UNIT VIII-SPECIAL PURPOSE ELECTRONIC DEVICES. 1. Explain tunnel Diode operation with the help of energy band diagrams.

Size: px
Start display at page:

Download "UNIT VIII-SPECIAL PURPOSE ELECTRONIC DEVICES. 1. Explain tunnel Diode operation with the help of energy band diagrams."

Transcription

1 UNIT III-SPECIAL PURPOSE ELECTRONIC DEICES 1. Explain tunnel Diode operation with the help of energy band diagrams. TUNNEL DIODE: A tunnel diode or Esaki diode is a type of semiconductor diode which is capable of very fast operation, well into the microwave frequency region, by using quantum mechanical effects. Impurity concentration in normal diode is 1 part in 8 10 in Tunnel diode 1 part in 3 10.Normally a electron or hole must have energy greater than or equal to potential energy barrier, to move to other side of the barrier. For very thin barrier there is a large probability of electron penetrating through the barrier which is called as Tunneling:. Under normal Forward bias operation As voltage begins to increase, electrons at first tunnel through the very narrow p n junction barrier because filled electron states in the conduction band on the n-side become aligned with empty valence band hole states on the p-side of the p-n junction. As voltage increases further these states become more misaligned and the current drops this is called negative resistance because current decreases with increasing voltage. As voltage increases yet further, the diode begins to operate as a normal diode, where electrons travel by conduction across the p n junction, and no longer by tunneling through the p n junction barrier. Thus the most important operating region for a tunnel diode is the negative resistance region. Reverse bias operation When used in the reverse direction they are called back diodes and can act as fast rectifiers with zero offset voltage and extreme linearity for power signals.under reverse bias filled states on the p-side become increasingly aligned with empty states on the n-side and electrons now tunnel through the pn junction barrier in reverse direction. ENERGY BAND STRUCTURE OF HIGHLY DOPED PN DIODE: GRIET-ECE G.Surekha Page 1

2 E E KT F C Similarly for P type E F = E +KT NC ln N for N type material If N C < N D, E F > E C D l n N N C A If N A > N C ; E F < E Fermi level lies in conduction band in N type as shown in Fig.5.3 (a). Fermi level lies in valence band in P type material. Fermi level is at same energy level on both sides. By reverse bailing barrier height increases as shown in fig.5.3 (b).fermi level on N side is lowered. Tunneling of electron from P to N side is the result. (From filled sates to empty states). If we increase the reverse bias, reverse current increases as shown in characteristics of (Fig.5.5) a. GRIET-ECE G.Surekha Page

3 Similarly for forward bias tunneling occurs from N to P type material as shown in Fig.5.4. Further increase in forward, the condition shown in 5.4(b)reached and maximum current follows (characteristics of Fig.5.5). Further increase will reduce the current as shown in fig.5.4(1) till a minimum current flows due to the condition shown in fig.5.4(d) section 3 of 5.5(a) Besides the above current due to tunneling normal diode current flows as shown in dotted lives in fig.5.5(a). Resultant is the graph shown in 5.5(b). The symbol and equivalent circuit is shown in the above fig5.6. Application: - 1. Used as oscillator at HF / UHF.. Ultra high speed switch. 3. Used as logic memory (storage) device. 4. Used as amplifier. Advantages Disadvantages 1) Low noise 1) Less voltage range of separation ) Ease of operation ) No isolation of input and output, 3) High speed as it is a two terminal device. 4) Low power.. Differences between Tunnel Diode and PN Diode. Impurity concentration in normal diode 1 part in 10 3 Impurity concentration in Tunnel diode 1 part in 10 Width of the junction barrio varies inversely as square root of impurity concentration GRIET-ECE G.Surekha Page 3 8

4 W B e A Where B is barrier potential, is the permitivity of material N A acceptor concentration. Width of junction for normal diode 5 microns m Width of junction Tunnel Diode < 100 A m Normally a electron or hole must have energy greater than or equal to potential energy barrier, to move to other side of the barrier. For very thin barrier there is a large probability of electron pert rating through the barrier which is called as Tunneling:. 3. Explain the principle and operation of varactor Diode. aractor or varicap diodes are used mainly in radio frequency (RF) circuits to be able to provide a capacitance that can be varied by changing a voltage in an electronics circuit. This can be used for tuning circuits including radio frequency oscillators and filters. Although both names: varactor and varicap diode are used, they are both the same form of diode. The name varactor meaning variable reactor, or reactance, and varicap meaning variable capacitance (vari-cap). Operation of a variable capacitor They key to understanding how a varactor or varicap diode works is to look at what a capacitor is and what can change the capacitance. As can be seen from the diagram below, a capacitor consists of two plates with an insulating dielectric between them.... the capacitance and the amount of charge that can be stored depends on the area of the plates and the distance between them... The capacitance of the capacitor is dependent upon the area of the plates - the larger the area the greater the capacitance, and also the distance between them - the greater the distance the smaller the level of capacitance. GRIET-ECE G.Surekha Page 4

5 A reverse biased diode has no current flowing between the P-type area and the N-type area. The N-type region and the P-type regions can conduct electricity, and can be considered to be the two plates, and the region between them - the depletion region is the insulating dielectric. This is exactly the same as the capacitor above. As with any diode, if the reverse bias is changed so does the size of the depletion region. If the reverse voltage on the varactor or varicap diode is increased, the depletion region of the diode increases and if the reverse voltage on varactor diode is decreased the depletion region narrows. Therefore by changing the reverse bias on the diode it is possible to change the capacitance. Change of varactor diode capacitance with reverse bias aractor or varicap circuit symbol The varactor diode or varicap diode is shown in circuit diagrams or schematics using a symbol that combines the diode and capacitor symbols. In this way it is obvious that it is being used as a varacor or varicap capacitor rather than a rectifying diode. Circuit symbol for a varactor diode / varicap diode When operated in a circuit, it is necessary to ensure the varactor diode remains reverse biased. This means that the cathode will be positive with respect to the anode, i.e. the cathode of the varactor will be more positive than the anode. aractor Diode or aractors are operated reverse biased so no current flows, but since the thickness of the depletion region varies with the applied bias voltage, the capacitance of the diode can be made to vary. Generally, the depletion region thickness is proportional to the square root of the applied voltage; and capacitance is inversely proportional to the depletion region thickness. GRIET-ECE G.Surekha Page 5

