LVDS signals and ground

[johnkaz77]

Hi everyone! I have a motherboared which sends 2 pairs of LVDS signals to a daughterboard through ffc cable. My question is, the receiver at daughterboard should it be supplied by vdd and ground coming from the original source of LVDS's signals(e.g. motherboard)? And if so, what is the minimum distance I should keep between LVDS lines and vdd & gnd? I know that for TTL signals a rule of thump is 3*S, where S is the distance between the lines of an LVDS pair, but since we are talking about dc voltage and there are no high transition times, is it ok if I use adjacent wires of the ff cable?

 

[gongdori]

I don't think the daughter card should get power and ground from the motherboard, but it can.
Can you elaborate your second question little bit?

 

[johnkaz77]

The LVDS signals will be transmitted through a 4 positions flat cable.Can I use 2 of these wires for one LVDS pair and the other 2 wires for vdd and gnd?

 

[FvM]

A GND reference is required to keep the common mode range. I don't see a general to reason to supply the LVDS receivers from the source side, but it's possible if you want to.