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DRV8353: Breaks continuously

Alejandro Jiménez Becerra
Prodigy 10 points
Part Number: DRV8353

Dear all,

I am actually working with DRV8353HMRTAT to control a 3-phase motor and it keeps breaking continuously. My current design is shown below:

Power side are 3 phases. I show only a single phase due to they are almost the same:

After a few days trying to check what was wrong on my first design, I noticed the following issues:

  • C5 Capacitor connected to VGLS had 16VDC derating voltage instead of 25VDC.
  • IDRIVE resistor was wrongly set. According to datasheet it should be 18K resistor.
  • 4K99 resitors between GHx/SHx and GLx/SLx caused driver to break.
  • Start-up process was not done as expected. Actually enable is set low, PWM are set low, enable is set high and finally PWM are introduced into DRV.

 Although this changes have been introduced in my PCB it keeps breaking suddenly. It seems to work fine but it suddenly it breaks. Could you help me with this isuue?

  • 0
    TI__Mastermind 26046 points

    Hi Alejandro,

    What do you mean by "break"? Is there a burn mark or known device damage? Is nFAULT always low after powerup?

    The best way to check for the exact damage in a hardware device is to measure the impedance of pins across the damaged device compared to a new device to look for any shorts or opens. Check with respect to GND for each pin, and check gate-to-source impedances if possible to see if there are any damaged gate driver outputs. 

    4.99kohm resistors are very small Rgs resistors, this will dissipate a lot of your gate current. I would try a couple of different things in evaluation first to help improve motor performance:

    - DRV835x devices include adjustable IDRIVE, so I would use the smallest IDRIVE settings at first to evaluate gate drive currents and MOSFET switching. You should use a 0-ohm gate series resistor (rather than 4.99 ohms) initially and remove the 4.99k Rgs resistors. Choose the IDRIVE setting based on this E2E FAQ: https://e2e.ti.com/support/motor-drivers-group/motor-drivers/f/motor-drivers-forum/796378/faq-selecting-the-best-idrive-setting-and-why-this-is-essential

    - Use this app note to help debug and improve high power BLDC designs based on known types of issues: https://www.ti.com/lit/pdf/slvaf66

    - Ensure capacitors are selected for rated voltages, including VM, VDRAIN-VCP, CPH-CPL, and VGLS caps

    - Ensure there is good PCB layout that mitigates parasitics in the gate drive current paths and motor current paths: https://www.ti.com/lit/pdf/slva959

    Thanks,
    Aaron