6 Applications: They are used in PLL, voltage controlled oscillators, harmonic generation, electronic tuning devices in tuners for television, mobiles, parametric amplification, AM radios, voltage-variable tuning, frequency multipliers, etc. 4. Describe the working principle of an SCR with -I characteristics and also explain two transistor analogy of an SCR. SILICON CONTROLLED RECTIFIER: Construction of SCR An SCR consists of four layers of alternating P and N type semiconductor materials. Silicon is used as the intrinsic semiconductor, to which the proper dopants are added. The junctions are either diffused or alloyed. The planar construction is used for low power SCRs (and all the junctions are diffused). The mesa type construction is used for high power SCRs. In this case, junction J is obtained by the diffusion method and then the outer two layers are alloyed to it, since the PNPN pellet is required to handle large currents. Construction Symbol GRIET-ECE G.Surekha Page 6

7 CHARACTERISTICS OF SCR. 1) SCR is a three terminal four layer semiconductor device. ) Leakage current is very small for SCR compared with germanium. 3) SCR acts as a switch when it is forward biased. 4) When gate is open i.e., I G = 0, and anode voltage is applied junctions P 1 N 1 and P N are forward biased where N 1 P is reverse biased. Only small reverse current flows. 5) If we increase anode voltage further, at one stage anode current increases suddenly and voltage across the SCR falls to holding voltage H. 6) Once SCR fires (conducts), it will remain in conduction till the current through the device is reduced less than IH, adding current by reducing applied voltage (to less than holding voltage) close to zero. 7) The firing angle can be varied by varying the Gate voltage. With very large positive (gate current break over may occur at very low voltage and SCR works as if it is a normal PN diode. TWO TRANSISTOR ERSION OF SCR. -T 1 is PNP and T is NPN. GRIET-ECE G.Surekha Page 7

8 I b1 = I A I e1 = I A - 1 I A = I A (1-1) - (1) I b1 = I c and I c = I k - () I b1 = I A (1-1) = I K - (3) We know I k = I A + Ig. ( I A = I C1 + I b1 ) - (4) Putting the value of I k from eqn. (4) in eqn. (3) I A (1-1) - (I A + Ig) I A (1-1) = (I A + Ig) I A (1-1 - ) = Ig. Or Ig I A -(5) 1 1 Equation 5 indicates that if( 1 + ) = 1, I A = - SCR is also called as Thyrister - Latching current (I L ) the min. current required to fire the device - Holding current (I H ) min. current to keep the SCR conductivity PI - oltage safety factor f RMS of operating voltage. alue of f is to.7. Application of SCRs 1. SCRs are mainly used in devices where the control of high power, possibly coupled with high voltage, is demanded.. Their operation makes them suitable for use in medium to high-voltage AC power control applications, such as regulators and motor control. 3. SCRs and similar devices are used for rectification of high power AC in high-voltage direct current power transmission. 5. Explain Rectifier circuits using SCR s. SCR Half wave Rectifier:- Below fig shows the circuit of an SCR half wave rectifier. GRIET-ECE G.Surekha Page 8

9 SCR does not conduct during negative half cycle (like normal PN diode) Firing angle depends on gate voltage Conduction angle is ( - ) During the positive half cycle of ac voltage appearing across secondary, the SCR will conduct provided proper gate current, the lesser the supply voltage at which the SCR is triggered ON. Reffering to above fig the gate current is adjusted to such a value that SCR is turned ON at a positive voltage 1 of ac secondary voltage which is less than the peak voltage m. Beyond this The SCR will be conducting till the applied voltage becomes zero. The angle at which the SCR starts conducting during the positive half cycle is called firing angle. There fore the conduction angle is ( ). Average DC output 1 av m sin wt. dwt m m m m 1 cos cos wt cos 0 cos 1 cos GRIET-ECE G.Surekha Page 9

10 RMS OLTAGE: RMS is given by RMS m 1 sin 1/ SCR FULL WAE RECTIFIER The SCR Full wave Rectifier is shown in below fig. During the Positive half cycle of the input signal, anode of the SCR1 becomes positive and the at the same time the anode of SCR becomes negative. When the input voltage reaches 1 as shown in below fig (b), SCR1 starts conducting and therefore only the shaded portion of positive half cycle will pass through the load. During the negative half cycle of the input, the anode of SCR1 becomes negative and the anode of SCR becomes positive. Hence SCR1 does not conduct and SCR conducts when the input voltage becomes 1. DC m 1 cos 6. Explain the principle and working of Photo Diode. PHOTO DIODES: The diagrams shown below are construction, biasing and symbol of Photo diode. Construction Biasing Symbol A P N K P N GRIET-ECE G.Surekha Page 10

11 - When light falls on reverse biased PN photo junction, holes and electron pairs are liberated which leads to current flow through the external load. - Current will be zero only for a positive voltage T. Current luminous flux - LEDs are used for displays, including seven-segment display. - A photodiode is a type of photo detector capable of converting light into either current or voltage, depending upon the mode of operation. A photodiode is a p-n junction or PIN structure. It is designed to operate in reverse bias. When a photon of sufficient energy strikes the diode, it excites an electron, thereby creating a free electron (and a positively charged electron hole). This mechanism is also known as the inner photoelectric effect. If the absorption occurs in the junction's depletion region, or one diffusion length away from it, these carriers are swept from the junction by the built-in field of the depletion region. Thus holes move toward the anode, and electrons toward the cathode, and a photocurrent is produced. This photocurrent is the sum of both the dark current (without light) and the light current, so the dark current must be minimised to enhance the sensitivity of the device. Applications P-N photodiodes are used in similar applications to other photo detectors, such as photoconductors, charge-coupled devices, and photomultiplier tubes. They may be used to generate an output which is dependent upon the illumination. Photosensors of all types may be used to respond to incident light, or to a source of light which is part of the the same circuit or system. A photodiode is often combined into a single component with an emitter of light, usually a light-emitting diode (LED), either to detect the presence of a mechanical obstruction to the beam (slotted optical switch), or to couple two digital or analog circuits while maintaining extremely high electrical isolation between them, often for safety (optocoupler). PIN diodes are much faster and more sensitive than p-n junction diodes, and hence are often used for optical communications and in lighting regulation. GRIET-ECE G.Surekha Page 11

