5V/2A Fixed Output Buck Boost Converter Design
Buck-Boost Converter has a annoyance for your application that it converts positive to negative polarity of voltage
You can see that here
There is a second option, of course as suggested in link, to make a boost and then buck.
Basic idea is to equalize input voltage to predefined value and then provide required current to this system, in essence locking down both voltage and current to a specific value.
Third option is to use a forward converter as it provides positive to positive voltage transition. Efficiency is not so great as with buck and or boost, but you get what you wanted.
Try searching for forward converter topology IC. Wiki
link for SEPIC and forward converter are given.
Flyback converter is simplest of these three and will get you to your goal.
LT 1171CT is example for this topology and I believe you can get a reference schematic for this IC (and maybe a evaluation board). This is sufficient to start your journey into Power electronics.
Schematic shown looks like a Ćuk converter (not a typo, it is named after its inverter) and will give you inverted voltage on output. For digital electronics this will not &quot;fly&quot;.
I hope that some other of given examples will help you on your search. Ask away if you have any more questions on this subject.