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    dual NPN and a Diode driveing a P-Channel MOSFET

    Hello, I've ran simulations with this driver circuitry, tested it in my bench, and is working nicely, but I've never seen this configuration before.

    If this topology have a name, what is it called?
    And what cautions should I take?
    I only need a max of 500Hz.

    Click image for larger version. 

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    Last edited by marcogmaia; 9th April 2020 at 20:13.

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  2. #2
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    Re: dual NPN and a Diode driveing a P-Channel MOSFET

    No idea... Common emitter driving common collector driving drain follower with slow rise and fall time output?

    I've seen a PNP used for fast FET turn off and to keep bounce loop inside MOS and PNP.

    I like this kind of circuit. What function does common collector serve? Along with diode, is it supposed to implement fast turn-on and fast turn-off?



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  3. #3
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    Re: dual NPN and a Diode driveing a P-Channel MOSFET

    Yes, I was trying to speed up the fall time of the FET


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    Re: dual NPN and a Diode driveing a P-Channel MOSFET

    Hi,

    Not that bad.
    But a lot of effort.
    There are high side power switches ... with additional features.
    Maybe something like this: NCP45524I

    Klaus
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    Re: dual NPN and a Diode driveing a P-Channel MOSFET

    For me cost is the problem, the circuit e in the picture costs about 10 - 15 cents.



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  6. #6
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    Re: dual NPN and a Diode driveing a P-Channel MOSFET

    Hi,

    I see.

    But you need to take the overall cost into consideration.
    * assembling cost for 8 additional parts
    * increased board size
    * stock costs
    * purchase costs
    * increased failure rate
    * and so on...

    Klaus
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