12 7. Describe the operation of Schottky diode. Schottky Diode Junction of lightly doped n-type semiconductor with a metal electrode. The junction of a doped semiconductor (usually n-type) with a metal electrode can produce a very fast-switching diode which is mainly used in high frequency circuits or high speed digital circuits. Under forward bias, the electrons move from the n-type material to the metal and give up their energy quickly. There are no holes (minority carriers), so the conduction quickly stops upon change to reverse bias. Schottky diodes find application as rectifiers for high frequency signals. Construction A metal-semiconductor junction is formed between a metal and a semiconductor, creating a Schottky barrier (instead of a semiconductor semiconductor junction as in conventional diodes). Typical metals used are molybdenum, platinum, chromium or tungsten; and the semiconductor would typically be N-type silicon.the metal sides acts as the anode and N-type semiconductor acts as the cathode of the diode. This Schottky barrier results in both very fast switching and low forward voltage drop. Reverse recovery time The most important difference between p-n and Schottky diode is reverse recovery time, when the diode switches from non-conducting to conducting state and vice versa. Where in a p-n diode the reverse recovery time can be in the order of hundreds of nanoseconds and less than 100 ns for fast diodes, Schottky diodes do not have a recovery time, as there is nothing to recover from (i.e. no charge carrier depletion region at the junction). The switching time is ~100 ps for the small signal diodes, and up to tens of nanoseconds for special high-capacity power diodes. It is often said that the Schottky diode is a "majority carrier" semiconductor device. This means that if the semiconductor body is doped n-type, only the n-type carriers (mobile electrons) play a significant role in normal operation of the device. The majority carriers are quickly injected into the conduction band of the metal contact on the other side of the diode to become free moving electrons. Therefore no slow, random recombination of n- and p- type carriers is involved, so that this diode can cease conduction faster than an ordinary p-n rectifier diode. This property in turn allows a smaller device area, which also makes for a faster transition. This is another reason why Schottky diodes are useful in switch-mode power converters; the high speed of the diode means that the circuit can operate at frequencies in the range 00 khz to MHz, allowing the use of small inductors and capacitors with greater efficiency than would be possible with other diode types. Small-area Schottky diodes are the heart of RF detectors and mixers, which often operate up to 50 GHz. GRIET-ECE G.Surekha Page 1

13 Limitations The most evident limitations of Schottky diodes are the relatively low reverse voltage rating for silicon-metal Schottky diodes, 50 and below, and a relatively high reverse leakage current. Diode designs have been improving over time. oltage ratings now can reach 00. Reverse leakage current, because it increases with temperature, leads to a thermal instability. Problems Q)1. An SCR FWR is connected to Hz mains to supply ac voltage to resistive load of 10 for firing angle of 90. Find DC output voltage and load current. Solution: - Given RMS = 30, R L = 10, = 90 DC =? I L =? RMS DC max m 1 Cos Or max = RMS = 50 = volts cos volts I L DC R L Amps Q ) A sinusoidal voltage = 00 sin 314 t is applied to an SCR whose forward break down voltage is 150. Determine the time during which SCR remain off. Solution: - Given 1 = 150, m = 00 W = 314 =? t =? m sin or sin sin 3/ m T = 1/f f =? w = f = 314 or f = 314/ = 50Hz. GRIET-ECE G.Surekha Page 13

14 T= 1/50 = 0.0sec = 0 m. sec t = T 0.7m sec Q 3) A half wave rectifier employing SCR is adjusted to have a gate current of 1mA and its forward breakdown voltage is 150. If a sinusoidal voltage of 400 peak is applied, determine. i) Firing angle (ii) Average output voltage Given iii) Average current for a load resistance of 00 iv) Power output. 1 = 150, m = 400, =? DC =? I DC =? P DC =? R L = 00 Solution: - 1 = m sin, or Sin = 1 / m = 150/400 = 3/8 = = Sin =. DC m cos (1 cos ) (1.97) 1.6volts I DC R DC L Amps. 00 P. I Watts. DC DC DC GRIET-ECE G.Surekha Page 14

Module 04.(B1) Electronic Fundamentals

Module 04.(B1) Electronic Fundamentals 1.1a. Semiconductors - Diodes. Module 04.(B1) Electronic Fundamentals Question Number. 1. What gives the colour of an LED?. Option A. The active element. Option B. The plastic it is encased in. Option

More information

1) A silicon diode measures a low value of resistance with the meter leads in both positions. The trouble, if any, is

1) A silicon diode measures a low value of resistance with the meter leads in both positions. The trouble, if any, is 1) A silicon diode measures a low value of resistance with the meter leads in both positions. The trouble, if any, is A [ ]) the diode is open. B [ ]) the diode is shorted to ground. C [v]) the diode is

More information

Objective Type Questions 1. Why pure semiconductors are insulators at 0 o K? 2. What is effect of temperature on barrier voltage? 3.

Objective Type Questions 1. Why pure semiconductors are insulators at 0 o K? 2. What is effect of temperature on barrier voltage? 3. Objective Type Questions 1. Why pure semiconductors are insulators at 0 o K? 2. What is effect of temperature on barrier voltage? 3. What is difference between electron and hole? 4. Why electrons have

More information

SRM INSTITUTE OF SCIENCE AND TECHNOLOGY (DEEMED UNIVERSITY)

SRM INSTITUTE OF SCIENCE AND TECHNOLOGY (DEEMED UNIVERSITY) SRM INSTITUTE OF SCIENCE AND TECHNOLOGY (DEEMED UNIVERSITY) QUESTION BANK I YEAR B.Tech (II Semester) ELECTRONIC DEVICES (COMMON FOR EC102, EE104, IC108, BM106) UNIT-I PART-A 1. What are intrinsic and

More information

Power Semiconductor Devices

Power Semiconductor Devices TRADEMARK OF INNOVATION Power Semiconductor Devices Introduction This technical article is dedicated to the review of the following power electronics devices which act as solid-state switches in the circuits.

More information

HOW DIODES WORK CONTENTS. Solder plated Part No. Lot No Cathode mark. Solder plated 0.

HOW DIODES WORK CONTENTS.  Solder plated Part No. Lot No Cathode mark. Solder plated 0. www.joeknowselectronics.com Joe Knows, Inc. 1930 Village Center Circle #3-8830 Las Vegas, NV 89134 How Diodes Work Copyright 2013 Joe Knows Electronics HOW DIODES WORK Solder plated 0.4 1.6 There are several

More information

UNIT-4. Microwave Engineering

UNIT-4. Microwave Engineering UNIT-4 Microwave Engineering Microwave Solid State Devices Two problems with conventional transistors at higher frequencies are: 1. Stray capacitance and inductance. - remedy is interdigital design. 2.Transit

More information

SCR- SILICON CONTROLLED RECTIFIER

SCR- SILICON CONTROLLED RECTIFIER SCR- SILICON CONTROLLED RECTIFIER Definition: When a pn junction is added to a junction transistor, the resulting three pn junction device is called a silicon controlled rectifier. SCR can change alternating

More information

Prepared by: Dr. Rishi Prakash, Dept of Electronics and Communication Engineering Page 1 of 5

Prepared by: Dr. Rishi Prakash, Dept of Electronics and Communication Engineering Page 1 of 5 Microwave tunnel diode Some anomalous phenomena were observed in diode which do not follows the classical diode equation. This anomalous phenomena was explained by quantum tunnelling theory. The tunnelling

More information

QUESTION BANK EC6201 ELECTRONIC DEVICES UNIT I SEMICONDUCTOR DIODE PART A. It has two types. 1. Intrinsic semiconductor 2. Extrinsic semiconductor.

