer. But, please verify the assembly, and probe GND at the pin in reference to the FET or system GND.

    Best,

    -Cole