Presentation is loading. Please wait.

Presentation is loading. Please wait.

Outline Introduction Transistors Types Bipolar Junction Transistors

Published bySuharto Hadiman Modified over 5 years ago

Similar presentations

Presentation on theme: "Outline Introduction Transistors Types Bipolar Junction Transistors"— Presentation transcript:

1 Outline Introduction Transistors Types Bipolar Junction Transistors
Field Effect Transistors Power Transistors Example

2 What is a Transistor? The most widely used products in the Electronics industries is a transistor and its also the major component of any electronics equipment, so its necessary for all of us to know what basically a transistor is and what can be its basic applications in daily life ?

3 Transistors BJT (PNP) Electrical Diagram Different types and sizes
Modern Electronics FET and BJT Transistor A transistor is a semiconductor device that amplifies, oscillates, or switches the flow of current between two terminals by varying the current or voltage between one of the terminals and a third. ( First Transistor

4 Purpose Modern Electronics
To amplify and switch electronic signals on or off (high or low) Modern Electronics Microprocessor Motor Controllers Cell Phones

5 Vacuum tubes Purpose Used as signal amplifiers and switches Advantages
High power and frequency operation Operation at higher voltages Less vulnerable to electromagnetic pulses Disadvantages Very large and fragile Energy inefficient Expensive

6 Invention Evolution of electronics 1947 Transistor Effect
In need of a device that was small, robust, reliable, energy efficient and cheap to manufacture 1947 John Bardeen, Walter Brattain and William Schockly invented transistor Transistor Effect “when electrical contacts were applied to a crystal of germanium, the output power was larger than the input.”

7 General Applications

8 Doping Process of introducing impure elements (dopants) into semiconductor wafers to form regions of differing electrical conductivity Negatively charged Semiconductor Positively charged semiconductor

9 Doping Effects P-type semiconductors N-type semiconductors
Created positive charges, where electrons have been removed, in lattice structure N-type semiconductors Added unbound electrons create negative charge in lattice structure Resulting material P-N junction

10 P-N junction Forward Biasing Reverse Biasing

11 Two P-N junctions (bipolar junction transistor, BJT)
Controls current flow via external voltage Two P-N junctions (bipolar junction transistor, BJT) Controls current flow and amplifies the current flow

12 Transistor Categories
Semiconductor material Structure Polarity Maximum power rating Maximum operating frequency Application Physical packaging Amplification factor

13 Types of Transistors Bipolar Junction Transistor (BJT)
Field Effect Transistors (FET) Power Transistors

14

15 BJT Introduction Bipolar Junction Transistors (BJT) consists of three “sandwiched” semiconductor layers The three layers are connected to collector (C), emitter (E), and base (B) pins Current supplied to the base controls the amount of current that flows through the collector and emitter

16 BJT Schematic NPN NPN PNP PNP BE forward bias BC reverse bias
BE reverse bias BC forward bias PNP

17 BJT Characteristic Curves
Transfer Characteristic Characteristic curves can be drawn to show other useful parameters of the transistor The slope of ICE / IBE  is called the Transfer Characteristic (β)

18 BJT Characteristic Curves
Input Characteristic The Input Characteristic is the base emitter current IBE against base emitter voltage VBE IBE/VBE shows the input Conductance of the transistor. The increase in slope of when the VBE is above 1 volt shows that the input conductance is rising There is a large increase in current for a very small increase in VBE.

19 BJT Characteristic Curves
Output Characteristic collector current (IC) is nearly independent of the collector-emitter voltage (VCE), and instead depends on the base current (IB) IB4 IB3 IB2 IB1

20 BJT Operating Regions Operating Region Parameters Mode Cut Off
VBE < Vcut-in VCE > Vsupply IB = IC = 0 Switch OFF Linear VBE = Vcut-in Vsat < VCE < Vsupply IC = β*IB Amplification Saturated VBE = Vcut-in, VCE < Vsat IB > IC,max, IC,max > 0 Switch ON

21 BJT Applications BJT Switch
Offer lower cost and substantial reliability over conventional mechanical relays.  Transistor operates purely in a saturated or cutoff state (on/off) This can prove very useful for digital applications (small current controls a larger current)

