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Basically it is a transistor that allows current to flow or it doesn't. it cant be something else, but what actually bothers me is V in to the mcu. Does MCU provide an output using Vcc input directly or this input is going through some other internal components.
If this is a transistor and 5v goes through it, do i get that Vce drop ? which is 0.2V. and therefore i actually get 4.8 volts on my pin ?
If i am performing some calculations how would apply a Kirchhoff rules to a circuit with micro controller if i don't know nothing about its internals, only datasheet data.