Demob,demodb said:a single ended signal is measured as the excitation with respect to a fixed reference. Differential signals are measured at two nodes and both nodes have a positive and a negative excitation. These excitations occur around a fixed reference.
The main advantage of differential is that many noise sources become common.
I think the phase shift is 180 deg, not 90, and there is no common reference for the differential signal. An example: A LAN 10Base connection. Where is the common reference? It is a differential connection!puviarasu said:Differential are previously used for precision circuits as it requires more resource compared with single ended. it works by sending a 90 degree phase shifted waves in 2 different lines with respect to a common reference. So when a EMR is applied it will affect both the wires so it will become a common mode signal so it is automatically filtered in amp in the front stage of the receiver, so it is used nowadays in high frequency systems as the effect of interference is more at high frequency operation.