From Simple English Wikipedia, the free encyclopedia
Anintegrated circuit (more often called anIC,microchip,silicon chip,computer chip, orchip) is a single piece of specially preparedsilicon (or anothersemiconductor) into which an electronic circuit is etched usingphotolithography. Silicon chips can containlogic gates,computer processors,memory and special devices. The chip is very fragile and so is normally surrounded by aplastic package to protect it. Electrical contact with the chip is provided through tiny wires that connect the chip to larger metal pins that stick out of the package.
An IC has two main advantages overelectronic circuits (or discrete circuits): cost and performance. Cost is low, because millions of transistors can be put onto one chip instead of building a circuit with single transistors. Performance is higher since the components can operate more quickly and use less power.
ICs are designed for different purposes. For example, a chip may be designed just for acalculator, which can only work as a calculator. Integrated circuits can be classified intoanalog,digital and mixed signal (both analog and digital on the same chip). ICs are found in many household items such as radios, computers, and telephones, and many others.
An early attempt at combining multiple electronic devices into a single package was the Loewe 3NFvacuum tube in 1926. This integrated vacuum tube contained almost all of the components needed to build aradio receiver. At the time, radio receivers weretaxed based on the number of tubes they contained, so combining everything into a single tube resulted in a lower tax.
In 1958 and 1959, two people had the idea for a semiconductor integrated circuit at almost exactly the same time. Transistors had become an everyday thing used in household devices such as radios. They affected everything from radios to phones and at the time manufacturers needed a smaller replacement for vacuum tubes. Transistors were smaller thanvacuum tubes, but for some of the newest electronics, for examplemissile guidance, they were not small enough.
One day in July, whileJack Kilby was working atTexas Instruments, he realized that all parts of a circuit, not just the transistor, could be made out of silicon. At the time, nobody was putting capacitors and resistors into ICs. This would change the future and make it easier to produce and sell integrated circuits.Kilby's boss liked the idea. By September 12,Kilby had built a working model, and on February 6, Texas Instruments filed apatent. Their first"Solid Circuit" was the size of a fingertip.
Meanwhile, in California, another man had the same idea. In January 1959,Robert Noyce was working at the small Fairchild Semiconductor startup company. He also realized a whole circuit could be put into a single chip. While Kilby had worked out the details of making individual components, Noyce thought of a much better way to connect the parts. The design was called a"unitary circuit". All that detail paid off because on April 25, 1961, the patent office awarded the first patent for an integrated circuit to Robert Noyce while Kilby's application was still being analyzed. Today, both men are acknowledged as having independently conceived of the idea.[1]
Sometime the term IC is also used for a single packaged circuit containing two or more chips -- more accurately called a hybrid IC (HIC) orMulti-chip Module.
