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LMK1C1104: Phase noise data

Part Number: LMK1C1104

On page 11 of the datasheet there are graphs that show the phase noise at the buffer output given a specific input signal. Figure 10 shows reference phase noise and figure 11 shows output phase noise at 3.3v.

What seems strange is that the output phase noise is better than the reference.

Could there be a swap between the graphs? Or is it something I am missing.

https://www.ti.com/lit/ds/symlink/lmk1c1104.pdf?ts=1590567678600

  • In the latest revision of the datasheet SNAS791A, the graphs appear to be correct. If you look closely at Figure 11, you can barely see the reference phase noise (light blue) overlapping the output phase noise (dark blue). The phase noise at the output is nearly identical to the phase noise at the input. In Figures 10 and 11, you can also see the RMS jitter integration, which shows that the 3.3V output in Figure 11 adds <1fs under this specific operating condition, a negligible impact on performance

    Kind regards,
    Lane

  • Thank you Lane.