Document Sample
   To introduce common electronic
    components used in industries
   To distinguish the characteristic
    differences among components

1.   Resistors
2.   Capacitors
3.   Diodes
4.   Transistors
5.   Integrated Circuits (ICs)
6.   Rectifiers
7.   Electronic Symbols          3
Chapter 2                       Resistors

     Most common
      component in
      electronic circuits.
     Main function – to
      limit current flow or
      reduce the voltage in a
     Fixed or variable.
     Basic unit is ohm.
     Symbol is Ω.                    4
Chapter 2                              Resistors

 Type of Fixed Resistors
 a.     Wire-Wound Resistors
 b.     Carbon-Composition Resistors
 c.     Film-Type Resistors
 d.     Surface-Mount Resistors
 e.     Fusible Resistors
 f.     Thermistors
Chapter 2                                                              Resistors

 Types of Fixed Resistors

                                          Film-Type Resistors

    Wire-Wound Resistors

         Resistor          Surface-Mount Resistors                           6
Chapter 2                                       Resistors

 Resistors Color Coding
            Digit   Color    Tolerance      Color
             0      Black      5%            Gold
             1      Brown
                               10%          Silver
             2       Red
                               20%       No color band
             3      Orange
             4      Yellow
             5      Green
             6       Blue
             7      Violet
             8      Grey
             9      White                             7
Chapter 2                      Resistors

 Resistors Color Coding (cont’d)

Chapter 2                     Resistors

 Type of Variable Resistors
 a.     Tapered
 b.     Decade
        Resistance Box
 c.     Rheostats
 d.     Potentiometers
Chapter 2   Resistors


Chapter 2    Resistors

 In Series

Chapter 2      Resistors

 In Parallel

Chapter 2          Resistors

 Voltage Divider

Chapter 2                                               Resistors

 Power Rating of Resistors
     The power rating of a resistor is a physical
      property that depends on the resistor
      construction, especially physical size.
           Larger physical size indicates a higher power
           Higher-wattage resistors can operate at higher
           Wire-wound resistors are physically larger with
            higher wattage ratings than carbon resistors.

Chapter 17                                      Capacitors

     Capacitors is a component that is able to hold
      or store an electric charge.
     Its physical construction consists of two metal
      plates separated by an insulator.
     Capacitors are used to block direct current
      (DC) but pass alternating current (AC).
     Basic unit is farad.
     Symbol is F.
Chapter 17                                            Capacitors

 Operational Principle
     Like a battery, a capacitor has two terminals.
     Inside the capacitor, the terminals connect to two
      metal plates separated by a dielectric.
     The dielectric can be air, paper, plastic or anything
      else that does not conduct electricity and keeps the
      plates from touching each other.
     You can easily make a capacitor from two pieces of
      aluminum foil and a piece of paper. It won't be a
      particularly good capacitor in terms of its storage
      capacity, but it will work.
Chapter 17                                  Capacitors

 Operational Principle (cont’d)
     When you connect a capacitor
      to a battery, here’s what
       The plate on the capacitor that
          attaches to the negative
          terminal of the battery accepts
          electrons that the battery is
       The plate on the capacitor that
          attaches to the positive
          terminal of the battery loses
          electrons to the battery.                17
Chapter 17                                                    Capacitors

 Operational Principle (cont’d)
     Once it's charged, the capacitor has the same voltage as the
      battery (1.5 volts on the battery means 1.5 volts on the
     For a small capacitor, the capacity is small. But large
      capacitors can hold quite a bit of charge.
     You can find capacitors as big as soda cans, for example,
      that hold enough charge to light a flashlight bulb for a minute
      or more.
     When you see lightning in the sky, what you are seeing is a
      huge capacitor where one plate is the cloud and the other
      plate is the ground, and the lightning is the charge releasing
      between these two “plates”.
     Obviously, in a capacitor that large, you can hold a huge
      amount of charge!
Chapter 17                            Capacitors

 Typical Capacitors
     Commercial capacitors are
      generally classified
      according to the dielectric –
      mica, paper, plastic film,
      and ceramic, plus the
      electrolytic type.
     Except for electrolytic
      capacitors, capacitors can be
      connected to a circuit
      without regard to polarity,
      since either side can be more
      positive plate.
Chapter 17                    Capacitors

