pdf to sdoc conversion is most likely searched by users looking for a way to recover previously exported Samsung Note files (.sdoc) from PDF format. The only way how to do this is to have a proper version of Notes as it is the only tool that can work with these files. It supports import of some .pdf files, so this is probably the way to go. We have not found any particular mentions about this though, so if you struggle with some particular issue, it might be best to simply contact Samsung support.
Updated: August 2, 2023