• State Resolved
  • Locked Locked
  • Replies 2 replies
  • Subscribers 33 subscribers
  • Views 325 views
  • Users 0 members are here
Support feedback
Options
Options
Related

This thread has been locked.

If you have a related question, please click the "Ask a related question" button in the top right corner. The newly created question will be automatically linked to this question.

TUSB7320 differential impedance

NAOKI AOYAMA
Guru 11215 points

Other Parts Discussed in Thread: TUSB7320

Hello,

My customer uses the TUSB7320. In PCI-Express interface, he uses it with 85ohrm or 90ohrm

differential impedance. I think that condition is not recommend.

Is it possible to use the TUSB7320 with above condition?

a) No problem

or

b) It operates, but it cannot run at  5Gb/s

or

c) It does not operate

Please tell me the answer.

Regards,

Naoki Aoyama

  • 0
    TI__Mastermind 36085 points

    Hello Aoyama-san,

        The impedance requirements for the PCI-Express differential pairs are the following:

    - PCIE_RXP/N must be 100-ohms differential (+/-10%)
    - PCIE_REFCLKP/N must be 100-ohms differential (+/-10%)

        Therefore the 90Ohms is in acceptable limit, but not 85Ohms. This mismatch on the impedance will not cause any malfunction, however this may impact on the performance of the device.

    Best regards,

    Diego.

  • 0 in reply to Diego Cortes
    Guru 11215 points

    Hello Diego,

    Thanks for your fast response.

    I will feedback to my customer this information.

    Thanks,

    Naoki