 Types of Capacitors
 1.     Mica Capacitors
 2.     Paper Capacitors
 3.     Film Capacitors
 4.     Ceramic Capacitors
 5.     Surface-Mount
 6.     Variable Capacitors
Chapter 17   Capacitors


In Parallel

         CT = C1 + C2 + ………. + CN

In Series

         1    1   1                 1
                   .......... 
        C EQ C1 C2                 CN
Chapter 17                                                   Capacitors

 Capacitance Units
     The unit of capacitance is a farad.
     A 1-farad capacitor can store one coulomb (coo-lomb) of
      charge at 1 volt. A coulomb is 6.25e18 (6.25 x 1018, or
      6.25 billion billion) electrons.
     One amp represents a rate of electron flow of 1 coulomb
      of electrons per second, so a 1-farad capacitor can hold 1
      amp-second of electrons at 1 volt.
     A 1-farad capacitor would typically be pretty big. It might
      be as big as a can of tuna or a 1-liter soda bottle, depending
      on the voltage it can handle.
     So you typically see capacitors measured in microfarads
      (millionths of a farad).

Chapter 17                                                       Capacitors

 Capacitance Units (Cont’d)
     To get some perspective on how big a farad is, think
      about this:
            A typical alkaline AA battery holds about 2.8 amp-hours.
            That means that a AA battery can produce 2.8 amps for an
             hour at 1.5 volts (about 4.2 watt-hours -- a AA battery can
             light a 4-watt bulb for a little more than an hour).
            Let's call it 1 volt to make the math easier. To store one
             AA battery's energy in a capacitor, you would need
             3,600 x 2.8 = 10,080 farads to hold it, because an amp-
             hour is 3,600 amp-seconds.
Chapter 17                                               Capacitors

 Temperature Coefficient
     Ceramic capacitors are often used for temperature
      compensation, to increase or decrease capacitance with a
      rise in temperature.
     The temperature coefficient is given in parts per million
      (ppm) per degree Celsius, with a reference of 25oC.
     Negative coefficient is labeled with preceding letter N.
      e.g. N750 means negative 750-ppm.
     Positive coefficient is labeled with preceding letter P.
      e.g. P750 means positive 750-ppm.
     Units that do not change in capacitance are labeled NPO.

Chapter 17                                      Capacitors

 Capacitors Tolerance
     Ceramic disk capacitors for general
      applications usually have a tolerance of
     For closer tolerances, mica or film capacitors
      are used – values of ±2 – 20%.
     Silver-plated mica capacitors are available
      with a tolerance of ±1%.

Chapter 17                                            Capacitors

 Voltage Rating
     It specifies the maximum potential difference that
      can be applied across the plates without puncturing
      the dielectric.
     Usually the voltage rating is for temperature up to
      about 60oC.
     Higher temperatures result in a lower voltage rating.
     Voltage rating for general-purpose paper, mica, and
      ceramic capacitors are typically 200 to 500 V.
      Ceramic capacitors with ratings of 1 to 20 kV are
      also available.
Chapter 17                                      Capacitors

 Capacitor Applications
     In most electronic circuits, a capacitor has DC
      voltage applied, combined with a much
      smaller AC signal voltage.
     The usual function of the capacitor is to block
      the DC voltage but pass the AC signal
      voltage, by means of the charge and discharge
     These applications include coupling,
      bypassing, and filtering for AC signals.
Chapter 17                                                    Capacitors

 Capacitor Applications (cont’d)
     The difference between a capacitor and a battery is that a
      capacitor can dump its entire charge in a tiny fraction of a
      second, where a battery would take minutes to completely
      discharge itself.
     That's why the electronic flash on a camera uses a capacitor --
      the battery charges up the flash's capacitor over several
      seconds, and then the capacitor dumps the full charge into the
      flash tube almost instantly.
     This can make a large, charged capacitor extremely
      dangerous -- flash units and TVs have warnings about
      opening them up for this reason. They contain big capacitors
      that can, potentially, kill you with the charge they contain.
Chapter 17                                                               Capacitors

