PLL loop filter design

Discussion in 'Radio and Communications' started by veerasamy, Oct 9, 2009.

  1. veerasamy

    veerasamy Thread Starter New Member

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    Please help on how to design PLL loop filter for specific loop band width? ( what is loop bandwidth anyway?). I have charge pump current and VCO sensitivity as input.

    Thanks &Regards,
    V.Veerasamy
     
  2. t_n_k

    t_n_k AAC Fanatic!

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  3. hgmjr

    hgmjr Moderator Staff Member

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    What is the part number of the PLL device have you chosen to use? And how are you planning to use the PLL?

    hgmjr
     
  4. veerasamy

    veerasamy Thread Starter New Member

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    Thanks t_n_k. To hgmjr: I am using PLL with integrated VCO (AD4350).
     
  5. Tesla23

    Tesla23 Active Member

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  6. hgmjr

    hgmjr Moderator Staff Member

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    Are you refering to the ADF4350 made by Analog Devices? I could not locate any information on the AD4350.

    hgmjr
     
  7. veerasamy

    veerasamy Thread Starter New Member

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    to hgmjr: Yes i am using ADF4350.
    to Tesla23: I am using AdsimPLL. but in AdsimPLL it assumes phase detector frequency and channel spacing are same. For me they are different
     
  8. Tesla23

    Tesla23 Active Member

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    If you are doing a Fractional-N design then make sure that you select this on ADIsimPLL, then you can select the modulus on the Chip page, and you will see the channel spacing is different to the PD frequency.

    As an example, if you choose the ADF4350 on the first page of the wizard and accept all the default parameter values you will get a Fractional-N design where the channel spacing is different to the PD frequency.
     
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