Thank you @PeteKnight , that clears most of my doubts. There is a LDO with voltage set at around 4,2V, so the same as mine. 0,8 drop is more than enough, as it appears from datasheet. There is also a voltage level converter onboard, but this is not that important.
NOTE: With LDO’s it is better to stay with lowest possible dropout, so a 12V would be too much and a lot of heat would probably appear.