 Capacitor Applications (cont’d)
     Capacitors are used in several different ways in electronic
            Sometimes, capacitors are used to store charge for high-speed
             use. That's what a flash does. Big lasers use this technique as
             well to get very bright, instantaneous flashes.
            Capacitors can also eliminate ripples. If a line carrying DC
             voltage has ripples or spikes in it, a big capacitor can even out
             the voltage by absorbing the peaks and filling in the valleys.
            A capacitor can block DC voltage. If you hook a small
             capacitor to a battery, then no current will flow between the
             poles of the battery once the capacitor charges (which is
             instantaneous if the capacitor is small). However, any
             alternating current (AC) signal flows through a capacitor
             unimpeded. That's because the capacitor will charge and
             discharge as the alternating current fluctuates, making it appear
             that the alternating current is flowing.                          31
Chapter 28                           Diode

     Diode is an electronic
      component that allows
      current to flow through it
      in one direction but not the
     Its main function is to
      change an AC voltage into
      a DC voltage.
     There are two leads coming
      out from a diode: cathode
      and anode.
Chapter 28                                                                          Diode

 Light Emitting Diodes
     Light emitting diodes, commonly
      called LEDs, are real unsung heroes in
      the electronics world.
     They do dozens of different jobs and
      are found in all kinds of devices.
     Among other things, they form the
      numbers on digital clocks, transmit
      information from remote controls, light
      up watches and tell you when your
      appliances are turned on.
     Collected together, they can form
      images on a jumbo television screen or
      illuminate a traffic light.
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Chapter 28                                                                 Diode

 Light Emitting Diodes (cont’d)
     Basically, LEDs are just tiny light bulbs that
      fit easily into an electrical circuit.
     But unlike ordinary incandescent bulbs, they
      don't have a filament that will burn out, and
      they don't get especially hot.
     They are illuminated solely by the movement
      of electrons in a semiconductor material, and
      they last just as long as a standard transistor.
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Chapter 28                                                                  Diode

 Diode Principle
     A diode is the simplest sort of semiconductor
     Broadly speaking, a semiconductor is a material with
      a varying ability to conduct electrical current.
     Most semiconductors are made of a poor conductor
      that has had impurities (atoms of another material)
      added to it.
     The process of adding impurities is called doping.

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Chapter 28                                                                  Diode

 Diode Principle (cont’d)
     In the case of LEDs, the conductor material is
      typically aluminum-gallium-arsenide (AlGaAs).
     In pure aluminum-gallium-arsenide, all of the atoms
      bond perfectly to their neighbors, leaving no free
      electrons (negatively-charged particles) to conduct
      electric current.
     In doped material, additional atoms change the
      balance, either adding free electrons or creating
      holes where electrons can go.
     Either of these additions make the material more
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Chapter 28                                                                       Diode

 Diode Principle (cont’d)
     A semiconductor with extra electrons is called N-type
      material, since it has extra negatively-charged particles.
     In N-type material, free electrons move from a negatively-
      charged area to a positively charged area.
     A semiconductor with extra holes is called P-type material,
      since it effectively has extra positively-charged particles.
     Electrons can jump from hole to hole, moving from a
      negatively-charged area to a positively-charged area.
     As a result, the holes themselves appear to move from a
      positively-charged area to a negatively-charged area.

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Chapter 28                                                                                 Diode

 Diode Principle (cont’d)
     A diode comprises a section of N-type
      material bonded to a section of P-type
      material, with electrodes on each end.
     This arrangement conducts electricity
      in only one direction.
     When no voltage is applied to the
      diode, electrons from the N-type
      material fill holes from the P-type
      material along the junction between
      the layers, forming a depletion zone.
     In a depletion zone, the
      semiconductor material is returned to
      its original insulating state -- all of
      the holes are filled, so there are no
      free electrons or empty spaces for
      electrons, and charge can't flow.

