I've seen some schematics where the input of a microcontroller was protected with two diodes : one from ground (A) to input (K) and the other from input (A) to power supply (K) and a limiting resistor in serie with input. If the input voltage is greater than power supply voltage + diode threshold voltage, the diode will conduct limiting voltage to Vcc+06V. But there will be a current in the diode. If the power supply is a simple LM7805 regulator, there is no risk for it since it will receive a current at output?
I assume no since there is the same protection inside the microcontroller but I doon't understand why?
Thanks a lot.