Expanded Answer: Transistor Amplifier Problem in January/February 2008 Morseman Column

Size: px
Start display at page:

Download "Expanded Answer: Transistor Amplifier Problem in January/February 2008 Morseman Column"

Transcription

1 Expanded Answer: Transistor Amplifier Problem in January/February 2008 Morseman Column Here s what I asked: This month s problem: Figure 4(a) shows a simple npn transistor amplifier. The transistor has = 220, and its base-emitter voltage is 0.7 V. What are the quiescent base and collector currents, and the collector voltage? Can you estimate the voltage gain, v 2 /v 1? Can you estimate the input impedance of the amplifier? What are the advantages and disadvantages of deriving the base biasing current from the collector rather than the positive line? Here is the Figure: Figure 1: Simple amplifier schematic. First, the dc conditions: We find the dc operating point by relating the voltage drop across the two resistors to the currents flowing through them: = (I c + I b ) R L + I b R b but I b = I c ( so 6 = I c ) R L + I c R b and 1 6 so I c R L + R b and I b = I c = = = µa. 3 ma also V c = 6.7 I c R L = = 3.7 V Small-signal Analysis Figure 2 (a) shows the circuit again, with input and output voltages renamed for convenience. The simplest useful small-signal equivalent circuit of a bi-polar transistor is shown in figure 2 (b). Small- 1

2 signal means that the circuit is linearized, and the two parameters involved ( and ) are evaluated at the transistor s dc operating point. More complex equivalent circuits are used in SPICE analysis, but this one is almost always good enough for simple estimates. Figure 2: (a) Circuit as drawn. (b) Equivalent small-signal transistor circuit. (c) Small-signal circuit of complete amplifier is now the small-signal beta, also known as h fe, 1 and is the slope of the versus I c characteristic of the transistor. Both the small and large-signal values are usually similar however, and is a very variable parameter anyway, so we will assume the same value. The resistance is the slope of the diode characteristic formed by the base-emitter junction, evaluated again at the operating point. If the diode is assumed to obey the ideal diode equation, its value is approximately 2 Figure 2 (c) shows the small-signal circuit of the complete amplifier. original circuit, and is derived with these assumptions: This looks nothing like the Both coupling capacitors have negligible impedance at the operating frequency, and can be replaced by short-circuits. Since we are considering only small-signal, ac excitation, and no ac voltage can exist on a perfect dc power supply, the power supply acts like a short-circuit at signal frequencies, and its positive and negative terminals can both be connected to ground (the bottom node). For convenience, we define two more currents, I in and I out, as shown. Then: v 2 = i 0 R L (1) i o = v 1 v 2 R b i b (2) i b = v 1 (3) 1 R eliminating i 0 and I b, A v = b (4) R L R b 1 h fe is so named because it is one of the parameters of the four-element h-parameter equivalent circuit, much used in the early days. The two-element circuit used here is an approximate form of this. 2 This expression for is proved in my text, Transistor Electronics, and other places. See also the appendix to this document. 2

3 = ( 1 ) R p Rb (5) where R p = R L R b (6) so A v R p since R b >> (7) and R b R L (8) so simplifying further, A v R L (9) but (10) ( ) 40Ic so A v R L 40V L (11) where V L = I c R L = the dc voltage across the load resistor. (12) whence A v = 120 (13) The approximate expression for the voltage gain given by equation (11) is the same as that of a standard bi-polar amplifier. In fact, the approximation is quite good, overestimating the gain by a few percent. To find the input impedance, consider the input current, i in. But this is the admittance of two resistors in parallel, or i in = v 1 + v 1 v 2 (14) R b i in = y in = 1 ( + 1 v ) 2 1 (15) v 1 v 1 R b assume v 2 v 1 R L (16) then y in R b + R L R b (17) y in 1 R b + 2 (18) Summarizing, we estimate: r in 1 R b y in 2 2 (19) r in 916 Ω 80I c (20) I c = 3 ma (21) I b = 13.6 µa (22) V c = 3.7 V (23) A v = 120 (24) r in = 916 Ω (25) We see that the voltage gain is very slightly less than a standard amplifier, the input admittance is about half that of a standard amplifier, 3

4 For typical component values, it is found that the fractional increase in collector current, I c, is about half that of the fractional increase in. Thus this circuit is best used to amplify very small signals, where operating point variations caused by variation will not cause non-linearity. An alternative viewpoint is to assume that the value of R b, the feedback resistor, is so large that we can ignore its effect on the gain, which becomes that of a standard common-emitter amplifier without feedback - as justified above. But its effect must be considered in the input impedance, particularly if the gain is high. We can include it using Miller s Theorem. This theorem says that if an amplifier has voltage gain A v, with an impedance z b connected between the input and output terminals, this is equivalent to removing z b, and connecting an impedance of z b /A v directly across the input terminals. If you work through this, you get the same approximate expressions as those for the voltage gain and input impedance as above. Advantages and Disadvantages You design a circuit like this by assuming some value of, and then choosing R b R L. This puts the quiescent dc collector voltage about half-way between the power supply voltage and ground, giving maximum signal swing. But as stated above, if is not quite right, it doesn t matter too much, because the negative dc feedback through R b partially compensates. This is an advantage. Another is that no biasing chain resistors nor associated by-pass capacitors are necessary. However, you can design an amplifier using one of the standard circuits with much better immunity to variation. This is a disadvantage. Another is that the input impedance is lowered by the negative feedback caused by R b. This can also be shown using Miller s theorem. An LTSpice Simulation Figure 3 shows (lower panel) an LTSpice model of the circuit and (upper panel) the waveform at the collector, for an input sinewave voltage of 1 mv peak-to-peak at 1 khz. I chose a BCW60B transistor (one supplied in the default LTSpice download) since it has nominal = 240, close enough to the design value. This is simulated using a transient analysis, and shows A v = 106 (estimated as -120 above) (26) V c = 3.5 V (estimated as 3.7 V above) (27) The input impedance can t be plotted using a transient analysis, since this requires dividing the input voltage, V 1, by the current through C 1, and both waveforms pass through zero, so the division blows up. However, plotting both and diving the peak value of V 1 by the peak current through C 1, which is 60 na, we get r in = 1.09 kω (estimated as 916 Ω above). (28) 4

