I'm trying to wrap my head around Ohm's law and there are plenty of similar questions already asked in this forum. But I just still don't understand it. It's about calculating resistor values.
Let's say that I have an IC which has an input pin I want to control high. I am doing this by connecting 3.3v to the input pin and I want to limit the current flowing to the pin to 2mA.
So by the use of Ohm's law I have calculated that 3.3 / 0.002 = 1650. So I would need a 1.65 KOhm resistor right?
So what happens to the voltage now? Shouldn't the voltage going to the pin be lower too because of the resistor? How can it still be 3.3v?
How about this? The supply voltage is still 3.3v but I need to lower the voltage to half for the IC, with a current of 1mA. So my calculation is (3.3 / 2) / 0.001 = 1650. The resistor value is exactly the same as before. 1.65 KOhm!
Can someone explain what I'm doing wrong? I feel really dumb right now.