22 BJT Applications BJT Amplifier

23 BJT Applications BJT Amplifier

24 Field Effect Transistors (FET)
Chase Thompson

25 FET Basics Electric Field Voltage Controlled
FET includes three distinct pieces Drain Source Gate Electric Field to control the conductivity of a channel. Drain: Carriers leave channel Source: Through which carriers( electroncs) enter the channel Gate: Variable Resister – permits electrons to flow from source to drain by applying a voltage

26 FET versus BJT? Difference: Voltage vs Current Input
Same: Applications: amplifier, switch, etc. Relies on PNP or NPN junctions to allow current flow Difference: Voltage vs Current Input Unipolar vs Bipolar Noise Higher input impedance Fragile and low gain bandwidth Less noise sensitive- tuners and low noise amplifiers for satellite receivers Higher input Impediance- 100Mega ohms or more.

27 Types of Field-Effect Transistors
Function Junction Field-Effect Transistor (JFET) Uses reversed biased p-n junction to separate gate from body Metal-Oxide-Semiconductor FET (MOSFET) Uses insulator (usu. SiO2) between gate and body Insulated Gate Bipolar Transistor (IGBT) Similar to MOSFET, but different main channel Organic Field-Effect Transistor (OFET) Uses organic semiconductor in its channel Nanoparticle Organic Memory FET (NOMFET) Combines the organic transistor and gold nanoparticles

28 JFET Reverse Biased PN- junction Depletion mode devices
Creates a potential gradient to restrict current flow. (Increases overall resistance)

29 JFET N-channel JFET P-channel JFET uses same principles but
Channel current is positive due to holes instead of electron donors Polarity of biasing voltage must be reversed

30 N-Type Characteristics
As voltage (+) increases, region pinches until channel turns off. Thusno current flows. Lower voltage or =0 = the channel is open and allows current to saturate the region.

31 Characteristics and Applications of FETs
JFETs Simplest type of FET – easy to make High input impedance and resistance Low Capacitance Slower speed in switching Uses? Displacement sensor High input impedance amplifier Low-noise amplifier Analog switch Voltage controlled resistor

32 MOSFET p-channel Similar to JFET A single channel of single doped SC material with terminals at end Gate surrounds channel with doping that is opposite of the channel, making the PNP or NPN type BUT, the MOSFET uses an insulator to separate gate from body, while JFET uses a reverse-bias p-n junction n-channel MOSFET enhanced mode MOSFET depleted mode

33 How does a MOSFET work? Simplified Notation No Voltage to Gate
Source Drain Source Drain n n Simplified Notation No current flow “Short” allows current flow

34 MOSFET Triode Mode/Linear Region
VGS > Vth and VDS < ( VGS - Vth ) Saturation/Active Mode VGS > Vth and VDS > ( VGS - Vth ) VGS : Voltage at the gate Vth : Threshold voltage VDS : Voltage from drain to source μn: charge-carrier effective mobility W: gate width L: gate length Cox : gate oxide capacitance per unit area λ : channel-length modulation parameter

35 Characteristics and Applications of FETs
MOSFETs Oxide layer prevents DC current from flowing through gate Reduces power consumption High input impedance Rapid switching More noise than JFET Uses? Again, switches and amplifiers in general The MOSFET is used in digital CMOS logic, which uses p- and n-channel MOSFETs as building blocks To aid in negating effects that cause discharge of batteries Use of MOSFET in battery protection circuit

36 Power Transistors Concerned with delivering high power
Used in high voltage and high current application In general Fabrication process different in order to: Dissipate more heat Avoid breakdown Different types: Power BJTs, power MOSFETS, etc.

37 Comparison Property BJT MOSFET JFET Gm Best Worst Medium Speed High
Low Noise Moderate Good Switch No Yes High-Z Gate ESD Sensitivity Less More (not the best source, but could not find a reliable one) Only possible uses for JFET over MOSFET would be for noise or ESD applications 37

38 References (32)

39 Questions?

Download ppt "Outline Introduction Transistors Types Bipolar Junction Transistors"

Similar presentations

MICROWAVE FET Microwave FET : operates in the microwave frequencies

MICROWAVE FET Microwave FET : operates in the microwave frequencies
Field Effect Transistor characteristics

Field Effect Transistor characteristics
Justin Chow Jacob Huang Daniel Soledad ME 4447/6405 Student Lecture.

