SNAA345 December   2020 LMK5C33216

 

  1.   Trademarks
  2. 1 Introduction
  3. 2 Wander Generation
    1. 2.1 Wander Generation MTIE Option 1, G.8262 EEC Option 1
    2. 2.2 Wander Generation TDEV G.8262 EEC Option 1
    3. 2.3 Wander Generation MTIE Stratum ITU-T G.8262 EEC Option 2
    4. 2.4 Wander Generation TDEV G.8262 EEC Option 2
  4. 3 Wander Transfer
    1. 3.1 Transfer Function of the PLL for Option 1 and Option 2
    2. 3.2 Wander Transfer TDEV G.8262 Option 2
  5. 4 Wander Tolerance
    1. 4.1 Wander Tolerance G.8262 Option 1
    2. 4.2 Wander Tolerance G.8262 Option 2
  6. 5 Jitter Tolerance
    1. 5.1 Jitter Tolerance G.8262 Option 1 and Option 2
  7. 6 Phase Transient Generation
    1. 6.1 Short-Term Phase Transient Response G.8262 Option 1
    2. 6.2 Short-Term Phase Transient Response G.8262 Option 2
    3. 6.3 Phase Transient Generation With Signal Interruptions G.8262 EEC Option 1
    4. 6.4 Phase Discontinuity G.8262 Option 1
    5. 6.5 Phase Discontinuity G.8262 Option 2
  8. 7 Holdover
    1. 7.1 Holdover G.8262 Option 1
    2. 7.2 Holdover G.8262 Option 2
  9. 8 Free-Run Accuracy
    1. 8.1 Free-Run Accuracy G.8262 Option 1 and Option 2
  10. 9 Pull-In and Hold-In
    1. 9.1 Pull-In Range G.8262 Option 1 and Option 2
  11. 10Conclusion
  12. 11References

6.2 Short-Term Phase Transient Response G.8262 Option 2

For this test, the device is forced into holdover for 15 seconds by performing a manual switch from a valid active clock input (IN0) to another input with no valid signal (IN1), then the holdover state is exited by manually switching back to the valid active clock input. The test is completed after an entry into holdover and exit from holdover has taken place within 15 seconds. The output will not exceed the green MTIE requirement shown in Figure 6-3 (Figure 14 in the G.8262 specification).

The below MTIE data captures the phase transient at the output of LMK5C33216 during multiple reference clock switchover events, displaying a passing result. The resolution of Calnex equipment is limited to 1 ns for MTIE. The unique phase cancellation scheme implemented in LMK5C33216 allows for a phase transient < 100 ps which cannot be measured accurately using this setup.

GUID-20201210-CA0I-6KDD-CLXN-MTHSTPMSG55X-low.svgFigure 6-3 Short-Term Phase Transient Option 2