Bend Optimization Guidelines - Intel Quark SoC X1000 Design Manual

General Differential Signals Design Guidelines—Intel
Figure A-10. Example - Via Placement 2
• For differential interfaces it is recommended 1:1 ratio of signal to GND via
everywhere it is possible
Figure A-11. Package Breakout Example - Via Placement 3
A.4.3

Bend Optimization Guidelines

Bends are a necessary component in routing differential signals. Guidelines for bends
are as follows:
• Keep bends to a minimum. Bends can introduce common mode noise into the
system, which can affect the signal integrity of the differential signal pair.
• If bends are required, they should be at a 135-degree angle or greater; there
should be no 90-degree bends or turns. An adequate air gap should be maintained
between the inside traces of a bend. The gap should be 4 times the trace width or
greater. The lengths of the segments in a bend should be 1.5 times the trace width
or greater. See
• Match the number of left bends to the number of right bends to minimize skew due
to length differences between each signal of the differential-pair.
• Alternate between left and right bends.
Matching the number of right and left turns and alternating bends helps to minimize the
amount of skew between rising or falling edges, which minimizes the differential to
common mode conversion.
June 2014
Order Number: 330258-002US
®
Quark™ SoC X1000
(Figure A-11).
Figure A-12 and Figure A-13 for examples.
®
Intel Quark™ SoC X1000
PDG
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