Talk:Three-state logic

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The Three State Logic and Tri-State Buffers should be put together and I think that the High Impedance (High-Z) shoudl be eloborated on more in the article.

I disagree. AW

Please give more information why you think so then. I put back the merge tag in the article. --Abdull 14:48, 7 March 2007 (UTC)
Done. three-state logic and tri-state buffer have been merged. -- (talk) 14:41, 29 April 2008 (UTC)


The table showing the inputs (A,B) and the output (C) is not clear at all. I referred to this article to learn, and therefore, I am not in a position to provide a fix. Could anyone else fix this? Thanks - Todd 15:00, 9 August 2007 (UTC)

Alas, there are too many articles that seem clear to people who already know the subject, but the article doesn't help people trying to learn. This seems to be one of them -- I already know the subject, so the table seems clear to me.
If we renamed "B" to "output enable", would that clarify that the output C is connected to A when the output is enabled, but the output C is disconnected from anything when the output is disabled? -- (talk) 14:41, 29 April 2008 (UTC)
If B was renamed to OE or HiZ it might make it clearer, but should also be reflected in the artwork. Jheiv (talk) 03:17, 27 May 2008 (UTC)

tristate multiplexing[edit]

The article currently mentions tristate multiplexing or Charlieplexing.

Is there some kind of tristate multiplexing other than Charlieplexing? -- (talk) 14:41, 29 April 2008 (UTC)

Tri-State Logic[edit]

  • My experience is that the term in the industry is much more frequently expressed as Tri-State logic, rather than Three-State logic... Comments? Jheiv (talk) 07:48, 24 May 2008 (UTC)
  • Interestingly, both references on this page have titles with "Tri-State" rather than "Three-State"... Jheiv (talk) 07:51, 24 May 2008 (UTC)
  • I thought "Tri-state" was still a National Semiconductor trademark? Now, I have been known to go Xerox something held together with Scotch tape, but shouldn't the Wikipedia photocopy things with adhesive tape? --Wtshymanski (talk) 14:46, 24 May 2008 (UTC)
  • Most books mention both; if tri-state is a trademark as The Art of Electronics says, then it would be more encyclopedic to stick with the generic three-state. Dicklyon (talk) 01:10, 31 May 2008 (UTC)
  • I thought that "tri-state" meant "in or linking three USA states". Anthony Appleyard (talk) 11:50, 2 June 2008 (UTC)
  • Tri-state is definitely a registered trademark of National Semiconductor. The following website lists the trademarks for National Semiconductor ( —Preceding unsigned comment added by (talk) 00:39, 2 June 2010 (UTC)
  • I checked with TRI-STATE is a trademark of National Semiconductor. It was filed Jun. 01, 1971, registered Aug. 22, 1972 with registration number 941335. The trademark was not renewed and therefore expired Jul. 29, 1993. It was filed again Jan. 28, 1997 and registered Feb. 24, 1998 with registration number 2138646. The current registration is alive and has been renewed Mar. 28, 2007. Olli Niemitalo (talk) 08:29, 7 March 2016 (UTC)

0/1 vs. Inactive/Active[edit]

Some editors are changing the article from 0 to 1 to active / inactive. I think this terminology just confuses things. Especially in an article about high-impedance outputs, an inactive output could be confused with a Hi-Z output.

Perhaps you could discuss this on the discussion page before reverting my edit, eh? (talk) 23:23, 21 July 2008 (UTC)
The edit was reverted once by another editor here. If you wanted to revert back, I would have suggested you brought it up on the talk page. Jheiv (talk) 23:29, 21 July 2008 (UTC)
We'll I did assume that the editor just didn't understand the edit, as there was no good reason given for the revert. Regardless of this, the idea that I should be held to a higher standard than the editor is utterly indefensible; it should clearly be the other way around. I suggest getting of the high horse at once. (talk) 01:03, 23 July 2008 (UTC)

My suggestion is that we stick to 1 and 0, on and off, and high and low -- and leave active and inactive off. These terms are not frequently used in this manner. Comments.... Jheiv (talk) 23:17, 21 July 2008 (UTC)

Nonsense, the terms are used everywhere in electronics; just go check some datasheets for "active low". Also, how are you going to denote the difference between the logical and physical levels, as it didn't make sense before. (talk) 23:21, 21 July 2008 (UTC)
While the term "active low" is indeed all over, the term "inactive output" when referring to a low output is hardly used at all (less than 5000 hits on Google ). Jheiv (talk) 23:29, 21 July 2008 (UTC)
Given that one can also have "active high", it's hardly sensible to imply the mapping 0 -> "inactive" and 1 -> "active". And how do these terms help "denote the difference between the logical and physical levels"? Oli Filth(talk) 07:52, 22 July 2008 (UTC)
That mapping is entirely appropriate; it refers to the logical state the signal. An active high signal is logically true, 1, active, or whatever else, when the voltage level is high. An active low signal is logically false, 0, inactive, or the inverse of whatever else, when the voltage level is low. (talk) 01:03, 23 July 2008 (UTC)
There is no such thing as an "active high" signal, or for that matter, an "active low" signal. There are, however "active high" and "active low" inputs. This is a crucial distinction. Active low inputs are, in fact, logically true when the voltage is low, but to say that the signal going into the input is active or inactive is misleading and ultimately incorrect. The fact is, that terminology is neither widely used in that manner, nor clear for an average reader -- it should be left off. Jheiv (talk) 16:30, 23 July 2008 (UTC)

An "active low" input simply means that it is triggered or enabled when the input signal is logically 0. Jheiv (talk) 23:35, 21 July 2008 (UTC)