Introduction to Electronics & Communication PDF

Department of Electronics & Communication Engineering Dr. Ravi kumar.M www.cambridge.edu.in Department of Electronics & Communication Engineering Dr. Ravi kumar.M www.cambridge.edu.in  Introduction to Electronics & Communication MODULE-1 Dr. RAVIKUMAR.M Associate Profes...

Department of Electronics & Communication Engineering Dr. Ravi kumar.M www.cambridge.edu.in Department of Electronics & Communication Engineering Dr. Ravi kumar.M www.cambridge.edu.in  Introduction to Electronics & Communication MODULE-1 Dr. RAVIKUMAR.M Associate Professor Department of Electronics & Communication Engineering www.cambridge.edu.in  MODULE-1 Introduction: What is electronics, need for electronics, electronic system block diagram (sensor, processing and actuation), applications of electronics: consumer electronics (gadgets, home appliances, audio and video systems, consumer devices, storage devices), industrial electronics (smart grid, automation, image processing), medical applications (medical devices and instruments), meteorological and oceanographic, defence and aerospace, automotive. Devices and components: Passive components (resistors, capacitor, inductor diodes, crystals, relays), types of passive components, selection of passive components, units for passive components, applications of passive components, electronic component and part numbers (understanding of data sheets), Integrated circuits, types of ICs, IC fabrication process (use video for demonstration), IC packaging (use video for demonstration), PCB and its functionality, types of PCBs, to discuss functionality few of the PCBs, Importance of VLSI design in India. Measuring Instruments: Voltmeter, ammeter, multimeter, working principal of measuring instruments, how to use these Instruments to measure voltage, current, power. Department of Electronics & Communication Engineering Dr. Ravi kumar.M www.cambridge.edu.in  Introduction What is electronics ? Electronics”, as the name implies relating to electrons. The word electronics arrived from electron mechanics The definition of electronics technically says “Electronics is an engineering branch that concerns with the flow of current through semiconductor. Electronics is an applied form of science that deals with electrons. It handles electric circuits containing active elements, passive elements and other underlying techniques making it as an important part of engineering. Department of Electronics & Communication Engineering Dr. Ravi kumar.M www.cambridge.edu.in  Need for electronics We are living in an electronic era where machine robots are capable to do human work with more ease and high efficiency. Capsules and tablets contain wireless sensors that collect information from the body to diagnose. Transparent smartphones will exist in the coming days, we can see through them and they may lead to the use of windows or mirrors in our home to be used as PC screens and TV monitors. Sensors are placed on the plants to detect the shortage of water and alert the farmers. Electronic devices are made up of active and passive elements and smaller IC memories. The ICs, diodes, and transistor are made of semiconductor materials and their working is dependent on current flow through them. Department of Electronics & Communication Engineering Dr. Ravi kumar.M www.cambridge.edu.in  History of Electronics Vacuum Diode – Invented by John Ambrose Fleming Electronics era came into existence with the invention of vacuum diode in the year 1897. Vacuum tube essentially consists two electrode plates i.e. anode and cathode. This allows current direction in one direction. But this diode is not able to control the current flow. In 1906 Lee De Forest modified and named it as Vacuum Triode. The Triode has 3 terminals. Anode, Cathode and Grid terminal. Grid electrode controls the current flow from anode to cathode. This feature could boost the power of electrical signals. Likewise, Tetrode and Pentode had evolved. Department of Electronics & Communication Engineering Dr. Ravi kumar.M www.cambridge.edu.in  Transistor – Invented by John Bardeen, Walter Brattain and William Shockley The real development started with the invention of the transistor in 1948 in Bell Laboratories. Large Bulky Vacuum diodes are replaced with junction transistor. Transistors are initially made with germanium material, later on, silicon BJT are grown up. Most of the devices developed today are made up of silicon only due to its low cost IC (Integrated Circuit) – Jack Kilby To reduce the size and cost of the entire circuit Jack Kilby introduced a new concept. This idea entirely changed the world. The complete interconnected circuit is placed on a single chip commonly called VLSI (Very Large Scale Integrated). Computer processors used today are made up of billions of transistors integrated on a single IC. Department of Electronics & Communication Engineering Dr. Ravi kumar.M www.cambridge.edu.in  Electronics System Block Diagram SENSORS : A device which provides a usable output in response to a specified measured quality. Sensor is a device that detects and responds to some type of input from the physical environment Controllers are typically programmed to perform specific tasks and are responsible for making decisions, executing commands, and regulating the operation of the system based on input data An actuator is a device that converts energy into a mechanical operation, such as rotation, linear movement, or bending. Department of Electronics & Communication Engineering Dr. Ravi kumar.M www.cambridge.edu.in  Microphone - a transducer which converts sound to voltage.  Pre-Amplifier - amplifies the small audio signal (voltage) from the microphone.  Tone and Volume Controls - adjust the nature of the audio signal. The tone control adjusts the balance of high and low frequencies. The volume control adjusts the strength of the signal.  Power Amplifier - increases the strength (power) of the audio signal.  