Stack up high speed design

[ing]

i am trying to design a USB 2.0 test fixture high speed (data rate 480Mbit/s , 240 Mhz , impedance 90ohm for D+/D-)
i need ur help about the Layer Stack manager for 4 Layers thickness... and how to choose my track/via width
Thank u in advance

[mairomaster]

Can you give a little bit more information please? What different chips do you have, what other interfaces, what else is happening on the board, etc.

If you need a cheap 4 layer board however, you will probably need to use a ready stack up with pre-defined layer thickness provided by the PCB manufacturer you are using. Depending on this stack, you will need to choose your track thickness to achieve the required impedance. The via size again will depend on the manufacturer capabilities.

[ing]

the board contains 2 usb2.0 connectors , switchers ,led, some resistance and capa that's all
Actually it is usb2.0 high speed electrical test fixture (host /device)
i have done the schematics for drop_droop_inrush test fixture and i am trying to do the Layout ( i wanted to similate it befor going to Layout but i dn't find a solution)

[robertferanec]

Hi ing, I do not have any 4 layer examples, but you can simply create it from 6 layer stackup (just do not use the two inner layers and keep the distance and materials on L1-L2 same as in the examples). Here they are: Download PCB Stackups – Free for your Projects

Of course, you will need to check with your PCB manufacturer if they can do it. I hope this helps.

[ing]

Thank you
I wish you all the best )