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DRV8251: Question about the maximum transient current

Jenson
Intellectual 2245 points
Part Number: DRV8251

Hi Team,

Can you let me know the maximum transient current for this device?

I would like to know the he maximum transient current the driver can withstand without causing damage to the chip.(for example: 8A  in  <600ns?)

There is this data in other datasheet datasheet, but I didn't find this

 

Thanks

Jenson

  • 0
    TI__Guru 54995 points

    Jenson,

    The DRV8251 will survive a direct short on the output to supply or GND and OCP will trip per the datasheet in 1.5us if current exceeds a level of 4.1A minimum.  That is really all that can be specified.

    Regards,

    Ryan

  • 0 in reply to Ryan Kehr
    TI__Intellectual 2245 points

    Hi Ryan,

    Thanks for your reply first.

    I think 4.1A just the max operate current right?

    If we have any test data can show the transient current ?just maximum transient current the driver can withstand without causing damage to the chip, you can refer yo allegro device A4950, max output current 3.5A ,but maximum transient current is 6A in <500ns.I just want to know if we have such data here.Can you kindly help to check with design or validation team to know if we have such data here.

    Thanks for your kindly support!

    Jenson

  • 0 in reply to Jenson
    TI__Guru 54995 points

    Jenson,

    OK...I can check, but please understand that the current will exceed the 4.1A during the 1.5us deglitch time and our device survives.  By how much depends on inductance, length of shorting cable.  

    Regards,

    Ryan

  • 0 in reply to Ryan Kehr
    TI__Intellectual 2245 points

    Hi Ryan,

    Thanks for your help here, This is because the customer thinks that the A4950 can be up to 6A<500ns without damaging the chip. But we don't have this data, only 4.1A. I explained it to the customer, but the customer needs specific data to continue the evaluation, so I hope to get this data to advance the DRV8251. Looking forward to your reply！

    Thanks!

    Jenson

  • 0 in reply to Jenson
    TI__Guru 54995 points

    Jenson,

    I understand.  This is going to take some time.  Please allow me at least 48 hours and don't reply until after that time for following up.

    Regards,

    Ryan

  • 0 in reply to Ryan Kehr
    TI__Mastermind 22240 points

    Hey Jenson,

    We're still waiting on the design team to get back to us on this issue.  I bumped up the priority of our request just now, hopefully they answer within another 48 hours.  

    Regards,

    Jacob

  • +1 in reply to Jacob Thompson
    TI__Mastermind 22240 points

    Hey Jenson,

    The attached pictures of DRV8251 have OUT short to GND & OUT short to VM at VM=50V. OUT node transition clarifies the short to VM/GND.

    C7(Red) show the device currents during short-circuits. 

    • OCP Trips after 1.5us deglitch time
      • High-side current shoots up to 30A and then stays > 10A for 1.5us
      • Low-side current shoots up to 25A and then stays > 10A for 1.5us

    So at least 10A for 1.5us.

    50V OUT1 to GND:

    50V OUT1 to VM:

    50V OUT2 to GND:

    50V OUT2 to VM:

    Regards,

    Jacob

  • 0 in reply to Jacob Thompson
    TI__Intellectual 2245 points

    Hi Jacob,

    Thanks! it is very helpful!

    Jenson