QUESTION BANK EC6201 ELECTRONIC DEVICES UNIT I SEMICONDUCTOR DIODE PART A. It has two types. 1. Intrinsic semiconductor 2. Extrinsic semiconductor. FATIMA MICHAEL COLLEGE OF ENGINEERING & TECHNOLOGY Senkottai Village, Madurai Sivagangai Main Road, Madurai - 625 020. [An ISO 9001:2008 Certified Institution] QUESTION BANK EC6201 ELECTRONIC DEVICES SEMESTER:

More information

SYED AMMAL ENGINEERING COLLEGE

SYED AMMAL ENGINEERING COLLEGE SYED AMMAL ENGINEERING COLLEGE (Approved by the AICTE, New Delhi, Govt. of Tamilnadu and Affiliated to Anna University, Chennai) Established in 1998 - An ISO 9001:2008 Certified Institution Dr. E.M.Abdullah

More information

CONTENTS. 2.2 Schrodinger's Wave Equation 31. PART I Semiconductor Material Properties. 2.3 Applications of Schrodinger's Wave Equation 34

CONTENTS. 2.2 Schrodinger's Wave Equation 31. PART I Semiconductor Material Properties. 2.3 Applications of Schrodinger's Wave Equation 34 CONTENTS Preface x Prologue Semiconductors and the Integrated Circuit xvii PART I Semiconductor Material Properties CHAPTER 1 The Crystal Structure of Solids 1 1.0 Preview 1 1.1 Semiconductor Materials

More information

Photodiode: LECTURE-5

Photodiode: LECTURE-5 LECTURE-5 Photodiode: Photodiode consists of an intrinsic semiconductor sandwiched between two heavily doped p-type and n-type semiconductors as shown in Fig. 3.2.2. Sufficient reverse voltage is applied

More information

Lecture 18: Photodetectors

Lecture 18: Photodetectors Lecture 18: Photodetectors Contents 1 Introduction 1 2 Photodetector principle 2 3 Photoconductor 4 4 Photodiodes 6 4.1 Heterojunction photodiode.................... 8 4.2 Metal-semiconductor photodiode................

More information

FET Channel. - simplified representation of three terminal device called a field effect transistor (FET)

FET Channel. - simplified representation of three terminal device called a field effect transistor (FET) FET Channel - simplified representation of three terminal device called a field effect transistor (FET) - overall horizontal shape - current levels off as voltage increases - two regions of operation 1.

More information

Intrinsic Semiconductor

Intrinsic Semiconductor Semiconductors Crystalline solid materials whose resistivities are values between those of conductors and insulators. Good electrical characteristics and feasible fabrication technology are some reasons

More information

Unit 2 Semiconductor Devices. Lecture_2.5 Opto-Electronic Devices

Unit 2 Semiconductor Devices. Lecture_2.5 Opto-Electronic Devices Unit 2 Semiconductor Devices Lecture_2.5 Opto-Electronic Devices Opto-electronics Opto-electronics is the study and application of electronic devices that interact with light. Electronics (electrons) Optics

More information

THERMIONIC AND GASEOUS STATE DIODES

THERMIONIC AND GASEOUS STATE DIODES THERMIONIC AND GASEOUS STATE DIODES Thermionic and gaseous state (vacuum tube) diodes Thermionic diodes are thermionic-valve devices (also known as vacuum tubes, tubes, or valves), which are arrangements

More information

Optical Fiber Communication Lecture 11 Detectors

Optical Fiber Communication Lecture 11 Detectors Optical Fiber Communication Lecture 11 Detectors Warriors of the Net Detector Technologies MSM (Metal Semiconductor Metal) PIN Layer Structure Semiinsulating GaAs Contact InGaAsP p 5x10 18 Absorption InGaAs

More information

Chapter 3 SPECIAL PURPOSE DIODE

Chapter 3 SPECIAL PURPOSE DIODE Chapter 3 SPECIAL PURPOSE DIODE 1 Inventor of Zener Diode Clarence Melvin Zener was a professor at Carnegie Mellon University in the department of Physics. He developed the Zener Diode in 1950 and employed

More information

CHAPTER 8 The PN Junction Diode

CHAPTER 8 The PN Junction Diode CHAPTER 8 The PN Junction Diode Consider the process by which the potential barrier of a PN junction is lowered when a forward bias voltage is applied, so holes and electrons can flow across the junction

More information

EDC Lecture Notes UNIT-1

EDC Lecture Notes UNIT-1 P-N Junction Diode EDC Lecture Notes Diode: A pure silicon crystal or germanium crystal is known as an intrinsic semiconductor. There are not enough free electrons and holes in an intrinsic semi-conductor

More information

Downloaded from

Downloaded from Question 14.1: In an n-type silicon, which of the following statement is true: (a) Electrons are majority carriers and trivalent atoms are the dopants. (b) Electrons are minority carriers and pentavalent

More information

UNIT 3 Transistors JFET

UNIT 3 Transistors JFET UNIT 3 Transistors JFET Mosfet Definition of BJT A bipolar junction transistor is a three terminal semiconductor device consisting of two p-n junctions which is able to amplify or magnify a signal. It

More information

Diode conducts when V anode > V cathode. Positive current flow. Diodes (and transistors) are non-linear device: V IR!

Diode conducts when V anode > V cathode. Positive current flow. Diodes (and transistors) are non-linear device: V IR! Diodes: What do we use diodes for? Lecture 5: Diodes and Transistors protect circuits by limiting the voltage (clipping and clamping) turn AC into DC (voltage rectifier) voltage multipliers (e.g. double

More information

Energy band diagrams Metals: 9. ELECTRONIC DEVICES GIST ρ= 10-2 to 10-8 Ω m Insulators: ρ> 10 8 Ω m Semiconductors ρ= 1 to 10 5 Ω m 109 A. Intrinsic semiconductors At T=0k it acts as insulator At room

More information

P-N Diodes & Applications

P-N Diodes & Applications P-N Diodes & Applications Outline Major junction diode applications are Electronics circuit control Rectifying (forward mode) Special break-down diodes: Zener and avalanche Switching Circuit tuning (varactor)

More information

Lecture 9: Limiting and Clamping Diode Circuits. Voltage Doubler. Special Diode Types.

