How to build my IC (4-bit counter SN7475)?


#1

First of all, sorry if this question has already been asked, I am a new user of the application and new to digital electronics altogether.

I am supposed to make a 4-bit counter using SN7475, to count up/down when pushing a button. http://circuits.datasheetdir.com/105/SN7475-pinout.jpg

And I do not know where to start. How to make the D latches for the connections? Any tips would be great. Thanks guys.


#2

You need to create a fritzing part for the 7475 because there doesn’t seem to be one available (there was one at some point but the github page no longer exists.) Changing the labels in a generic IC is probably the easiest course for that. I expect that process is covered in the tutorials here:

Peter


#3

I know that I have to create a part, and setting the pins and changing the label names was the only thing that I managed to do.

Implementing the logic behind is hard. In order for my board to work, I have to make 4 D-latches and connect them like in this picture, and the Q’s are the bits of the counter.

My problem is how to make the D-latches, and I can’t get over this step.


#4

I think perhaps your expectations of Fritzing are too high :-). It only produces the schematic and pcb, it doesn’t do simulation so it doesn’t need (unless you want it for the schematic) the internals of the part. It doesn’t care what the part does, only what connections it has to other parts. So as long as you have the pin names on the box you can connect power supplies, resistors and switches to the pins to make your circuit. The idea is that you then build it physically on a real breadboard and do the testing there.

Peter


#5

Hi Peter!

Thanks a lot for your insight. I have solved the problem now