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  1. #1
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    How drive 200pF load on 15MHz?

    I have TTL clock 15MHz and need drive 200pF load
    Now I use 5 inverter from 74HC04, It works fine, but case SOIC14 is to big and i search small solution.
    Can you help me?

    Click image for larger version. 

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    Re: How drive 200pF load on 15MHz?

    Hi rock

    I'm thinking of the LT1010 it comes in 3mm × 3mm × 0.75mm 8-Pin DFN Package

    https://www.analog.com/media/en/tech...ets/LT1010.pdf



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  3. #3
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    Re: How drive 200pF load on 15MHz?

    You forgot to tell the intended rise and fall time.



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    Re: How drive 200pF load on 15MHz?

    In first version was as clock used 15MHz crystal with one inverter from 74HC04, 5pcs inverter increase current for driving 200pF Load.
    In second version is as clock source used crystal oscillator any as KC2520K on 3.3V, rise and fall time is 5ns output can drive 15pF load, current increase 74hc04 still.



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    Re: How drive 200pF load on 15MHz?

    Single gate driver like LVC1G04 has about 10 ohms output impedance. Two in parallel should work. Or single LVC2G.



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    Re: How drive 200pF load on 15MHz?

    Thank you.
    Unfortunately, I forgot to emphasize one desired feature. I need hi level output voltage over 5,6V. 74HC04 permits Vcc 6V, I use 5,7 - 5,8V and Hi voltage level = Vcc.
    in the picture, I said Vcc 6V, but I forgot about it in the text, sorry.
    LVC2G and LVC1G04 have max Vcc=5.5V.



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    Re: How drive 200pF load on 15MHz?

    I forgot to mention that there may be also a save operation area problem when operating the small gates at 15 MHz with large C load. Multiple 74HC gates isn't that bad at all. Or use a small CMOS gate driver IC.



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