DSLVDS1048: undesirable spikes at the output of DSLVDS1048

Md Faisal Rahman

Part Number: DSLVDS1048

Hello

This a follow up of this thread : e2e.ti.com/.../4178276

After reducing the intrapair skews, I am still seeing undesirable spikes on channels which are suppose to be LOW. Here is a picture of this.

The Schematic is given below

Top layer and bottom layer views are:

Please help.

Thank you

best

Faisal

The

over 2 years ago

0 Michael Ikwuyum over 2 years ago

TI__Guru 50136 points

Hi Faisal,

I would suggest adding additional decoupling capacitors to the power supply similar to section 11.1.1 of the datasheet, while also taking a look at the referenced guidelines.

Furthermore, could you double confirm if the cables are balanced? Thanks.

Best Regards,

Michael.

0 Md Faisal Rahman over 2 years ago in reply to Michael Ikwuyum

Prodigy 170 points

Hello Michael

Thanks for the reply. Yes my cables are balanced. My lvds signal bandwidth is 250MHz. I am wondering is it creating the problem with spikes? Can it be a reason?

Thanks

Best

Faisal

0 Michael Ikwuyum over 2 years ago in reply to Md Faisal Rahman

TI__Guru 50136 points

Hi Faisal,

Md Faisal Rahman said:
Can it be a reason?

Very much so as this device specifies up to 400 Mbps (200 MHz). There is also a signal integrity relationship between the trace / cable lengths to the frequency and would suggest reducing both (if feasible) to confirm how it impacts the signal, thanks.

Best Regards,

Michael.

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DSLVDS1048: undesirable spikes at the output of DSLVDS1048