Logic Diagram for IC CD4020

Hi all, I want to include ICs in my schematics so I have gone about drawing one I need in Logic form.

I have attempted to copy the diagram from a Datasheet, but may have miss-read parts.

My question is what is the correct way to wire the pin-outs?

Look forward to your points :)

Thanks Dave

by Davelarave
March 24, 2013

Forgot the link to the circuit!

by Davelarave
March 24, 2013

Not sure if this answers your question but it looks as though CL allows you to give a net multiple labels and - as long as they're unique - will connect them consistently to same-named nets elsewhere in a schematic and plot voltages under either or indeed both names.

So if you had a net with two labels A and B then a resistor with one end at ground and a label A at the other will see the same voltage at the A end as a similar resistor with B at the non-grounded end:

by signality
March 24, 2013

Thanks, thats really useful and will make my circuit far simpler!

With regards to my problem I should probably re-phrase it as I can see that you have answered what I asked initially.

I'm actually stuck with the CD4020 circuit; in copying it from a product data sheet I haven't been able to figure out the correct pin-out arrangement i.e. there are more wires than I have pins for....

Page3 - logic diagram for cd4020b http://www.jameco.com/Jameco/Products/ProdDS/12802TI.pdf

by Davelarave
March 25, 2013

If you look carefully at the datasheet you'll see that he CD4020 doesn't bring all the possible counter outputs to pins. Only a subset that will fit into the 16 pin box:

Q1, Q4 - Q14 plus Vdd, Vss, clock input and reset.

Map those onto the ones in your circuit as you seem to have done and off you go.

Although for logic in CL you don't need a Vdd supply (and don't forget that in CL logic high is fixed at present = 5V), you do need a ground connected to Vss if you want to try to simulate it ...

Oh and have a cup of tea ready. It could take a while.


by signality
March 25, 2013

Ah, ok. Yes that does make sense. Thank you so much. I'll let you know how many cups it takes!

Thanks again!

by Davelarave
March 26, 2013

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