5 A small-signal, AC analysis can plot the input impedance directly, since this uses a linearized model with transistor parameters chosen at the dc operating point. This shows the same voltage gain, and r in = 1.11 kω. Figure 3: Top: Waveform at the collector. Bottom: The simulated circuit. Design Equations Practical rules for designing an amplifier like this are Set the dc voltage at the collector, V c, halfway between the supply voltage and ground. Decide on a suitable collector current, I c. The value of the load resistor required is then R L = V c 2I c. Estimate (or find from some spec sheet) for this transistor. The value of the bias resistor required is then R b = R L. Choose the value of the input coupling capacitor (C 1 in the simulation diagram) such that C 100I c (29) f where f = the lowest operating frequency required. (30) 5

6 Appendix: Transistor Parameters I have used the relationship = : The least technically obscure reference leading to the derivation of this expression starts on page 80 of the excellent practical reference by Horowitz and Hill. 3 The collector current, I c, of a bi-polar transistor is almost exactly related to the voltage applied across the base-emitter junction, V be, by the ideal diode equation. This is I c = ( )] Vbe I s [exp 1 (31) where I s = diode leakage current, (32) V be = appplied base-emitter diode voltage, (33) = threshold voltage, = kt q (34) k = Boltmann s constant, (35) T = absolute (Kelvin) temperature, (36) q = charge on electron. (37) evaluating, 25.3mV at room temperature (38) For convenience, I round this off to = 25 mv. The second term ( 1) dominates in the reverse region, where V be is negative, making the exponential term very small. It represents the saturation current, which is just I s. For forward currents in excess of a few tens of microamp, it can be neglected. Then, to a very good approximation, differentiating, I c = I s [exp I c V be = I s [ exp ( )] Vbe V ( T )] Vbe (39) = I c (40) therefore inverting, V be I c = I c (41) But the input resistance seen between the base and emitter is taken with respect to the base current, I b. This is times less, so this input resistance will be times higher. thus = I b (42) substituting I b = I c (43) = (I c /) = = I c I c (44) or more conveniently, = (45) 3 The Art of Electronics, Paul Horowitz and Winfield Hill, Cambridge, second edition. 6

Experiment No. 9 DESIGN AND CHARACTERISTICS OF COMMON BASE AND COMMON COLLECTOR AMPLIFIERS

Experiment No. 9 DESIGN AND CHARACTERISTICS OF COMMON BASE AND COMMON COLLECTOR AMPLIFIERS Experiment No. 9 DESIGN AND CHARACTERISTICS OF COMMON BASE AND COMMON COLLECTOR AMPLIFIERS 1. Objective: The objective of this experiment is to explore the basic applications of the bipolar junction transistor

More information

PHYS225 Lecture 6. Electronic Circuits

PHYS225 Lecture 6. Electronic Circuits PHYS225 Lecture 6 Electronic Circuits Transistors History Basic physics of operation Ebers-Moll model Small signal equivalent Last lecture Introduction to Transistors A transistor is a device with three

More information

After the initial bend, the curves approximate a straight line. The slope or gradient of each line represents the output impedance, for a particular

After the initial bend, the curves approximate a straight line. The slope or gradient of each line represents the output impedance, for a particular BJT Biasing A bipolar junction transistor, (BJT) is very versatile. It can be used in many ways, as an amplifier, a switch or an oscillator and many other uses too. Before an input signal is applied its

More information

EXPERIMENT #3 TRANSISTOR BIASING

EXPERIMENT #3 TRANSISTOR BIASING EXPERIMENT #3 TRANSISTOR BIASING Bias (operating point) for a transistor is established by specifying the quiescent (D.C., no signal) values of collector-emitter voltage V CEQ and collector current I CQ.

More information

I1 19u 5V R11 1MEG IDC Q7 Q2N3904 Q2N3904. Figure 3.1 A scaled down 741 op amp used in this lab

I1 19u 5V R11 1MEG IDC Q7 Q2N3904 Q2N3904. Figure 3.1 A scaled down 741 op amp used in this lab Lab 3: 74 Op amp Purpose: The purpose of this laboratory is to become familiar with a two stage operational amplifier (op amp). Students will analyze the circuit manually and compare the results with SPICE.

More information

Current Mirrors. Basic BJT Current Mirror. Current mirrors are basic building blocks of analog design. Figure shows the basic NPN current mirror.

