Mike Tuthill, who has died at the age of 71, was a genius of his time who broke barriers faster than anybody else and shaped the semiconductor industry worldwide. A long-time employee of Analog Devices, Limerick, he was a true pioneer who developed innovations that pushed technology and performance frontiers.

Foundations of the 3” Wafer Fab

[caption id="attachment_50955" align="alignright" width="235"] Pioneer of semiconductor industry Mike Tuthill.[/caption] Limerick man Mike Tuthill was one of the very early hires into Analog Devices Inc (ADI) in Limerick, starting in 1977 when the foundations of the 3” Wafer Fab were just being laid. While already an accomplished design engineer, Mike learned the art of integrated circuit design through working alongside Hank Krabbe who had moved from the US to Ireland to set up Analog Devices’ first CMOS Wafer Fab in a country with no experience of semiconductor process technology and no IC designers. Despite these challenges, the very first product run through the Fab, the AD7520, a 10-bit multiplying DAC, designed and laid out by Mike and Hank, along with Paul Egan, was a success and from then on the Irish operation went from strength to strength. By the early 1980s Hank had returned to America and Mike Tuthill continued to design several industry breakthrough products, including the first monotonic 16-bit DAC, but it was with Mike’s pioneering work on a fully integrated 12-bit, 5us ADC that the world really took notice. This required new process development in the Limerick fab, moving from CMOS to BiCMOS and the success of that product resulted in an expansion of the Limerick operation - both R&D and manufacturing. Mike, as the lead designer of a small team, that included among others, Dick Meaney and Peter Real, was influential in the formative years of many people’s careers.   He was elected to be an ADI fellow in 1988, the company’s highest engineering level and technical honour and thus became the first Limerick site fellow.

Original designs that spawned whole new product lines

Mike had a long track record of original designs that spawned whole new product lines. Examples include disk drive, interface and temperature sensors. Mike was also instrumental in setting up ADI Limerick’s RF product line in the mid 1990s. He was the lead designer of ADI’s first PLL synthesiser, which exceeded the performance of the industry leader at the first attempt. This initiative subsequently grew into a full portfolio offering, resulted in large revenue growth and a further expansion of the operation in Limerick. [caption id="attachment_50957" align="alignright" width="420"] Dick Meaney (design), Mike Tuthill (design), Mike Curtin (applications) and Donal Murphy (layout), Analog Devices circa 1981.[/caption] Mike grew up in Limerick and graduated from University College Cork with a BE in electrical engineering but not before he married his lifelong partner Marie, with whom he celebrated a 50th wedding anniversary in 2018. After Mike’s graduation, they moved to London where he worked on RF and microwave radio design at Marconi Company Ltd.

Transitioning to digital exchanges

In the mid-1970s, they came back to Ireland, taking a job at Telectron in Tallaght, an Irish company set up to serve the telecoms market that was at that time transitioning to digital exchanges and a nascent form of data communications called telex. However, Mike and Marie yearned to return to Limerick and their chance came when a colleague at Telectron, Bill Hunt, spotted a job advertisement in the paper for design engineers wanted at an American company starting up an operation in Limerick. Mike applied and got the job. Bill Hunt later joined him. From a technology point of view, Mike went full circle. He started out with Marconi designing microwave circuits optimising noise and distortion and his final work with ADI was on RF and microwave circuits optimising noise and distortion, although at significantly higher RF frequencies. In between, through his breakthrough data converter designs at ADI, he made the digitisation/quantisation noise he had first encountered at Telectron, into a non-issue. [caption id="attachment_50958" align="alignright" width="424"] Analog Devices, Limerick.[/caption] Leo McHugh, vice-president of instrumentation products for ADI, said: “From the start of his career, right through the 39 years he spent with ADI, Mike developed very successful breakthrough products that always pushed performance frontiers and are some of our industry’s most innovative solutions.

The ‘go to person’ for technical questions

"It was his innovative approach to circuit architectures and design expertise that made him the ‘go to person’ for many technical questions, but it was his patience, willingness to share, and humble nature that made him the person most people just wanted to spend time with. “His contribution to the success of Analog Devices and, specifically, to the success of the Limerick site was enormous and for that we are forever grateful. He will be missed by his many friends at Analog Devices and, indeed, the wider microelectronics industry in Ireland. "To his wife, Marie, his daughters, Eve and Jean, and extended family, we extend our heartfelt sympathy at this time. May he rest in peace."