Topics created by jecci

@Igor-Antolić if you want to help the original author of the question, posting an answer on the linked stackexchange thread will probably be more efficient. The original author is not likely to look in a different forum, almost 5 years later.

Not near a cad program at the moment, but try the following: Connect output of U8 / capacitor C34 pin 2, to pin 1 of D1, connect J1 pin 4 (vcc) to D1 pin 2, and attach your +5V to D1 pin 3. This way the source with the highest voltage will supply your circuit.. The actual VCC will be Vin - drop voltage over D1 (0.3V usually), that is 4.7V in your example. But that is next to nothing..

@jecci if you will be driving inductive loads I would suggest to include a snubber circuit. A good article and design considerations here