• State
  • Locked Locked
  • Replies 2 replies
  • Subscribers 22 subscribers
  • Views 921 views
  • Users 0 members are here
Support feedback
Options
Options
Related

This thread has been locked.

If you have a related question, please click the "Ask a related question" button in the top right corner. The newly created question will be automatically linked to this question.

LMX2594EVM: Which external oscillator did TI use for its measurements for phase noise?

Manuel Preuschoff
Prodigy 20 points

Part Number: LMX2594EVM
Other Parts Discussed in Thread: LMX2594, LMX2582

Hi,


as I measured phase noise of the LMX2594, I couldn´t achieve the required results given in the data sheet and user guide. I used the "internal" reference oscillator which is included in the EVM. For better comparison, i want to work with an external reference. Which one did TI use for its measurements for the phase noise plots given in the data sheet? There is only mentioned, that it should be a very clean 100MHz Wenzel oscillator. But which one exactly?


Thank you very much and best regards,

Manuel

  • 0
    TI__Expert 8615 points

    Input reference impact on phase noise.pptx

    Hi Manuel,

    The Wenzel model number is 501-04623. Attached is an example experiment done with the LMX2582 to show that a Wenzel is good enough to showcase the PLL phase phase, whereas the CWX813-100M is convenient for EVM initial start-up but is not good enough phase noise. As you know the LMX2594 PLL phase noise is even lower than that of LMX2582, so even the Wenzel when scaled to the corresponding output frequency is approaching the levels of our PLLs phase noise and become the dominant source of noise. Hope this clarifies your question and you can find a reference source that let's you see this difference. Thanks!

    Regards,

    Brian Wang

  • 0 in reply to Brian Wang
    Prodigy 20 points

    Hi Brian,

    thank you lots for your answer. This clarifies the problem.


    Best regards,


    Manuel Preuschoff