DS90UB953-Q1: Eye diagram check

Hello Yuanqing,

Thank you for reaching out with your questions.

I have begun looking into your concern regarding the eye diagram.

To improve the eye diagram, you will have to layout the PCB and layout the connector(s) to improve the following RF properties: insertion loss and return loss. You can check the s-parameters for insertion and return loss or Time Domain Reflectometer (TDR) impedance measurements for ensuring signal integrity in a PCB board design. You should also consider the cable length you are using to make sure it is not degrading signal integrity. 

We do not define the criteria for the DS90UB953 without DS90UB954 since the channel specifications along with other specifications must be taken into consideration while measuring eye diagrams.

There is a MAP tool that you can use for margin analysis of the system. ALP is the GUI that has this tool integrated.

Here are two useful documents on MAP:

FPD Link Margin Analysis Program (MAP) user’s guide: https://www.ti.com/lit/ug/snlu243/snlu243.pdf?ts=1629322007847&ref_url=https%253A%252F%252Fwww.google.com%252F

Margin Analysis Program (MAP) and strobe positions for DS90UB954-Q1 and DS90UB960-Q1: https://www.ti.com/lit/an/snla301/snla301.pdf?ts=1629322019491&ref_url=https%253A%252F%252Fwww.google.com%252F

Best Regards,

Shruti More