I'm in the process of trying to make my first PCB with USB 2.0 on it.
Right now I'm trying to work out what the trace width and clearance for the differential pair should be to get the correct impedance.
According to this: http://www.usb.org/developers/docs/hs_usb_pdg_r1_0.pdf
they normally use 7.5 mil(0.19mm) traces with 7.5mil clearance on a 63 mil board (1.6mm)
That should give the traces around 90 Ohms differential impedance according to the PDF, but when I try to input it to my impedance calculator (Saturn PCB toolkit V7.03) it gives me almost 160 Ohm - and even if use 53mil conductor height or anything I cannot get the 90 Ohm differential impedance.
What am I doing wrong here?