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DRV8343-Q1: Gate resisters

Tomoaki Yoshida91
Genius 5255 points
Part Number: DRV8343-Q1

Hi team,

I have some question about gate resister.

1. Can DRV8343 also drive FETs in parallel?

2. Does DRV8343 need gate resisters when driving FETs in parallel?

3. If gate resister is required, how should the gate resister be determined?

(Is it needed to consider the balance with the setting value of gate current etc.)

4. Will adding the gate resister affect the FET gate state monitoring function etc. of the IC?

Best regards,

Tomoaki Yoshida

  • 0
    TI__Guru 65190 points
    Yoshida-San,

    Let me assign this to the correct expert.

    Regards,

    -Adam
  • 0 in reply to Adam Sidelsky
    Genius 5255 points

    Hi team,

    Anyupdate on this issue?

    I look forward to your reply.

    Best regards,

    Tomoaki Yoshida

  • 0 in reply to Tomoaki Yoshida91
    TI__Intellectual 2595 points
    Hi Yoshida-san,

    Sorry for the delay. Please see the following:
    HI Yoshida-san,


    1) Yes, as long as combined Qg of all parallel FETs does not exceed the charge pump load rating of the DRV8343

    2) Yes. Gate resistors are necessary to prevent coupling/ringing between the MOSFETs when the first one turns on

    3) Gate resistor should be sized to achieve desired gate turn-on/turn-off speed. As you mentioned, the combination of IDRIVE and gate resistance will determine the final turn-on/turn-off time.

    4) If a high gate resistor is used, then a short circuit condition on the gate (gate-to-source or gate-to-GND) may not trip the Vgs monitors. For example, if using 1 amp IDRIVE and a 10 ohm resistor, this would cause 10V to be seen at the gate of the device, so Vgs fault would not trip until device switches to the lower IHOLD drive current.


    Thanks,
    Garrett