Help: LVDS calculate trace width and separation. Need help understanding

Marko S

I calculate an Edge Coupled Microstrip for LVDS, for example on http://www.eeweb.com/toolbox/edge-coupled-microstrip-impedance/

As I understand, the differential impedance must be 100 ohm and the odd impedance 50 ohm (testing only one of the differential traces).

But what should I aim for in the even and common impedance?

I also read that the route spacing should be the minimum spacing specified by your PCB vendor for line-to-line spacing. This minimizes the noise they say.

over 12 years ago

0 Mark Sauerwald88474 over 12 years ago

TI__Genius 13475 points

Marko

You will find good information on this in the 'LVDS Owners Manual" available here: http://www.ti.com/lit/ml/snla187/snla187.pdf

Personally, unless your system is in a very noisy environment, I would not use minimum spacing, as it is easier to control the impedance with something slightly larger, but there are many factors that would go into proper transmission line design.

0 Michael Peffers over 12 years ago

TI__Mastermind 20820 points

Hi Marko,

The LVDS Owners Manual is definitely a great document to review when designing a system such as this but please also examine this: http://www.polarinstruments.com/support/cits/AP157.html as it may help you understand odd and even mode impedance better.

Regards,

Mike

Interface

Interface forum

Help: LVDS calculate trace width and separation. Need help understanding