Galvanic separation for a DC/DC converter means that the input and output lines are not interconnected. As an easy example, take a simple 3-pin regulator into consideration (the one you are using). You put 12V on the input and get 5V on the output. However, the 0V line is shared on the in- and outputs and hence there is an electrical (galvanic) coupling between the two.

If you have a transformer (not an auto-transformer!), the output has no common connections to the input: it is galvanically separated.

DC/DC converters come in two types: galvanically separated and non-galvanically separated. You need the first one.


There are many manufacturers of these devices. You could start at Newport (http://www.dc-dc.com) just to name one.