IDT
TM
/ICS
TM
Frequency Generator for CPU, QPI, FBD, PCIe Gen 2 & SATA 0839O—12/03/08
ICS9FG104
Frequency Generator for CPU, QPI, FBD, PCIe Gen 2 & SATA
13
DIF Reference Clock
Common Recommendations for Differential Routing Dimension or Value Unit Figure
L1 length, Route as non-coupled 50 ohm trace. 0.5 max inch 1
L2 length, Route as non-coupled 50 ohm trace. 0.2 max inch 1
L3 length, Route as non-coupled 50 ohm trace. 0.2 max inch 1
Rs 33 ohm 1
Rt 49.9 ohm 1
Down Device Differential Routing Dimension or Value Unit Figure
L4 length, Route as coupled microstrip 100 ohm differential trace.
2 min to 16 max inch 1
L4 length, Route as coupled stripline 100 ohm differential trace.
1.8 min to 14.4 max inch 1
Differential Routing to PCI Express Connector Dimension or Value Unit Figure
L4 length, Route as coupled microstrip 100 ohm differential trace.
0.25 to 14 max inch 2
L4 length, Route as coupled stripline 100 ohm differential trace.
0.225 min to 12.6 max inch 2
Figure 1 Down device routing.
Rs
Rs
Rt Rt
HSCL Output
Buffer
PCI Ex Board
Down Device
REF_CLK Input
L1 L2
L3’
L4
L1’ L2
L3
L4’
Figure 1
Figure 2 PCI Express Connector Routing.
Rs
Rs
Rt Rt
HSCL Output
Buffer
PCI Ex
Add In Board
REF_CLK Input
L1 L2
L3’
L4
L1’ L2’
L3
L4’
Figure 2
