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Bart
Guest
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 Posted:
Mon Dec 12, 2005 5:35 pm Post subject:
Logic Gates |
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I look at all the symbols for the different logic gates, NAND, NOR, XNOR,
etc. and on some of them they have a little circle on the output. I look at
datasheets for different IC's and I see the same little circle on some of
the pin designations. My electronics books show these but I can't find what
it means.
Any help is appreciated,
Bart
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Richard
Guest
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| Posted:
Mon Dec 12, 2005 5:35 pm Post subject:
Re: Logic Gates |
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"Bart" <consultec@fuse.net> wrote in message
news:3d947$439d7d90$d8442dec$6948@FUSE.NET...
| Quote: | I look at all the symbols for the different logic gates, NAND, NOR, XNOR,
etc. and on some of them they have a little circle on the output. I look
at
datasheets for different IC's and I see the same little circle on some of
the pin designations. My electronics books show these but I can't find
what
it means.
Any help is appreciated,
Bart
First, if your book doesn't cover this material, you need a different book. |
You'll see these circles on inputs and outputs in various schematic
diagrams.
Try a Google search for 'logic gate symbols'.
The first hit I got was http://www.kpsec.freeuk.com/gates.htm, and there
were several others.
Richard Seriani |
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John Popelish
Guest
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| Posted:
Mon Dec 12, 2005 5:35 pm Post subject:
Re: Logic Gates |
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Bart wrote:
| Quote: | I look at all the symbols for the different logic gates, NAND, NOR, XNOR,
etc. and on some of them they have a little circle on the output. I look at
datasheets for different IC's and I see the same little circle on some of
the pin designations. My electronics books show these but I can't find what
it means.
Any help is appreciated,
Bart
A small circle on either input or output means an inversion takes |
place, there. So an OR gate with a ball on the output means that the
output is low when any input is high, instead of high when any input
is high. It just takes the output from an OR gate and inverts it.
The result is called a NOR (not OR). It would have been more logical
if it had been called a ORN (OR not) but that is harder to pronounce,
I guess.
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neon
Joined: 25 Feb 2006
Posts: 570
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Sat Feb 25, 2006 2:36 pm Post subject:
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| the little circle denotes an inverter function like this and gate no circle nand gate circle got that ok |
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