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Chapter 28                                                                                 Diode

    Diode Principle (cont’d)
    To get rid of the depletion zone, you have
     to get electrons moving from the N-type
     area to the P-type area and holes moving in
     the reverse direction.
    To do this, you connect the N-type side of
     the diode to the negative end of a circuit
     and the P-type side to the positive end.
    The free electrons in the N-type material
     are repelled by the negative electrode and
     drawn to the positive electrode.
    The holes in the P-type material move the
     other way.
    When the voltage difference between the
     electrodes is high enough, the electrons in
     the depletion zone are boosted out of their
     holes and begin moving freely again.
    The depletion zone disappears, and charge
     moves across the diode.                    http://electronics.howstuffworks.com/led.htm   39
Chapter 28                                                                                  Diode

 Diode Principle (cont’d)
     If you try to run current the other way,
      with the P-type side connected to the
      negative end of the circuit and the N-
      type side connected to the positive
      end, current will not flow.
     The negative electrons in the N-type
      material are attracted to the positive
     The positive holes in the P-type
      material are attracted to the negative
     No current flows across the junction
      because the holes and the electrons
      are each moving in the wrong
      direction. The depletion zone

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Chapter 28                                                                        Diode

 Light from LEDs
     Light is a form of energy that can be released by an atom.
     It is made up of many small particle-like packets that have
      energy and momentum but no mass.
     These particles, called photons, are the most basic units of
     Photons are released as a result of moving electrons.
     In an atom, electrons move in orbitals around the nucleus.
     Electrons in different orbitals have different amounts of
     Generally speaking, electrons with greater energy move in
      orbitals farther away from the nucleus.
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Chapter 28                                                                         Diode

 Light from LEDs (cont’d)
     As we saw in the last section, free electrons moving across a
      diode can fall into empty holes from the P-type layer.
     This involves a drop from the conduction band to a lower
      orbital, so the electrons release energy in the form of photons.
     This happens in any diode, but you can only see the photons
      when the diode is composed of certain material.
     The atoms in a standard silicon diode, for example, are
      arranged in such a way that the electron drops a relatively
      short distance.
     As a result, the photon's frequency is so low that it is invisible
      to the human eye -- it is in the infrared portion of the light
      spectrum. This isn't necessarily a bad thing, of course:
      Infrared LEDs are ideal for remote controls, among other
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Chapter 28                                                   Diode

 Light from LEDs (cont’d)

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Chapter 28                                                   Diode

 Light from LEDs (cont’d)

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Chapter 28                                                   Diode

 Light from LEDs (cont’d)

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Chapter 28                                                                           Diode

 Light from LEDs (cont’d)
     Visible light-emitting diodes (VLEDs), such as the ones that light
      up numbers in a digital clock, are made of materials characterized
      by a wider gap between the conduction band and the lower orbitals.
     The size of the gap determines the frequency of the photon -- in
      other words, it determines the color of the light.
     While all diodes release light, most don't do it very effectively.
     In an ordinary diode, the semiconductor material itself ends up
      absorbing a lot of the light energy.
     LEDs are specially constructed to release a large number of
      photons outward.
     Additionally, they are housed in a plastic bulb that concentrates the
      light in a particular direction.
     As you can see in the diagram, most of the light from the diode
      bounces off the sides of the bulb, traveling on through the rounded
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Chapter 28                                                                        Diode

 Light from LEDs (cont’d)
     LEDs have several
      advantages over conventional
      incandescent lamps.
     For one thing, they don't have
      a filament that will burn out,
      so they last much longer.
     Additionally, their small
      plastic bulb makes them a lot
      more durable.
     They also fit more easily into
      modern electronic circuits.

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Chapter 28                                                                        Diode

 Advantage of LEDs
     But the main advantage is efficiency. In conventional
      incandescent bulbs, the light-production process involves
      generating a lot of heat (the filament must be warmed).
     This is completely wasted energy, unless you're using the
      lamp as a heater, because a huge portion of the available
      electricity isn't going toward producing visible light.
     LEDs generate very little heat, relatively speaking.
     A much higher percentage of the electrical power is going
      directly to generating light, which cuts down on the electricity
      demands considerably.

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Chapter 28                                                                        Diode

 LEDs Applications
     Up until recently, LEDs were too expensive to use for most
      lighting applications because they're built around advanced
      semiconductor material.
     The price of semiconductor devices has plummeted over the
      past decade, however, making LEDs a more cost-effective
      lighting option for a wide range of situations.
     While they may be more expensive than incandescent lights
      up front, their lower cost in the long run can make them a
      better buy.
     In the future, they will play an even bigger role in the world
      of technology.

