• State Resolved
  • Locked Locked
  • Replies 5 replies
  • Answers 2 answers
  • Subscribers 30 subscribers
  • Views 454 views
  • Users 0 members are here
Support feedback
Options
Options
Related

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.

DRV8434S: What means full-scale at 2.5A or 1.8A root mean square (rms) output current

aiwen chen
Intellectual 625 points
Part Number: DRV8434S

 Stepper motor drive requires rated current of about 1.5A, voltage support 36V, SPI interface, currently evaluating DRV8434S, the chip full-scale at 2.5A or 1.8A root mean square (rms) output current, but ambient temperature, supply voltage and PCB thermal performance will have a certain impact, these affect how much loss does the glow? The actual value may not reach 2.5A, but the customer wants to know, how much can the actual value be reached? Can you meet the customer's 1.5A? Or is there any other suitable recommendation. Please help to confirm, thank you!

  • 0
    TI__Mastermind 37683 points

    Hi Aiwen,

    I'm assuming the 1.5A requirement is for the full-scale. If that is the case, the DRV8434S is capable of driving the motor with 1.5A full-scale. Thermal starts becoming a problem if DC current is high(for example when holding current of motor is high). When motor is driving, the current will be sinusoidal and the power loss will in average be lower than when driving motor at DC current. 

    Regards,

    Pablo Armet

  • 0 in reply to Pablo Armet
    Intellectual 625 points

    Hi  Pablo；

    Thanks for your  reply

    Sorry, I didn't understand what you meant，you said that Thermal starts becoming a problem if DC current is high? If there will definitely be losses, The actual value may not reach 2.5A.  Subtract losses  current，how much can the actual current value be reached? I need  at least  1.5A， , Can i chose  DRV8434S （2.5A） for design ? Are there any other selection suggestions？

    I sincerely look forward to your reply, I wish your organization the Samson and prosperity! 

  • 0 in reply to aiwen chen
    TI__Mastermind 37683 points

    Aiwen,

    What I meant to say is if the current is continuous 1.5A (always 1.5A), there will be higher power dissipation than if it is only 1.5A during the full scale step.

    Regards,

    Pablo Armet

  • 0 in reply to Pablo Armet
    Intellectual 625 points

    Hi Pablo；

    Thank you for the explanation，Besides，Subtract  power loss, load and other factors， DRV8434S‘s  drive current does not reach full scale 2.5A, Can the actual drive current reach my original 1.5A drive current requirement?Will the drive current be lower than the 1.5A I need in practice?  Do I need to choose a device with a range greater than 2.5A?

    Thanks！

    Best  Regards！

  • 0 in reply to aiwen chen
    TI__Mastermind 37683 points

    Hi Aiwen,

    The DRV8434S can drive at 2.5A full scale.

    Regards,

    Pablo Armet