Current Mirrors. Basic BJT Current Mirror. Current mirrors are basic building blocks of analog design. Figure shows the basic NPN current mirror. Current Mirrors Basic BJT Current Mirror Current mirrors are basic building blocks of analog design. Figure shows the basic NPN current mirror. For its analysis, we assume identical transistors and neglect

More information

The Common Emitter Amplifier Circuit

The Common Emitter Amplifier Circuit The Common Emitter Amplifier Circuit In the Bipolar Transistor tutorial, we saw that the most common circuit configuration for an NPN transistor is that of the Common Emitter Amplifier circuit and that

More information

L02 Operational Amplifiers Applications 1

L02 Operational Amplifiers Applications 1 L02 Operational Amplifiers Applications 1 Chapter 9 Ideal Operational Amplifiers and Op-Amp Circuits Donald A. Neamen (2009). Microelectronics: Circuit Analysis and Design, 4th Edition, Mc-Graw-Hill Prepared

More information

Chapter 6. BJT Amplifiers

Chapter 6. BJT Amplifiers Basic Electronic Devices and Circuits EE 111 Electrical Engineering Majmaah University 2 nd Semester 1432/1433 H Chapter 6 BJT Amplifiers 1 Introduction The things you learned about biasing a transistor

More information

UNIT 4 BIASING AND STABILIZATION

UNIT 4 BIASING AND STABILIZATION UNIT 4 BIASING AND STABILIZATION TRANSISTOR BIASING: To operate the transistor in the desired region, we have to apply external dec voltages of correct polarity and magnitude to the two junctions of the

More information

DEPARTMENT OF ELECTRONICS AND COMMUNICATION ENGINEERING III SEMESTER EC 6304 ELECTRONIC CIRCUITS I. (Regulations 2013)

DEPARTMENT OF ELECTRONICS AND COMMUNICATION ENGINEERING III SEMESTER EC 6304 ELECTRONIC CIRCUITS I. (Regulations 2013) DEPARTMENT OF ELECTRONICS AND COMMUNICATION ENGINEERING III SEMESTER EC 6304 ELECTRONIC CIRCUITS I (Regulations 2013 UNIT-1 Part A 1. What is a Q-point? [N/D 16] The operating point also known as quiescent

More information

EEE225: Analogue and Digital Electronics

EEE225: Analogue and Digital Electronics EEE225: Analogue and Digital Electronics Lecture II James E. Green Department of Electronic Engineering University of Sheffield j.e.green@sheffield.ac.uk This Lecture 1 One Transistor Circuits Continued...

More information

Tutorial 2 BJTs, Transistor Bias Circuits, BJT Amplifiers FETs and FETs Amplifiers. Part 1: BJTs, Transistor Bias Circuits and BJT Amplifiers

Tutorial 2 BJTs, Transistor Bias Circuits, BJT Amplifiers FETs and FETs Amplifiers. Part 1: BJTs, Transistor Bias Circuits and BJT Amplifiers Tutorial 2 BJTs, Transistor Bias Circuits, BJT Amplifiers FETs and FETs Amplifiers Part 1: BJTs, Transistor Bias Circuits and BJT Amplifiers 1. Explain the purpose of a thin, lightly doped base region.

More information

Analysis and Design of a Simple Operational Amplifier

Analysis and Design of a Simple Operational Amplifier by Kenneth A. Kuhn December 26, 2004, rev. Jan. 1, 2009 Introduction The purpose of this article is to introduce the student to the internal circuits of an operational amplifier by studying the analysis

More information

5.25Chapter V Problem Set

5.25Chapter V Problem Set 5.25Chapter V Problem Set P5.1 Analyze the circuits in Fig. P5.1 and determine the base, collector, and emitter currents of the BJTs as well as the voltages at the base, collector, and emitter terminals.

More information

Small signal ac equivalent circuit of BJT

Small signal ac equivalent circuit of BJT UNIT-2 Part A 1. What is an ac load line? [N/D 16] A dc load line gives the relationship between the q-point and the transistor characteristics. When capacitors are included in a CE transistor circuit,

More information

Diode and Bipolar Transistor Circuits

Diode and Bipolar Transistor Circuits Diode and Bipolar Transistor Circuits 2 2.1 A Brief Review of Semiconductors Semiconductors are crystalline structures in which each atom shares its valance electrons with the neighboring atoms. The simple

More information

UNIVERSITY OF PENNSYLVANIA EE 206

UNIVERSITY OF PENNSYLVANIA EE 206 UNIVERSITY OF PENNSYLVANIA EE 206 TRANSISTOR BIASING CIRCUITS Introduction: One of the most critical considerations in the design of transistor amplifier stages is the ability of the circuit to maintain

More information

Experiment 8 Frequency Response

Experiment 8 Frequency Response Experiment 8 Frequency Response W.T. Yeung, R.A. Cortina, and R.T. Howe UC Berkeley EE 105 Spring 2005 1.0 Objective This lab will introduce the student to frequency response of circuits. The student will

More information

Electronics 1. Lecture 4

Electronics 1. Lecture 4 Electronics 1 Lecture 4 Bipolar Junction Transistors. Structure, Characteristics, Basic Circuit Configurations, Biasing Literature 1. Tony R. Kuphaldt: Lessons In Electric Circuits, Volume II AC, 2007

More information

Physics 623 Transistor Characteristics and Single Transistor Amplifier Sept. 12, 2017

Physics 623 Transistor Characteristics and Single Transistor Amplifier Sept. 12, 2017 Physics 623 Transistor Characteristics and Single Transistor Amplifier Sept. 12, 2017 1 Purpose To measure and understand the common emitter transistor characteristic curves. To use the base current gain

