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LM5143-Q1: GaN

Part Number: LM5143-Q1
Other Parts Discussed in Thread: LM5143, TPSM265R1, LM5140-Q1, LM5141-Q1

Hi Champs,

are there limitations/concerns using LM5143-Q1 with GaN FETs?

  • HI Simon:

     LM5143 controller is designed for mosfet, and there is no 5V drive clamping for protect the GaN.  Currently we don't have experience whether LM5143 fitting for driving GaN fet, Customer may try by their selves They need very careful about the layout if they decide to use LM5143 bcause the high dv/dt of GaN turn on and off will affect the controller if layout is not good.

    Thanks

  • Hi Daniel

    I asked Simon about this in the first place. If I drive VDDX from an external 5V source (e.g. TPSM265R1) would it help protecting the GaNs from overvoltage or would you still recomend using Zener to protect them.

    Best Regards

    Theo

  • HI Theo:

    I will suggest add a 5V zener . it can help protect the potential risk of parasitic inductor in PCB resonanting with the gs capacitor. 

    Thanks

  • Hi Daniel

    Thanks for your help. I saw the LM5140-Q1 on the EPC website as a sugested Buck Controller for GaN and while looking for a single Output version i found the LM5143-Q1 which looked quite similar. I read something about canceling the ringing on GaN gates with ferrites. I will give both a try an hope that the solution with a coupled inductor instead of seperate one will work.

    If this will not work I will try the LM5141-Q1 with a single phase.

    Best regards

    Theo

  • Hi Theo:

    thanks, I will close this ticket, if you have further question , you can reopen it.

    Thanks