Differential and common mode signals

[Rahul Soni]

Differential and common mode signals are AC signals or DC signals ?
They are AC up to my knowledge but in the traces of PCB, we use DC signals only. Then how it is possible to use these signals on a PCB ?

 

[Surendhar M]

It depends from what is the supply which you have connected AC or DC. If it is from sensor which operates under DC then of course it is DC. Moreover you can call it as Analog and not digital and that is the correct term for identifying differential signals.

 

[Rahul Soni]

It depends from what is the supply which you have connected AC or DC. If it is from sensor which operates under DC then of course it is DC. Moreover you can call it as Analog and not digital and that is the correct term for identifying differential signals.

How it will behave, in case of high speed digital designs?
I have seen the references. All of them gives the example of Diff. mode signal as an AC signal.. But now i am in confusion that how the can propagate in a PCB, where we only use DC signals.

 

[marce]

Single ended or differential signals can be either digital or analogue....
Why cant these signal propagate on your PCB.... There is a severe lack of information here please supply us with more details...
I also think your view of ac and dc signals may need to change or evolve.