Computer History MuseumSemiconductor History

1963 - Standard Logic IC Families introduced

Diode Transistor Logic (DTL) families create a high-volume market for digital ICs but speed, cost, and density advantages establish Transistor Transistor Logic (TTL) as the most popular standard logic configuration by the late 1960s.

Integrated versions of discrete diode transistor logic (DTL) circuits became the first high-volume IC product lines. Designed by Orville Baker in 1962, the Signetics SE100 Series DTL family was overtaken in 1964 by the better noise immunity and lower cost of Fairchild's 930 Series establishing a competitive industry leap-frog pattern that continues today.

Patented by James Buie of Pacific Semiconductor in 1961, TTL (Transistor Transistor Logic) emerged as the most popular logic configuration of the next two decades. Unaware of Buie's work but inspired by an "all transistor" logic circuit described by Ruegg and Beeson of Fairchild, Thomas Longo led the design of the first TTL family, Sylvania Universal High-level Logic (SUHL) in 1963. Encouraged by SUHL's success in winning a high-profile Hughes military design (the Phoenix missile), TI introduced the competing SN5400 Series TTL family the following year. The company announced the SN7400 Series in low cost plastic packages for industrial customers in 1966 and quickly gained a greater than 50% share of the logic market.

By 1968 lithography advances significantly increased the number of transistors that could be integrated on a chip. Eager to win a share of the TTL business, Fairchild (9300 Series) and Signetics (8200 Series) pioneered the design of TTL-MSI (Medium Scale Integration - up to 100 logic gates per chip) functions such as counters, shift registers, and arithmetic logic units. Many vendors applied Schottky (1969 Milestone) and CMOS (1963 Milestone) technology to build larger, faster, and lower power TTL-compatible functions that extended the useful life and range of applications of this popular logic configuration.



Contemporary Documents

Buie, James L. "Coupling transistor logic and other circuits," U. S. Patent 3,283,170 (Filed: September 1961. Issued: November 1, 1966).

Ruegg, H. W. and Beeson, R. H. "New Forms of 'All Transistor' Logic," Fairchild Semiconductor Technical Paper TP-21 (1961).

Longo, T.A., Feinberg, I., and Bohn, R. "Universal high level logic monolithic circuits," Electron Devices Meeting, 1963 International, Vol. 9 (1963) p. 66.

Engineering Staff, The. The TTL Data Book for Design Engineers. Texas Instruments (1973)

More Information

Lécuyer, Christophe. Making Silicon Valley: Innovation and the Growth of High Tech 1930-1970. (Cambridge, MA: The MIT Press, 2006) pp. 230-248.

Swann, Peter and Gill, Jas. Corporate Vision and Rapid Technological Change: The Evolution of Market Structure. (London: Routledge, 1993) pp. 139-156.