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Progress in electronic technology

20 January, 2016 - 15:30

Transistors are a key component in all electronic devices – cell phones, computers, portable music players, wrist watches, etc. A team of physicists at the Bell Telephone research laboratory in the United States invented the first transistor, shown below.

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Figure 7.4 The first transistor 
 

This prototype was about the size of a 25 cent coin, and, like the Wright brothers’ first plane, it had no practical value, but was a proof of concept. Engineers soon improved upon the design. In 1954, Texas Instruments began manufacturing transistors. They were about the size of a pencil eraser, and several would be wired together to make a circuit for a device like a transistor radio. In the late 1950s, engineers began making integrated circuits (ICs or chips) which combined several transistors and the connections between them on a small piece of silicon. Today, a single IC can contain millions of transistors and the cost per transistor is nearly zero.

Consider the central processing unit (CPU) chip that executes the instructions in personal computers and other devices. Most personal computers use CPU chips manufactured by Intel Corporation, which offered the first commercial microprocessor (a complete CPU on a chip) in 1971. That microprocessor, the Intel 4004, contained 2,300 transistors. As shown here, Intel CPU transistor density has grown exponentially since that time: 1

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Figure 7.5 Improvement in electronic technology 
 

With the packaging of multiple CPU cores on a single chip, transistor counts are now well over one billion.

Intel co-founder Gordon Moore predicted this exponential growth in 1965. He formulated Moore’s Law, predicting that the number of transistors per chip that yields the minimum cost per transistor would increase exponentially. He showed that transistor counts had pretty much doubled every year up to the time of his article and predicted that improvement rate would remain nearly constant for at least ten years. 2

We have used Intel CPU chips to illustrate exponential improvement in electronic technology, but we should keep in mind that all information technology uses electronic components. Every computer input, output or storage device is controlled and interfaced electronically, and computer memory is made of ICs. Communication systems, home appliances, autos, and home entertainment systems all incorporate electronic devices.