More information

Experiment 6: Biasing Circuitry

Experiment 6: Biasing Circuitry 1 Objective UNIVERSITY OF CALIFORNIA AT BERKELEY College of Engineering Department of Electrical Engineering and Computer Sciences EE105 Lab Experiments Experiment 6: Biasing Circuitry Setting up a biasing

More information

DC Bias. Graphical Analysis. Script

DC Bias. Graphical Analysis. Script Course: B.Sc. Applied Physical Science (Computer Science) Year & Sem.: Ist Year, Sem - IInd Subject: Electronics Paper No.: V Paper Title: Analog Circuits Lecture No.: 3 Lecture Title: Analog Circuits

More information

LM125 Precision Dual Tracking Regulator

LM125 Precision Dual Tracking Regulator LM125 Precision Dual Tracking Regulator INTRODUCTION The LM125 is a precision, dual, tracking, monolithic voltage regulator. It provides separate positive and negative regulated outputs, thus simplifying

More information

Lab 2: Discrete BJT Op-Amps (Part I)

Lab 2: Discrete BJT Op-Amps (Part I) Lab 2: Discrete BJT Op-Amps (Part I) This is a three-week laboratory. You are required to write only one lab report for all parts of this experiment. 1.0. INTRODUCTION In this lab, we will introduce and

More information

Experiment #8: Designing and Measuring a Common-Collector Amplifier

Experiment #8: Designing and Measuring a Common-Collector Amplifier SCHOOL OF ENGINEERING AND APPLIED SCIENCE DEPARTMENT OF ELECTRICAL AND COMPUTER ENGINEERING ECE 2115: ENGINEERING ELECTRONICS LABORATORY Experiment #8: Designing and Measuring a Common-Collector Amplifier

More information

Analog Integrated Circuit Configurations

Analog Integrated Circuit Configurations Analog Integrated Circuit Configurations Basic stages: differential pairs, current biasing, mirrors, etc. Approximate analysis for initial design MOSFET and Bipolar circuits Basic Current Bias Sources

More information

PHYS 3152 Methods of Experimental Physics I E2. Diodes and Transistors 1

PHYS 3152 Methods of Experimental Physics I E2. Diodes and Transistors 1 Part I Diodes Purpose PHYS 3152 Methods of Experimental Physics I E2. In this experiment, you will investigate the current-voltage characteristic of a semiconductor diode and examine the applications of

More information

Module-1 BJT AC Analysis: The re Transistor Model. Common-Base Configuration

Module-1 BJT AC Analysis: The re Transistor Model. Common-Base Configuration Module-1 BJT AC Analysis: BJT AC Analysis: BJT AC Analysis: BJT Transistor Modeling, The re transistor model, Common emitter fixed bias, Voltage divider bias, Emitter follower configuration. Darlington

More information

BIPOLAR JUNCTION TRANSISTOR (BJT) NOISE MEASUREMENTS 1

BIPOLAR JUNCTION TRANSISTOR (BJT) NOISE MEASUREMENTS 1 4. BIPOLAR JUNCTION TRANSISTOR (BJT) NOISE MEASUREMENTS 4.1 Object The objective of this experiment is to measure the mean-square equivalent input noise, v 2 ni, and base spreading resistance, r x, of

More information

Transistor Biasing. DC Biasing of BJT. Transistor Biasing. Transistor Biasing 11/23/2018

Transistor Biasing. DC Biasing of BJT. Transistor Biasing. Transistor Biasing 11/23/2018 Transistor Biasing DC Biasing of BJT Satish Chandra Assistant Professor Department of Physics P P N College, Kanpur www.satish0402.weebly.com A transistors steady state of operation depends a great deal

More information

EEE225: Analogue and Digital Electronics

EEE225: Analogue and Digital Electronics EEE225: Analogue and Digital Electronics Lecture I James E. Green Department of Electronic Engineering University of Sheffield j.e.green@sheffield.ac.uk Introduction This Lecture 1 Introduction Aims &

More information

Early Effect & BJT Biasing

Early Effect & BJT Biasing Early Effect & BJT Biasing Early Effect DC BJT Behavior DC Biasing the BJT 1 ESE319 Introduction to Microelectronics Early Effect Saturation region Forward-Active region 4 3 Ideal NPN BJT Transfer V Characteristic

More information

The Difference Amplifier Sept. 17, 1997

The Difference Amplifier Sept. 17, 1997 Physics 63 The Difference Amplifier Sept. 17, 1997 1 Purpose To construct a difference amplifier, to measure the DC quiescent point and to compare to calculated values. To measure the difference mode gain,

More information

Experiment #7: Designing and Measuring a Common-Emitter Amplifier

Experiment #7: Designing and Measuring a Common-Emitter Amplifier SCHOOL OF ENGINEERING AND APPLIED SCIENCE DEPARTMENT OF ELECTRICAL AND COMPUTER ENGINEERING ECE 2115: ENGINEERING ELECTRONICS LABORATORY Experiment #7: Designing and Measuring a Common-Emitter Amplifier

More information

EXPERIMENT 5 CURRENT AND VOLTAGE CHARACTERISTICS OF BJT

EXPERIMENT 5 CURRENT AND VOLTAGE CHARACTERISTICS OF BJT EXPERIMENT 5 CURRENT AND VOLTAGE CHARACTERISTICS OF BJT 1. OBJECTIVES 1.1 To practice how to test NPN and PNP transistors using multimeter. 1.2 To demonstrate the relationship between collector current

