Guys,
Since I have to deal with differential circuits now, and I am only use to single-ended, I was wondering if the characteristic impedance of a differential trace matters. To clarify: If I design differential traces to terminate into say, 100-ohms differential, I could use traces that are 90 mils wide with a trace-to-trace spacing of 100 mils to accomplish this, or I could use traces that were 30 mils wide with a spacing of 5 mils. Is either OK, even though the characteristic impedance of each individual trace is significantly different in the two examples? Would it matter to the circuit at all, as it does with the characteristic impedance of a microstrip trace in a single-ended circuit -- or is it only the differential impedance that matters in such applications?
Thanks!
-Bill