More and more PCB designers are interested in impedance track for USB circuit board of 90 ohm impedance.
For 90 ohm impedance, there are two options of circuit track to get that:
One option is to get 90ohm impedance by single-end impedance track, with stack up as below:
The other option is by differential impedance track to get the 90ohm value with the stack up below:
The final stack up depend on your exact PCB Gerber file, copper thickness, Er value,etc. For more questions, you can contact us via firstname.lastname@example.org.