Loudspeaker - a transducer which converts the audio signal to sound. Department of Electronics & Communication Engineering Dr. Ravi kumar.M www.cambridge.edu.in  Applications of Electronics Consumer electronics (gadgets, home appliances, audio and video systems, consumer devices, storage devices) Consumer Electronics : This industry is most applicable to the common people. Consumer Electronics are devices and equipment meant for everyday use. Office Gadgets such as calculators, Personal computers, Scanners and Printers, FAX machine, Front Projector etc. Home appliances such as Washing Machine, Refrigerator, Air Conditioner, Microwave Oven, Vacuum Cleaner etc. Advanced Consumer Devices such as Setup Box, ATM, Dishwasher, Smart Phones, PDA (personal digital assistant), Barcode Scanners, POS terminals. Storage Devices for optical playback and taping, and portable infotainment. Examples are DVDs, HDD jukebox, Portable MP3 player. Department of Electronics & Communication Engineering Dr. Ravi kumar.M www.cambridge.edu.in  Industrial electronics (smart grid, automation, image processing) This industry is powerful in making real-time automation. This include: Industrial automation and motion control, Machine learning, motor drive control, Mechatronics and robotics, Power converting technologies, Photo voltaic systems, Renewable energy applications, Power electronics, and Biomechanics. Smart grid systems : Smart electric systems collect information from the communication technology and react accordingly based on power consumption. It is an application of intelligence, computing, and networked electricity systems. Example: Smart Meters Features of smart grid Digital system based on two-way communication Interactive Sensors Self-monitoring and Debugging Valid Distribution of electricity Department of Electronics & Communication Engineering Dr. Ravi kumar.M www.cambridge.edu.in  Industrial automation and motion control Machines are replacing humans these days with increased productivity, time and cost. Moreover, safety is also considered for unmanageable works. Hence to delegate the human’s, automation has become the preferable choice for industries. Image processing 3D world has been evolved from a single or multiple 2D images. Various algorithms are developed to extract 3D information from 2D patterns. Moreover, image processing has involved in computer graphics, Artificial intelligence, Robotics for navigation, Inspection and Assembly, Computer Vision for Face and gesture recognition, Virtual reality, medical analysis Department of Electronics & Communication Engineering Dr. Ravi kumar.M www.cambridge.edu.in  Medical applications (medical devices and instruments) Medical applications : Advanced sophisticated instruments are being developed for data recording and physiological analysis. Some of the medical devices and equipment used are: Stethoscope to listen inner sounds happening inside the human or animal body. Respiration Monitors for knowing the patient condition due to change in body temperature, pulse, respiration and blood flow. Defibrillator causes electrical shock to heart muscles and brings backs the heart to the normal working condition. Glucose meter for measuring sugar levels in the blood. Pace Maker for reducing and increasing the count of the heart beat. Department of Electronics & Communication Engineering Dr. Ravi kumar.M www.cambridge.edu.in  Meteorological and Oceanographic Environmental monitoring is done through various sensors and Automatic weather stations. Some of them are: Anemometer measures the wind speed and wind direction. Barometer for predicting the weather is good or bad. It gives atmospheric pressure level as an indication. Tipping Bucket Rain gauge for measuring the rainfall periodically stored in the Automatic weather station such as Datalogger. Data logger for storing the data collected from various sensors like humidity, temperature, wind speed and direction, solar radiation, Rain scale. Hygrometer measuring Humidity Drifter Buoy measures current, temperature, and pressure levels in the ocean Department of Electronics & Communication Engineering Dr. Ravi kumar.M www.cambridge.edu.in  Defence and Aerospace Defence and Aeronautical applications include: Missile Launching systems Rocket Launchers for space Aircraft systems Cockpit controllers Military Radars Boom barrier for military applications Department of Electronics & Communication Engineering Dr. Ravi kumar.M www.cambridge.edu.in  Automotive (Automobiles) Anti-collision unit Infotainment console Anti-lock braking system Cruise control Traction control Window regulators Electronic Control Unit (ECU) Airbag control Department of Electronics & Communication Engineering Dr. Ravi kumar.M www.cambridge.edu.in  Electronics vs. Electrical Department of Electronics & Communication Engineering Dr. Ravi kumar.M www.cambridge.edu.in  DEVICES AND COMPONENTS The electronic industry's growth is on a rising level due to the increasing demand for electronic equipment. Let's discuss the type of electronic devices The different types of electronic devices are listed below: *Active *Passive Active Components: The active components generally supply energy or produce power. It includes oscillators, Integrated circuits, and transistors. These components depend on the external power for their functioning. Passive components: The passive components in electronics can only store, absorb, or dissipate the received energy in the electric or magnetic field. It includes resistors, capacitors, and inductors. Department of Electronics & Communication Engineering Dr. Ravi kumar.M www.cambridge.edu.in  Active vs. Passive components Department of Electronics & Communication Engineering Dr. Ravi kumar.M www.cambridge.edu.in  Passive Devices: Generally resistors, capacitors, inductors, diodes, crystals, relays Resistor : The resistor is a passive electrical component whose function is to introduce resistance to the flow of electric current in an electrical circuit, to limit the current. The magnitude of the opposition to the flow of current is called the resistance of the resistor. The resistance is measured in ohms and its equation is as follows : R = V/I(). The higher the resistance R, lower is the current I for for a given voltage V. It is a linear device. Resistors dissipates the electrical energy as P = I2 R Department of Electronics & Communication Engineering Dr. Ravi kumar.M www.cambridge.edu.in  A through-hole resistor is a fixed resistor that has long, pliable leads that can be stuck into a breadboard, or wave-soldered into a printed circuit board (PCB). A surface mount resistor is a tiny rectangular ceramic body with silver conductive edges on