This module convert DC input from range (7.5-45)V DC to 5V DC output. It is based on TPS54340. Originally it is made for accumulator battery powered RaspbreyPi.
Detail view with schematic and all layouts are prestened in /DC-DC Step-Down Converter/DC-DC Step-Down Converter.PDF
This project is under CERN Open Hardware Licence v1.2 and it's integral parts are free to use.
If you recognize improvements feel free to write comments, create issues and make a pull request.