I am currently designing a circuit where we have a lipo battery powering two rails:
- Rail 1: some RGB LED with 5V power supply
- Rail 2: a bluetooth chip with 3.3V power supply
Option 1: use 2 buck boost converter to go up from [3V-4.2V] to 5V one side and to 3.3V on the other side
Option 2: use 1 buck boost converter to go up to 5V creating rail 1, then use rail 1 + a LDO or DC-DC to go from 5V to 3.3V to create rail 2
What is it better to do and why?