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Thread: WS2812 Logic Level Converter Recommendation

  1. #1
    Senior Member fdaniels's Avatar
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    WS2812 Logic Level Converter Recommendation

    Ladies and Gentleman,

    i'd like to drive some WS2812 via a Logic Level converter for security reasons. As real estate is precious on my project i'd like to go with a SMT type, preferably one single 3,5>5V converter.

    Has anyone a recommendation ?? Any help is highly appreciated, im lost a bit here!

    Thanks,
    Frank

  2. #2
    Senior Member PaulS's Avatar
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    Here you go: 74AHCT1G126.
    You need the ..T.. part.

    Paul

  3. #3
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    TI has a single gate smd logic line. Would a 74HCT1G125 work? Here the datasheet https://www.ti.com/product/SN74AHCT1G125-Q1

    Ups, 1 minute to late :-)

  4. #4
    Senior Member fdaniels's Avatar
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    Are these look OK? I guess its just a wrong Picture?

    https://www.ebay.de/itm/16X-74AHCT1G....c100005.m1851

  5. #5
    Senior Member PaulS's Avatar
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    Perhaps better order them here? 10pcs for euro 0.82.

    Paul

  6. #6
    Senior Member fdaniels's Avatar
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    Quote Originally Posted by PaulS View Post
    Perhaps better order them here? 10pcs for euro 0.82.

    Paul
    Sadly TME adds 5,9€ Shipping and i currently have no other parts to source, so the eBay Seller is cheaper.
    Besides this, can you recommend TME?

  7. #7
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    Actually, TME is my favorite EU seller. They have a very large assortment and deliver fast. (Usually I get my parts in 2-3 days to Germany)

  8. #8
    Senior Member PaulS's Avatar
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    Agree with Luni, ordered several times there - no problems.

    Paul

  9. #9
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    Mosfet? cheap BSS138 and 2 resistors. HV in this case would be 5V.

    Click image for larger version. 

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  10. #10
    Quote Originally Posted by PhilB View Post
    Mosfet? cheap BSS138 and 2 resistors. HV in this case would be 5V.

    Click image for larger version. 

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    I've had mixed results with this level converter circuit driving ws2812, as the low to high transition speed is limited by the 10k pull-up. Or I could have been doing something else wrong, I suppose.

  11. #11
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    a lower HV pullup is needed. Probably 470 or 680 ohms.

  12. #12
    Senior Member fdaniels's Avatar
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    Thanks for the suggestion, but i simply havent enough space to squeeze in a MosFet and 2 Resistors...

    BTW: as i understand OE must be tied to VCC=5V, right? I neeeeeed more coffee.

  13. #13
    Senior Member PaulS's Avatar
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    OE is an active-high signal, so yes, connect to 5V or 3V3.

    Paul

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