555 Timer IC, the Stuff of Silicon Legends

Posted by Pieter van Nuenen  /   August 22, 2012  /   Posted in News, Social  /   9 Comments

In 1970s, Swiss electronics engineer Hans Camenzind was working in Silicon Valley as a design engineer for Signetics (later acquired by Philips). It was there that Hans designed the 555 timer IC, his most famous invention and a device that would become key to the success of Signetics and the commercialisation of semiconductors.

The 555 timer IC which is used in a variety of chip designs to provide time-delays revolutionized chip design with a simple concept that time did not have to be dependent upon power supply voltage. The chip was based on a superb understanding of the functional requirements, which were subsequently implemented in optimized bipolar (analog) technology.

Engineers who grew up before microprocessors were readily available and affordable fondly recall working with the 555 timer in sequential logic for many early designs that continue to be used today. Back then the semiconductor business was still in its infancy and investment in R&D and manufacturing capability was modest.

The 555 IC entered full scale production in 1972 and was an overnight sensation, becoming one the most successful devices in the industry’s history, helping to building upon the growth of Silicon Valley as the epicenter of technology, a reputation that holds today despite the fact that many fabs which produce semiconductor silicon are now located elsewhere.

Highlights from industry describe the 555 as…the Swiss army knife of analog ICs, the best and most useful chip ever designed and some go as far as describing it as not merely another circuit idea, but a philosophy.

Last week, electrical engineer and inventor Hans Camenzind died at the age of 78.

Today over one billion 555 timer ICs are still produced every year and billions of the handcrafted chips, with 23 transistors, 16 resistors and 2 diodes, have been incorporated into countless electronic applications. Versions of the device are still being made by major semiconductor companies today, including NXP. The NE555 was listed in the IEEE Spectrum 2009 list of 25 Microchips that Shook the World. While rock music may have their legends, engineers have inventors who create technologies that touch the very fabric of everyday lives. At NXP we salute Camenzind for his contribution to the field of electronic engineering.

Further reading:

A comprehensive introduction to CMOS and bipolar analog IC design: Designing Analog Chips RIP Hans Camenzind – Make:
Hans Camenzind, 555 timer inventor, dies – EETimes
Hans Camenzind – Mannerisms / Electronics Weekly
Hans R. Camenzind – Wikipedia



Pieter van Nuenen

About Pieter van Nuenen

In his role as Global Head of Corporate Communications, Pieter is responsible for strategic communications planning, digital communications and global agency network management.


  1. Gitesh August 22, 2012 10:38 pm Reply

    I first came across the 555 during a long summer break from school aged 11. A friend and I spent some time following a book armed only with due soldered components and a breadboard. I will always have a certain fondness for this chip, and it is great to hear about it’s lineage. Thank you, I’m now off to search the internet for more articles about Hans Camenzind.

  2. Rubens Moreno August 24, 2012 1:03 am Reply

    In 1976 I started using this fantastic chip, at University, as frequency divider, Monostable, Astable, Clock Time base for logical circuits and current generator, during my practical Electronic Classes. During the 80s I could use it in my firsts projects.
    Congratulations Michael Kriek, for the article.

  3. Madhusudan August 24, 2012 5:30 am Reply

    I still remember the thrill of being introduced to 555 timer during the second semester of grad school and doing scores of interesting projects with it.

    News about hardware greats passing away makes one sad.
    Rest in peace Hans.

  4. Tony Friel August 24, 2012 8:20 am Reply

    I’ve used the 555 in many, many electronic projects over the years; its amazing where this great little chip can be found.
    RIP Mr Camenzind.

  5. Henri August 31, 2012 3:51 pm Reply

    RIP Hans Camenzind, what a great legacy you have left to all of us! Thank you!!!

  6. JS Yoo September 6, 2012 7:44 am Reply

    impressive legacy story; will you allow me to translate this and post on Korean language site?

  7. Patrick Chung March 27, 2013 12:16 pm Reply

    NE555 is probably most widespread chip in the world. Now astable multivibrator with ne555 can be online simulated on:


  8. David (Dave) E. Colglazier January 24, 2014 5:33 pm Reply

    I was a Signetics Field Sales Engineer back in the early 1970s covering the Minneapolis/St.Paul account base but just before that I was working for Magic Dot, a startup company, designing and building thick film touch capacitance switches. These devices required a highly sensitive input, that had to be protected from static discharges, and an output capable of driving various electro-mechanical devices and logic circuits. The first device was a skin resistance/breath touch switch and our company had been working with Hans at Interdesign to design the IC chip. Hans chose to use and 555 timer and change the top metal layer to accommodate our needs. I used this modified chip in its die form to build our switches in the small thick-film fab area we had. I met with Hans in the Bay area as we were developing a keyboard BCD encoded version that we subsequently had made in the CDC fab plant in Bloomington, MN. When I left Magic Dot to join the Signetics sales team, I received five samples of a device printed NE557V that I still have. After many years I contacted Hans about this device and asked him what he thought it was. I have the email where he said that he wasn’t aware of a device in the timer series that had that numbering and suggested it was probably a misprinted NE567V that is a phase locked loop tone detector that I believe he worked on also…I have my samples of that device too!. When digging through my ancient sales literature given to us Field Sales people, I came upon a handout from September 1973 called the Special Linear Issue. Within it is an article published June 21, 1973 in Electronics magazine that mentions that the 556 will be released in late August and the 557 will be released in mid-September. It states that “This model, which will contain a constant-current source, is intended to provide long timing intervals, of 2 to 3 hours, without the need for large expensive capacitors.” Mystery solved! I also discovered a hand-out introducing the 553 and 554 Quad Timers that eventually were re-numbered the 558 and 559 and are mentioned in the 1979 Linear circuits manual. It seems from this evidence that this part of the company might have been running a bit ragged at the time. I wasn’t able to let Hans know that I solved the mystery but I really doubt it bothered him much since he was a very disciplined engineer. Peace my friend! Dave

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