Dual Voltage Teensy LC

[Joegi]

I want to use this: https://www.pololu.com/product/2560 voltage regulator set to 3.0V to power a Teensy LC via Vin. The question is, do I have to cut the Vin-Vusb connection, or instead have to use a schottky diode or can I assume that my regulator has a internal diode that protects current backflow?
Thanks for the answers in advance!

 

[Theremingenieur]

Without cutting the trace and optionally putting a Schottky diode, you will for sure kill the voltage regulator.

 

[Joegi]

I remembered that I did that without a diode before (and read somewhere that some regulators have a protection against current backflow), so I gave it a try and up to now (after a couple of code uploads) nothing bad happened. I might have to add that the Voltage regulator is fed by two parallel 5F caps (3V) which are charged by a power supply which (at the moment) is switched off during code upload. The power supply which is charging the caps will be replaced by two small solar cells in the final circuit.