Prof. Dr. Thorsten Jungmann (last updated 2026-10-03)
Hans R. Camenzind (1934–2012) was a Swiss-born electronics engineer, known for designing the 555 timer IC in 1971 under contract to Signetics. He was born and raised in Zürich, Switzerland, and moved to the United States in 1960. There he received a master’s degree in electrical engineering from Northeastern University and an MBA from the University of Santa Clara. In 1962 he joined the Laboratory for Physical Science at P. R. Mallory in Burlington, Massachusetts, and in 1968 he moved to California to join Signetics. Later he started Interdesign, a semiconductor design company, which he headed for seven years before selling it, and then worked as an independent analogue IC design consultant.
The 555 timer IC is an integrated circuit used in a variety of timer, delay, pulse generation and oscillator applications. Signetics had hired Camenzind in 1968 to develop a phase-locked loop (PLL) IC, and he had designed an oscillator for it whose frequency did not depend on the power supply voltage or temperature. Development of the PLL was frozen after Signetics had laid off half of its employees during the 1970 recession. Camenzind then proposed a universal circuit based on this oscillator. Prototypes of the 555 were completed in 1971; Signetics first marketed it in 1972, using bipolar junction transistors. According to Camenzind, the 555 timer was manufactured by 12 companies in 1972 and became a best-selling product. Camenzind noted in 1997 that ‘nine out of 10 of its applications were in areas and ways I had never contemplated’.
The 555 can work as an astable (free-running) oscillator, as a monostable (one-shot) pulse generator, as a bistable set-reset latch and as a Schmitt trigger inverter. According to his own account, he designed more than 150 standard and custom ICs, among them the first integrated class D amplifier, introduced the phase-locked loop to integrated circuits and invented the semicustom IC. He was the inventor on 20 US patents, wrote several books, among them Designing Analog Chips and Much Ado About Almost Nothing (2007), a general audience book about the history of electronics, and lectured at the University of Santa Clara. He died on 8 August 2012.
Reference and further reading:
https://en.wikipedia.org/wiki/Hans_Camenzind
https://en.wikipedia.org/wiki/555_timer_IC