• State
  • Locked Locked
  • Replies 3 replies
  • Subscribers 29 subscribers
  • Views 863 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.

DRV8870: DRV8870

Hoa Nguyen4
Prodigy 70 points
Part Number: DRV8870

Hi,

   I have a linear actuator which draw max current at 1.5A. I have Vref connected to 3.3V, and my ISEN connects to gnd. Will DRV8870 output max 3.6A? Does DRV8870 require a flyback diode protection for the DRV8870?

Thanks,

Hoa

  • 0
    TI__Expert 4435 points
    Hi Hoa,

    Yes, if ISEN is directly connected to ground the will be no current regulation so current will output to whatever the load allows it to.
    where would you place the flyback diode?
  • 0 in reply to Luis Riveros
    Prodigy 70 points
    Hi Luis,
    Thanks for your confirmation. I place fly back diodes on both the Out1 and Out2
    I am controlling a linear actuator which draws 1.5A with load exert on it and without load it will draw only 0.8A at 24V.
    When the linear actuator draw 0.8A, the DRV8870 does not have any issue output efficient current.
    And when the actuator draw 1.5A, there is zero current output from the DRV8870, and the voltage across the Out2 and Out1 is 5V. I have a 100uF-50V bulk cap on the VM pin, and the ISEN connects to gnd, what would causing the DRV8870 enter the current regulation mode?
    Thank you for your advice.
  • 0 in reply to Hoa Nguyen4
    TI__Expert 4435 points
    Hi Hoa,

    I apologize for the delayed response. If you are still experiencing this behavior, could you please share some scope capture of the output current and voltages. Thank you.