I was reading through the Data Sheet for the Photon, an IoT dev board: https://docs.particle.io/datasheets/photon-datasheet/ and under the Power section it says:
When the Photon is powered via the USB port, VIN will output a voltage of approximately 4.8VDC due to a reverse polarity protection series schottky diode between V+ of USB and VIN. When used as an output, the max load on VIN is 1A.
How is it that it outputs 4.8V due to the "reverse polarity protection series Schottky diode"? How does the Schottky diode influence Vin in such a way that it outputs 4.8V?
Also what does it mean when it's between "V+ of USB and VIN"? Is it that it's connected across the positive terminal of the USB pin, to VIN?