Skip to main content

Thomas A. Longo


Distinguished Alumnus 2011

  • PhD '57, Purdue University, Physics
  • MS '53, Purdue University, Physics
  • BS '47, Purdue University, Physics and Chemistry
  • BS '47, Purdue University, Naval Science

Dr. Longo joined the navy at the age of 17 in 1944 and entered an officers’ training program. In 1947, at the age of 20 he received two degrees from Purdue (BS in Naval Science and a BS in Physics and Chemistry). At that time he was commissioned as an officer in the U.S. Navy. In 1950, he resigned his regular naval commission and accepted a reserve commission to return to graduate school at Purdue. In 1953, after receiving an MS in Physics, he began working on silicon research for Dr. Karl Lark-Horovitz and received a PhD in 1957, then was appointed as an Assistant Professor in the Department of Physics.

In 1958, Dr. Longo became Manager of Device Research at Sylvania Semiconductor in Massachusetts, eventually rising to the position of Director of Research and Engineering. While at Sylvania, he introduced the first sub-10 nanosecond high-performance integrated circuits, transistor to transistor logic (TTL) in 1963 and developed the first semiconductor memory, a 16-bit random access memory (RAM) in 1966.

Dr. Longo joined Fairchild Semiconductor in 1970 as Vice-President in charge of integrated circuits. At Fairchild, he introduced the first practical sub-nanosecond emitter coupled logic (ECL – F100K) and 1 Kbit ECL RAM. In 1975, after supplying all of the logic and memory ECL circuits for the first Cray computers, the fastest and most powerful computers in the world, he became a member of the Cray Board of Directors, where he served until 1992.

In 1985, Dr. Longo started the company Performance Semiconductor to develop submicron CMOS technology and microprocessors for military application. In 1987 Performance Semiconductor introduced the first submicron CMOS technology, and the PACE 1750A became the armed forces first standard microprocessor for avionics, missiles, and satellite applications and remained so for the next 15 years. Dr. Longo retired in 2003 after 50 years of continuous silicon activities.

Career Highlights

  • 1989 Performance Semiconductor CMOS PACE 1750A selected by the armed forces as microprocessor standard
  • 1975 Appointed to Cray Research Board of Directors
  • 1973 Named by Electronic News as one of the top contributors in the first 25 years of the semiconductor industry
  • 1972 Named an IEEE fellow for the development of high performance TTL and the first semiconductor memory, 16-bit RAM
  • 1957 Appointed Assistant Professor of Physics immediately after receiving PhD.
Last Updated: Apr 29, 2016 3:33 PM

Department of Physics and Astronomy, 525 Northwestern Avenue, West Lafayette, IN 47907-2036 • Phone: (765) 494-3000 • Fax: (765) 494-0706

Copyright © 2023 Purdue University | An equal access/equal opportunity university | Copyright Complaints

Trouble with this page? Disability-related accessibility issue? Please contact the College of Science.