26-04-2017, 03:27 PM
Large-scale integration (VLSI) is the process of creating an integrated circuit (IC) by combining thousands of transistors into a single chip. VLSI began in the 1970s when the semiconductor complex and communication technologies were being developed. The microprocessor is a VLSI device. Prior to the introduction of VLSI technology most ICs had a limited set of functions that they could perform. An electronic circuit may consist of a CPU, ROM, RAM, and other glue logic. VLSI allows designers to add all this on a single chip.
The history of the transistor dates back to the mid-1920s when several inventors tried devices that were intended to control current in solid-state diodes and turn them into triodes. The success came after World War II, when the use of silicon and germanium crystals radar detectors led to improvements in manufacturing and theory. Scientists who had been diverted to radar development returned to the development of solid-state devices. With the invention of transistors at Bell Labs in 1947, the field of electronics changed from vacuum tubes to solid state devices.
With the small transistor in their hands, the electrical engineers of the 50s saw the possibilities of building much more advanced circuits. As the complexity of circuits grew, arose problems.
One problem was the size of the circuit. A complex circuit, like a computer, depends on speed. If the computer components were too large or the cables interconnecting them too long, the electrical signals could not travel fast enough through the circuit, thus making the computer too slow to be effective.
The history of the transistor dates back to the mid-1920s when several inventors tried devices that were intended to control current in solid-state diodes and turn them into triodes. The success came after World War II, when the use of silicon and germanium crystals radar detectors led to improvements in manufacturing and theory. Scientists who had been diverted to radar development returned to the development of solid-state devices. With the invention of transistors at Bell Labs in 1947, the field of electronics changed from vacuum tubes to solid state devices.
With the small transistor in their hands, the electrical engineers of the 50s saw the possibilities of building much more advanced circuits. As the complexity of circuits grew, arose problems.
One problem was the size of the circuit. A complex circuit, like a computer, depends on speed. If the computer components were too large or the cables interconnecting them too long, the electrical signals could not travel fast enough through the circuit, thus making the computer too slow to be effective.