Converting .dsn files directly to .pdf format.
Converting OrCAD Design Files directly to Adobe Portable Document Format (.dsn to .pdf conversion) appears to be only possible using the original software, OrCAD PSpice Designer. Load the .dsn file, and print it as a PDF document using the virtual PDF printer, or the designated 'Export to PDF' function.
In some OrCAD versions you won't find a default 'Export to PDF' function, so your only choice might be using the 'Print to PDF' method.