IC Number origins - like the LM555

Thread Starter

thatoneguy

Joined Feb 19, 2009
6,359
The 555 was named after the 3 5k resistors forming the internal voltage divider.

What other ICs are named after interesting things, such as year designed, or some whacky reason besides "it was next in the series"?
 

Wendy

Joined Mar 24, 2008
21,906
I don't think so, this has been documented. I even put the base links in my "Introduction to the 555" article for the AAC book.

Excerpt from "An Interview with Hans Camenzind", the inventor of the 555 chip.

http://semiconductormuseum.com/Transistors/LectureHall/Camenzind/Camenzind_Index.htm

How did the 555 name come about?
Signetics had “500” numbers, and the earlier product I worked on was the 565, 566 and 567. It was just arbitrarily chosen. It was Art Fury (Marketing Manager) who thought the circuit was gonna sell big who picked the name “555”.
 
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Thread Starter

thatoneguy

Joined Feb 19, 2009
6,359
I found it on This Page

--ETA: There is a comment section to advise them the information is incorrect. I stumbled across it when looking at power supplies somehow.
 
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Wendy

Joined Mar 24, 2008
21,906
Sounds like an internet myth in the making. I notice the author published his site after my timer article, including the color coding of how the timer works. They are not the same drawings, but very, very similar.
 

Thread Starter

thatoneguy

Joined Feb 19, 2009
6,359
Didn't mean to start a war.

I'm just curious how many ICs are named for a reason other than something obvious, like 5V in 7805.
 

SgtWookie

Joined Jul 17, 2007
22,210
Well, I'm afraid that I'll have to take Hans Camenzind's word for it ... who knows what was really going through Art's mind when he chose 555 for the name; if Hans did not give a specific reason, I don't know who really WOULD know.

In the meantime, I found a very interesting book written by Hans Camenzind on Google Books called "Designing Analog Chips" :
http://books.google.com/books?id=hYKsXD1BiVYC&pg=SA11-PA2&lpg=SA11-PA2&dq=Art+Fury+signetics&source=bl&ots=tdNamG7Otw&sig=xU0pWTqbs_wVRJLL4hLjrj0LOlQ&hl=en&sa=X&ei=HOfrTpzzPIyJtwfBtdiwCg&ved=0CEEQ6AEwAw#v=onepage&q=Art Fury signetics&f=false

In it he shows a design for an improved 555 IC on page 11-6 that takes care of a number of idiosyncrasies of the original timer; the output Darlington is replaced by a PNP/NPN pair to eliminate the voltage drop; the spike during output transition is reduced considerably, power consumption is reduced from 3mA to ~0.8mA, operating range extends down to 3v, and various other enhancements. I wonder why nobody has picked up and run with this design? It couldn't be all that much more expensive to make than the original 555. Even if it sold at a loss for the first few hundred thousand, seems to me it would sooner or later take over.
 
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