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Need source for 25MHz resonator for SX28 — Parallax Forums

Need source for 25MHz resonator for SX28

BeanBean Posts: 8,129
edited 2005-07-06 13:47 in General Discussion
Does anyone know of a 25MHz resonator that will work with the SX28 ?
I bought some from digikey, but they turned out to be 3rd overtone and they won't work.
Bean.


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"SX-Video·Module" Now available from Parallax for only $28.95

http://www.parallax.com/detail.asp?product_id=30012

Product web site: www.sxvm.com

"What's the difference between ignorance and apathy ?"
"I don't know, and I don't care."
·

Comments

  • Guenther DaubachGuenther Daubach Posts: 1,321
    edited 2005-06-30 19:13
    Bean,

    I once also had the need for "odd" clock frequencies. I have used crystals instead of resonators as they are available for many different frequencies and they are not too expensive either.

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    Greetings from Germany,

    G
  • Paul BakerPaul Baker Posts: 6,351
    edited 2005-06-30 21:03
    Another option is using a TTL oscillator, since they are typically in half and full can sizes a board redesign will be nessesary, but since you are using a SMD resonator (only digikey product that fits your description is SMD) a redesign will likely be required anyways.

    Fox semiconductor makes SMD oscillators, but finding a distributor that offers easy purchase (digikey, mouser, etc) could be a challange. Findchips shows Harry Krantz and Rydek have stock, but they use the old quote system of ordering.
  • BeanBean Posts: 8,129
    edited 2005-06-30 23:10
    Yes I forgot to mention that I needed SMD.
    I saw some xtals on digikey, and that is probably the way I will go.
    I can't believe they make 20MHz and 50MHz but not 25mHz Arrrg
    Of course 20MHz is not quite fast enough, 50MHz will work, but uses about twice the current....
    Bean.

    ▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
    "SX-Video·Module" Now available from Parallax for only $28.95

    http://www.parallax.com/detail.asp?product_id=30012

    Product web site: www.sxvm.com

    "What's the difference between ignorance and apathy ?"
    "I don't know, and I don't care."
    ·
  • Peter VerkaikPeter Verkaik Posts: 3,956
    edited 2005-06-30 23:22
    The Javelin uses a 25MHz crystal/oscillator

    for the SX48BD, don't know the type though.

    regards peter
  • william chanwilliam chan Posts: 1,326
    edited 2005-07-01 13:23
    Dear Bean,

    I use 3rd Overtone 50Mhz resonators all the time ( with 1M ohm resistor across OSC1 and OSC2 )
    and they always worked fine....

    William
  • BeanBean Posts: 8,129
    edited 2005-07-01 15:09
    Hmmmm,
    I will try it again. I don't think I had the resistor across it when I tried it.
    Bean.

    ▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
    "SX-Video·Module" Now available from Parallax for only $28.95

    http://www.parallax.com/detail.asp?product_id=30012

    Product web site: www.sxvm.com

    "What's the difference between ignorance and apathy ?"
    "I don't know, and I don't care."
    ·
  • william chanwilliam chan Posts: 1,326
    edited 2005-07-04 07:18
    Mr Bean,

    It's been a few days.
    Did it work ?
  • cbmeekscbmeeks Posts: 634
    edited 2005-07-05 14:10
    Sorry to get OT, but since we are talking about crystals and resonators, which is better usually? Is there any advantages over crystals/resonators (besides physical space)?

    thanks

    cb
  • BeanBean Posts: 8,129
    edited 2005-07-05 15:06
    William,
    I haven't had a chance to try it again. I'm working on another project at the moment.
    What I was hoping for was a "known good" resonator.

    cb
    A xtal is more accurate than a resonator. A xtal may be something like 50PPM (0.0050 %), where a resonator is something like 0.1%. If you need extremely accurate timing a xtal is the way to go. Or maybe even a TCXO oscillator that could be 1PPM (0.0001%).

    Bean.

    ▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
    "SX-Video·Module" Now available from Parallax for only $28.95

    http://www.parallax.com/detail.asp?product_id=30012

    Product web site: www.sxvm.com

    "What's the difference between ignorance and apathy ?"
    "I don't know, and I don't care."
    ·
  • cbmeekscbmeeks Posts: 634
    edited 2005-07-06 13:47
    Bean (Hitt Consulting) said...
    William,
    cb
    A xtal is more accurate than a resonator. A xtal may be something like 50PPM (0.0050 %), where a resonator is something like 0.1%. If you need extremely accurate timing a xtal is the way to go. Or maybe even a TCXO oscillator that could be 1PPM (0.0001%).

    Bean.

    Cool...thanks!

    cbmeeks
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