Lecture 9: Limiting and Clamping Diode Circuits. Voltage Doubler. Special Diode Types. Whites, EE 320 Lecture 9 Page 1 of 8 Lecture 9: Limiting and Clamping Diode Circuits. Voltage Doubler. Special Diode Types. We ll finish up our discussion of diodes in this lecture by consider a few more

More information

55:041 Electronic Circuits

55:041 Electronic Circuits 55:041 Electronic Circuits Chapter 1 & 2 A. Kruger Diode Review, Page-1 Semiconductors licon () atoms have 4 electrons in valence band and form strong covalent bonds with surrounding atoms. Section 1.1.2

More information

Lecture 2 p-n junction Diode characteristics. By Asst. Prof Dr. Jassim K. Hmood

Lecture 2 p-n junction Diode characteristics. By Asst. Prof Dr. Jassim K. Hmood Electronic I Lecture 2 p-n junction Diode characteristics By Asst. Prof Dr. Jassim K. Hmood THE p-n JUNCTION DIODE The pn junction diode is formed by fabrication of a p-type semiconductor region in intimate

More information

EC T34 ELECTRONIC DEVICES AND CIRCUITS

EC T34 ELECTRONIC DEVICES AND CIRCUITS RAJIV GANDHI COLLEGE OF ENGINEERING AND TECHNOLOGY PONDY-CUDDALORE MAIN ROAD, KIRUMAMPAKKAM-PUDUCHERRY DEPARTMENT OF ECE EC T34 ELECTRONIC DEVICES AND CIRCUITS II YEAR Mr.L.ARUNJEEVA., AP/ECE 1 PN JUNCTION

More information

ELECTRONIC DEVICES AND CIRCUITS

ELECTRONIC DEVICES AND CIRCUITS ELECTRONIC DEVICES AND CIRCUITS 1. At room temperature the current in an intrinsic semiconductor is due to A. holes B. electrons C. ions D. holes and electrons 2. Work function is the maximum energy required

More information

OFCS OPTICAL DETECTORS 11/9/2014 LECTURES 1

OFCS OPTICAL DETECTORS 11/9/2014 LECTURES 1 OFCS OPTICAL DETECTORS 11/9/2014 LECTURES 1 1-Defintion & Mechanisms of photodetection It is a device that converts the incident light into electrical current External photoelectric effect: Electrons are

More information

Electronic Devices 1. Current flowing in each of the following circuits A and respectively are: (Circuit 1) (Circuit 2) 1) 1A, 2A 2) 2A, 1A 3) 4A, 2A 4) 2A, 4A 2. Among the following one statement is not

More information

CHAPTER 8 The PN Junction Diode

CHAPTER 8 The PN Junction Diode CHAPTER 8 The PN Junction Diode Consider the process by which the potential barrier of a PN junction is lowered when a forward bias voltage is applied, so holes and electrons can flow across the junction

More information

Università degli Studi di Roma Tor Vergata Dipartimento di Ingegneria Elettronica. Analogue Electronics. Paolo Colantonio A.A.

Università degli Studi di Roma Tor Vergata Dipartimento di Ingegneria Elettronica. Analogue Electronics. Paolo Colantonio A.A. Università degli Studi di Roma Tor Vergata Dipartimento di Ingegneria Elettronica Analogue Electronics Paolo Colantonio A.A. 2015-16 Introduction: materials Conductors e.g. copper or aluminum have a cloud

More information

Reg. No. : Question Paper Code : B.E./B.Tech. DEGREE EXAMINATION, NOVEMBER/DECEMBER Second Semester

Reg. No. : Question Paper Code : B.E./B.Tech. DEGREE EXAMINATION, NOVEMBER/DECEMBER Second Semester WK 5 Reg. No. : Question Paper Code : 27184 B.E./B.Tech. DEGREE EXAMINATION, NOVEMBER/DECEMBER 2015. Time : Three hours Second Semester Electronics and Communication Engineering EC 6201 ELECTRONIC DEVICES

More information

Diodes. Analog Electronics Lesson 4. Objectives and Overview:

Diodes. Analog Electronics Lesson 4. Objectives and Overview: Analog Electronics Lesson 4 Diodes Objectives and Overview: This lesson will introduce p- and n-type material, how they form a junction that rectifies current, and familiarize you with basic p-n junction

More information

Electronic devices-i. Difference between conductors, insulators and semiconductors

Electronic devices-i. Difference between conductors, insulators and semiconductors Electronic devices-i Semiconductor Devices is one of the important and easy units in class XII CBSE Physics syllabus. It is easy to understand and learn. Generally the questions asked are simple. The unit

More information

Sharjah Indian School, Sharjah ELECTRONIC DEVICES - Class XII (Boys Wing) Page 01

Sharjah Indian School, Sharjah ELECTRONIC DEVICES - Class XII (Boys Wing) Page 01 ELECTRONIC DEVICES - Class XII (Boys Wing) Page 01 Electronics is the fast developing branch of Physics. Before the discovery of transistors in 1948, vacuum tubes (thermionic valves) were used as the building

More information

Solid State Devices- Part- II. Module- IV

Solid State Devices- Part- II. Module- IV Solid State Devices- Part- II Module- IV MOS Capacitor Two terminal MOS device MOS = Metal- Oxide- Semiconductor MOS capacitor - the heart of the MOSFET The MOS capacitor is used to induce charge at the

More information

Review Energy Bands Carrier Density & Mobility Carrier Transport Generation and Recombination

Review Energy Bands Carrier Density & Mobility Carrier Transport Generation and Recombination Review Energy Bands Carrier Density & Mobility Carrier Transport Generation and Recombination Current Transport: Diffusion, Thermionic Emission & Tunneling For Diffusion current, the depletion layer is

More information

SUMMER 13 EXAMINATION Subject Code: Model Answer Page No: / N

SUMMER 13 EXAMINATION Subject Code: Model Answer Page No: / N Important Instructions to examiners: 1) The answers should be examined by key words and not as word-to-word as given in the model answer scheme. 2) The model answer and the answer written by candidate

More information

Physics 160 Lecture 5. R. Johnson April 13, 2015

Physics 160 Lecture 5. R. Johnson April 13, 2015 Physics 160 Lecture 5 R. Johnson April 13, 2015 Half Wave Diode Rectifiers Full Wave April 13, 2015 Physics 160 2 Note that there is no ground connection on this side of the rectifier! Output Smoothing

More information

WINTER 14 EXAMINATION. Model Answer. 1) The answers should be examined by key words and not as word-to-word as given in the

WINTER 14 EXAMINATION. Model Answer. 1) The answers should be examined by key words and not as word-to-word as given in the WINTER 14 EXAMINATION Subject Code: 17213 Model Answer Important Instructions to examiners: 1) The answers should be examined by key words and not as word-to-word as given in the model answer scheme. 2)

More information

Electronics for Analog Signal Processing - I Prof. K. Radhakrishna Rao Department of Electrical Engineering Indian Institute of Technology - Madras

