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LM5069: How to raise the overcurrent detection level at start up

Kaji@PAN
Mastermind 7815 points
Part Number: LM5069
Other Parts Discussed in Thread: TPS2663

Hello,

I'm thinking of a way that overcurrent detection doesn't work at start up.
Because the capacity of the capacitor on the output side is large and overcurrent is detected when the capacitor is charged.

As a method, as shown in the figure, the sense resistors are connected in parallel and turned on and off with the Power Good Pin.
Are there any concerns about this method?

Also, is there any other way to increase the overcurrent detection level at start up?

Best regards,

  • +1
    TI__Guru** 105791 points

    Hi Kaji,

    Thanks for reaching out!

    We can use LM5069 in dVdT startup mode to charge large output capacitance. we also have TPS2663 eFuse solution which runs in thermal regulation loop during startup to charge large Cout. Please refer https://www.ti.com/lit/an/slvaeb9a/slvaeb9a.pdf 

    Few questions:-

    Can you let me know how much is the output capacitance ? and any additional load along with capacitance during startup ?

    What is the system voltage ? 

    Do you have any startup timing constraint ?

    If you want to proceed with LM5069, please fill the design calculator and share with me to work further.

    Best Regards,

    Rakesh