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Chapter 30                  Transistors

     A transistor is an
      component that can
      be used to amplify
      small AC signals or
      switch a DC

Chapter 30                                        Transistors

 Types of Transistors
 1.     Bipolar Junction Transistors
 2.     Common Emitter Amplifier
 3.     Common Collector Amplifier
 4.     Common Base Amplifier
 5.     Field-Effect Transistors (FET)
      1.      Insulated-Gate FET
      2.      Junction FET (JFET)
             1.   JFET Common Source Amplifier
             2.   JFET Common Drain Amplifier
 6.     Metal-Oxide Field-Effect Transistors (MOSFET)
Chapter 30                                                                    Transistors

 Transistors Introduction (Intel)
     Microprocessors are essential to many of the products we use
      every day such as televisions, cars, radios, home appliances,
      and, of course, computers.
     Transistors are the main components of microprocessors.
     At their most basic level, transistors may seem simple.
     But their development actually required many years of
      painstaking research.
     Before transistors, computers relied on slow, inefficient
      vacuum tubes and mechanical switches to process
      information. In 1958, engineers (one of them Intel co-founder
      Robert Noyce) managed to put two transistors onto a silicon
      crystal and create the first integrated circuit, which led to the
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Chapter 30                                                               Transistors

 How Transistors Work
     Transistors are miniature electronic
      switches. They are the building
      blocks of the microprocessor which
      is the brain of the computer.
     Similar to a basic light switch,
      transistors have two operating
      positions, on and off. This on/off,
      or binary, functionality of
      transistors enables the processing of
      information in a computer.

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Chapter 30                                                                          Transistors

 Simple Electric Switch
     How a Simple Electric Switch Works
     The only information computers understand are
      electrical signals that are switched on and off.
     To comprehend transistors, it is necessary to have an
      understanding of how a switched electronic circuit
     Switched electronic circuits consist of several parts.
     One is the circuit pathway where the electrical
      current flows-typically through a wire.
     Another is the switch, a device that starts and stops
      the flow of electrical current by either completing or
      breaking the circuit's pathway.
     Transistors have no moving parts and are turned on
      and off by electrical signals.
     The on/off switching of transistors facilitates the
      work performed by microprocessors.
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Chapter 30                                                                        Transistors

 The Flow of Information
     How a Transistor Handles
     A Binary Counter is something that
      has only two states, like a transistor,
      and can be referred to as binary.
     The transistor's "on" state is
      represented by a 1, and the "off"
      state is represented by a 0.
     Specific sequences and patterns of
      1's and 0's generated by multiple
      transistors can represent letters,
      numbers, colors, and graphics.
     This is known as binary notation.
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Chapter 30                                                                           Transistors

 Transistor is a Semiconductor
     Conductors and Insulators
     Many materials, such as most
      metals, allow electrical current to
      flow through them. These are
      known as conductors.
     Materials that do not allow
      electrical current to flow through
      them are called insulators.
     Pure silicon, the base material of
      most transistors, is considered a
      semiconductor because its
      conductivity can be modulated
      by the introduction of impurities.

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Chapter 30                                                                    Transistors

 Anatomy of Transistors
     Semiconductors and the Flow of
     Adding certain types of impurities
      to the silicon in a transistor
      changes its crystalline structure
      and enhances its ability to conduct
     Silicon containing boron
      impurities is called p-type silicon-
      p for positive or lacking electrons.
     Silicon containing phosphorus
      impurities is called n-type silicon-
      n for negative or having a
      majority of free electrons.
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Chapter 30                                                                    Transistors

 Principle Operation (Intel)
     Transistors consist of three
      terminals: the source, the
      gate, and the drain.

     In the n-type transistor,
      both the source and the
      drain are negatively
      charged and sit on a
      positively charged well of

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Chapter 30                                                                      Transistors

 Principle Operation (cont’d)
     When positive voltage is
      applied to the gate, electrons
      in the p-silicon are attracted
      to the area under the gate,
      forming an electron channel
      between the source and the

     When positive voltage is
      applied to the drain, the
      electrons are pulled from the
      source to the drain. In this
      state the transistor is on.

