Within AutoCAD itself, you're limited to dealing with one drawing at a time, if you wish to create a single, multi-page PDF containing all layouts (and/or the Model tab) from that particular drawing. Using the Batch Plot button within the latest releases would be the fastest way to get that kind of output. You can also use AutoCAD's Publish command to create larger PDFs, which contain pages from multiple DWG files, all in one, but that doesn't sound like what you want, given the information in your post.
There are also 3rd party utilities out there, though, which purport to do more along the lines of what you're after. I just did a bit of Google searching and I ran the trial version of AutoDWG's DWG to PDF Converter program. It seems to have options to do what you're proposing. You can select individual/multiple drawings or entire folders full of DWGs. You also have the option to create one giant PDF, a PDF per DWG, or a separate PDF per layout within the DWGs. This post is not meant to be any kind of endorsement from Autodesk for any non-Autodesk software. Rather, it is just a demonstration that, indeed, there appear to be software solutions out there which will provide the results you seek.
Can't find what you're looking for? Ask the community or share your knowledge.