either end. Department of Electronics & Communication Engineering Dr. Ravi kumar.M www.cambridge.edu.in  Resistors are used in Analog circuits where precise reference voltage is needed and also in circuit interfaces. Department of Electronics & Communication Engineering Dr. Ravi kumar.M www.cambridge.edu.in  Capacitor The Capacitor is a passive electrical component whose function is to store electrical energy and deliver it to the circuit when required. The capacity of a capacitor to store electrical charge is known as capacitance of that capacitor. It is denoted by C. The unit of capacitance is Farad (F) and can range from µF, nF to pF. The capacitor equation is as follows : C= Q/V. Q denotes charge, V denotes voltage across capacitor and C is capcitance. Since current i = dq/dt, i.e rate of change of charge. I = C dv/dt. Department of Electronics & Communication Engineering Dr. Ravi kumar.M www.cambridge.edu.in  If the voltage across capacitor is constant, there will be no current flow through the capacitor; And current will only flow across the capacitor if the voltage across it is changing with time. The energy stored in capacitor C, which has been charged to voltage V is given by E = 1/2CV2 Capacitance of parallel plate capacitor is given by C = ξ A/d Department of Electronics & Communication Engineering Dr. Ravi kumar.M www.cambridge.edu.in Department of Electronics & Communication Engineering Dr. Ravi kumar.M www.cambridge.edu.in Department of Electronics & Communication Engineering Dr. Ravi kumar.M www.cambridge.edu.in Department of Electronics & Communication Engineering Dr. Ravi kumar.M www.cambridge.edu.in Department of Electronics & Communication Engineering Dr. Ravi kumar.M www.cambridge.edu.in  Inductor The Inductor is a passive two terminal electrical component that stores magnetic energy when an electric energy is passed through it. It’s an insulated wire wound into a coil around a core of some material in a spiral form. The inductor is denoted by inductance L and the measuring unit is Henry (H) Inductance have values that range from 1µH to 2000mH. Department of Electronics & Communication Engineering Dr. Ravi kumar.M www.cambridge.edu.in  When the time varying current flows through an inductor, the magnetic field is created which induces electromotive force (e.m.f) Voltage V across inductor L is given by V= Ldi/dt. The energy stored in an inductor with value L Henries is given by E = ½ Li2 Department of Electronics & Communication Engineering Dr. Ravi kumar.M www.cambridge.edu.in  Types of Inductor Inductors are mainly classified according to the core material used and operating frequency. Types of Inductor  Iron cored Inductors  Air cored Inductors  Powdered Iron cored Inductors  Ferrite cored Inductors  Variable Inductors  Audio frequency Inductors  Radio frequency Inductors Department of Electronics & Communication Engineering Dr. Ravi kumar.M www.cambridge.edu.in  DIODES The diode is a two terminal semiconductor device that allows electric current to flow in one direction, while blocking it in reverse direction. The diode is made of semiconductor device with P-type and N-type material. Typical materials used in diode manufacturing is silicon and germanium. They conduct when a minimum forward voltage(0.7V) is applied across it and remain off during reverse bias condition. Department of Electronics & Communication Engineering Dr. Ravi kumar.M www.cambridge.edu.in Department of Electronics & Communication Engineering Dr. Ravi kumar.M www.cambridge.edu.in  Crystals The Crystal is made of thin piece of Quartz wafer, this wafer is made from silicon material. Wafer is tightly fitted and controlled between two parallel metallized surfaces, which make an electrical connection. When an external voltage is applied to the plates, the crystal vibrates with certain fundamental frequency which creates alternating waveform that swings between high and low level. This Phenomenon is known as Piezoelectric effect. Because of this property they are used in electronic components to create stable clock to the processor. Department of Electronics & Communication Engineering Dr. Ravi kumar.M www.cambridge.edu.in  Crystals Department of Electronics & Communication Engineering Dr. Ravi kumar.M www.cambridge.edu.in Department of Electronics & Communication Engineering Dr. Ravi kumar.M www.cambridge.edu.in  Relays An Relay is an Electromagnetic switch that opens and closes potential free contacts. An Electromagnetic Relay consists of armature, coil, string and contacts. When the voltage is applied to the coil, it generates a magnetic field. This attracts the armature and causes a change in the open/close state of the circuit. It is mainly used to control High power circuits using low power signal. Based on construction, there are two types of Relays: Electromechanical(EMR) Solid-state Relays (SSR) Department of Electronics & Communication Engineering Dr. Ravi kumar.M www.cambridge.edu.in Department of Electronics & Communication Engineering Dr. Ravi kumar.M www.cambridge.edu.in  The solid state Relay has photo diode at its input side and a switching device such as Transistor at its output side. When a specific voltage is applied at its input, photodiode conducts and triggers the base of the transistor to cause the switching. Due to its fast switching and miniaturized form factor, low voltage requirement, eliminating the mechanical arching and electrical noise and contact bounce, its is widely used in applications compared to mechanical relay. Department of Electronics & Communication Engineering Dr. Ravi kumar.M www.cambridge.edu.in   An SPDT (Single Pole Double Throw) relay works by allowing a single input to switch between two different output circuits.  An SPST Single Pole Single Throw relay, is an electromechanical switch that controls a single circuit with a single input and output.  An DPST Double Pole Single Throw DPST relay is the equivalent of 2 SPST switches.  DPDT stands for Double Pole Double Throw. A DPDT relay is a type of electrical switch that controls two circuits and has two sets of switching positions. Department of Electronics & Communication Engineering Dr. Ravi kumar.M www.cambridge.edu.in Department of Electronics & Communication Engineering Dr. Ravi kumar.M www.cambridge.edu.in Department of Electronics & Communication Engineering Dr. Ravi kumar.M www.cambridge.edu.in  Active devices The basic electronic components that depend on an external power source for their operation are called active components. They can amplify signals and/or process signals. Some of the active components are transistor, integrated circuits ICs. Transistor  The transistor is a non-linear semiconductor three-terminal device.  