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Chapter 30                                                                     Transistors

 Principle Operation (cont’d)
     If the voltage at the gate is
      removed, electrons aren't
      attracted to the area between
      the source and drain. The
      pathway is broken and the
      transistor is turned off.

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Chapter 30                                                                   Transistors

 Transistors Applications
     The binary function of transistors
      gives microprocessors the ability to
      perform many tasks, from simple
      word processing to video editing.
     Microprocessors have evolved to a
      point where transistors can execute
      hundreds of millions of instructions
      per second on a single chip.
     Automobiles, medical devices,
      televisions, computers, and even the
      Space Shuttle use microprocessors.
     They all rely on the flow of binary
      information made possible by the
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Chapter 32                                           Integrated Circuits

     Integrated circuits (ICs) have reduced the
      size, weight, and power requirements of
      today’s electronic equipment.
     They are replacing transistors in
      electronic circuits just as transistors once
      replaced vacuum tubes.
     It is actually microelectronic circuits.
     Contained within the IC itself are
      microscopically small electronic
      components such as diodes, transistors,
      resistors, and capacitors.

   An integrated circuit (IC) is a thin chip consisting of at least
    two interconnected semiconductor devices, mainly
    transistors, as well as passive components like resistors.
   As of 2004, typical chips are of size 1 cm2 or smaller, and
    contain millions of interconnected devices, but larger ones
    exist as well.
   Among the most advanced integrated circuits are the
    microprocessors, which drive everything from computers to
    cellular phones to digital microwave ovens.
   Digital memory chips are another family of integrated circuits
    that are crucially important in modern society.

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Overview (cont’d)
   The integrated circuit was made possible by mid-20th-century
    technology advancements in semiconductor device
    fabrication and experimental discoveries that showed that
    semiconductor devices could perform the functions
    performed by vacuum tubes at the time.
   The integration of large numbers of tiny transistors onto a
    small chip was an enormous improvement to the manual
    assembly of finger-sized vacuum tubes.
   The integrated circuit's small size, reliability, fast switching
    speeds, low power consumption, mass production capability,
    and ease of adding complexity quickly pushed vacuum tubes
    into obsolescence.
                                   http://en.wikipedia.org/wiki/Integrated_circuits   64
Overview (cont’d)
   Only a half century after their
    development was initiated,
    integrated circuits have
    become ubiquitous.
   Computers, cellular phones,
    and other digital appliances
    are now inextricable parts of
    the structure of modern
   Indeed, many scholars believe
    that the digital revolution
    brought about by integrated
    circuits was one of the most
    significant occurrences in the
    history of mankind.               http://en.wikipedia.org/wiki/Integrated_circuits   65
Significance of ICs
   Integrated circuits can be classified into analog, digital and mixed signal
    (both analog and digital on the same chip).
   Digital integrated circuits can contain anything from one to millions of
    logic gates, flip-flops, multiplexers, etc. in a few square millimeters. The
    small size of these circuits allows high speed, low power dissipation, and
    reduced manufacturing cost compared with board-level integration.
   The growth of complexity of integrated circuits follows a trend called
    "Moore's Law", first observed by Gordon Moore of Intel. Moore's Law in
    its modern interpretation states that the number of transistors in an
    integrated circuit doubles every two years. By the year 2000 the largest
    integrated circuits contained hundreds of millions of transistors. It is
    difficult to say whether the trend will eventually slow down (see
    technological singularity).
   The integrated circuit is one of the most important inventions of the 20th
    century. Modern computing, communications, manufacturing, and
    transportation systems, including the Internet, all depend on its existence.

