Because of the holidays, TI E2E™ design support forum responses will be delayed from Dec. 25 through Jan. 2. Thank you for your patience.

  • State Resolved
  • Locked Locked
  • Replies 7 replies
  • Subscribers 30 subscribers
  • Views 2003 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.

DRV8840 OCP detection time

masahiko shimizu
Guru 11235 points
Other Parts Discussed in Thread: DRV8840

Hi

My customer is using DRV8840 .
Could you let me know the OCP detection time?

Thanks,
Shimizu

  • 0
    TI__Expert 8885 points

    Shimizu,

    The worst case OCP time for DRV8840 can be considered as 3.75usec , mentioned as blanking time.

    If over-current limit occurs within 3.75usec after enabling the H-bridge , OCP trip will trip after 3.75usec, and if over-current limit crosses after 3.75 usec of enabling H-bridge, OCP should occur immediately.

    This is my understanding from data-sheet, However I will re-confirm the same with designer  and let you know, in case there is any anomaly in above explanation.

    Best Regards

    Milan-Motor Application Team

  • 0 in reply to Milan Rajne
    Guru 11235 points
    Hi Milan

    Thank you for your support.
    I use your answer as first result.
    I wait your confirming.

    Thanks
    Shimizu
  • 0 in reply to masahiko shimizu
    Guru 11235 points

    Hi all,

    I want to re-confirm about Tocp (Over current detection time).
    Could you let me know Tocp of DRV8840, please?

    And I add a question about the Iocp(Min 6A) in datasheet.
    Is this value Design value or Guaranteed value?

    Best regards,
    Shimizu

  • 0 in reply to masahiko shimizu
    TI__Guru** 114905 points
    Hi Shimizu-san,

    The typical Tocp is 3.75us.

    What do you mean "Design value or Guaranteed value"?
  • 0 in reply to Rick Duncan
    Guru 11235 points
    Hi Rick-san,

    Thank you for your support.

    >What do you mean "Design value or Guaranteed value"?
    -> 6A is checked at ATE? or 6A is theoretical value?
    Are there devices which has the value of under 6A as Iocp?

    and I add a question.
    Add Q: Absolute Maximum Ratings in datasheet, shows below.
    "Peak motor drive output current, t < 1 μS"
    Does this mean that device has damage by being applied over 6A current for the period of time of over 1us?

    Best regards,
    Shimizu
  • 0 in reply to masahiko shimizu
    Guru 11235 points
    Hi Rick-san,

    How is the progress about this question?

    Best regards,
    Shimizu
  • 0 in reply to masahiko shimizu
    TI__Guru** 114905 points
    Hi Shimizu-san,

    Sorry for the delay.

    >What do you mean "Design value or Guaranteed value"?
    -> 6A is checked at ATE? or 6A is theoretical value?
    Are there devices which has the value of under 6A as Iocp?

    >>> This value is tested at ATE.

    and I add a question.
    Add Q: Absolute Maximum Ratings in datasheet, shows below.
    "Peak motor drive output current, t < 1 μS"
    Does this mean that device has damage by being applied over 6A current for the period of time of over 1us?

    >>> The device has internal protection for this condition. Please note section 7.3.6.1 of the datasheet:

    An analog current limit circuit on each FET limits the current through the FET by removing the gate drive. If this analog current limit persists for longer than the OCP time, all FETs in the H-bridge will be disabled and the nFAULT pin will be driven low. The device will remain disabled until either nRESET pin is applied, or VM is removed and re-applied.