SN75DP130: SN75DP130 - Jitter and Equalisation

Hi Julian,

Maximum data rate of Dp130 is 5.4Gbps.

This device is a redriver, so the input jitter won't be cleaned.

If you need to clean jitter you need a retimer, please take a look at DP in x-mode.

Regards

Hi Moises,

Thanks for your reply. Sorry I meant 5.4Gbps, not 5.6.

So are the 'Total Output Jitter' figures in Figure 4 for example, to be added to the input jitter? So for our situation we have 90ps in and 120ps out, so the figure with respect to the data sheet is 30ps, which seems more inline with the data bearing in mind we on the wrong EQ setting. So do you think we have a reasonable PCB layout and are getting the correct performance from the device?

Thanks

Julian

Hi Julian,

The numbers make sense, however, just with that number I wouldn't say the layout is fine.
In layout to have to control impedance, x-talk, intra-pair, inter-pair skew, refer to TI Hihg-Speed Interface Layout Guidelines: www.ti.com/.../spraar7f.pdf

DP130 may clean some jitter produced by noise, jitter produced by GPU will be unaffected.

DP159 is a retimer, it will remove input jitter if it is not too low frequency jitter.

Regards

Hi Moises

We followed the layout guidelines and designed for impedance and skew, so I think it will be worth us playing with the EQ setting to try and optimise the jitter.

Thanks for your help. If we need further assistance can we contact you directly ?

Regards

Julian

Hi Julian,

We prefer to keep all questions that don't involve confidential information in E2E so the whole community can benefit from answered questions.
If you want to escalate an issue you can ask your FAE to place a HelpMe ticket
Issues handled by email can be easilly lost in tons of emails, but we can use it to share confidential information.

Regards

Hi Moises,

OK, I understand.

Could I ask you one last question; do you have any recommendations or guidance for testing and verifying DisplayPort devices. Ideally we wanted to try something on the bench here in the UK. I've looked at some of the main brands, but it's seems very complex and daunting!

Thanks

Julian