I have to calculate trace width for my design... i dont know input current and rise in temperature.. i just know the differential mode and single ended impedance.... how to calculate the trace width from the given impedance...
There are free PCB transmission line 2D field solvers that can be used. TNT ( http://mmtl.sourceforge.net/ ), has a good interface and gives good results.
MDTL ( http://sourceforge.net/projects/mdtlc ) isn't as well developed, but it still gives good results for differential traces. If all you want are close numbers, and precision isn't required, there are a bunch of online and free calculators on the web. Just do a Google search.