I need help to understand this arrangement. I will use two sources V5-9V_VIN and V5V_SDA (USB). The document says that multiple DC power sources can be provided simultaneously because protection is provided ( schottky diodes). BTW notice that the same diodes are used, hence the Vforward is the same for all diodes and the voltage supplied could be the same too (threshold turning on/off is the same).
But what happens when I feed, say, USB 5V and VIN=5v simultaneously? One diode turns on allowing +5V to the regulator input and not allowing the other diode to turn on because there is not enough forward potential difference? Can they turn on at the same time? If only one diode can turn on at a time, then which one? I need to make sure that VIN will be the source whenever/if I connect VIN to the board, otherwise USB supplies the power.