SNAA393 January   2024 LMK6H

 

  1.   1
  2.   Abstract
  3.   Trademarks
  4. 1Introduction
    1. 1.1 Why use a Phase Noise Analyzer?
  5. 2Understanding Phase Noise Plots
  6. 3Phase Noise Analyzer Measurement Settings
    1. 3.1 Start or Stop Frequency
    2. 3.2 Averaging and Correlation
    3. 3.3 Persistence
    4. 3.4 Spurious View Modes
    5. 3.5 Other Settings
  7. 4Hardware Setup for Different Clocking Formats
    1. 4.1 LVCMOS
    2. 4.2 LVDS
    3. 4.3 LVPECL/HCSL
    4. 4.4 Balun Recommendations
  8. 5Typical Measurements with Different Termination Schemes
    1. 5.1 LVCMOS
    2. 5.2 LVDS
    3. 5.3 LVPECL
    4. 5.4 HCSL
  9. 6Summary
  10. 7References

4 Hardware Setup for Different Clocking Formats

Always AC-couple the inputs of the PNA to prevent damaging the measurement equipment. If AC-coupling capacitors are not placed on the output of the clock source, a DC block can be used directly at the input of the PNA. Note that PNAs usually have an internal 50Ω termination to match the impedance of most coaxial cables. These are both important considerations when deciding how to terminate the clock source to maximize power and reduce signal reflections.

The following sections detail different measurement setups for TI's LMK6x family of oscillators.