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Transistor-Transistor Logic

TTL, or transistor-transistor logic, is a digital circuit that uses multiple transistors to derive its output.^[1] It was first created in 1965.

Overview

The first family of transistors, Sylvania Universal High-level Logic (SUHL), was produced in 1963. TTL is most often used with integrated circuitry. TTL first became popular with designers after Texas Instruments released the 5400 series which had a military grade temperature range, allowing the integrated circuits to work in hot or cold climates. ^[2] In transistor-transistor logic, transistors can both amplify the output and isolate the inputs; a step up from the previous resistor-transistor logic and diode-transistor logic. TTL is bipolar logic, meaning it contains at least one BJT, or a bipolar junction transistor, which contributes to the amplifying power of transistor-transistor logic.

TTL devices were packaged in through-hole, dual in-line packages. Through-hole meaning devices that have pins that are inserted through holes in circuit boards and are then soldered on the other side and dual in-line meaning the device has a rectangular housing with parallel pins on both sides that are pointed downward allowing for through hole soldering to a circuit board.

Significance

The low cost of transistors made digital techniques using transistor-transistor logic more economically practical. Also, previously analog tasks switched to digital like how TV switched from analog to digital recently.

References

1. ↑ [[1]]. Computer Hope
2. ↑ [[2]]. Wikipedia

Links

http://en.wikipedia.org/wiki/Transistor–transistor_logic

http://www.computerhistory.org/semiconductor/timeline/1963-TTL.html