Achieving 90R impedance for USB Type C on a four layer board

Discussion in 'Digital Circuit Design' started by dhinesh.ganesan, Aug 7, 2018.

  1. dhinesh.ganesan

    Thread Starter Member

    Oct 19, 2017
    48
    1
    Hi All

    I am designing a USB type C 90R impedance controlled tracks. This is the first time I am doing high-speed tracks. I have some doubts regarding the impedance calculations. I will provide all the information as much as I know to succeed.

    Below is the 4 layer PCB thickness
    ZOT PCB.PNG
    ZOT PCB-1.PNG

    This is the calculator I have used from EEWeb to match the 90R impedance
    90R impedance controlled.PNG
    The board stack up I would like to use is
    Board Stackup.PNG

    Could anyone help me with the calculations I have created for 90R impedance is correct? Thanks
     
  2. Picbuster

    Active Member

    Dec 2, 2013
    739
    90
    I am missing frequency used needed to calculate the impedance.

    Picbuster
     
  3. dhinesh.ganesan

    Thread Starter Member

    Oct 19, 2017
    48
    1
    I think the frequency is 2.4GHz (it is for USB 3.0) and the speed should be 5 Gbps or 10Gbps
     
  4. Picbuster

    Active Member

    Dec 2, 2013
    739
    90
    The Kicad calculator is able to calculate using the frequency.

    Picbuster
     
  5. dhinesh.ganesan

    Thread Starter Member

    Oct 19, 2017
    48
    1
    Thanks. I've found out the trace width of 0.22mm and trace spacing of 0.125mm. Do you know how to find out the via size of the trace?
     
  6. Picbuster

    Active Member

    Dec 2, 2013
    739
    90
    use the default net classes for that track.
    See eurocircuits.com for the standards to be used.

    Picbuster
     
  7. dhinesh.ganesan

    Thread Starter Member

    Oct 19, 2017
    48
    1
    upload_2018-8-10_9-30-7.png

    now it is set to this readings. Are they look right?
     
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