The transistor is considered to be one of the most important devices in the field of electronics.  There are two main functions of transistors, to amplify input signals and to acts as solid-state switches.  The transistor acts as a switch when operated either in saturation or cut-off region. Whereas it amplifies signals when used in the active region. It offers very high input resistance and very low output resistance.  Transistors are categorized into bipolar junction transistor and field effect transistor based on their construction. Department of Electronics & Communication Engineering www.cambridge.edu.in  Type of transistor:  BJT: NPN and PNP,  FET: JFET, P-MOSFET and N-MOSFET. The most popular and commonly used transistors are BC547, 2N2222 Given below are a few common transistor packages: Transistor symbol is represented as below Transistor packages Department of Electronics & Communication Engineering www.cambridge.edu.in  MOSFET  The MOSFET (metal oxide semiconductor field-effect transistor) transistor is a semiconductor device that is different than bipolar junction transistor in terms of construction though the applications remain the same as switching and amplifying.  It has four terminals such as drain, gate, source, and body. The body is shorted with a source terminal. The gate is insulated from the channel near an extremely thin layer of metal oxide. Due to which it offers very high resistance compared to BJT.  By controlling the gate voltage (VGS +ve/-ve) width of a channel along which charge carriers flow (electrons or holes) from source to drain can be controlled.  The P-Channel MOSFET has a P-Channel region between the source and drain and for N-channel MOSFET has an N-channel region. Department of Electronics & Communication Engineering www.cambridge.edu.in  Advantages of MOSFET over BJT:  Very high input resistance  Low on-state resistance  Low power loss  High frequency of operations Application of transistors (BJT/FET)  Amplification of analog signals  Used as switching devices in SMPS, microcontrollers, etc.  Oscillators  Over/under voltage protection  Modulation circuits & demodulation of signals  Power control in invertors and chargers (high-current power transistors) Department of Electronics & Communication Engineering www.cambridge.edu.in  Types of transistor packages In terms of packaging BJT and MOSFET, transistors are available in through-hole (DIP) and SMD versions. e.g. DIP: TO-92, TO- 220 and SMD: SOT23, SOT223, TO-252, D2PAK. Transistor selection parameters While selecting a transistor in any circuit, the user needs to take care of the following parameters:  Maximum collector current (Ic), Max collector voltage (Vce) & VBE voltage  Saturation Vce (sat) voltage  Current gain, hfe/ß  Input resistance & Output resistance  Reverse breakdown voltage, Max reverse current & Power dissipation  Operating junction temperature  Size & Switching time/frequency Manufacturers: Analog Devices, Rohm Semiconductor, Diodes Incorporated, On Semi, Texas Instrument, Panasonic, Infineon, Honeywell, etc. Department of Electronics & Communication Engineering www.cambridge.edu.in  Electronic component and part numbers Basic Electronic component are identified with their respective manufacturing part numbers (MPN). They are also identified with their Distributive/Vendor part number(VPN). Each Basic electronic component has a data sheet, which explains its performance, features and specifications. The part number typically consists of a series of alphanumeric characters that provide specific information about the part, such as its type, characteristics, and supplier. For example, a part number for a capacitor might include information about its capacitance, voltage rating, and physical size. Department of Electronics & Communication Engineering Dr. Ravi kumar.M www.cambridge.edu.in  Component Distributors : Electronic Component distributors are the key source for supply chain management. They are single window source of components where designers can buy components directly rather than buying from individual manufacturer. Distributors stock components from different manufacturers and provide a simple and efficient web portal interface for selecting and purchasing components. Department of Electronics & Communication Engineering Dr. Ravi kumar.M www.cambridge.edu.in  Integrated circuits, types of ICs, IC fabrication process, IC packaging An Integrated circuits (IC) is an electronic circuit built on semiconductor wafer, usually made of silicon. On this wafer, there are miniaturised transistors, resistors, capacitors which are connected by metal traces. IC’s are powered by an external power supply for their operations. Ics perform special functions such as data processing and signal processing. Because od its small size, ICs has low power consumption. Types of ICs ICs are categorised as Digital, Analog and Mixed signal ICs, based on their circuit functionality. Department of Electronics & Communication Engineering Dr. Ravi kumar.M www.cambridge.edu.in  Digital ICs Digital ICs can be divided into further two categories for the sake of simplicity:  Simple ICs: Timer, counter, register, switches, digital logic gates, adder, etc.  Complex ICs: Microprocessor, memories, switching ICs, ethernet MAC/PHY.  A microprocessor/microcontroller is an integrated circuit, which can process the digital data.  For example, temperature sensor data can be read by a microprocessor and using its internal logic to perform control functions such as switching an air-conditioner ON or OFF.  The ability to program a microprocessor gives it the flexibility to be used in a wide range of applications.  Some of the applications are consumer electronics (microwave, washing machine, TV), industrial applications (motor control, process control), communication applications (wireless communication, telephony, satellite communication). Department of Electronics & Communication Engineering www.cambridge.edu.in   A microprocessor is a complex IC having an inbuilt central processing unit (CPU) consisting of an arithmetic logic unit (ALU), registers, buffer memory, clock.  