LVDS pairs need 100 ohms differential impedance. However, I am having trouble achieving that in my design.
My design requires that the pairs travel over very thin flexible PCB, about 50mm total transmission length. The substrate is 50um, with a 50um coverlay. Using Saturn's PCB Toolkit, it seems to be extremely difficult to achieve 100R impedance without making the tracks too thin to manufacture, or the S/H ratio going out of spec.
However, I can achieve 80R impedance without too much difficulty.
My question is: Can I just use 80R tracks, and terminate them with a 80R resistor?
As far as I understand it, as long a every part of my transmission line has the same impedance, I shouldn't get any reflections. The only down side will be a reduced voltage at the receiver, but since I should have very few other losses in the system, that should still be plenty of voltage swing for the receiver.