More information

Experiment 6: Biasing Circuitry

Experiment 6: Biasing Circuitry 1 Objective UNIVERSITY OF CALIFORNIA AT BERKELEY College of Engineering Department of Electrical Engineering and Computer Sciences EE105 Lab Experiments Experiment 6: Biasing Circuitry Setting up a biasing

More information

Improving Amplifier Voltage Gain

Improving Amplifier Voltage Gain 15.1 Multistage ac-coupled Amplifiers 1077 TABLE 15.3 Three-Stage Amplifier Summary HAND ANALYSIS SPICE RESULTS Voltage gain 998 1010 Input signal range 92.7 V Input resistance 1 M 1M Output resistance

More information

University of Michigan EECS 311: Electronic Circuits Fall 2008 LAB 4 SINGLE STAGE AMPLIFIER

University of Michigan EECS 311: Electronic Circuits Fall 2008 LAB 4 SINGLE STAGE AMPLIFIER University of Michigan EECS 311: Electronic Circuits Fall 2008 LAB 4 SINGLE STAGE AMPLIFIER Issued 10/27/2008 Report due in Lecture 11/10/2008 Introduction In this lab you will characterize a 2N3904 NPN

More information

SET - 1 Code No: II B. Tech II Semester Regular Examinations, April/May 2009

SET - 1 Code No: II B. Tech II Semester Regular Examinations, April/May 2009 SET - 1 Code No: 3220401 II B. Tech II Semester Regular Examinations, April/May 2009 PULSE AND DIGITAL CIRCUITS ( Common to E.C.E, B.M.E, E.Con.E, I.C.E ) Time: 3 hours Max Marks: 80 Answer Any FIVE Questions

More information

BJT Circuits (MCQs of Moderate Complexity)

BJT Circuits (MCQs of Moderate Complexity) BJT Circuits (MCQs of Moderate Complexity) 1. The current ib through base of a silicon npn transistor is 1+0.1 cos (1000πt) ma. At 300K, the rπ in the small signal model of the transistor is i b B C r

More information

INDIANA UNIVERSITY, DEPT. OF PHYSICS, P400/540 LABORATORY FALL Laboratory #5: More Transistor Amplifier Circuits

INDIANA UNIVERSITY, DEPT. OF PHYSICS, P400/540 LABORATORY FALL Laboratory #5: More Transistor Amplifier Circuits INDIANA UNIVERSITY, DEPT. OF PHYSICS, P400/540 LABORATORY FALL 2008 Laboratory #5: More Transistor Amplifier Circuits Goal: Use and measure the behavior of transistor circuits used to implement different

More information

(a) BJT-OPERATING MODES & CONFIGURATIONS

(a) BJT-OPERATING MODES & CONFIGURATIONS (a) BJT-OPERATING MODES & CONFIGURATIONS 1. The leakage current I CBO flows in (a) The emitter, base and collector leads (b) The emitter and base leads. (c) The emitter and collector leads. (d) The base

More information

Document Name: Electronic Circuits Lab. Facebook: Twitter:

Document Name: Electronic Circuits Lab.  Facebook:  Twitter: Document Name: Electronic Circuits Lab www.vidyathiplus.in Facebook: www.facebook.com/vidyarthiplus Twitter: www.twitter.com/vidyarthiplus Copyright 2011-2015 Vidyarthiplus.in (VP Group) Page 1 CIRCUIT

More information

Gechstudentszone.wordpress.com

Gechstudentszone.wordpress.com 8.1 Operational Amplifier (Op-Amp) UNIT 8: Operational Amplifier An operational amplifier ("op-amp") is a DC-coupled high-gain electronic voltage amplifier with a differential input and, usually, a single-ended

More information

55:041 Electronic Circuits The University of Iowa Fall Exam 3. Question 1 Unless stated otherwise, each question below is 1 point.

55:041 Electronic Circuits The University of Iowa Fall Exam 3. Question 1 Unless stated otherwise, each question below is 1 point. Exam 3 Name: Score /65 Question 1 Unless stated otherwise, each question below is 1 point. 1. An engineer designs a class-ab amplifier to deliver 2 W (sinusoidal) signal power to an resistive load. Ignoring

More information

Chapter Three " BJT Small-Signal Analysis "

Chapter Three  BJT Small-Signal Analysis Chapter Three " BJT Small-Signal Analysis " We now begin to examine the small-signal ac response of the BJT amplifier by reviewing the models most frequently used to represent the transistor in the sinusoidal

More information

Lab 4. Transistor as an amplifier, part 2

Lab 4. Transistor as an amplifier, part 2 Lab 4 Transistor as an amplifier, part 2 INTRODUCTION We continue the bi-polar transistor experiments begun in the preceding experiment. In the common emitter amplifier experiment, you will learn techniques

More information

7. Bipolar Junction Transistor

7. Bipolar Junction Transistor 41 7. Bipolar Junction Transistor 7.1. Objectives - To experimentally examine the principles of operation of bipolar junction transistor (BJT); - To measure basic characteristics of n-p-n silicon transistor

More information

Chapter 7 EMITTER-COUPLED LOGIC

Chapter 7 EMITTER-COUPLED LOGIC Chapter 7 EMITTER-COUPLED LOGIC The major speed limitation of TTL is the turn-off time of saturated transistors. To be sure, TTL has come a long way from the 100 ns time of DTL to the 2-4 ns propagation