Electronics for Analog Signal Processing - I Prof. K. Radhakrishna Rao Department of Electrical Engineering Indian Institute of Technology - Madras Electronics for Analog Signal Processing - I Prof. K. Radhakrishna Rao Department of Electrical Engineering Indian Institute of Technology - Madras Lecture # 11 Varactor Diode Today, it is going to be

More information

IENGINEERS- CONSULTANTS QUESTION BANK SERIES ELECTRONICS ENGINEERING 1 YEAR UPTU

IENGINEERS- CONSULTANTS QUESTION BANK SERIES ELECTRONICS ENGINEERING 1 YEAR UPTU ELECTRONICS ENGINEERING Unit 1 Objectives Q.1 The breakdown mechanism in a lightly doped p-n junction under reverse biased condition is called. (A) avalanche breakdown. (B) zener breakdown. (C) breakdown

More information

Experiment Topic : FM Modulator

Experiment Topic : FM Modulator 7-1 Experiment Topic : FM Modulator 7.1: Curriculum Objectives 1. To understand the characteristics of varactor diodes. 2. To understand the operation theory of voltage controlled oscillator (VCO). 3.

More information

Lecture -1: p-n Junction Diode

Lecture -1: p-n Junction Diode Lecture -1: p-n Junction Diode Diode: A pure silicon crystal or germanium crystal is known as an intrinsic semiconductor. There are not enough free electrons and holes in an intrinsic semi-conductor to

More information

UNIT IX ELECTRONIC DEVICES

UNIT IX ELECTRONIC DEVICES UNT X ELECTRONC DECES Weightage Marks : 07 Semiconductors Semiconductors diode-- characteristics in forward and reverse bias, diode as rectifier. - characteristics of LED, Photodiodes, solarcell and Zener

More information

Coherent Receivers Principles Downconversion

Coherent Receivers Principles Downconversion Coherent Receivers Principles Downconversion Heterodyne receivers mix signals of different frequency; if two such signals are added together, they beat against each other. The resulting signal contains

More information

Key Questions ECE 340 Lecture 28 : Photodiodes

Key Questions ECE 340 Lecture 28 : Photodiodes Things you should know when you leave Key Questions ECE 340 Lecture 28 : Photodiodes Class Outline: How do the I-V characteristics change with illumination? How do solar cells operate? How do photodiodes

More information

Downloaded from

Downloaded from SOLID AND SEMICONDUCTOR DEVICES (EASY AND SCORING TOPIC) 1. Distinction of metals, semiconductor and insulator on the basis of Energy band of Solids. 2. Types of Semiconductor. 3. PN Junction formation

More information

Chapter 6. FM Circuits

Chapter 6. FM Circuits Chapter 6 FM Circuits Topics Covered 6-1: Frequency Modulators 6-2: Frequency Demodulators Objectives You should be able to: Explain the operation of an FM modulators and demodulators. Compare and contrast;

More information

Chapter Semiconductor Electronics

Chapter Semiconductor Electronics Chapter Semiconductor Electronics Q1. p-n junction is said to be forward biased, when [1988] (a) the positive pole of the battery is joined to the p- semiconductor and negative pole to the n- semiconductor

More information

2) The larger the ripple voltage, the better the filter. 2) 3) Clamping circuits use capacitors and diodes to add a dc level to a waveform.

2) The larger the ripple voltage, the better the filter. 2) 3) Clamping circuits use capacitors and diodes to add a dc level to a waveform. TRUE/FALSE. Write 'T' if the statement is true and 'F' if the statement is false. 1) A diode conducts current when forward-biased and blocks current when reverse-biased. 1) 2) The larger the ripple voltage,

More information

Class XII - Physics Semiconductor Electronics. Chapter-wise Problems

Class XII - Physics Semiconductor Electronics. Chapter-wise Problems lass X - Physics Semiconductor Electronics Materials, Device and Simple ircuit hapter-wise Problems Multiple hoice Question :- 14.1 The conductivity of a semiconductor increases with increase in temperature

More information

Department of Electrical Engineering IIT Madras

Department of Electrical Engineering IIT Madras Department of Electrical Engineering IIT Madras Sample Questions on Semiconductor Devices EE3 applicants who are interested to pursue their research in microelectronics devices area (fabrication and/or

More information

FIBER OPTICS. Prof. R.K. Shevgaonkar. Department of Electrical Engineering. Indian Institute of Technology, Bombay. Lecture: 20

FIBER OPTICS. Prof. R.K. Shevgaonkar. Department of Electrical Engineering. Indian Institute of Technology, Bombay. Lecture: 20 FIBER OPTICS Prof. R.K. Shevgaonkar Department of Electrical Engineering Indian Institute of Technology, Bombay Lecture: 20 Photo-Detectors and Detector Noise Fiber Optics, Prof. R.K. Shevgaonkar, Dept.

More information

Basic Electronics Prof. T.S. Natarajan Department of Physics Indian Institute of Technology, Madras

Basic Electronics Prof. T.S. Natarajan Department of Physics Indian Institute of Technology, Madras Basic Electronics Prof. T.S. Natarajan Department of Physics Indian Institute of Technology, Madras Lecture 39 Silicon Controlled Rectifier (SCR) (Construction, characteristics (Dc & Ac), Applications,

More information

Lecture 16 Microwave Detector and Switching Diodes

Lecture 16 Microwave Detector and Switching Diodes Basic Building Blocks of Microwave Engineering Prof. Amitabha Bhattacharya Department of Electronics and Communication Engineering Indian Institute of Technology, Kharagpur Lecture 16 Microwave Detector

More information

CHAPTER FORMULAS & NOTES

CHAPTER FORMULAS & NOTES Formulae For u SEMICONDUCTORS By Mir Mohammed Abbas II PCMB 'A' 1 Important Terms, Definitions & Formulae CHAPTER FORMULAS & NOTES 1 Intrinsic Semiconductor: The pure semiconductors in which the electrical

More information

Lecture 3: Diodes. Amplitude Modulation. Diode Detection.

