The previews of font files can be certainly printed as whole sheets to PDF format, simply by double clicking on the font file in Windows and using the print function and virtual PDF printer instead installing the font to the system.
But perhaps this conversion can also mean completely different thing, such as using particular font in some software, or printing just the individual symbols from the fonts. It might also be searched by users looking for a way to embedding fonts before export to PDF. So it is actually very difficult to give a precise answer, except for the fact that no such thing as ttf to pdf converter most likely exists.
Updated: July 19, 2023