More information

Concepts to be Covered

Concepts to be Covered Introductory Medical Device Prototyping Analog Circuits Part 2 Semiconductors, http://saliterman.umn.edu/ Department of Biomedical Engineering, University of Minnesota Concepts to be Covered Semiconductors

More information

Electronic Circuits EE359A

Electronic Circuits EE359A Electronic Circuits EE359A Bruce McNair B206 bmcnair@stevens.edu 201-216-5549 Lecture 4 0 Bipolar Junction Transistors (BJT) Small Signal Analysis Graphical Analysis / Biasing Amplifier, Switch and Logic

More information

Mini Project 3 Multi-Transistor Amplifiers. ELEC 301 University of British Columbia

Mini Project 3 Multi-Transistor Amplifiers. ELEC 301 University of British Columbia Mini Project 3 Multi-Transistor Amplifiers ELEC 30 University of British Columbia 4463854 November 0, 207 Contents 0 Introduction Part : Cascode Amplifier. A - DC Operating Point.......................................

More information

ES 330 Electronics II Homework # 1 (Fall 2016 SOLUTIONS)

ES 330 Electronics II Homework # 1 (Fall 2016 SOLUTIONS) SOLUTIONS ES 330 Electronics II Homework # 1 (Fall 2016 SOLUTIONS) Problem 1 (20 points) We know that a pn junction diode has an exponential I-V behavior when forward biased. The diode equation relating

More information

LM78S40 Switching Voltage Regulator Applications

LM78S40 Switching Voltage Regulator Applications LM78S40 Switching Voltage Regulator Applications Contents Introduction Principle of Operation Architecture Analysis Design Inductor Design Transistor and Diode Selection Capacitor Selection EMI Design

More information

HOME ASSIGNMENT. Figure.Q3

HOME ASSIGNMENT. Figure.Q3 HOME ASSIGNMENT 1. For the differential amplifier circuit shown below in figure.q1, let I=1 ma, V CC =5V, v CM = -2V, R C =3kΩ and β=100. Assume that the BJTs have v BE =0.7 V at i C =1 ma. Find the voltage

More information

BJT AC Analysis CHAPTER OBJECTIVES 5.1 INTRODUCTION 5.2 AMPLIFICATION IN THE AC DOMAIN

BJT AC Analysis CHAPTER OBJECTIVES 5.1 INTRODUCTION 5.2 AMPLIFICATION IN THE AC DOMAIN BJT AC Analysis 5 CHAPTER OBJECTIVES Become familiar with the, hybrid, and hybrid p models for the BJT transistor. Learn to use the equivalent model to find the important ac parameters for an amplifier.

More information

Carleton University ELEC Lab 1. L2 Friday 2:30 P.M. Student Number: Operation of a BJT. Author: Adam Heffernan

Carleton University ELEC Lab 1. L2 Friday 2:30 P.M. Student Number: Operation of a BJT. Author: Adam Heffernan Carleton University ELEC 3509 Lab 1 L2 Friday 2:30 P.M. Student Number: 100977570 Operation of a BJT Author: Adam Heffernan October 13, 2017 Contents 1 Transistor DC Characterization 3 1.1 Calculations

More information

Homework Assignment 12

Homework Assignment 12 Homework Assignment 12 Question 1 Shown the is Bode plot of the magnitude of the gain transfer function of a constant GBP amplifier. By how much will the amplifier delay a sine wave with the following

More information

R 1 R 2. (3) Suppose you have two ac signals, which we ll call signals A and B, which have peak-to-peak amplitudes of 30 mv and 600 mv, respectively.

R 1 R 2. (3) Suppose you have two ac signals, which we ll call signals A and B, which have peak-to-peak amplitudes of 30 mv and 600 mv, respectively. 29:128 Homework Problems 29:128 Homework 0 reference: Chapter 1 of Horowitz and Hill (1) In the circuit shown below, V in = 9 V, R 1 = 1.5 kω, R 2 = 5.6 kω, (a) Calculate V out (b) Calculate the power

More information

GATE SOLVED PAPER - IN

GATE SOLVED PAPER - IN YEAR 202 ONE MARK Q. The i-v characteristics of the diode in the circuit given below are : v -. A v 0.7 V i 500 07 $ = * 0 A, v < 0.7 V The current in the circuit is (A) 0 ma (C) 6.67 ma (B) 9.3 ma (D)

More information

ECE 310 Microelectronics Circuits

ECE 310 Microelectronics Circuits ECE 310 Microelectronics Circuits Bipolar Transistors Dr. Vishal Saxena (vishalsaxena@boisetstate.edu) Jan 20, 2014 Vishal Saxena 1 Bipolar Transistor n the chapter, we will study the physics of bipolar

More information

ES330 Laboratory Experiment No. 9 Bipolar Differential Amplifier [Reference: Sedra/Smith (Chapter 9; Section 9.2; pp )]

ES330 Laboratory Experiment No. 9 Bipolar Differential Amplifier [Reference: Sedra/Smith (Chapter 9; Section 9.2; pp )] ES330 Laboratory Experiment No. 9 Bipolar Differential Amplifier [Reference: Sedra/Smith (Chapter 9; Section 9.2; pp. 614-627)] Objectives: 1. Explore the operation of a bipolar junction transistor differential

