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LM5069: Any possible make external MOSFET damage when LM5069 protect function active

Part Number: LM5069

Sorry to bother

Customer want to know any possible make external MOSFET damage when LM5069 protection function active.

They are concern it because external mosfet damage at OCP happened. ( use other hot swap)

Customer want to check this issue before they use LM5069.

  • Hi,

    Any MOSFET can be damaged if the application violates it's SOA curve. Usually, this isn't a problem with our customers because we recommend that their designs have around 30% or more of SOA margin. In order to make sure your design has enough margin, we have an easy to fill out calculator tool with the LM5069. You can find it by going to www.ti.com/hotswap ==> click on “Tools & software” ==> then click on “Hot Swap design calculator tools”

    Using the calculator tool is highly recommend to create a design with our hot swap controllers. For help on filling out the cells on the excel spreadsheet, our team created video tutorials on how to fill it out. They explain cell by cell what each one means and how to enter the correct value. The videos are at www.ti.com/hotswap ==> Click on “Support & Training” tab.

    If the customer would like a detailed explanation on all of the equations and methodologies behind the calculator tool and on how our hot-swap controllers work in general, please go to our app note at www.ti.com/hotswap ==> Click on “Technical Documents” ==> Click on “Robust Hot Swap”. It goes step by step to explain what the SOA/PLIM means and how it’s calculated.

    I hope this helps!

    -Aramis P. Alvarez

  • Thanks for your reply, base on your answer.
    How do we choose the correct MOSFET SOA parameter when OCP happened?

    for example, Vload = 12V and Iocp=5A , it means position Vds 12V, Ids 5A should inside of SOA DC area. right??
  • Hi,

    The best way to check if the MOSFET chosen will have enough SOA margin is to use the calculator tool mentioned above. Step 2 of the calculator tool allows the user to input the information from a FET's datasheet and it will compute how much SOA margin is in the design, along with other inputs from Steps 1, 3, and 4. If you like, you can fill out the calculator tool and attach it, so that I can review the design and give comments and feedback :-)

    Best Regards,
    Aramis P. Alvarez