History of Electronics

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History of Electronics

• The is a story of the twentieth century
• three key componentsthe vacuum tube, the
  transistor, and the integrated circuit.
• 1883, Thomas Alva Edison discovered that
  electrons will flow from one metal conductor to
  another through a vacuum. ( Edison effect)
• In 1904, John Fleming applied the Edison effect
  in inventing a two-element electron tube called a
  diode,
• Lee De Forest followed in 1906 with the
  three-element tube, the triode.

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• Guglielmo Marconi pioneered the development of
  the wireless telegraph in 1896 and long-distance
  radio communication in 1901. Vacuum tubes
  strengthened weak audio signals and allowed these
  signals to be superimposed on radio waves.
• In 1918, Edwin Armstrong invented the
  "super-heterodyne receiver" that could select
  among radio signals or stations and could receive
  distant signals.
• Armstrong also invented wide-band frequency
  modulation (FM) in 1935

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• Television, which was invented in the 1920s but
  didn't become widely available until 1947. (Bell
  Laboratories)
• Vladimir Zworykin, an engineer with the Radio
  Corporation of America (RCA), is considered the
  "father of the television" because of his
  inventions, the picture tube and the iconoscope
  camera tube.
• Radar ( RAdio Detection And Ranging,).
• By the mid-1950s, television had surpassed radio
  for home use and entertainment.

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• In 1947, the transistor was invented by a team
  of engineers from Bell Laboratories. (Nobel
  prize)
• The transistor functions like the vacuum tube,
  but it is tiny by comparison, weighs less,
  consumes less power, is much more reliable, and
  is cheaper to manufacture with its combination of
  metal contacts and semiconductor materials.

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• Integrated circuit was proposed in 1952 by
  Geoffrey W. A. Dummer, Throughout the 1950s,
  transistors were mass produced on single wafers
  and cut apart.
• By 1961, integrated circuits were in full
  production at a number of firms, and designs of
  equipment changed rapidly and in several
  directions to adapt to the technology.
• Bipolar transistors and digital integrated
  circuits were made first, but analog ICs,
  large-scale integration (LSI), and
  very-large-scale integration (VLSI) followed by
  the mid-1970s. VLSI consists of thousands of
  circuits with on-and-off switches or gates
  between them on a single chip.

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• Small Scale Integrated Circuits (SSI) Less than
  100 Transistors per Integrated Circuit or
  chipMedium Scale Integrated Circuits (MSI) 100
  to 1000 Transistors per Integrated Circuit or chip

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• Large Scale Integrated Circuits (LSI) 1000 to
  10000 Transistors per Integrated Circuit or chip
• Very Large Scale Integrated Circuits (VLSI)
  10000 to 1 million Transistors per Integrated
  Circuit or chip

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• Ultra Large Scale Integrated Circuits (ULSI)
  over 1 million Transistors per Integrated Circuit
  or Chip

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• Microcomputers, medical equipment, video cameras,
  and communication satellites are only examples of
  devices made possible by integrated circuits.

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Chapter 1

• SEMICONDUCTORS

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What is Electricity

• Everything is made of atoms
• There are 118 elements, an atom is a single part
  of an element
• Atom consists of electrons, protons, and neutrons

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• When atoms lose or gain electrons, they become
  ions.
• Cations are positive and are formed by elements
  on the left side of the periodic chart.
• Anions are negative and are formed by elements on
  the right side of the periodic chart.

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• Valence electrons

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• Electrons (- charge) are attracted to protons (
  charge), this holds the atom together
• Some materials have strong attraction and refuse
  to lose electrons, these are called insulators
  (air, glass, rubber, most plastics)
• Some materials have weak attractions and allow
  electrons to be lost, these are called conductors
  (copper, silver, gold, aluminum)
• Electrons can be made to move from one atom to
  another, this is called a current of electricity.

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• The controlled flow of charged particles is
  fundamental to the operation of all electronic
  devices
• How do we distinguish semiconductors from
  insulators and conductors?
• There are two principal charge transport
  processes
• Drift motion of charges produced by an electric
  field
• Diffusion motion resulting from a nonuniform
  charge distribution

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FORCES, FIELDS AND ENERGY

• Charged Particles
• Charge of electron is ve 1.610-19 C
• The mass of electron 9.1 10-31 kg
• No. of electrons in 1 C 61018
• 1pA is due to movement of 6 million electrons /
  sec
• For ions the charge is a multiple of the electron
  charge but ve
• The mass of an atom having atomic weight unity
  1.6610-27
• The mass of any atom having atomic weight n
  n 1.6610-27

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Field intensity

• The charged particle exerts a force on other
  charged particles as given by Coulombs law
• The motion of q2 is obtained by applying Newtons
  second law
• The electric field intensity is the force exerted
  on a unit positive charge

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Potential

• Definition
• In one dimension, with A at xo and B at an
  arbitrary distance x, it follows that
• Differentiation
• the potential energy U
• If an electron is being considered, q is replaced
  by -q .
• The electron volt (eV) unit of energy (work),
  defined as
• 1 eV 1.60 x 10-19J

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Energy

• Law of conservation of energy
• As an illustration of this law, consider two
  parallel plates A and B separated by a distance d
  
• An electron leaves the surface of A toward B with
  an initial velocity vo in the x direction. What
  speed will the electron have if it reaches B?