                                         http://en.wikipedia.org/wiki/Integrated_circuits   66
Types of ICs
1.   Small-Scale Integration (SSI)
2.   Medium-Scale Integration (MSI)
3.   Large-Scale Integration (LSI)
4.   Very Large-Scale Integration (VLSI)
5.   Ultra Large-Scale Integration (ULSI)
6.   Wafer-Scale Integration (WSI)
7.   System-On-Chip (SOC)
Small-Scale Integration (SSI)
   The first integrated circuits contained only a few transistors.
    Called "Small-Scale Integration" (SSI), they used circuits
    containing transistors numbering in the tens.
   SSI circuits were crucial to early aerospace projects, and vice-
    versa. Both the Minuteman missile and Apollo program
    needed lightweight digital computers for their inertially-
    guided flight computers; the Apollo guidance computer led
    and motivated the integrated-circuit technology, while the
    Minuteman missile forced it into mass-production.
   These programs purchased almost all of the available
    integrated circuits from 1960 through 1963, and almost alone
    provided the demand that funded the production
    improvements to get the production costs from $1000/circuit
    (in 1960 dollars) to merely $25/circuit (in 1963 dollars).
                                   http://en.wikipedia.org/wiki/Integrated_circuits   68
Medium-Scale Integration (MSI)
   The next step in the development of integrated
    circuits, taken in the late 1960s, introduced devices
    which contained hundreds of transistors on each
    chip, called "Medium-Scale Integration" (MSI).
   They were attractive economically because while
    they cost little more to produce than SSI devices,
    they allowed more complex systems to be produced
    using smaller circuit boards, less assembly work
    (because of fewer separate components), and a
    number of other advantages.

                              http://en.wikipedia.org/wiki/Integrated_circuits   69
Large-Scale Integration (LSI)
   Further development, driven by the same
    economic factors, led to "Large-Scale
    Integration" (LSI) in the mid 1970s, with tens
    of thousands of transistors per chip.
   LSI circuits began to be produced in large
    quantities around 1970, for computer main
    memories and pocket calculators.

                           http://en.wikipedia.org/wiki/Integrated_circuits   70
Very Large-Scale Integration (VLSI)
   The final step in the development process, starting in the 1980s and
    continuing on, was "Very Large-Scale Integration" (VLSI), with
    hundreds of thousands of transistors, and beyond (well past several
    million in the latest stages).
   For the first time it became possible to fabricate a CPU or even an
    entire microprocessor on a single integrated circuit. In 1986 the
    first one megabit RAM chips were introduced, which contained
    more than one million transistors. Microprocessor chips produced
    in 1994 contained more than three million transistors.
   This step was largely made possible by the codification of "design
    rules" for the CMOS technology used in VLSI chips, which made
    production of working devices much more of a systematic
    endeavour. (See the 1980 landmark text by Carver Mead and Lynn
    Conway referenced below.)

                                     http://en.wikipedia.org/wiki/Integrated_circuits   71
Ultra Large-Scale Integration
   To reflect further growth of the complexity, the term
    ULSI that stands for Ultra-Large Scale Integration
    was proposed for chips of complexity more than 1
    million of transistors.
   However there is no qualitative leap between VLSI
    and ULSI, hence normally in technical texts the
    "VLSI" term covers ULSI as well, and "ULSI" is
    reserved only for cases when it is necessary to
    emphasize the chip complexity, e.g., in marketing.

                              http://en.wikipedia.org/wiki/Integrated_circuits   72
Wafer-Scale Integration (WSI)
   The most extreme integration technique is
    wafer-scale integration (WSI), which uses
    whole uncut wafers containing entire
    computers (processors as well as memory).
   Attempts to take this step commercially in the
    1980s (e.g. by Gene Amdahl) failed, mostly
    because of defect-free manufacturability
    problems, and it does not now seem to be a
    high priority for industry.
                          http://en.wikipedia.org/wiki/Integrated_circuits   73
System-On-Chip (SOC)
   The WSI technique failed commercially, but
    advances in semiconductor manufacturing allowed
    for another attack on the IC complexity, known as
    System-on-Chip (SOC) design.
   In this approach, components traditionally
    manufactured as separate chips to be wired together
    on a printed circuit board, are designed to occupy a
    single chip that contains memory, microprocessor(s),
    peripheral interfaces, Input/Output logic control,
    data converters, etc., i.e., the whole electronic

