zl30101 Zarlink Semiconductor, zl30101 Datasheet - Page 15

• Manufacturer Part Number: zl30101
• Description: T1/e1 Stratum 3 System Synchronizer
• Manufacturer: Zarlink Semiconductor

Examples:
HMS=1: When 10 Normal to Holdover to Normal mode transitions occur and in each case the Holdover mode was
entered for 2 seconds, then the accumulated phase change (MTIE) could be as large as 330 ns.
where:
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Output
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REF
Output
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REF
Output
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Phase
Phase
Phase
0.01 ppm is the accuracy of the Holdover mode
0 ns is the maximum phase discontinuity in the transition from the Normal mode to the Holdover mode
holdover_drift
mode_change
10 changes
= 10 x (20 ns + 13 ns) = 330 ns
TIE_CLR=0
HMS = 0
Normal mode
Phase drift in Holdover mode
Return to Normal mode
= 0.01 ppm x 2 s = 20 ns
= 0 ns + 13 ns = 13 ns
Figure 7 - Timing Diagram of Hitless Mode Switching
Zarlink Semiconductor Inc.
ZL30101
15
REF
Output
Clock
REF
Output
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REF
Output
Clock
REF
Output
Clock
HMS = 1
TIE_CLR=0
Return to Normal mode
Normal mode
Phase drift in Holdover mode
Data Sheet