zl30121 Zarlink Semiconductor, zl30121 Datasheet - Page 20

• Manufacturer Part Number: zl30121
• Description: Sonet/sdh Low Jitter System Synchronizer
• Manufacturer: Zarlink Semiconductor

1.8
In addition to the static delay compensation described in the “External Feedback Inputs” section on page 20, the
ZL30121 also provides the option of dynamic delay compensation to minimize path delay variation associated with
external clock drivers and long PCB traces. This is accomplished by re-directing the internal DPLL1 feedback path
to external pins and closing the loop externally as shown in Figure 9.
clk_in
fp_in
External Feedback Inputs
clk_out
fp_out
clk_in
fp_in
ref
sync
fb_clk
fb_fp
DPLL1
Figure 9 - External Feedback Configuration
realignment of input and output clocks
Zarlink Semiconductor Inc.
SONET/P0/P1
Synthesizers
Synthesizer
Feedback
ZL30121
20
fb_clk
fb_fp
ZL30121
clk
fp
ext_fb_fp
ext_fb_clk
Path Delay
Data Sheet
clk_out
fp_out