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DRV3201-Q1 Qg of FET for driving

Other Parts Discussed in Thread: DRV3201-Q1

Hi

My customer will use DRV3201-Q1.
He has a question about Qg of FET for driving.
Could you tell me about the following question?

There is the following sentence in datasheet.
"Drives 6 Separate N-Channel Power MOSFETs up to 250 nC Gate Charge"

1. Can DRV3201-Q1 drive FET of Qg=600nC?
2. I think that Qg value which is able to drive is decided by switching speed and Max Iboost of Boost converter.
    Is this idea correct?
3. How much is Max output current of Iboost?
4.I think that Max output current of Iboost is 200mA.
     This was expected from mentioning of a data seat which is "ISW,fail Internal second level current limit" .
     Is this guess proper?

Best regards
Shimizu

  • Hi Shimizu-san,

    Our expert has been notified and should reply soon.
  • Shimizu-san,

    The main issues with driving a FET with such a high gate charge are Input Frequency, Thermal Dissipation, VDS/VGS error detection timing since it will take longer to charge with high current running through the device.

    The spec for the actual drive current as well as the boost current can be found on page 6 of the datasheet.

    How fast does the customer plan to switch the gates, and are they planning to use all 6 gate drivers?

    Regards,
    Will Toth
  • Hi Will-san

    Thank you for your support.

    1.My customer will select one from the following FET.

    IR AUIRF8739L2TR
    ON Semi NVMFS5C404NL
    Feachild FDBL9401_F085

    *I'm sorry, Above FET is not 600nC.
    Could you comfirm with above FET?

    2.And my customer wanst to use DRV3201-Q1 with 20kHz~30kHz pwm input frequency.

    3.Is the spec for the actual drive current 40mA(Max)?

    Best regards
    Shimizu

  • Shimizu-san,

    One more follow up, what kind of control algorithm does the customer plan to use (i.e. are all 6 FETs constantly driving)?

    1. & 2.
    I have the following total gate charge values:
    AUIRF8739L2TR: 375nC
    NVMFS5C404NL: 181nC
    FDBL9401_F085: 220(typ)nC, 295(max)nC

    If the customer plans to use the device at 30kHz and switching all 6 FETs at once using control such as FOC, then gate charge >250nC as in the datasheet will not work.

    For 6 state control the load from switching the FETs is greatly reduced, and the device can drive FETs with higher gate charge, though the customer must be careful about thermal dissipation. Make sure the customer has 5-10ohm on each FET gate.

    3. Iboost in the datasheet of 40mA is the spec for the internal load current. The actual driver currents are listed higher on that page under "Gate-Driver" and are called "IGC2C..IGC0C" for the charge current and "IGD2D...IGD0D" for the drain current.

    Regards,
    Will Toth
  • Shimizu-san,

    As a reference, our EVM uses this part: IRFS3004PBF

    Regards,
    Will Toth
  • Hi Will-san

     Thank you for your support.

     I understood.

     My customer drives all 6 FETs constantly.  

     I will suggest the under 250nC FET to customer which is NVMFS5C404NL or IRFS3004PBF.

    Best regards,

    Shimizu