More information

Operational Amplifiers

Operational Amplifiers Operational Amplifiers Table of contents 1. Design 1.1. The Differential Amplifier 1.2. Level Shifter 1.3. Power Amplifier 2. Characteristics 3. The Opamp without NFB 4. Linear Amplifiers 4.1. The Non-Inverting

More information

ECE 334: Electronic Circuits Lecture 2: BJT Large Signal Model

ECE 334: Electronic Circuits Lecture 2: BJT Large Signal Model Faculty of Engineering ECE 334: Electronic Circuits Lecture 2: BJT Large Signal Model Agenda I & V Notations BJT Devices & Symbols BJT Large Signal Model 2 I, V Notations (1) It is critical to understand

More information

Audio, Dual-Matched NPN Transistor MAT12

Audio, Dual-Matched NPN Transistor MAT12 Data Sheet FEATURES Very low voltage noise: nv/ Hz maximum at 00 Hz Excellent current gain match: 0.5% typical Low offset voltage (VOS): 200 μv maximum Outstanding offset voltage drift: 0.03 μv/ C typical

More information

Mini Project 2 Single Transistor Amplifiers. ELEC 301 University of British Columbia

Mini Project 2 Single Transistor Amplifiers. ELEC 301 University of British Columbia Mini Project 2 Single Transistor Amplifiers ELEC 301 University of British Columbia 44638154 October 27, 2017 Contents 1 Introduction 1 2 Investigation 1 2.1 Part 1.................................................

More information

Designing an Audio Amplifier Using a Class B Push-Pull Output Stage

Designing an Audio Amplifier Using a Class B Push-Pull Output Stage Designing an Audio Amplifier Using a Class B Push-Pull Output Stage Angel Zhang Electrical Engineering The Cooper Union for the Advancement of Science and Art Manhattan, NY Jeffrey Shih Electrical Engineering

More information

BASIC ELECTRONICS PROF. T.S. NATARAJAN DEPT OF PHYSICS IIT MADRAS

BASIC ELECTRONICS PROF. T.S. NATARAJAN DEPT OF PHYSICS IIT MADRAS BASIC ELECTRONICS PROF. T.S. NATARAJAN DEPT OF PHYSICS IIT MADRAS LECTURE-13 Basic Characteristic of an Amplifier Simple Transistor Model, Common Emitter Amplifier Hello everybody! Today in our series

More information

Electronic Devices, 9th edition Thomas L. Floyd. Input signal. R 1 and R 2 are selected to establish V B. If the V CE

Electronic Devices, 9th edition Thomas L. Floyd. Input signal. R 1 and R 2 are selected to establish V B. If the V CE 3/9/011 lectronic Devices Ninth dition Floyd hapter 5: Transistor ias ircuits The D Operating Point ias establishes the operating point (Q-point) of a transistor amplifier; the ac signal (ma) moves above

More information

Midterm 2 Exam. Max: 90 Points

Midterm 2 Exam. Max: 90 Points Midterm 2 Exam Name: Max: 90 Points Question 1 Consider the circuit below. The duty cycle and frequency of the 555 astable is 55% and 5 khz respectively. (a) Determine a value for so that the average current

More information

Physics 160 Lecture 11. R. Johnson May 4, 2015

Physics 160 Lecture 11. R. Johnson May 4, 2015 Physics 160 Lecture 11 R. Johnson May 4, 2015 Two Solutions to the Miller Effect Putting a matching resistor on the collector of Q 1 would be a big mistake, as it would give no benefit and would produce

More information

Linear Voltage Regulators Power supplies and chargers SMM Alavi, SBU, Fall2017

Linear Voltage Regulators Power supplies and chargers SMM Alavi, SBU, Fall2017 Linear Voltage Regulator LVRs can be classified based on the type of the transistor that is used as the pass element. The bipolar junction transistor (BJT), field effect transistor (FET), or metal oxide

More information

Chapter 3 Bipolar Junction Transistors (BJT)

Chapter 3 Bipolar Junction Transistors (BJT) Chapter 3 Bipolar Junction Transistors (BJT) Transistors In analog circuits, transistors are used in amplifiers and linear regulated power supplies. In digital circuits they function as electrical switches,

More information

Chapter Two "Bipolar Transistor Circuits"

Chapter Two Bipolar Transistor Circuits Chapter Two "Bipolar Transistor Circuits" 1.TRANSISTOR CONSTRUCTION:- The transistor is a three-layer semiconductor device consisting of either two n- and one p-type layers of material or two p- and one

More information

ET215 Devices I Unit 4A

ET215 Devices I Unit 4A ITT Technical Institute ET215 Devices I Unit 4A Chapter 3, Section 3.1-3.2 This unit is divided into two parts; Unit 4A and Unit 4B Chapter 3 Section 3.1 Structure of Bipolar Junction Transistors The basic

More information

(Refer Slide Time: 05:47)

(Refer Slide Time: 05:47) Solid State Devices Dr. S. Karmalkar Department of Electronics and Communication Engineering Indian Institute of Technology, Madras Lecture - 29 Bipolar Junction Transistor (Contd ) So we have been discussing

More information

EE 332 Design Project

EE 332 Design Project EE 332 Design Project Variable Gain Audio Amplifier TA: Pohan Yang Students in the team: George Jenkins Mohamed Logman Dale Jackson Ben Alsin Instructor s Comments: Lab Grade: Introduction The goal of