The processor does not have inbuilt memory and needs to interface RAM and ROM externally.  Applications: computers, laptops, servers, basically for high-end processing.  A microcontroller is an integrated circuit that has CPU, inbuilt memory, general-purpose IO’s, communication interface such as SPI, I2C, UART, ADC, DAC, PWM.  Depending on the size of memory and interface microcontrollers are targeted for specific applications.  Applications: Embedded devices such as washing machines, weighing scales, CNC machines, etc. Digital signal processing (DSP) controllers are a type of processor which are used in high- computing applications such as image processing, speech processing, video compression, etc. Department of Electronics & Communication Engineering www.cambridge.edu.in   Analog ICs Operational amplifiers, differential amplifiers, instrumentation amplifiers, RF devices, ADCs, DACs.  Interfacing ICs – RS232 driver, ethernet, CAN bus drivers, buffers, and level converters.  Power ICs – Voltage regulators such as linear regulators, LDOs, switching regulators  Field programmable gate array – FPGA, mixed-signal FPGA IC packages IC’s are available in different packages and pin counts such as DIP and SMD. Below are some of the popular and widely used packages. Package Package name and pin count Small Outline Integrated Circuit(SOIC) Small outline package SOIC-8,12,14,16, 24 TSSOP Thin-shrink small outline package(TSSOP) Through-hole package DIP-8,12,14,16,24, Ball grid array BGA 44, 48… 1000, etc. Flat package QFN , DFM 44 etc. Department of Electronics & Communication Engineering www.cambridge.edu.in  Typical selection parameters While selecting an IC in any circuit user need to consider about following parameters apart from the application/usage. Digital ICs  Operating voltage (Vcc): +2.5V, +3.3V, +1.8V, +5V, +12V/-12V  Maximum operating frequency,Switching time and maximum data rates  IO voltage level (TTL5V, CMOS), max tolerance, VIH, VIL, VOH, VOL  IO setup time, hold time, data valid time  Type of IO: Digital or analog pin  Total number of IOs required for application  Type of communication interfaces such as SPI or I2C and speed  Commercial 0° C to 60° C, mil-grade -55° C to 125° C, industrial -40° C to 85° C  Size & Power dissipation. Department of Electronics & Communication Engineering www.cambridge.edu.in  Analog ICs  Operating voltage (Vcc): +2.5V, +3.3V, +1.8V, +5V, +12V/-12V  Ref voltages, Maximum and minimum output voltage  CMRR, PSRR, Offset voltages and current  Input signal magnitude range  Type of digital communication interface and speed  Power dissipation & Size  Commercial 0° C to 60° C, mil-grade -55° C to 125° C, industrial -40° C to 85° C SMT device sizes  The component sizes of the selected SMT components are important while manufacturing the electronic product.  The assembler should have the capability to assemble the small size components on the PCBs.  The SMT component sizes are given in inches as well as metric systems. Department of Electronics & Communication Engineering www.cambridge.edu.in  IC Fabrication Process  Integrated Circuits are the set of electronic circuits mounted on the small electronic chip.  Large numbers of devices, such as MOSFETs (Metal Oxide Semiconductor Field Effect Transistor), transistors, microcontrollers, computer processors, etc., are created with the help of the fabrication process.  The most preferred materials in the semiconductor industry for fabrication are silicon and germanium because of their stable structure.  Other materials preferred in fabrication industries are carbon steel, silver, aluminum, magnesium, copper, wood, thermoplastics, resins, etc. Fabrication is the process of constructing an industrial product. We can also define it as a set of methods to manufacture an electronic device or product. For example, silicon semiconductor chips, etc  In the case of metals, fabrication is a process used to convert the raw materials into the finished product.  The smaller components manufactured by the fabrication process can be further used to make large electronic components. Department of Electronics & Communication Engineering www.cambridge.edu.in  The Discuss in detail about the functionality of resistors & capacitors as passive components are as follows:  Wafer Preparation  Oxidation  Diffusion  Ion Implantation  Chemical-Vapor Deposition  Photolithography  Metallization  Packaging Department of Electronics & Communication Engineering www.cambridge.edu.in  Wafer Preparation  A wafer is a thin material used for making various Integrated circuits and transistors.  Wafer acts as a base for such devices. The material of a wafer is the semiconductor, especially crystalline silicon.  The silicon crystals used for the wafer manufacturing are highly pure. The process of extracting pure metal from the melt is known as a boule.  The impurities are further added to the molten state of the material in a specific amount to make it n-type or p-type.  The wafer preparation is the first step for IC fabrication. It involves cutting, shaping, and polishing the wafer material to make it suitable for further fabrication.  Some wafers are modified because of their sharp edges, irregular surface, and shape to convert them to the required wafer. Department of Electronics & Communication Engineering www.cambridge.edu.in  Oxidation is the process of adding oxygen. In a semiconductor, the oxygen and the silicon react to form silicon dioxide.  The oxidation is carried out in furnaces at high temperatures upto 1250 degrees Celsius.  Oxidation is classified as wet oxidation or dry oxidation.  Wet oxidation is fast, while dry oxidation has good electrical properties.  Wet oxidation is also known as steam. Both types of oxidation have excellent electrical insulation properties.  The deposition of silicon dioxide on the silicon wafer protects from many impurities.  An example of oxide layer on the substrate is shown below: Department of Electronics & Communication Engineering Dr. Ravi kumar.M www.cambridge.edu.in  Diffusion : Diffusion is a process of adding impurities atoms from a region with high concentration to a region of low concentration.  