No announcement yet.

Layout Review for a PCIE to USB3 converting board

  • Time
  • Show
Clear All
new posts

  • Layout Review for a PCIE to USB3 converting board


    I'm designing a board that converts from PCI-E to USB3 through a USB host controller from VIALABS (VL805).
    I attached the PDF of the schematic and the file that includes the layout.
    I also included 6 images of the 6 layers of the layout.
    I was hoping to get some feedback regarding the layout routing and if there is something that I should change.
    main important high speed traces are USB3, PCIE.
    I attached the stack-up for information about the impedances.


    Attached Files
    Last edited by Firasgany7; 01-13-2021, 07:25 AM.

  • #2
    Is the impedance of the tracks correct? The USB signals on L1 seems to me routed super close to each other.


    • Firasgany7
      Firasgany7 commented
      Editing a comment
      Hi Robert, the USB2 track Impedance is 85 ohm, and the distance between the USB2 tracks that are connected to L1 is ~10 mils. is that a problem?
      a previous board with the same routing for the USB2 tracks has already worked. now I only added the VL805 chip with all the extra connection it needs.
      what spacing between USB2 traces do you use? and can you provide me with a manual that sums up all the standard spacings that you use for each protocol?

  • #3
    I mean these tracks (see the picture below). USB track geometry (track width and gap) is always based on stackup - so it depends on what stackup you use.

    Click image for larger version

Name:	usb tracks.PNG
Views:	402
Size:	326.5 KB
ID:	16454