Hello everybody.
I have a question regarding the mandatory diode for the XIAO ESP32-C3 5V power pin.
As stated by the docs, you must place a diode between the 5V power pin and the power source. Does anybody know why this is required? Is there any back flow risk when it is only powered by this pin? Is there any risk if it is not placed?
Thanks in advance!
Hi Kashmir54,
When connected to USB for upload, without a diode, an unwanted current will flow from the higher voltage to the lower voltage. With a diode, the external 5V voltage is reduced by a forward voltage drop (about 0.5V), so that the external 5V is always lower than the USB.
USB can power XIAO’s internal circuit and external 5V can power external circuit.
Thank you soy much for the explanation @msfujino.
So I believe that, if I plan to power it through the pin and I do not plan to connect to the USB, I won’t need the diode.
Thanks again!