I use this voltage regulator to convert a 12 volts battery to 5 volts output.
It include a enable pin that can be set "high" (>1.4V) to turn the regulator on or "low" (0V) to turn it off. So far so good.
I discover that the regulator board pull the enable pin high through a 200k resistor if left unconnected. This way the regulator do it's job if enable pin is not used. I measure a voltage of 6.14volts on this pin and in my application it is connected to one uC GPIO pin through a 1k resistor. Obviously this voltage exceed the 3.3v gpio pin rating although it only represent 62uA of current for the pin to sink. Strange enough the high voltage do not destroy my uC pin and I don't know what to think or do about this?
It's true that at program startup, the digital pin is quickly turn to "low" thus sinking this 62uA current and dropping the voltage to 0 which effectively cut the regulator 5v output. Does 6.14v be a problem or there is so little current involve that voltage do not really matter in this case?
I can probably include a voltage divider to further drop the 6.14v to about 3v (adding the green 1k resistor in the drawing below). Another option migth be to change the digital pin mode from output to input_pulldown and combine this to the voltage divider? Any comments appreciated!
Thanks