where can I find schematic diagrams for logic gates using PNP transistors?

Question

I have looked at a lot of sites on the internet and can't find any schematics that use PNP transistors. Any logic gates are fine. Also is it possible to put the output(Q) of an OR gate back into one of its inputs, creating a memory circuit?

Answer 1

Hi,

It is not a good idea to put the output(Q) of an OR gate back into one of its inputs in order to create a memory circuit. This is because you will not be able to modify the content of the memory. For example, assume it stores "1", then the output = 1 and one of the input =1 (feedback one) also. Then you can never change the value of the memory to 0 by changing the other input because "1 OR 0" is 1.

The schematic diagram should be straight forward. Please let us know if you want us to draw for you.

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KodKodKod Learning Consulting - http://www.kodkodkod.com

Answer 2

Unfortunately there I have not found any either but I did find a very good book entitled "Digital Circuits" written by Kenneth Muchow, Anthony Zeppa & Bill Deem. The one I found was a bit dated (copyright 1987) but it gave me the basics. Hope this helps.

Also, I don't know if Radio Shack still has their book series on electronics but at one time they did have on on digital circuits and transistors. Check the website www.radioshack.com.