Pololu 5V Step-Up/Step-Down 1A Voltage Regulator S7V7F5
With supported input from 2.7V to 11.8V and extremely stable and clean 5V output this Pololu is what you've been looking for to build 1S capable FPV racing drone!
This high quality step up/down voltage regulator offers 1A when stepping down; 500 mA when stepping up in incredible tiny dimensions.
Input: DC 2.7 – 11.8V
Output Voltage: 5V
Output Current: 500mA / 1A
Size: 9 mm × 12 mm × 3 mm