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CDCM6208: Phase noise floor in case of Fout=10, 100, 1k, 10k, 100k, 1M and 10MHz

Hirotaka Matsumoto
Guru 27585 points
Part Number: CDCM6208


Hi all

Would you mind if we ask CDCM6208?

There is the description 6.17 LVDS (Low-Power CML) Output Characteristics.
Our customer requested us Phase noise floor in case of Fout=10, 100, 1k, 10k, 100k, 1M and 10MHz.

How much is the input cryctal frequency?
And could you share us the crystal model?(for Enter Custom Phase Noise for Reference or VCO/VCXO on Webench.)
Because we will simulate using this model on Webench.

Kind regards,

Hirotaka Matsumoto 

  • 0
    TI__Expert 5370 points
    HEllo Matsumoto,

    thank you for your interest in the CDCM6208.

    Could you provide more details on the request.

    We do not have data for all configuration but we may have the informatino you are looking for.

    These seems to be the offset you are looking to know the phase noise for: 10, 100, 1k, 10k, 100k, 1M and 10MHz. What is the desired output frequency?

    The Xtal oscillator on CDCM6208 can accept Xtal from 10 to 50 MHz. See section 6.11.

    I understand you are looking for a Xtal oscllator mode phase noise specification. I am not able to see that in the D/S for a given xtal. This should be measured for the xtal you intent to use.

    Regards, Simon.
  • 0 in reply to Simon Damphousse
    Guru 27585 points

    Simon san

    Thank you so much for your reply.

    We appologize that our explanation makes you confuse.

    There is the description 6.17 LVDS (Low-Power CML) Output Characteristics.

    We would like to know how much the the Xtal oscillator is for these characteristics.
    And we would like to know what kind of crystal model you used for these characteristics.

    Our customer would like to know Phase noise at each offset frequency 10, 100, 1k, 10k, 100k, 1M and 10MHz using Webench.

    The condtion : Xtal oscillator XXMHz -> fOUT= 122.88 MHz

    I understand you are looking for a Xtal oscllator mode phase noise specification.
    I am not able to see that in the D/S for a given xtal.
    This should be measured for the xtal you intent to use.
    ->We would like to confirm one point. On the datasheet, are these data(6.17 LVDS (Low-Power CML) Output Characteristics) measured data or simulation data? 
       And in these case, Xtal(XXMHz) used to get some characteristics.
       If our recognition is not correct, could you give us some comments?

    We appreciate your help always.

    Kind regards,

    Hirotaka Matsumoto

  • 0 in reply to Hirotaka Matsumoto
    TI__Expert 5325 points
    Dear Hirotaka-san,
    phase noise simulation in webench should follow the EVM GUI simulation tool. This uses a crystal as input. Regarding the characterization condition: This was a R&S SMA100 fed to the external input of a HP 8133A pulse gen which then connected to PRI_REF. The provided frequency was 30.72 MHz.
    The simulation tools are correlated to typical measurements on the customer EVM using crystal as source. You can find tested models in footnote 1 of table 6.11.

    Best regards,
    Patrick