CY7C68013A, CY7C68014A
CY7C68015A, CY7C68016A
12. PCB Layout Recommendations
Follow these recommendations to ensure reliable high
performance operation:
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Bypass and flyback caps on VBus, near connector, are
recommended.
DPLUS and DMINUS trace lengths should be kept to within
2 mm of each other in length, with preferred length of 20 to
30 mm.
Maintain a solid ground plane under the DPLUS and DMINUS
traces. Do not allow the plane to split under these traces.
Do not place vias on the DPLUS or DMINUS trace routing.
Isolate the DPLUS and DMINUS traces from all other signal
traces by no less than 10 mm.
Four layer impedance controlled boards are required to
maintain signal quality.
Specify impedance targets (ask your board vendor what they
can achieve).
To control impedance, maintain trace widths and trace spacing.
Minimize stubs to minimize reflected signals.
Connections between the USB connector shell and signal
ground must be near the USB connector.
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Note
25. Source for recommendations:
EZ-USB FX2™PCB Design Recommendations,
and
High Speed USB Platform Design Guidelines,
http://www.usb.org/developers/docs/hs_usb_pdg_r1_0.pdf.
Document #: 38-08032 Rev. *V
Page 61 of 66
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