• State Resolved
  • Locked Locked
  • Replies 3 replies
  • Answers 1 answer
  • Subscribers 30 subscribers
  • Views 437 views
  • Users 0 members are here
Support feedback
Options
Options
Similar topics

This thread has been locked.

If you have a related question, please click the "Ask a related question" button in the top right corner. The newly created question will be automatically linked to this question.

Original question:

DRV8323: DRV8323 gate drive fault

DRV8323: DRV8323 gate drive fault

x z
Prodigy 40 points
Part Number: DRV8323

Hi Anthony,

    We are working on the problem of DRV8323 again, I want to confirm one thing

     Is it normal for the VGS to have negative voltage when we use the 8323 to drive the motor,  is it within the expectations of your chip design?

    If this negative voltage is also generated during your use, and you think it is normal.We will not think that the 8323 damage is caused by it,

    and then we will not waste time on researching how to reduce the negative voltage

e2e.ti.com/.../drv8323-drv8323-gate-drive-fault

Thanks

ZX

  • 0
    TI__Mastermind 18916 points

    Hi ZX, 

    Thanks for reaching out regarding this topic -

    Anthony is current out on rotation w/ another group currently, but I will be here to help answer your questions. 

    In the case where the negative transients you are observing is -0.6V for a very brief amount of time (around 100nSec), it does not seem likely that this would result in damage to the device under normal operating conditions. 

    • I think from the previous debug, it still wasn't fully understood what the damage to the device was (no obvious short-circuit/open-circuit on IC pins). 

    • I would say that short-duration negative transients like you are observing are not uncommon in most systems, but there are ways to mitigate it

    I see that in the previous post, there was already a lot of advice given in terms of slowing down MOSFET gate switching speed (reducing IDRIVE) and also improving layout.

    Best Regards, 
    Andrew 

  • 0 in reply to Andrew Liu
    Prodigy 40 points

    Hi Andrew,

          Thanks for your reply.

           There is one part of the datasheet that I can't understand,

           I'd like to ask you about the areas circled in the picture below

          'Transient 200-ns' does this limit mean that the time for the GHX voltage to rise from 0V to Vvcp+0.5V or the time for falling from Vvcp+0.5V to 0V cannot    be  less than 200ns? Or does it mean that the max time that the max /min voltage can be held is 200ns?

      Thanks

    ZX

  • +1 in reply to x z
    TI__Mastermind 18916 points

    Hi ZX, 

    Your second statement should be correct. In terms of validating the spec, I believe that is how we would have tested the transient performance in the past. 

    The device abs max rating will be based on the device's ability to endure that voltage value for some short duration (like 200nSec) and not result in damage to the IC. 

    x z said:
    that the max time that the max /min voltage can be held is 200ns?

    Best Regards, 

    Andrew