• State Resolved
  • Locked Locked
  • Replies 7 replies
  • Answers 4 answers
  • Subscribers 33 subscribers
  • Views 662 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.

DS90UH949A-Q1: DS90UH949A-Q1 - maximum cable length

Sunset
Genius 13995 points
Part Number: DS90UH949A-Q1

Hello Team,

by using the DS90UH949A-Q1 and DS90UH948, building a demo with the evaluation board:

  • can we get a link up to 15m?
  • Would be 30m also feasible?
  • Out of test data, what would be the maximum distance vs. bit rate?
  • Do we have any reference design/schematic that would allow reaching 30m?
  • In regards to the Rosenberger HSD connector, used on the evaluation board, do we have recommendation for any alternative part number from other vendors?

Thanks,

SunSet 

  • 0
    TI__Guru** 103215 points
    Hello,

    Please see the 948 datasheet table 6 for typical insertion loss vs data rate. Typically 10m is suggested at 170MHz. Depending on the quality of cable, 15m is possible as well at lower date rates but 30m is most likely not possible. At this time we do not have a different part number to recommend for the connector specifically, but the key characteristics for the connector are strong impedance continuity and low loss. Plus in automotive applications the connector is typically chosen to ensure excellent vibration performance to avoid accidental disconnection.

    Best Regards,
    Casey
  • 0 in reply to Casey McCrea
    Prodigy 150 points
    Hello,

    If we used a good Leoni Cable (4x0,14), can be used the one cable for the both FPD Links?
    Or we shut be used separately cable for each line?

    If we used the Equalizer (D4S1EQ-S01A5-YY) or repeater, it is possible to send the signal up to 30m?

    Regards,
    IM
  • 0 in reply to Iliya
    TI__Guru** 103215 points

    Hello Iliya,

    We have not tested such a solution so we can not make any guarantees. I find it unlikely that 30m would function well across all conditions within the datasheet which is our key metric. 

    Best Regards,

    Casey 

  • 0 in reply to Casey McCrea
    Prodigy 150 points
    Hello Casey,
    I have order the Demoboards to test the max. distance.

    Can you give me a tip for a TI repeater?

    Best Regards,
    IM
  • 0 in reply to Iliya
    TI__Guru** 103215 points
    Hello IM,

    When you say repeater do you mean a passive connector to extend cable length or do you mean an active repeater to apply equalization? We have not tested any active repeaters with FPD Link because the protocol uses bidirectional data transfer on a single line which is not supported by any active equalizer I am aware of. The FPD Link deserializer has a CTLE and CDR integrated to compensate for channel loss and ISI.

    Best Regards,
    Casey
  • 0 in reply to Casey McCrea
    Prodigy 150 points
    Hello Casey,
    According the datasheet from DS90UH949A-Q1 page 4 (DOUT0/1- and DOUT0/1+) are defined as Outputs.
    Figure 28 and 29 shows the unidirectional Drivers.
    We Need only unidirectional communication for the Video data.
    Best Regards,
    IM
  • 0 in reply to Iliya
    TI__Guru** 103215 points
    Hello IM,

    FPD Link III is a bidirectional protocol. The high speed forward channel is used for transfering video, audio, and control data from the serializer to the deserializer, while the back channel is used to transfer control and status data the other direction. The high speed forward channel performance is primarily what drives the cable length requirement since the high speed signals experience more insertion loss.

    Best Regards,
    Casey