The PCB circuit I'm using expects 5V input voltage which it then converts to 3.3V using an AMS1117-3.3 voltage regulator. The power supply I'm using is 3.3V. What happens if I feed the 3.3V to the input of the 5 to 3.3 voltage regulator?
The input of the voltage regulator has an easily accessible jumper header. Whereas bypassing the voltage regulator would require the use of bodge wires. Can I get by with just feeding the 3.3V into the regulator? What are possible drawbacks if it even works? What would happen when the PSU voltage drops below 3.3V (as I doubt it will provide a precise and constant 3.3V)?