This thread has been locked.

If you have a related question, please click the "Ask a related question" button in the top right corner. The newly created question will be automatically linked to this question.

LMG3410-HB-EVM: Fault Signal to Adjust Slew Rate?

Part Number: LMG3410-HB-EVM

Hi,

I am looking into a interesting fact of LMG3410-HB-EVM: The !FAULT output is routed to adjust the slew rate of low-side FET. What's the consideration under this design?

Peiheng.

  • Hello Peiheng,

    Thanks for asking. Actually the thoughts behind it is like this: During the startup transient, the upper side FET can be ready later, and lower side FET can be on first due to the turn on delay. To make sure the dv/dt on the switching node is not too high during startup, we use the fault information of the upper FET to increase the resistance of RDRV on the lower FET to allow a slower turn on of lower FET. This is to avoid possible dv/dt induced EMI. 

    But this method is just a safety prevention. We have also tested the board without having this function enabled, and the half-bridge can still stand the dv/dt without problem. So please feel free to remove this part if you want. Thanks!

    Lixing

  • Lixing,

    Thanks you for your prompt sharing! I am sure that this info could help more for anyone looking for the same insights from this forum.

    Peiheng.