The dopants or impurity atoms are added to the silicon, which changes its resistivity.  The process of diffusion is highly dependent on the temperature.  It is carried out in high-temperature furnaces between 1000 to 1200 degrees Celsius.  The depth and width of the impurities depend on the temperature range and the timings.  The high doping concentration improves the conductivity of a metal.  The dopants can be of any state, solid, liquid, or gas.  The preferred dopants are pentavalent impurities or n-type, such as antimony, phosphorous pentoxide, and arsine (gas).  The trivalent impurities or p-type are gallium, indium, boron, etc. Department of Electronics & Communication Engineering Dr. Ravi kumar.M www.cambridge.edu.in  Ion Implantation : The ion implantation is a process of accelerating ions from the element to the solid target. The accelerated ions on the solid can change its properties. The ions are applied at a low temperature and high energy.  The low temperature allows it to work at room temperature. But, the excess energy can also damage the crystal structure of the solid.  Ion implantation introduces impurity atoms in the crystal.  The accelerated atom gets embedded when it strikes the surface of the crystal.  The energy and accelerating field voltage determine the depth of the penetration of the ions.  Hence, ion implantation is more accurate due to the controlled current, voltage, and energy. Department of Electronics & Communication Engineering Dr. Ravi kumar.M www.cambridge.edu.in  Chemical-Vapor Deposition(CVD) :  Chemical Vapor deposition is used to produce high-quality solid materials.  It produces thin films in the semiconductor industry.  The process is carried out at a pressure below the atmospheric pressure, also known as vacuum deposition.  The chemicals and vapors react to form solids on the surface of a substrate.  The protective layers on the substrate, such as silicon dioxide, polysilicon, and silicon nitride, are deposited using the CVD process. CVD can be performed at very low pressures, low pressures, atmospheric pressures, sub-atomic pressures, and ultra high pressures. Department of Electronics & Communication Engineering Dr. Ravi kumar.M www.cambridge.edu.in  Photolithography : is also known as optical lithography, using light to produce thin films.  It is used to pattern thin films on the substrate, such as silicon wafers.  The types of light used to introduce mask patterns on the silicon wafer include UV light, X-rays, and extreme UV that emits at different frequencies.  The silicon wafer or the substrate is first coated with a photoresist.  On the photoresist layer, a mask pattern with the help of photolithography is applied to the silicon wafer.  The exposed areas of the wafer become soft and can be removed. It creates a pattern on the wafer.  The wavelength of each type of light determines the feature size impressed on the photoresist. Department of Electronics & Communication Engineering Dr. Ravi kumar.M www.cambridge.edu.in  Metallization : is defined as the process of coating a metal layer on the metallic surface or non-metallic surface.  The coating can be of aluminum, zinc, or silver.  The metal coating in CMOS fabrication is aluminum, which protects the surface from external environmental factors, as dust, air, water, etc.  Metallization is also used to interconnect various components that form an Integrated circuit.  The components can be resistors, capacitors, transistors, relays, etc.  The metal layer is first deposited on the surface of the silicon wafer, as shown.  After that, the required pattern or area for interconnected is etched, as shown below: Department of Electronics & Communication Engineering Dr. Ravi kumar.M www.cambridge.edu.in  Packaging is the last stage of the IC fabrication process. The finished silicon wafer or chips of various sizes with number of small components are tested electrically to recheck their working. The testing is performed using an automatic probing station. It is a cost effective testing machine that includes microwave and radio-frequency testing. The default circuits are separated from all the circuits. The good circuits are sent for packaging or headers. Packaging is a connection between the manufacturing and end use of a device. It makes a product suitable for its end use. The package is finally sealed with epoxy or plastic to prevent it from atmospheric dust. It is performed under vacuum or an inert atmosphere, which prevents the material from oxygen that may get trap in the packaging. Department of Electronics & Communication Engineering Dr. Ravi kumar.M www.cambridge.edu.in wafer and IC fabrication processes Department of Electronics & Communication Engineering Dr. Ravi kumar.M www.cambridge.edu.in  PCB and its functionality, types of PCBs What is a Printed Circuit Board? A printed circuit board (PCB) is an electronic assembly that uses copper conductors to create electrical connections between components. PCBs also provide mechanical support for electronic components so that a device can be mounted in an enclosure. All PCBs are built from alternating layers of conductive copper with layers of electrically insulating material. Conductive features on printed circuit boards include copper traces, pads, and conductive planes. The mechanical structure is made up of the insulating material laminated between the layers of conductors. Department of Electronics & Communication Engineering Dr. Ravi kumar.M www.cambridge.edu.in Department of Electronics & Communication Engineering Prof. Ravi kumar.M www.cambridge.edu.in  Types of PCBs Single-sided - This board only has components mounted on one surface. The back surface is typically fully copper (ground) and coated with a solder mask. Double-sided - This type of circuit board has components mounted on both surfaces. Each surface is defined as a signal layer in the PCB stack-up, so the surfaces will contain traces that carry signals between components. Multi-layer PCBs - These boards have conductors on internal layers that carry electrical signals between components, or the internal layers could be conductive plane layers. Multi-layer PCBs may be single-sided or double-sided. Rigid-flex PCBs - Rigid-flex PCBs use a flexible polyimide ribbon that connects two or more rigid sections in a printed circuit board assembly. A