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UCC21520: Driving 2 parallel SiC MOSFETs

Intellectual 820 points

Replies: 4

Views: 89

Part Number: UCC21520

Hi Team,

Our customer is designing an LLC full-bridge converter and they want to use 2 parallel SiC instead of 1 for a switch in full-bridge.

Can the UCC21520 output for driving 2 paralleled SiC MOSFETs? What are the needed considerations?

Thanks in advance.

Regards,

Jejomar

  • Hi Jejomar,

    Thank you for your question. I work on the applications team in the high power drivers group.

    UCC21520 has 4A/6A source/sink capability and should be able to drive the capacitive load of paralleled SiC FETs. There are often a few considerations to take to when paralleling high power FETs to ensure the FETs do not have gate-to-gate oscillations. Recommended circuit considerations vary from manufacturer to manufacturer.

    For example, feel free to read through this application note from Cree/Wolfspeed.

    https://www.wolfspeed.com/downloads/dl/file/id/553/product/0/dynamic_and_static_behavior_of_packaged_silicon_carbide_mosfets_in_paralleled_applications.pdf

    What is the SiC FET part number/manufacturer?

    If this answered your question, could you please press the green button? If not, feel free to ask more questions.

    Thanks and best regards,

    John

  • In reply to John Geiger:

    Hi John,

    Thank you for the answer and sharing the application note. We will use C2M0080120D (or C2M0040120D as an alternative), CREE SiC MOSFETs.

    Best regards.

    Muhammed Yusuf

  • In reply to John Geiger:

    Hello John,

    Can you help us with the needed considerations for the mentioned SiC MOSFET about to be used by our customer?

    Thank you so much in advance.

    Kind Regards,

    Jejomar

  • In reply to MUHAMMED YUSUF CANDAN:

    Hi Muhammed,

    When running FETs in parallel, it is important to try and equalize the drive circuits as much as possible, in order achieve good dynamic current balancing between each FET. This is described in the Cree app note I linked before.

    A good example of gate drive layout is found in section 3.1 of the app note linked below.

    http://www.ti.com/lit/an/slua897/slua897.pdf

    If this answered your question, could you please press the green button? If not, feel free to ask more questions.

    Thanks and best regards,

    John