• State Resolved
  • Locked Locked
  • Replies 2 replies
  • Subscribers 32 subscribers
  • Views 688 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.

TUSB1046A-DCI: AC coupling capacitor between HOST/GPU and TUSB1046A-DCI

K.Yaita
Guru 29720 points
Part Number: TUSB1046A-DCI
Other Parts Discussed in Thread: TUSB1044

Hi Team,

My customer considers to use the following AC coupling capacitor value for TUSB1046A-DCI.
- red part: 330nF (from ECN)
- blue part: 220nF



I would like to ask the following two questions in this case.

1)
Should my customer use 220nF for green part?

2)
I believe orange part can be left as 100nF.
Is my understanding correct?

Best Regards,
Yaita / Japan disty 

  • 0
    TI__Genius 16150 points
    Hi Yaita,

    1. ECR to Display Port Alt Mode spec recommends 220nF.
    2. Your assessment is correct, both 100nF and pull-up/down resistors are required for AUXP/N.

    The total series capacitance can be slighted reduced. Although, combined value of 100nF (TX side) and 330nF (Optional RX side) can be meet the minimum capacitance requirement for RX detection (75nF~265nF) and there is no expected effect.
    Regarding the 220nF, a Gen2 capable design that uses a 220nF AC cap will violate the spec when connected to a Gen1 link partner.

    Best Regards,
    Luis Omar Moran
    High Speed Interface
    SWAT Team
  • 0 in reply to Luis Omar Moran
    Guru 29720 points

    Hi Luis-san,

    Thank you for your support.

    Do you know when TUSB1046A-DCI datasheet will be update about AC coupling capacitor?
    Regarding TUSB1044 (new device), it is updated in Typical Application Circuit of Figure 36 (page 47).
    http://www.tij.co.jp/jp/lit/ds/symlink/tusb1044.pdf

    Best Regards,
    Yaita