rigid-flex board might be used when the design must have some movable element, such as a folding or bending enclosure.. Department of Electronics & Communication Engineering Dr. Ravi kumar.M www.cambridge.edu.in  Flex PCBs - Fully flexible PCBs do not use any rigid materials and are made entirely of flexible polyimide ribbons. These boards can have components mounted and soldered on the, just like rigid and rigid-flex printed circuit boards. Printed flex PCBs - These PCBs use a flexible material as the base, and copper conductors are printed onto the flexible material in an inkjet process or in a similar additive process. The resulting boards are very similar to flex PCBs. Metal-core PCBs (or insulated metal substrate (IMS) PCBs) - These boards use a metal slab in the core layer (normally aluminum) in order to provide much greater rigidity and heat dissipation than in typical rigid printed circuit boards. These boards are common in high-power lighting and some industrial applications. Department of Electronics & Communication Engineering Dr. Ravi kumar.M www.cambridge.edu.in  Ceramic PCBs - These boards are less common and are used in applications that require very high thermal conductivity such that the board can dissipate large amounts of heat away from components. HDI PCBs - These PCBs use very high pin count components that require a specialized manufacturing process and specialized materials to accommodate a very high density of copper connections. UHDI and Substrate-like PCBs - These PCBs are so small and dense that they have bypassed capabilities of subtractive etching, and instead they require a specialized additive manufacturing process used to build IC packages Department of Electronics & Communication Engineering Prof. Ravi kumar.M www.cambridge.edu.in  Front-end engineering Schematic capture Material selection and PCB stack-up design Printed Circuit board (PCB) design Basic process: Component placement Routing Design review and verification Preparing for Manufacturing Department of Electronics & Communication Engineering Prof. Ravi kumar.M www.cambridge.edu.in  Front-end engineering - Major components are selected based on its functionality in the board. Schematic capture - This is the stage where ECAD software is used to translate simple circuit diagrams into electronic drawings. Material selection and PCB stack-up design - laminate materials are selected and the stack-up is designed to accommodate the need for plane layers, signal layers, dedicated routing channels, and specific material properties. Component placement - Components are arranged in the layout to comply with the design's mechanical requirements. Routing - Routing tools in ECAD software are used to set Trace geometry may be determined in this stage with the goal of ensuring impedance control (for high-speed signals). Design review and verification - To inspect and evaluate the design to ensure there are no mistakes or unresolved problems. Preparing for Manufacturing - It's time to prepare for production by generating standard manufacturing files. These files are used in automated fabrication and assembly equipment. Department of Electronics & Communication Engineering Dr. Ravi kumar.M www.cambridge.edu.in  Unit 3: Measuring instruments Voltmeters  A voltmeter is an instrument that measures the difference in electrical potential between two points in an electric circuit.  An analog voltmeter moves a pointer across a scale in proportion to the circuit’s voltage.  A digital voltmeter provides a numerical display. Department of Electronics & Communication Engineering Dr. Ravi kumar.M www.cambridge.edu.in  Voltmeter in Parallel: To measure a device’s voltage, Voltmeter must be connected in parallel to that device. Because objects in parallel experience the same potential difference.  (a) To measure the potential difference in this series circuit, the voltmeter (V) is placed in parallel with the voltage source or either of the resistors.  Note that terminal voltage is measured between points a and b. It is not possible to connect the voltmeter directly across the EMF without including its internal resistance, r.  (b) A digital voltmeter in use Department of Electronics & Communication Engineering Dr. Ravi kumar.M www.cambridge.edu.in  Ammeters  An ammeter measures the electric current in a circuit. The name is derived from the name for the SI unit for electric current, amperes (A).  In order for an ammeter to measure a device’s current, it must be connected in series to that device.  This is necessary because objects in series experience the same current. Ammeter in Series:  An ammeter (A) is placed in series to measure current. All of the current in this circuit flows through the meter.  The ammeter would have the same reading if located between points d and e or between points f and a, as it does in the position shown. (Note that the script capital E stands for EMF, and r stands for the internal resistance of the source of potential difference. ) Department of Electronics & Communication Engineering Dr. Ravi kumar.M www.cambridge.edu.in  Galvanometers (Analog Meters)  Analog meters have needles that swing to point at numbers on a scale, as opposed to digital meters, which have numerical readouts.  The heart of most analog meters is a device called a galvanometer, denoted by G. Current flow through a galvanometer IG, produces a proportional movement, or deflection, of the needle.  The two crucial characteristics of any galvanometer are its resistance and its current sensitivity.  Current sensitivity is the current that gives a full-scale deflection of the galvanometer’s needle  In other words, the maximum current that the instrument can measure.  For example, a galvanometer with a current sensitivity of 50 μA has a maximum deflection of its needle when 50 μA flows through it, is at the scale’s halfway point when 25 μA flows through it, and so on.  If such a galvanometer has a 25-Ω resistance, then a voltage of only V=IR=(50μA)(25Ω)=1.25mV produces a full-scale reading. By connecting resistors to this galvanometer in different ways, you can use it as either a voltmeter or ammeter to measure a broad range of voltages or currents. Department of Electronics & Communication Engineering Dr. Ravi kumar.M www.cambridge.edu.in  Galvanometers as Voltmeters  A galvanometer can function as a voltmeter when it is connected in series with a large resistance R. The value of R is determined by the maximum voltage that will be measured.  