pll freq synthesis

Discussion in 'Analog & Mixed-Signal Design' started by pager48, Nov 30, 2018.

  1. pager48

    Thread Starter New Member

    Nov 25, 2018
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    can the cd4046 synthesize signals with greater or less than the input frequency?

    can it synthesize multiple frequencies or does it have just 1 output?

    thank you.
     
  2. ericgibbs

    Moderator

    Jan 29, 2010
    6,180
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    hi pager,
    Welcome to AAC.
    Look thru this 4046 Apps PDF.
    E
     
  3. dl324

    AAC Fanatic!

    Mar 30, 2015
    7,421
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    Yes.
    It can synthesize multiple frequencies, but only one at a time.
     
  4. danadak

    Well-Known Member

    Mar 10, 2018
    1,881
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    You can use a programmable divider in feedback loop to
    produce x N synthesizer. Page 19 of previous attachment doc.

    Regards, Dana.
     
  5. DickCappels

    Moderator

    Aug 21, 2008
    5,000
    1,517
    You can also pass the reference clock through a divider, making the function fo = M/N
     
  6. danadak

    Well-Known Member

    Mar 10, 2018
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  7. DickCappels

    Moderator

    Aug 21, 2008
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    Perhaps the finest book on the subject every written.
     
  8. danadak

    Well-Known Member

    Mar 10, 2018
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    For sure. There was another gent, can't remember, who did extensive analysis
    on non linear behavior, more accurate lock calculations, S/N....but book cost
    more than my net worth. Maybe at the pearly gates I will get a peek if I am
    good....damn, too late for that :)

    Regards, Dana.
     
  9. bertus

    Administrator

    Apr 5, 2008
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    Hello,

    Here I have a zipfile with 28 pdf files concerning PLL's

    Bertus
     
    LvW, DickCappels and ericgibbs like this.
  10. pager48

    Thread Starter New Member

    Nov 25, 2018
    15
    0
    I noticed the IC's are specified with Min Typ and Max frequencies, does this mean they wont work with any frequency below the minimum specified value?
     
  11. ericgibbs

    Moderator

    Jan 29, 2010
    6,180
    1,171
    hi 48,
    The clip that have posted is for the Lowest Maximum frequency.
    eg: at 15Vdd typical Fmax = 2.7MHz, but a device may only have a Fmax =1.3MHz as a worst case.
    E
    Note: there always a spread in a performance parameter about the stated Typical value.
     
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