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.

Original question:

CDCM6208: About output format.

  • TI Thinks Resolved

CDCM6208: LVPECL output matching network

Intellectual 2900 points
Lacey Lin

Replies: 5

Views: 430

Part Number: CDCM6208

Hi team,

For the LVPECL output, does the CDCM6208 only support the AC coupling?

If I use the DC coupling to connect the CDCM6208 output to a LVPECL receiver, will this cause issue?

Lacey

Thanks a lot!

Intellectual 2900 points
Lacey Lin
  • Genius 9775 points
    Lane Boyd
    Hi Lacey,

    Yes, the output only supports AC-coupling for LVDS or LVPECL outputs. DC coupling can cause issues.

    Kind regards,
    Lane

    ____________________________________________________________________________________

    To design your own Clock Tree solution, visit WEBENCH Clock Architect ! ​​​​

    More information Clock and Timing System products: http://www.ti.com/clock-and-timing/overview.html

  • Intellectual 2900 points
    Lacey Lin

    In reply to Lane Boyd:

    Hi Lane，
    Can you help to share the detail structure or reason for why the DC coupling will cause issue?
    And what's the issue?
    Customer need the detail information to evaluate the solution.
    Lacey
    Thanks a lot!
  • Expert 4400 points
    Madhu Balasubramanian

    In reply to Lacey Lin:

    Hi Lacey, there is no device issue with DC coupling but we need to recommend the right interface if customer prefer to DC couple in order to support both the output common mode voltage for CDCM6208 as well as the input common mode voltage for the LVPECL receiver. Can you share the specifications of the LVPECL receiver, like Vicm, Vid etc so that we can look into the correct recommendation. AC coupling will always be the easiest.
  • Intellectual 2900 points
    Lacey Lin

    In reply to Madhu Balasubramanian:

    Hi Madhu，
    For my understanding, the CDCM6208 can support DC LVPECL, because the common mode voltage of the CDCM6208 in LVPECL-Like is not the same as the standard LVPECL. right?
    So what's the common mode voltage of CDCM6208 in the LVPECL-Like output?
    Customer said they need to double check with the receiver vendor to make sure the LVPECL receiver specs.
    Lacey
    Thanks a lot!
  • Expert 8290 points
    Shawn Han

    In reply to Lacey Lin:

    Hi Lacey,

    Datasheet shows it as below. Notice it is a CML driver internal for this LVPECL-like output.

    Best Regards,

    Shawn

    ____________________________________________________________________________________

    To design your own Clock Tree solution, visit WEBENCH Clock Architect ! ​​​​

    More information Clock and Timing System products: http://www.ti.com/clock-and-timing/overview.html

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.


All content and materials on this site are provided "as is". TI and its respective suppliers and providers of content make no representations about the suitability of these materials for any purpose and disclaim all warranties and conditions with regard to these materials, including but not limited to all implied warranties and conditions of merchantability, fitness for a particular purpose, title and non-infringement of any third party intellectual property right. No license, either express or implied, by estoppel or otherwise, is granted by TI. Use of the information on this site may require a license from a third party, or a license from TI.

Content on this site may contain or be subject to specific guidelines or limitations on use. All postings and use of the content on this site are subject to the Terms of Use of the site; third parties using this content agree to abide by any limitations or guidelines and to comply with the Terms of Use of this site. TI, its suppliers and providers of content reserve the right to make corrections, deletions, modifications, enhancements, improvements and other changes to the content and materials, its products, programs and services at any time or to move or discontinue any content, products, programs, or services without notice.

TI Worldwide | Contact Us | my.TI Login | Corporate Citizenship

TI is a global semiconductor design and manufacturing company. Innovate with 100,000+ analog ICs and
embedded processors, along with software, tools and the industry’s largest sales/support staff.

© Copyright 1995-2019 Texas Instruments Incorporated. All rights reserved.
Trademarks | Privacy Policy | Terms of Use