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  1. #1
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    over current protection in LDO design

    hi, all,

    now i am designing the over-current-protection function in LDO. i am confused about the stability of OCP loop, but not the main loop in LDO. why do we need to stable the OCP loop? and i am also puzzled with the function of OCP. is that only to prevent the great current in pass device when Vin is powered on?

    thanks
    leebluer

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  2. #2
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    Re: over current protection in LDO design

    hi, all,

    how to realize the over-current-protection in design? i have used a current-mirror to realize it, but which destroy the stability of LDO loop. i want to know others how to realize it. pls. give me some help:(

    Thanks in advance
    leebluer



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  3. #3
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    over current protection in LDO design

    by means of the shunt, you can try again!



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  4. #4
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    Re: over current protection in LDO design

    hi, wonbef,

    thank you for your reply. but i also cannot get your meaning. could you explain it more detailed?

    Thanks
    Leebluer



  5. #5
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    Re: over current protection in LDO design

    The most accurate way would be to use a current mirror (N:1) ratio of power FET to sensor. You can then make the drains of the two transistors equal using an amplifier and generate a "reference gate voltage" on the sensor transistor. Use this voltage to clamp the gate of the power transistor when the current is exceeded.



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