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DS90UB960-Q1: Max coax cable length

Stefan Koncar
Genius 3050 points
Part Number: DS90UB960-Q1
Other Parts Discussed in Thread: ALP

Hi all,

I have following setup: IMX390 Sensor -> UB953-Q1 Serializer -> RG174 Coax cable -> DS90UB960-Q1 Deserializer -> TDA2p (ISP)

Sensor outputs FULL HD @ 60 fps. With short cable (< 2 m) everything is ok, but with longer cables (> 4 m) video is not stable, flickering happens.

My questions are:

1. Can this be solved by changing values in AEQ registers 0xD2-0xD5. If yes, can you help me with that? I tried to set ADAPTIVE_EQ_FLOOR_VALUE to different values, but there are no changes.

2. Is the length determined only by cable quality and total insertion loss of all components in the signal path? What is correct formula for max cable length calculation for this setup?

3. Can something else cause this kind of problems?

Best Regards,

Stefan.

  • 0
    TI__Genius 10475 points
    Stefan,
    What is the status of LOCK with the longer cable? Flickering can be caused by a variety of reasons including power supply noise, jittery reference clock, PCB signal integrity issues etc. It is recommended to set AEQ to auto so it can track the voltage or temperature variations.

    For debug purposes you can read AEQ status or set the values manually. Please refer to the 960 datasheet AEQ section for additional information.

    We have a margin analysis tool in the ALP which will show you how much margin you have across AEQ and strobe position settings in your actual system.

    You need to install both the ALP and ALP-PROFILE-UPDATE here to use the margin analysis tool:
    http://www.ti.com/tool/alp