I have another question about PCB layout. I'm designing using this guide:
I don't find nothing about problems between power planes and USB traces. Will it be problems if I create a power plane under the component and USB traces? Thank you so much!
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\$\begingroup\$ Have you calculated what is the effect to trace impedance? Usually USB pair is routed on top of reference plane, which usually is a ground plane, but with care, you can change the reference plane to supply plane. The trace width would at least change whether you have a reference plane or no plane at all. \$\endgroup\$– JustmeCommented Apr 21, 2021 at 9:49
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USB 2.0 interfaces up to 12 Mbit/s (full speed) won't have problems if you put a ground plane beneath or not, provided you draw the PCB traces D+ and D- of the same length and short: the shorter the better.
In 2016 I designed a PCB with NXP LPC2388 microcontroller which has a USB 2.0 interface running at 12 Mbit/s.
The length of the PCB traces were 18 mm.
Both host (USB flash drive) and device (removable hard disk) interfaces worked perfectly.
answered Apr 21, 2021 at 10:35