Lecture 3: Diodes. Amplitude Modulation. Diode Detection. Whites, EE 322 Lecture 3 Page 1 of 10 Lecture 3: Diodes. Amplitude Modulation. Diode Detection. Diodes are the fourth basic discrete component listed in Lecture 2. These and transistors are both nonlinear

More information

2 MARKS EE2203 ELECTRONIC DEVICES AND CIRCUITS UNIT 1

2 MARKS EE2203 ELECTRONIC DEVICES AND CIRCUITS UNIT 1 2 MARKS EE2203 ELECTRONIC DEVICES AND CIRCUITS UNIT 1 1. Define PN junction. When a p type semiconductor is joined to a N type semiconductor the contact surface is called PN junction. 2. What is an ideal

More information

EXPERIMENTS USING SEMICONDUCTOR DIODES

EXPERIMENTS USING SEMICONDUCTOR DIODES EXPERIMENT 9 EXPERIMENTS USING SEMICONDUCTOR DIODES Semiconductor Diodes Structure 91 Introduction Objectives 92 Basics of Semiconductors Revisited 93 A p-n Junction Operation of a p-n Junction A Forward

More information

Diodes (non-linear devices)

Diodes (non-linear devices) C H A P T E R 4 Diodes (non-linear devices) Ideal Diode Figure 4.2 The two modes of operation of ideal diodes and the use of an external circuit to limit (a) the forward current and (b) the reverse voltage.

More information

Section:A Very short answer question

Section:A Very short answer question Section:A Very short answer question 1.What is the order of energy gap in a conductor, semi conductor, and insulator?. Conductor - no energy gap Semi Conductor - It is of the order of 1 ev. Insulator -

More information

EXPERIMENT 10: SCHOTTKY DIODE CHARACTERISTICS

EXPERIMENT 10: SCHOTTKY DIODE CHARACTERISTICS EXPERIMENT 10: SCHOTTKY DIODE CHARACTERISTICS AIM: To plot forward and reverse characteristics of Schottky diode (Metal Semiconductor junction) APPARATUS: D.C. Supply (0 15 V), current limiting resistor

More information

Analog Electronic Circuits

Analog Electronic Circuits Analog Electronic Circuits Chapter 1: Semiconductor Diodes Objectives: To become familiar with the working principles of semiconductor diode To become familiar with the design and analysis of diode circuits

More information

1- Light Emitting Diode (LED)

1- Light Emitting Diode (LED) Content: - Special Purpose two terminal Devices: Light-Emitting Diodes, Varactor (Varicap)Diodes, Tunnel Diodes, Liquid-Crystal Displays. 1- Light Emitting Diode (LED) Light Emitting Diode is a photo electronic

More information

UNIT II JFET, MOSFET, SCR & UJT

UNIT II JFET, MOSFET, SCR & UJT UNIT II JFET, MOSFET, SCR & UJT JFET JFET as an Amplifier and its Output Characteristics JFET Applications MOSFET Working Principles, SCR Equivalent Circuit and V-I Characteristics. SCR as a Half wave

More information

UNIT I POWER SEMI-CONDUCTOR DEVICES

UNIT I POWER SEMI-CONDUCTOR DEVICES UNIT I POWER SEMI-CONDUCTOR DEVICES SUBJECT CODE SUBJECT NAME STAFF NAME : EE6503 : Power Electronics : Ms.M.Uma Maheswari 1 SEMICONDUCTOR DEVICES POWER DIODE POWER TRANSISTORS POWER BJT POWER MOSFET IGBT

More information

VALLIAMMAI ENGINEERING COLLEGE SRM Nagar, Kattankulathur

VALLIAMMAI ENGINEERING COLLEGE SRM Nagar, Kattankulathur VALLIAMMAI ENGINEERING COLLEGE SRM Nagar, Kattankulathur 603 203. DEPARTMENT OF ELECTRONICS & COMMUNICATION ENGINEERING SUBJECT QUESTION BANK : EC6201 ELECTRONIC DEVICES SEM / YEAR: II / I year B.E.ECE

More information

55:041 Electronic Circuits

55:041 Electronic Circuits 55:041 Electronic Circuits Chapter 1 & 2 A. Kruger Diode Review, Page-1 Semiconductors licon () atoms have 4 electrons in valence band and form strong covalent bonds with surrounding atoms. Section 1.1.2

More information

Chapter 14 Semiconductor Electronics Materials Devices And Simple Circuits

Chapter 14 Semiconductor Electronics Materials Devices And Simple Circuits Class XII Chapter 14 Semiconductor Electronics Materials Devices And Simple Circuits Physics Question 14.1: In an n-type silicon, which of the following statement is true: (a) Electrons are majority carriers

More information

Analog & Digital Electronics Course No: PH-218

Analog & Digital Electronics Course No: PH-218 Analog & Digital Electronics Course No: PH-218 Lec-5: Bipolar Junction Transistor (BJT) Course nstructors: Dr. A. P. VAJPEY Department of Physics, ndian nstitute of Technology Guwahati, ndia 1 Bipolar

More information

Optical Receivers Theory and Operation

Optical Receivers Theory and Operation Optical Receivers Theory and Operation Photo Detectors Optical receivers convert optical signal (light) to electrical signal (current/voltage) Hence referred O/E Converter Photodetector is the fundamental

More information

Summer 2015 Examination. 1) The answers should be examined by key words and not as word-to-word as given in the model answer scheme.

Summer 2015 Examination. 1) The answers should be examined by key words and not as word-to-word as given in the model answer scheme. Summer 2015 Examination Subject Code: 17215 Model Answer Important Instructions to examiners: 1) The answers should be examined by key words and not as word-to-word as given in the model answer scheme.

More information

MAHARASHTRA STATE BOARD OF TECHNICAL EDUCATION (Autonomous) (ISO/IEC Certified) Subject Code: Model Answer Page No: 1/

MAHARASHTRA STATE BOARD OF TECHNICAL EDUCATION (Autonomous) (ISO/IEC Certified) Subject Code: Model Answer Page No: 1/ MAHARASHTRA STATE BOARD OF TECHNICAL EDUCATION (Autonomous) (ISO/IEC 27001 2005 Certified) SUMMER 13 EXAMINATION Subject Code: 12025 Model Answer Page No: 1/ Important Instructions to examiners: 1) The

More information

CHAPTER 8 The pn Junction Diode

CHAPTER 8 The pn Junction Diode CHAPTER 8 The pn Junction Diode Consider the process by which the potential barrier of a pn junction is lowered when a forward bias voltage is applied, so holes and electrons can flow across the junction

More information

1. (a) Determine the value of Resistance R and current in each branch when the total current taken by the curcuit in figure 1a is 6 Amps.

1. (a) Determine the value of Resistance R and current in each branch when the total current taken by the curcuit in figure 1a is 6 Amps. Code No: 07A3EC01 Set No. 1 II B.Tech I Semester Regular Examinations, November 2008 ELECTRICAL AND ELECTRONICS ENGINEERING ( Common to Civil Engineering, Mechanical Engineering, Mechatronics, Production

More information

FINALTERM EXAMINATION Fall 2009 PHY301- Circuit Theory (Session - 2) Time: 120 min Marks: 70 Question No: 1 ( Marks: 1 ) - Please choose one Charge of 2c and 5c will attract each other repel each other

More information

14.2 Photodiodes 411

14.2 Photodiodes 411 14.2 Photodiodes 411 Maximum reverse voltage is specified for Ge and Si photodiodes and photoconductive cells. Exceeding this voltage can cause the breakdown and severe deterioration of the sensor s performance.

