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DRV8305: Will DRV8305 shoot through protection prevent cycling of low side switches without cycling hi side?

Part Number: DRV8305

I have a 3phase BLDC motor driver using DRV8305.  During deceleration, I'm considering closing only the low side switches (all 3 simultaneously) to perform eddy current braking while using low side shunts to monitor the current so the PWM duty cycle can be adjusted to prevent overloading the switches or motor wiring.  For this reason, I would prefer not to close the high side switches since I can't monitor current there.

Will the shoot-through protection on the DRV trigger an error condition if I am only using the low side switches and not closing the high side switches at all in this operation mode?

Thanks!

  • Hey Ben,

    Thank you for posting your question to E2E.

    We will aim to provide a response before the end of the week.

    Best Regards,

    Akshay

  • Hey Ben,

     

    If you plan on turning on the low side MOSFETS to slow the motor (low side braking) and leave the high side MOSFETS off, then it shouldn’t trigger the shoot through protection. The shoot through protection will be triggered when both the high side and the low side MOSFETS are on at the same time. The high side MOSFET shouldn’t be on unless the INHx pin is on or there is high voltage between GHx and SHx pins.

     

    The DRV8305 has an automatic handshake feature to prevent shoot through event from taking place.

     

    I hope this resolves your issue.

     

    Best Regards,

    Akshay