clock xtal multiplier help

Discussion in 'General Electronics Chat' started by raffter, Jul 5, 2008.

  1. raffter

    Thread Starter Active Member

    Feb 28, 2008
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    Hello,

    Is there simple way to "multiply" an xtal frequency 100x.... like a watch xtal 32.768KHz to 3.2768MHz??



    -Ralph
     
  2. bertus

    Administrator

    Apr 5, 2008
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    Hello,

    Multiplying can be done with a Phase Locked Loop.
    http://www.educypedia.be/electronics/pll.htm
    In a PLL an oscilator can be compared with a reference.
    If you divide the oscillatorfrequency you will get a stabelised frequency that is mutiplied by the division factor.

    Greetings,
    Bertus
     
  3. raffter

    Thread Starter Active Member

    Feb 28, 2008
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    Hi bertus,

    Seems NOT an easy task eh... :) I was hoping for a simpler approach(just to clock a PIC)


    Ralph
     
  4. bertus

    Administrator

    Apr 5, 2008
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    Hello,

    An other posibility is multiplier stages.
    A multiplier stage is a non linear amplifier with a tuned circuit at the multiple of the input.
    Multply stage follow for 100 X are 2 X 2 X 5 X 5 X.
    But 5 X stages are nor so easy.

    Here is some text from a radioamatuer page.

    FREQUENCY MULTIPLIER
    The oscillator is generally designed to operate on a low frequency, because it is more stable. In order to achieve output on the higher frequencies, it is necessary to employ one or more stage of frequency multiplication. An advantage gained from this arrangement is that by operating the oscillator at a relatively low frequency, it is easier to achieve the necessary frequency stability. A single multiplier stage may produce twice the fundamental frequency (frequency doubler) or three times (tripler) or more. Usually, however, the frequency multiplication in one stage is limited to three. It is undesirable to feed the antenna directly from a multiplier since harmonics, other than the wanted signal, are produced and maybe radiated simultaneously.

    Greetings,
    Bertus
     
    Last edited: Jul 6, 2008
  5. raffter

    Thread Starter Active Member

    Feb 28, 2008
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    0
    sigh... really hard to find that 3.2768MHz xtal... all I got is 3.5xxMHz.. will be using it to clock the EPE LCf meter project... can a 3.5xxMHz xtal be -slowed down- by replacing the 22pF caps with 100p caps??


    Ralph
     
  6. bertus

    Administrator

    Apr 5, 2008
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    Last edited: Jul 8, 2008
  7. sanjay04313

    New Member

    Aug 19, 2008
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    0
    send me full information about single stage amplifier
     
  8. SgtWookie

    Expert

    Jul 17, 2007
    22,182
    1,728
    Kind of late, but DigiKey has 3.2768MHz crystal oscillators in stock; over 400 of them.
    http://search.digikey.com/scripts/DkSearch/dksus.dll?Cat=852334;keywords=3.2768MHz

    Sanjay04313,
    you are "hijacking" the topic, which is very much frowned upon. If you wish to start a new topic, please do so. However, we generally do not "send" information to a poster; instead replies are made to the thread. You can elect to be notified about additions to your thread by clicking the "subscribe to this thread" button.
     
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