Suppose you want 10 V to produce a full-scale deflection of a voltmeter containing a 25-Ω galvanometer with a 50-μA sensitivity. Then 10 V applied to the meter must produce a current of 50 μA. The total resistance must be: Rtot=R+r=V/I=10V/50μA=200kΩ or R=Rtot−r=200kΩ−25Ω≈200kΩ (R is so large that the galvanometer resistance, r, is nearly negligible. ) Note that 5 V applied to this voltmeter produces a half-scale deflection by sending a 25-μA current through the meter, and so the voltmeter’s reading is proportional to voltage, as desired. This voltmeter would not be useful for voltages less than about half a volt, because the meter deflection would be too small to read accurately. Department of Electronics & Communication Engineering Dr. Ravi kumar.M www.cambridge.edu.in  Galvanometers as Ammeters  The same galvanometer can also function as an ammeter when it is placed in parallel with a small resistance R, often called the shunt resistance.  Since the shunt resistance is small, most of the current passes through it, allowing an ammeter to measure currents much greater than those that would produce a full-scale deflection of the galvanometer. Suppose, for example, we need an ammeter that gives a full-scale deflection for 1.0 A and that contains the same 25-Ω galvanometer with 50-μA sensitivity. Since R and r are in parallel, the voltage across them is the same. Department of Electronics & Communication Engineering Dr. Ravi kumar.M www.cambridge.edu.in  Multimeter What is a Multimeter?  A Multimeter is an electronic instrument, every electronic technician and engineer’s widely used piece of test equipment. A multimeter is mainly used to measure the three basic electrical characteristics of voltage, current, and resistance.  It can also be used to test continuity between two points in an electrical circuit.  The multimeter has multi functionalities like, acts like ammeter, voltmeter, and ohmmeter.  It is a handheld device with positive and negative indicator needles over a numeric LCD digital display. Multimeters can be used for testing batteries, household wiring, electric motors, and power supplies.  The essential parts of the multimeter mainly include a display, power source, probes, and controls Department of Electronics & Communication Engineering Dr. Ravi kumar.M www.cambridge.edu.in  How to use a Multimeter?  The function and operation of a multimeter are similar for both analog and digital types. This instrument includes two leads or probes namely red and black & three ports.  The black color lead is used to plug into the common port, whereas the red color leads plug into other ports based on the requirement.  Once the leads are plugged in, the knob can be switched ON in the center of the instrument so that the appropriate function can be done for the specific component test. Department of Electronics & Communication Engineering Dr. Ravi kumar.M www.cambridge.edu.in  Functions of Multimeters  These instruments are capable of different readings based on the model. So basic types of multimeter are mainly used to measure amperage, resistance, voltage, checks continuity and a complete circuit can be tested like the following.  Resistance in Ohms  Capacity in Farads  The temperature in Fahrenheit/ Celsius  AC Voltage & Amperage  Inductance Henrys  DC Voltage & Amperage  Frequency in Hz  Conductance in Siemens  Decibels  Duty Cycle Department of Electronics & Communication Engineering Dr. Ravi kumar.M www.cambridge.edu.in  Types of Multimeter Analog Multimeter  The Analog Multimeter or VOM (Volt-Ohm-Milliammeter) is constructed using a moving coil meter and a pointer to indicate the reading on the scale. The moving coil meter consists of a coil wound around a drum placed between two permanent magnets. Digital Multimeters  We mostly used a multimeter is a digital multimeter (DMM). The DMM performs all functions from AC to DC other than analog. It has two probes positive and negative indicated with black and red color is shown in the figure. The black probe connected to COM JACK and the red probe connected by user requirement to measure ohm, volt, or amperes. Department of Electronics & Communication Engineering Dr. Ravi kumar.M www.cambridge.edu.in Department of Electronics & Communication Engineering Dr. Ravi kumar.M www.cambridge.edu.in  Difference between Analog Multimeter and Digital Multimeter Analog Multimeter Digital Multimeter Digital Multimeter is used to compute various electrical Analog Multimeter is used to gauge restricted electrical quantities like voltage, current, capacitance, resistance, quantities like resistance, voltage & current. values of diode and impedance, etc. The size of the analog multimeter is larger The size of the digital multimeter is smaller This meter provides the reading on a scale next to the This meter provides the reading in the form of numeric on pointer. an LCD. These are calibrated manually. These are calibrated automatically. These are less cost These are expensive The frequency range is up to2kHZ. The frequency range is high as compared to analog Analog Multimeter measures the current with the help of a Digital Multimeter measures voltage with ADC Galvanometer. It has less electric noise It has more electric noise Department of Electronics & Communication Engineering Dr. Ravi kumar.M www.cambridge.edu.in  Advantages and Disadvantages of Digital Multimeters  It gives an automatic o/p display.  The measurement results of the meter can record and store in memory and synchronizes through a PC  It includes auto polarity functions  It ensures accuracy  Resistance toward mechanical damage.  Multifunctionality  Zero adjustments cannot be required  Measurement accuracy is high  Measuring ranges can be selected through manual or automatically The disadvantages of digital multimeter include the following  As compared to analog, it is expensive  This multimeter does not work properly through measurement fluctuations. It can be tricky to discover one for your exact needs. Department of Electronics & Communication Engineering Dr. Ravi kumar.M www.cambridge.edu.in  Thank you Any Queries? Department of Electronics & Communication Engineering Prof. Ravi kumar.M www.cambridge.edu.in