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DS90UB954-Q1: voltage output differential (vod) settings

Part Number: DS90UB954-Q1
Other Parts Discussed in Thread: ALP

We have a question  about    1<- > DS90UB913/933 link connection configuration.

 

Is it possible to configure VOD (Voltage output differential) level of

DS90UB913/33 DOUT+/-  pins, for COAX cable (Via local registers or Back channel ) ?

Thanks

  • Tamir,
    The VOD is not configurable. What is the reason you are looking at making a VOD change?
  • Hi,

    We are a company working with FPD products (such as DS90UB953/54/13/33/34/60/64 etc)

    in challenging environments (industrial, automotive) and with different third party Hardware.

    Our goal is to bring our FPD links to the highest level of stability and   robustness.

    We would like to understand what "tools" are enabled  by TI to "play" with link parameters for best signal integrity.

    For example, AEQ registers are one tool that can be used by the user.

    Another one is mentioned in 954 datasheet in section : "7.4.10.1 Code Example for CMLOUT FPD-Link III RX Port 0"

    Its seems that 954 enables indirect access to differential eye opening.

    However, documentation is very limited about it.

    Pls. advise.

    Thanks

  • Tamir,
    Correct CMLOUT can be enabled to look at the post-EQ signal inside the RX to identify any gross issues. The status of EQ settings can be read from the devices through registers. It is recommended to set to Auto EQ to track any temperature/voltage variations or cable aging to get the most optimum performance but it is also possible to change the EQ settings manually through registers.
    Please refer to the FPD-Link datasheets for additional information. For eg refer to the 954 datasheet as it includes a good amount of information.

    We also have a margin analysis tool integrated into ALP that lets you measure the eye margin in the system and see which EQ settings gives you the best margin. Please download the ALP profile update from www.ti.com/tools/ALP, the device folders under "PreDefScripts" in the ALP installation location comes with some sample scripts for many use cases.