USB differential pair using Saturn PCB

[Rajinder]

Hi all,
I am currently looking to use USB 2.0 (480Mbps speed) on a design. The USB differential signal coming in from a USB connector to a PIC microcontroller.
I have tried using Saturn to give me a 90 Ohm differential impedance (see below), I am using FR4 PCB and 1oz copper (i.e. 18um copper + 19um plating = 35micros i.e. 1oz).

I can't get the required Z differential of 90ohms. Can anyone help and assist? Not sure what I am doing wrong. Also is the length of the track going to be critical, it will be about 10mm?



Thanks in advance.

 

[Harald Kapp]

Adjust conductor spacing. ~ 100 µm will result in Z_diff ~ 90 Ω.

 

[Rajinder]

Adjust conductor spacing. ~ 100 µm will result in Z_diff ~ 90 Ω.

Thanks.

 

[Rac]

Adjust conductor spacing. ~ 100 µm will result in Z_diff ~ 90 Ω.

@Harald Kapp
Hi I am new to this forum and I'm starting to learn differential routing. Is it not required to have Zo to be 45 ohm if the Zdifferential is 90 ohms?