RIP Hans Camenzind - from EDN Magazine:
Hans Camenzind rememberedClass D amplification has revolutionised music amplification. The "gold standard" back in the '70's - '80's was the Crown DC-300 amplifier with 150 watts per channel. It weighed about 45 pounds. A very good amp, solid, very clean and bulletproof. It weighed 45 pounds. Doing several channels of amplification meant a very heavy rack. All of the other roadies would vanish when it came time to do the load-out on the PA system. Now, thanks to Class-D amplification, I can buy a Crown XTi 2002 amplifier which sources up to 2,000 watts and weighs 18.5 pounds. Adjusted for inflation, the price is about 30% of what the DC-300 cost. Phase Locked Loops are an incredible tool -- I used a lot of them. Some trade-offs but a very powerful tool for signal processing. The absolute gem in Camenzind's tiara is the 555 Integrated Circuit. It was a very simple circuit designed to do basic timing functions but hackers soon realised that it was actually an eight pin kit of very useful electronics modules. The 555 has been used for thousands of non-timing circuit designs. Here is a site with just a few examples. His book is available for free PDF download here: Designing Analog Chips The Electronics (and Hackers) World is lessened by his passing.
Hans Camenzind, the Swiss emigre analog guru who invented one of the most successful circuits in electronics history and introduced the concept of phase-locked loop to IC design, passed away in his sleep at the age of 78 on August 15, 2012.
Hans Camenzind was born and raised in Switzerland and moved to the U.S. after college. He received an MSEE from Northeastern University and an MBA from the University of Santa Clara. After several years doing research in the Boston area, he moved to the West Coast to join Signetics (now Philips) and later started his own company, Interdesign.
After heading it for seven years he sold Interdesign to Plessey. Since then he had been an independent design consultant in analog IC design, operating under the name Array Design in San Francisco. During his career at four different companies he designed the first integrated class D amplifier, introduced the phase-locked loop concept to ICs, invented the semi-custom IC and created the 555 timer. He had designed 151 standard and custom ICs.
