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Oral History – Hans Camenzind
Continued)
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What patents are related to
the 555?
There are no patents on the
555. Signetics did not want to
apply for a patent. You see, the
situation with patents in Silicon Valley in 1970 was entirely different
than it is now. Everybody was stealing from everybody else. I designed the 555 Signetics produced
it, and six months, or before a year later, National had it, Fairchild had
it, and nobody paid any attention to patents. The people at Signetics told me they didn’t want to apply
for a patent, because what would happen if they tried to enforce that
patent, is the people from Fairchild would come back with a Manhattan-sized
telephone book and say “These are our patents, now let’s see what you’re
violating”. It was a house of cards – if you blew on it, the whole thing
collapsed. It took about ten years
to change. I guess it was some new companies that didn’t have ancient
history and did have a strong patent, and started enforcing, and that
changed to whole situation. It is
very intense now. The same thing – I have a patent on the phase locked
loop, and that would have been a very strong patent, but no enforcement.
Hans, thank you for taking
the time for this very informative interview on such a important aspect of
IC history. Any final comments on why the 555 design has been so resilient
for so long?
The thing is that this is not a
good design (the 555). I had a few
years of experience, I’d say about five years, but I had no teacher, and I
had to learn it by myself.
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Oral History – Hans Camenzind
(Continued)
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You know it was really the
beginning of design, so looking at it now, I would say “I wouldn’t do it
like that again”. But nobody has
actually changed it - it is still
the same. They have shrunk it, they
shrunk the dimensions. It was a 10
micrometer design, that was the standard size. You could make it in four (micrometers) now. This is more die per wafer, but nobody
has changed the arrangement or the schematic.
As a timer, you know, you
trigger it and it runs for a certain time, it is very good. It has a temperature coefficient of like
23 parts per million. Over a large
temperature range, that’s like .1
%. Its very stable. In free running mode, as an oscillator,
its not so good, about 150 parts per million. And that you could improve
down to about 10 ppm. So you could make an improved product. I’m amazed and stunned that in 30 years,
somebody hasn’t looked at the schematic and said, “I can make this better”,
so for the same area and same cost, and then they have a better
product. Nobody has done that.
Camenzind
Historic Audio Recordings
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