Justin Chow Jacob Huang Daniel Soledad ME 4447/6405 Student Lecture.
TRANSISTOR. TRANSISTOR Background and Introduction A semiconductor device that Amplifies, Oscillates, or Switches the flow of current between two terminals.

TRANSISTOR. TRANSISTOR Background and Introduction A semiconductor device that Amplifies, Oscillates, or Switches the flow of current between two terminals.
Transistors These are three terminal devices, where the current or voltage at one terminal, the input terminal, controls the flow of current between the.

Transistors These are three terminal devices, where the current or voltage at one terminal, the input terminal, controls the flow of current between the.
MOSFETs Monday 19 th September. MOSFETs Monday 19 th September In this presentation we will look at the following: State the main differences between.

MOSFETs Monday 19 th September. MOSFETs Monday 19 th September In this presentation we will look at the following: State the main differences between.
The metal-oxide field-effect transistor (MOSFET)

The metal-oxide field-effect transistor (MOSFET)
Chap. 5 Field-effect transistors (FET) Importance for LSI/VLSI –Low fabrication cost –Small size –Low power consumption Applications –Microprocessors –Memories.

Chap. 5 Field-effect transistors (FET) Importance for LSI/VLSI –Low fabrication cost –Small size –Low power consumption Applications –Microprocessors –Memories.
Principles & Applications

Principles & Applications
ME 6405 Student Lecture Transistor Cong Zhao Feifei Qian Kuan-Wen Tung October 2, 2012 Georgia Institute of Technology.

ME 6405 Student Lecture Transistor Cong Zhao Feifei Qian Kuan-Wen Tung October 2, 2012 Georgia Institute of Technology.
Chapter 28 Basic Transistor Theory. 2 Transistor Construction Bipolar Junction Transistor (BJT) –3 layers of doped semiconductor –2 p-n junctions –Layers.

Chapter 28 Basic Transistor Theory. 2 Transistor Construction Bipolar Junction Transistor (BJT) –3 layers of doped semiconductor –2 p-n junctions –Layers.
Module 2 Bipolar Junction Transistor. Learning Outcomes 1.The 3 terminals or regions of a BJT. 2.Construction and symbol of NPN and PNP types 3.Low power.

Module 2 Bipolar Junction Transistor. Learning Outcomes 1.The 3 terminals or regions of a BJT. 2.Construction and symbol of NPN and PNP types 3.Low power.
Principles & Applications

Principles & Applications
G.K.BHARAD INSTITUTE OF ENGINEERING DIVISION :D (C.E.) Roll Number :67 SUBJECT :PHYSICS SUBJECT CODE :2110011 Presentation By: Kartavya Parmar.

G.K.BHARAD INSTITUTE OF ENGINEERING DIVISION :D (C.E.) Roll Number :67 SUBJECT :PHYSICS SUBJECT CODE : Presentation By: Kartavya Parmar.
Chapter 5: Field Effect Transistor

Chapter 5: Field Effect Transistor
© 2013 The McGraw-Hill Companies, Inc. All rights reserved. McGraw-Hill 5-1 Electronics Principles & Applications Eighth Edition Chapter 5 Transistors.

© 2013 The McGraw-Hill Companies, Inc. All rights reserved. McGraw-Hill 5-1 Electronics Principles & Applications Eighth Edition Chapter 5 Transistors.
BJTs. Transistor The transistor is the main building block “element” of electronics. A transistor is a semiconductor device used to amplify and switch.

BJTs. Transistor The transistor is the main building block “element” of electronics. A transistor is a semiconductor device used to amplify and switch.
Field Effect Transistor. What is FET FET is abbreviation of Field Effect Transistor. This is a transistor in which current is controlled by voltage only.

Field Effect Transistor. What is FET FET is abbreviation of Field Effect Transistor. This is a transistor in which current is controlled by voltage only.
Field Effect Transistors

Field Effect Transistors
McGraw-Hill 5-1 © 2013 The McGraw-Hill Companies, Inc. All rights reserved. Electronics Principles & Applications Eighth Edition Chapter 5 Transistors.

McGraw-Hill 5-1 © 2013 The McGraw-Hill Companies, Inc. All rights reserved. Electronics Principles & Applications Eighth Edition Chapter 5 Transistors.

Similar presentations

Ads by Google