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  1. #1
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    74lvc425

    Hi guys,

    Newbie here. I am trying to interface a microcontroller 3.3 V logic HIGH with 5 V logic HIGH microcontroller. I required to interface 18 parallel pins from 3.3 V to 5 V logic. I used a chip 74LVC425 to do the interfacing. I was wondering is there any easier method to do the interfacing?

    Thanks

    •   Alt26th July 2006, 07:10

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  2. #2
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    Re: How to interface 3.3V logic with 5V logic

    If you need to support both directions then the LVC(LVT)245 is the simplest solution ..

    Regards,
    IanP



    •   Alt26th July 2006, 07:57

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  3. #3
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    Re: How to interface 3.3V logic with 5V logic

    use line level buffers for 3.3 and 5 volts. As per what ianp said those are line level buffers. Use CMOS going one way and use TTL line buffer going the other way. The thresholds of each do level translations.
    Any other questions let me know

    when going from 3.3 input to 5v output logic use TTL line buffer
    TTL translates anything above 2.4 volts as logic 1 and anything below .5 as a logic 0.

    use cmos going the other way



    •   Alt28th July 2006, 17:27

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  4. #4
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    Re: How to interface 3.3V logic with 5V logic

    y can't you use transistor at the output of the low voltage µc as a switchof 5V



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    Re: How to interface 3.3V logic with 5V logic

    try to use serial resistance 200 or 220R between 3.3 and 5V. it may solve the problem.



  6. #6
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    Re: How to interface 3.3V logic with 5V logic

    You can use level shifters or translators, many vendors have these ICs. pls check in the web.



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