More information

Chapter 16 Other Two-Terminal Devices

Chapter 16 Other Two-Terminal Devices Chapter 16 Other Two-Terminal Devices 1 Other Two-Terminal Terminal Devices Schottky diode Varactor diode Power diodes Tunnel diode Photodiode Photoconductive cells IR emitters Liquid crystal displays

More information

Diodes and Applications

Diodes and Applications Diodes and Applications Diodes and Applications 2 1 Diode Operation 2 2 Voltage-Current (V-I) Characteristics 2 3 Diode Models 2 4 Half-Wave Rectifiers 2 5 Full-Wave Rectifiers 2 6 Power Supply Filters

More information

Lesson 5. Electronics: Semiconductors Doping p-n Junction Diode Half Wave and Full Wave Rectification Introduction to Transistors-

Lesson 5. Electronics: Semiconductors Doping p-n Junction Diode Half Wave and Full Wave Rectification Introduction to Transistors- Lesson 5 Electronics: Semiconductors Doping p-n Junction Diode Half Wave and Full Wave Rectification Introduction to Transistors- Types and Connections Semiconductors Semiconductors If there are many free

More information

SEMICONDUCTOR ELECTRONICS: MATERIALS, DEVICES AND SIMPLE CIRCUITS. Class XII : PHYSICS WORKSHEET

SEMICONDUCTOR ELECTRONICS: MATERIALS, DEVICES AND SIMPLE CIRCUITS. Class XII : PHYSICS WORKSHEET SEMICONDUCT ELECTRONICS: MATERIALS, DEVICES AND SIMPLE CIRCUITS Class XII : PHYSICS WKSHEET 1. How is a n-p-n transistor represented symbolically? (1) 2. How does conductivity of a semiconductor change

More information

UNIT-III Bipolar Junction Transistor

UNIT-III Bipolar Junction Transistor DC UNT-3.xplain the construction and working of JT. UNT- ipolar Junction Transistor A bipolar (junction) transistor (JT) is a three-terminal electronic device constructed of doped semiconductor material

More information

OBJECTIVE TYPE QUESTIONS

OBJECTIVE TYPE QUESTIONS OBJECTIVE TYPE QUESTIONS Q.1 The breakdown mechanism in a lightly doped p-n junction under reverse biased condition is called (A) avalanche breakdown. (B) zener breakdown. (C) breakdown by tunnelling.

More information

This tutorial will suit all beginners who want to learn the fundamental concepts of transistors and transistor amplifier circuits.

This tutorial will suit all beginners who want to learn the fundamental concepts of transistors and transistor amplifier circuits. About the Tutorial An electronic signal contains some information which cannot be utilized if doesn t have proper strength. The process of increasing the signal strength is called as Amplification. Almost

More information

Electro - Principles I

Electro - Principles I The PN Junction Diode Introduction to the PN Junction Diode Note: In this chapter we consider conventional current flow. Page 11-1 The schematic symbol for the pn junction diode the shown in Figure 1.

More information

UNIT IV POWER DEVICES

UNIT IV POWER DEVICES UNIT IV POWER DEVICES UNI-JUNCTION TRANSISTOR The UJT as the name implies, is characterized by a single pn junction. It exhibits negative resistance characteristic that makes it useful in oscillator circuits.

More information

UNIT-VI FIELD EFFECT TRANSISTOR. 1. Explain about the Field Effect Transistor and also mention types of FET s.

UNIT-VI FIELD EFFECT TRANSISTOR. 1. Explain about the Field Effect Transistor and also mention types of FET s. UNIT-I FIELD EFFECT TRANSISTOR 1. Explain about the Field Effect Transistor and also mention types of FET s. The Field Effect Transistor, or simply FET however, uses the voltage that is applied to their

More information

FINALTERM EXAMINATION. Spring PHY301- Circuit Theory

FINALTERM EXAMINATION. Spring PHY301- Circuit Theory Date 14/2/2013 Eini FINALTERM EXAMINATION Spring 2010 PHY301- Circuit Theory Time: 90 min Marks: 60 Question No: 1 If we connect 3 capacitors in parallel, the combined effect of all these capacitors will

More information

Electronic Circuits I. Instructor: Dr. Alaa Mahmoud

Electronic Circuits I. Instructor: Dr. Alaa Mahmoud Electronic Circuits I Instructor: Dr. Alaa Mahmoud alaa_y_emam@hotmail.com Chapter 27 Diode and diode application Outline: Semiconductor Materials The P-N Junction Diode Biasing P-N Junction Volt-Ampere

More information

Exam Model Answer. Question 1 (15 marks) Answer this question in the form of table. Choose the correct answer (only one answer is accepted).

Exam Model Answer. Question 1 (15 marks) Answer this question in the form of table. Choose the correct answer (only one answer is accepted). Benha University Faculty of Engineering Shoubra Electrical Engineering Department First Year Communications. Answer all the following questions Illustrate your answers with sketches when necessary. The

More information

IT-T32- Electronic Devices and Circuits UNIT II - SPECIAL DEVICES

IT-T32- Electronic Devices and Circuits UNIT II - SPECIAL DEVICES IT-T32- Electronic Devices and Circuits UNIT II - SPECIAL DEVICES SILICON CONTROLLED RECTIFIER (SCR) Introduction The SCR stand for Silicon Control Rectifier, it is used in industries because it can handle

More information

UNIT I PN JUNCTION DEVICES

UNIT I PN JUNCTION DEVICES UNIT I PN JUNCTION DEVICES 1. Define Semiconductor. 2. Classify Semiconductors. 3. Define Hole Current. 4. Define Knee voltage of a Diode. 5. What is Peak Inverse Voltage? 6. Define Depletion Region in

More information

Lecture Notes. Uncontrolled PSDs. Prepared by Dr. Oday A Ahmed Website: https://odayahmeduot.wordpress.com

Lecture Notes. Uncontrolled PSDs. Prepared by Dr. Oday A Ahmed Website: https://odayahmeduot.wordpress.com Lecture Notes 3 Uncontrolled PSDs Prepared by Dr. Oday A Ahmed Website: https://odayahmeduot.wordpress.com Email: 30205@uotechnology.edu.iq Scan QR Contents of this Lecture: Power Diode Characteristics

More information

I E I C since I B is very small

I E I C since I B is very small Figure 2: Symbols and nomenclature of a (a) npn and (b) pnp transistor. The BJT consists of three regions, emitter, base, and collector. The emitter and collector are usually of one type of doping, while

More information