• State TI Thinks Resolved
  • Locked Locked
  • Replies 3 replies
  • Answers 2 answers
  • Subscribers 21 subscribers
  • Views 234 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.

LMX2572LP: Test Configuration for Validating Phase Noise Performance

James Phillips
Prodigy 10 points
Part Number: LMX2572LP


Tool/software:

I just built a coupon board to test out the LMX2572LP. I've been able to get the chip up and running and get an output at my intended frequency. I would like to validate the performance of the chip, and my board, with a phase noise measurement by trying to recreate Figure 9 from the LMX2572LP datasheet. 

Is there an app note or white paper that I could reference that talks about the test set up when these phase noise measurements were performed? Specifically, were the harmonics filtered out before the measurement was done? The LMX2572LP dev board doesn't appear to have any filtering for harmonic rejection. 

Thanks for your help!

-James

  • 0
    TI__Guru** 109350 points

    Hi James,

    Please refer to the EVM users guide for test setup.

    https://www.ti.com/tool/LMX2572LPEVM

    Phase noise measurement does not need to remove harmonics, the test equipment will automatically select the strongest signal to analysis.

  • 0 in reply to Noel Fung
    Prodigy 10 points

    So the test demonstrated in the EVM user's guide is the exact test that was done to generate Figure 9 in the datasheet?

    It is unclear exactly what piece of test equipment was used in the EVM. I assume it was a dedicated phase noise analyzer? Do all phase noise analyzers only look at the strongest signal? 

    Is there a simple explanation for why the harmonics do not need to be removed before a phase noise measurement? From what I know of how this test is done, the harmonics being present represent a similar problem to any spurs that might exist and would have similar effect on the phase noise. 


  • 0 in reply to James Phillips
    TI__Guru** 109350 points

    Hi James,

    Yes, we use phase noise analyzer to take the measurement. 

    Our products cover a few MHz to > 20GHz, it is not possible to use filter. 

    For test equipment question, please ask the equipment vendor.