                             http://en.wikipedia.org/wiki/Integrated_circuits   74
Other Developments
   In the 1980s programmable integrated circuits were developed. These
    devices contain circuits whose logical function and connectivity can
    be programmed by the user, rather than being fixed by the integrated
    circuit manufacturer. This allows a single chip to be programmed to
    implement different LSI-type functions such as logic gates, adders and
    registers. Current devices named FPGAs (Field Programmable Gate
    Arrays) can now implement tens of thousands of LSI circuits in
    parallel and operate up to 400 MHz.
   The techniques perfected by the integrated circuits industry over the
    last three decades have been used to create microscopic machines,
    known as MEMS. These devices are used in a variety of commercial
    and defense applications, including projectors, ink jet printers, and are
    used to deploy the airbag in car accidents.
   In the past, radios could not be fabricated in the same low-cost
    processes as microprocessors. But since 1998, a large number of radio
    chips have been developed using CMOS processes. Examples include
    Intel's DECT cordless phone, or Atheros's 802.11 card
   The earliest integrated circuits were packaged in ceramic flat
    packs, which continued to be used by the military for their
    reliability and small size for many years.
   Commercial circuit packaging quickly moved to the dual in-line
    package (DIP), first in ceramic and later in plastic.
   In the 1980s pin counts of VLSI circuits exceeded the practical
    limit for DIP packaging, leading to pin grid array (PGA) and
    leadless chip carrier (LCC) packages.
   Surface mount packaging appeared in the early 1980s and became
    popular in the late 1980s, using finer lead pitch with leads formed
    as either gull-wing or J-lead, as exemplified by SOIC and PLCC
   In the late 1990s, PQFP and TSOP packages became the most
    common for high pin count devices, though PGA packages are still
    often used for high-end microprocessors.
                                     http://en.wikipedia.org/wiki/Integrated_circuits   76
Chapter 29                           Diode

     Most electronic equipment
      requires DC power, and if
      the equipment draws its
      power from an AC supply
      it is necessary to convert
      the AC supply into a
      suitable DC voltage source.
     Rectifiers are the main part
      of a DC power supply.

Chapter 29                                 Diode

 Half-Wave Rectifier
     The diode is the component
      which does the rectification,
      since it permits current flow in
      one direction only. The resistor
      RL represents the resistance of
      the load drawing the power.
     Let's analyse this circuit
      assuming the diode is ideal.
      When vS > 0, the diode is
      forward biased, and so switched
      on; therefore vout = vS.
     But when vS < 0, the diode is
      reverse biased, i.e. switched off,
      and hence vout = 0 V. This is
      illustrated in the second figure.

Chapter 29                                                 Diode

 Full-Wave Rectifier
     In the half-wave rectifier the voltage is zero for
      half of the cycle.
     Full-wave rectifiers are designed using two or
      more diodes so that voltage is produced over
      the whole cycle.
     First figure shows a full-wave rectifier
      designed using two diodes and a center-tapped
      AC supply (i.e. center-tapped transformer).
     The waveforms are shown in second figure.
     The center tapping implies that the two source
      voltages v1 and v2 are a half cycle out of phase.
     We see that diode D1 conducts when source v1
      is positive, and D2 conducts when v2 is
      positive, giving the waveform vout.
Chapter 29                            Diode

 Full-Wave Rectifier (cont’d)
     Alternatively, full-wave
      rectifier can also be
      constructed by using four
      diodes and a single AC
     This is known as bridge
     The waveform of vout is the
      same as for the center-tapped
      full-wave rectifier.

Chapter 29                                     Diode

 Capacitor Filters
     It can be seen from the previous two
      waveform, vout is not very smooth.
     For many applications it is desired to
      have a much smoother DC
      waveform, and so a filtering circuit
      is used – first figure.
      The waveform produced by this
      filtered half-wave rectifier is shown
      in second figure, illustrating the
     Here, ripple is defined as the
      difference between the maximum
      and minimum voltages on the
      waveform, third figure.

   Electronic symbols represent the actual
    components in the outline of the circuit under
   The symbols are merely used in various
    electronic schematic diagrams for analysis,
    detail outline, etc..

Resistors Symbols

Capacitors Symbols

Diodes Symbols

Transistors Symbols

Audio and Radio Devices

Meters and Oscilloscope



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