Wait, so if I want to put 0 on a pin, I should connect it to - (GND) ?You cannot leave an input connected to nothing. The input impedance is very high and will float to any undetemined voltage.
You must connect ALL inputs to logic LOW or logic HIGH.
Yes.Wait, so if I want to put 0 on a pin, I should connect it to - (GND) ?
Ground.When I used transistors for logic gates when I wanted to put 0 on an input I didn't
connect base to nothing.
What would happen if I would connect transistor base to - in that case?
Schematics are better able to convey thoughts about circuits...But how do I implement switches with TTLs ?
If I'd go from + to a swtch and from switch to a pin when switch is off there is nothing
connected to a pin, and I can't connect both + and - to a pin what should I do in this case ?
EDIT: I can connect 2 switches one leading - to the pin and one leading + and make a rule that one switch should always be on and one off but how can I do this with just one switch so its either 0 or 1, not 1 or nothing :/
You will not find input resistance in the data sheet. What you will find is the input current or input leakage current, 0.1nA typical, 1μA max. Hence you are looking at input resistance of the order of 10MΩ or greater.Hmm what is the input resistance of the input pin ?
I looked in a datasheet and could find any infromation about that.
The lowest value for pull-up or pull-down resistors is determined by whatever will be driving that input. The driver needs to be able to sink or source an appropriate amount of current.Hmm what is the input resistance of the input pin ?
Absolutely not. Check the data sheet!If you connect the gate input to 5V, the input current is IIH = 40μA for 74LS08.
If you connect the gate input to GND, the input current is IIL = -1.6mA for 74LS08.
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