Advantech SOM-Express Design Guide
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Chapter 5 Carrier Board Design Guidelines
directly to a mobile SATA connector, we recommend the trace length be 9.5 inches
for microstrip routing and 7 inches for stripline routing.
!
The SATA differential pair trace should be trace length matched. The difference of
two line traces in a TX or RX differential pair should be restricted to less than 20
mils, but even less trace mismatch is encouraged.
Figure 5-53 shows an example of SATA trace length pair matching. L
A
must equal to
L
A
‘
, L
B
must equal to L
B
‘
, …and so on. We recommend minimizing layer change,
ensuring that the differential pairs are equal if necessary.
Figure 5-53 Example of SATA trace length pair matching
