zl30410 Zarlink Semiconductor, zl30410 Datasheet - Page 22

• Manufacturer Part Number: zl30410
• Description: Multi-service Line Card Pll
• Manufacturer: Zarlink Semiconductor

Two types of transitions are possible:
•
•
In both cases, the change of references provides “hit-less” switching.
5.2
Figure 13 presents a complete filtering arrangement that is recommended for applications requiring maximum jitter
performance.
Semi-automatic transition, which involves changing RefSel input to select a secondary reference clock
without changing the mode select inputs MS2,MS1=00 (Normal mode). This forces the ZL30410 to
momentarily transition through the Holdover state and automatically return to Normal mode after
synchronizing to a secondary reference clock.
Manual transition, which involves switching into Holdover mode (MS2,MS1=01), changing references with
RefSel, and manual return to the Normal mode (MS2, MS1=00).
Power Supply Filtering
RESET=1
RESET
unconditional return from
any state to Free-run
MS2,MS1=10 forces
FREE-
RUN
10
MS2,MS1=00
MS2,MS1=01
OR
MS2,MS1=01 OR
RefSel change
Figure 12 - Manual Reference Switching
HOLD-
OVER
01
Zarlink Semiconductor Inc.
MS2,MS1=00
Ref: OK AND
ZL30410
{AUTO}
22
RefSel Change
MS2,MS1=01
NORMAL
00
OR
Ref: OK-->FAIL AND
MS2,MS1=00
{AUTO}
HOLD-
OVER
AUTO
{AUTO}
Ref: FAIL-->OK AND
MS2,MS1=00
Data Sheet