DS90UB953-Q1: DS90UB953-Q1: DS90UB953-Q1 STP signal

user6250071

Part Number: DS90UB953-Q1

In STP asynchronous mode, the waveform of LVDS is as shown below. Is it correct?

From the waveform, the amplitude is much higher, there is also a high overshoot, and the quality of the eye diagram is not good.

How to improve, related to where the parameter settings? How to set it up?

over 5 years ago

0 Casey McCrea over 5 years ago

TI__Guru** 103215 points

Hello,

Is this waveform taken when the SER is connected to the DES? If so then the measurement is expected to look distorted like this because FPD-Link III is a bidirectional signaling topology. There are forward and back signals occupying the same conducting pair. If you want to look at the eye quality, then you can use the CMLOUT feature of the deserializer.

Best Regards,

Casey

0 user6250071 over 5 years ago in reply to Casey McCrea

Prodigy 50 points

That waveform was measured between SEN and DES. (Between DS90UB953-Q1 and DS90UB954-Q1)

However, I turn off the BCC function between 954 and 953. Is the waveform of FPD-LINK normal when used in this way ? (We want to achieve the data flow is only one-way transmission from 953 to 954)

How can I see a high-quality eye diagram on FPD-LINK? How to judge the signal quality of FPD-LINK?

0 Casey McCrea over 5 years ago in reply to user6250071

TI__Guru** 103215 points

Hello,

It is recommended to leave the back channel functional for FPD-Link since it is a bidirectional protocol. For judging the signal quality between 954/953 we would recommend utilizing the Margin Analysis Tool in our Analog Launchpad GUI. You can find documentation about that here:

https://www.ti.com/lit/ug/snlu243/snlu243.pdf

http://www.ti.com/lit/pdf/snla301

Best Regards,

Casey

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DS90UB953-Q1: DS90UB953-Q1: DS90UB953-Q1 STP signal