The transistor revolution: How transistors changed the world

When these lists are compiled, one invention often gets overlooked: the invention of the transistor. This article examines the history of transistors and highlights the importance of transistor technology in the modern world.

What Is a Transistor?

In its simplest form, a transistor is a tiny, semiconductor-based switch that functions like a standard light switch. Transistors regulate or control current or voltage flow on a microscopic level. Modern transistors consist of three electrical leads: the source, the drain, and the gate. When a small electrical signal is applied to the gate of the transistor, the larger primary electrical signal is permitted through the drain.

Various modern configurations allow different primary and secondary voltages to be applied to these leads, which is often a function of the semiconductor materials used. For example, standard silicon-based metal-oxide-semiconductor field-effect transistors (MOSFETS) require 1000mm*Rds(on) at a 5V gate voltage and a 200 drain-to-source voltage, while Galium Nitride semiconductors only need 60mm*Rds(on) at the same voltages (a 16x reduction).

How Are Transistors Used?

Transistors are used in nearly all modern electronics. They are the foundation of integrated circuits (IC), microchips, microprocessors, FPGAs, memory chips, electronic switches, power supplies, and much more. As a result, nearly every modern electronic device consists of at least one transistor, if not millions of them.

For example, a standard Apple iPhone charging adapter consists of a single high-frequency MOSFET switching transistor and a single flyback transformer. These two transformers work together, amongst many other passive components, to take a wide range of ‘dirty’ input AC power and convert it into ‘clean,’ well-filtered DC output voltages used to charge an iPhone.

A modern personal computer consists of billions of transistors. For example, Dell XPS 15 Laptop utilizes a 12ᵗʰ Gen Intel® Core™ i9-12900HK as its core Central Processing Unit (CPU). While Intel no longer discloses its total transistor count, an Apple M1 Max CPU consists of 57 billion transistors. In professional graphics-rendering computers that utilize both CPU and GPUs, total transistor counts can exceed hundreds of billions.

A Brief History of Transistors

The conceptual foundation of a transistor is rooted in thermionic vacuum tubes, invented in 1907 and primarily used in radio technology, televisions, radar, and long-distance communications. These vacuum tube amplifiers consumed a lot of energy, were very expensive to manufacture, could be very large and heavy, and were very fragile.

Thermionic vacuum tubes use an input signal to control the electric current flower between electrodes. The tubes require heated filament in a vacuum, which consumes additional energy and makes them prone to catastrophic failure.

Solid-state field-effect transistors were first patented by physicist Julius Edgar Lilienfeld in 1925 in Canada, and subsequently in 1926 and 1928 in the US. These patents identified the principles of solid-state transistors and their use as an alternative solution to thermionic vacuum tubes, but Lilienfeld’s credit as the grandfather of transistor technology ended there. In the 1920s, the ability to manufacture the high-quality semiconductor materials needed to construct Lilienfeld’s concepts had not yet been invented.

The first functional transistor, the point-contact transistor, was invented in 1947 by American physicists John Bardeen, Walter Brattain, and William Shockley at Bell Labs. Their original research in semiconductor behavior was tangentially related to the concepts outlined in Lilienfeld’s work, but their failed attempts to construct field-effect transistors (FETS) led them to the discovery and invention of bipolar point-contact and junction transistors. Shockley filed the US patent for the first bipolar junction transistor technology in June 1948.

Interestingly, German physicists Herbert Matare and Heinrich Welker, working for a Westinghouse subsidiary in Paris, were researching very similar topics in early 1948. Upon their subsequent discoveries and realization that they were racing Shockley’s team in transistor research, they filed for their first transistor patent on August 13, 1948, in France.

By the early 1950s, transistors were already being produced at a small scale for use in radio communications. Several landmark discoveries and products followed during the mid-1950s:

• Bell Labs developed the first working silicon transistor on January 26, 1954.
• Texas Instruments built the first commercial silicon transistor in late 1954.
• The first transistor radio, the Regency TR-1, was released in October 1954.
• The first production all-transistor car radio was developed by Chrysler and Philco and unveiled on April 28, 1955.
• The first mass-produced transistor radio, the Sony TR-63, was released in 1957 and sold seven million units leading to mass market adoption of transistor radios in the late 1950s and early 1960s.

By the 1960s, transistor technology had become a dominant technological force. Vacuum tubes were quickly made obsolete. In 1965, Gordon Moore, the founder of Fairchild Semiconductor and Intel, predicted that the number of transistors on microchips would double every two years. Moore’s Law defines a linear log relationship of this transistor density over time. In 1970, ICs had around 2000 transistors. By 2020, state-of-the-art ICs had well over 10,000,000,000.

Image Source: Wikipedia

The Global Significance of the Transistor

In less than a decade of its inception, the transistor revolutionized modern electronics and research institutes. Physicists all around the globe furiously unearthed the potential of transistor technology.

Bell Labs’ William Shockley, John Bardeen, and Walter Brattain received the Nobel Prize in Physics in 1956 “for their research on semiconductors and their discovery of the transistor effect.” While this award holds enormous recognition, the impact on humankind and future technology was far more significant.

Transistors have become the foundation for nearly every electronic device, electrical system, and industry around the planet. In 2022, the global semiconductor chip industry is expected to surpass $600 billion.

Whether you’re an air-traffic controller in Australia, a banker in Belgium, a car dealer in Canada, an educator in Egypt, a farmer in France, a securities investor in Singapore, or a video gamer in Venezuela, you utilize transistor technology in your everyday life. The invention of the transistor may be the most important invention of the 20th century. Without transistors, commonplace fundamental technologies such as the internet, cell phones, modern medicine, and modern transportation may have never existed.