PDF to DWG (CAD/Software/Computers)
PDF to DWG
Actually, PDF's can contain vector geometry. Depending on how the PDF was made, it could contain vector lines that could then be converted to a dwg. I haven't used any converters myself, but I know of one from a reputable spot. You can see it here: http://www.dotsoft.com/pdf2dwg.htm.
Since, I think, Autocad 2010 you can natively insert PDF's into your drawing. If the PDF contains vector geometry you can then actually draw over and snap to endpoints of lines and so forth. If the layer information is included in the PDF then you can also turn the layers on and off just like a DWG.
Hope this helps.
PDF to DWG
Warning, I used some scanning software years ago that scanned directly into AutoCAD, but it was more trouble than it was worth because all the line work looked good but was off by a few hundredths and seconds (or worse). The drawing was okay for small revisions but useless for computations.
I tried several programs to convert from PDF to DWG and they all left something to be desired. Mostly handling curves and some line work. Custom linetypes were a disaster and some text converted to a strange very large font.
That was a few years ago and I would expect the programs are a little better at translation. However, AutoCAD has made enormous changes to its program as well over these years.
I thought I saw Angels
But I could have been wrong!