First of all, if you have AutoCAD viewers, no matter if it is a Full version of AutoCAD, an LT AutoCAD or even if it is an AutoCAD DWGTrueView, you can use a PDF virtual printer to get PDF directly from AutoCAD.
For AutoCAD users
DWG to PDF.pc3:
There is a default DWG to PDF.pc3 listed in AutoCAD printers, use this PC3 file to get PDF files.
Virtual PDF printer:
If you have a virtual printer, you can now directly print to PDF with it.
For non-AutoCAD users
If you still need to view drawings before getting the PDF, you need to find some applications which can view and let you convert to PDF.
Autodesk DWGTrueView and other viewers:
Get a free download of Autodesk DWGTrueView and print the drawing into DWG with some virtual printer in DWGTrueView.
Other viewers which can view and print or convert CAD drawings into PDF:
Search online and you will find there are lots of applications which are capable to do the both. See the related links below that I recommend.
AIGraph CAD Viewer:
Supports batch converting DWF/DXF and Dgn files to PDF.
DWG to PDF Converter:
DWG to PDF Converters should be able to batch convert DWG/DXF/DWF drawings for most of them are shareware and you need to pay to get the conversion or service. Such converters should be capable to:Batch convert DWG/DXF/DWFConvert all the drawings in a list into a single PDF
Convert separate drawings into PDF one by one
Convert one PDF per layout in the drawingXREF files and ShX fonts supportivePDF page sizeColor modeLine weight
You can convert DWG to PDF in just three steps. Follow the guide below the source: How to convert DWG to PDF easily.