• State TI Thinks Resolved
  • Locked Locked
  • Replies 4 replies
  • Answers 2 answers
  • Subscribers 30 subscribers
  • Views 331 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.

DRV8332: emi perturbation, commutation time

first_name last_name
Prodigy 40 points
Part Number: DRV8332

Hello,

I have developed a motor board with a  DRV8332DKD. When the component drive a motor, i get ground bounce during pwm edge change. Is it possible to increase the rising and the falling time of the driver (actually around 14 ns) to reduce high di/dt?

Thank you in advance.

  • 0
    TI__Mastermind 26046 points

    Hello,

    Ensure the grounding is sufficient on layout, there may be inductance between DRV8332 GND and analog/digital ground causing the bounce on PWM edge change. Have you tried connecting a wire from DRV8332 ground to MCU ground to see if this improves the edge bouncing?

    There are not any ways to change the slew rate of the driver since it is fixed in the device. 

    Thanks,
    Aaron

  • 0 in reply to Aaron Barrera
    Prodigy 40 points

    Thank you for you fast response,

    We do not have separated the DRV8332 GND and analog/digital ground, we use the same ground plane, can it be the problem?

    Here is a part of our schematic:

  • 0 in reply to first_name last_name
    TI__Mastermind 26046 points

    Hello,

    Thanks for sharing schematic. Shared GND should not be an issue as long as motor current, when switching, does not couple noise into digital signals. Only issue is that when using common GND, if the power and analog/digital signals are mixed in layout, then it increases the risk of noise coupling. It is best to place PGND on one side of board, and AGND/PGND on other side of board (i.e. star grounding topology). 



    If you would like, could you share layout of the board? Feel free to send over the thread or over PM if privacy is needed.

    Thanks,
    Aaron

  • 0 in reply to Aaron Barrera
    TI__Mastermind 26046 points

    Hello,

    I left feedback over PM. 

    Thanks,
    Aaron