History of integrated circuits or ICs starts with the start of the electronics in Solid state devices.
Started with the vacuum tubes, the first vacuum tube was invented by J.A (John Ambrose) Fleming in 1897 is known as vacuum diode and Fleming also gave left-hand rule for motors.
Then in 1906 a new vacuum was developed which is known as Triode which is used for amplification.
HISTORY OF INTEGRATED CIRCUIT OR IC
INVENTION OF TRANSISTOR
Then after almost 40 years in the year 1947, William Shockley at Bell labs invented the transistor which started a new era in the electronics industry.
Transistors replace (partially not completely) those bulky vacuum tubes because they (transistors) are small in size and use less power to operate as well application appliances demand less power.
Then circuits were constructed from discrete components means that all components (like transistor, resistor, diode) are separated by each other and fixed on PCB (printed circuit board) by hand and can be manipulated by hands these are said to be non-integrated circuits, which consumes much space and power as well and most importantly output/response is not so smooth.
INVENTION OF INTEGRATED CIRCUIT OR IC
Then in the year 1959 IC (integrated circuit) was developed. Integrated Circuit IC, in which many numbers of components can be fabricated on a single silicon wafer.
IC takes low power to operate and gives smooth output. With time passes the number of transistors on IC also increases.
History of Integrated Circuit
Evolution of IC from SSI, MSI, LSI to VLSI
- Firstly, between 1961-1965 in SSI (small scale integration) transistors were fabricated about 10 to 100 on a single chip. This technology is used for making logic gates, flip flops.
- In 1966-1970 in MSI (medium scale integration) transistors were fabricated about 100 to 1000 on a single chip. This technology is used for making counters, multiplexers, decoders.
- In 1971-1979 in LSI (large scale integration) transistors were fabricated about 1000 to 20000 on a single chip. This technology is used for making microprocessor, RAM, ROM
- In 1980-1984 in VLSI (very large scale integration) transistors were fabricated about 20000 to 50000 on a single chip. This technology is used for making DSP (digital signal processing) IC’s, RISC microprocessor, 16-bit and 32-bit microprocessors.
- From 1985- present technology is ULSI (ultra large scale integration), in which transistors are fabricated about greater than 50000 to billions on a single chip. This technology is used for making 64-bit microprocessors.
HOW TRANSISTOR REQUIREMENT INCREASES WITH TIME
In 1965 Moore’s gave a law, in which he observed the number of transistors in a dense integrated circuit doubles about every year.
Moreover, he also observed in the year 1965 the number of components fabricated on chip is 32 and in 1966 number of components fabricated on chip is 64. He predicted in 1975 the number of components fabricated on chip will be 65000, so he has to wait for 10 years to check his prediction. And in the year 1975 he adjusted his pace and said density is doubling every two years.
Today’s processors like Intel i3, i5 and i7 have more than 4 billion transistors on chip. In microcontroller ATMEGA328 approximately 50000 transistors were fabricated on chip.
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