More information

ECEN 325 Lab 7: Characterization and DC Biasing of the BJT

ECEN 325 Lab 7: Characterization and DC Biasing of the BJT ECEN 325 Lab 7: Characterization and DC Biasing of the BJT 1 Objectives The purpose of this lab is to characterize NPN and PNP bipolar junction transistors (BJT), and to analyze and design DC biasing circuits

More information

Exercises 6.1, 6.2, 6.3 (page 315 on 7 th edition textbook)

Exercises 6.1, 6.2, 6.3 (page 315 on 7 th edition textbook) Exercises 6.1, 6.2, 6.3 (page 315 on 7 th edition textbook) Recapitulation and Equivalent Circuit Models Previous slides present first order BJT model. Assumes npn transistor in active mode. Basic relationship

More information

Application Note 1293

Application Note 1293 A omparison of Various Bipolar Transistor Biasing ircuits Application Note 1293 Introduction The bipolar junction transistor (BJT) is quite often used as a low noise amplifier in cellular, PS, and pager

More information

SAMPLE FINAL EXAMINATION FALL TERM

SAMPLE FINAL EXAMINATION FALL TERM ENGINEERING SCIENCES 154 ELECTRONIC DEVICES AND CIRCUITS SAMPLE FINAL EXAMINATION FALL TERM 2001-2002 NAME Some Possible Solutions a. Please answer all of the questions in the spaces provided. If you need

More information

(Refer Slide Time: 01:33)

(Refer Slide Time: 01:33) Solid State Devices Dr. S. Karmalkar Department of Electronics and Communication Engineering Indian Institute of Technology, Madras Lecture - 31 Bipolar Junction Transistor (Contd ) So, we have been discussing

More information

BIPOLAR JUNCTION TRANSISTORS (BJTs) Dr Derek Molloy, DCU

BIPOLAR JUNCTION TRANSISTORS (BJTs) Dr Derek Molloy, DCU IPOLAR JUNCTION TRANSISTORS (JTs) Dr Derek Molloy, DCU What are JTs? Two PN junctions joined together is a JT Simply known as a transistor! ipolar? Current carried by electrons and holes Will see FETs

More information

Transistor Biasing and Operational amplifier fundamentals. OP-amp Fundamentals and its DC characteristics. BJT biasing schemes

Transistor Biasing and Operational amplifier fundamentals. OP-amp Fundamentals and its DC characteristics. BJT biasing schemes Lab 1 Transistor Biasing and Operational amplifier fundamentals Experiment 1.1 Experiment 1.2 BJT biasing OP-amp Fundamentals and its DC characteristics BJT biasing schemes 1.1 Objective 1. To sketch potential

More information

Paper-1 (Circuit Analysis) UNIT-I

Paper-1 (Circuit Analysis) UNIT-I Paper-1 (Circuit Analysis) UNIT-I AC Fundamentals & Kirchhoff s Current and Voltage Laws 1. Explain how a sinusoidal signal can be generated and give the significance of each term in the equation? 2. Define

More information

Linear IC s and applications

Linear IC s and applications Questions and Solutions PART-A Unit-1 INTRODUCTION TO OP-AMPS 1. Explain data acquisition system Jan13 DATA ACQUISITION SYSYTEM BLOCK DIAGRAM: Input stage Intermediate stage Level shifting stage Output

More information

Chapter 5 Transistor Bias Circuits

Chapter 5 Transistor Bias Circuits Chapter 5 Transistor Bias Circuits Objectives Discuss the concept of dc biasing of a transistor for linear operation Analyze voltage-divider bias, base bias, and collector-feedback bias circuits. Basic

More information

UNIT I BIASING OF DISCRETE BJT AND MOSFET PART A

UNIT I BIASING OF DISCRETE BJT AND MOSFET PART A UNIT I BIASING OF DISCRETE BJT AND MOSFET PART A 1. Why do we choose Q point at the center of the load line? 2. Name the two techniques used in the stability of the q point.explain. 3. Give the expression

More information

Operational amplifiers

Operational amplifiers Operational amplifiers Bởi: Sy Hien Dinh INTRODUCTION Having learned the basic laws and theorems for circuit analysis, we are now ready to study an active circuit element of paramount importance: the operational

More information

KOM2751 Analog Electronics :: Dr. Muharrem Mercimek :: YTU - Control and Automation Dept. 1 2 (CONT D - II) DIODE APPLICATIONS

KOM2751 Analog Electronics :: Dr. Muharrem Mercimek :: YTU - Control and Automation Dept. 1 2 (CONT D - II) DIODE APPLICATIONS KOM2751 Analog Electronics :: Dr. Muharrem Mercimek :: YTU - Control and Automation Dept. 1 2 (CONT D - II) DIODE APPLICATIONS Most of the content is from the textbook: Electronic devices and circuit theory,

More information

(b) 25% (b) increases

(b) 25% (b) increases Homework Assignment 07 Question 1 (2 points each unless noted otherwise) 1. In the circuit 10 V, 10, and 5K. What current flows through? Answer: By op-amp action the voltage across is and the current through

More information

Georgia Institute of Technology School of Electrical and Computer Engineering. Midterm Exam

Georgia Institute of Technology School of Electrical and Computer Engineering. Midterm Exam Georgia Institute of Technology School of Electrical and Computer Engineering Midterm Exam ECE-3400 Fall 2013 Tue, September 24, 2013 Duration: 80min First name Solutions Last name Solutions ID number

More information

ELT 215 Operational Amplifiers (LECTURE) Chapter 5

ELT 215 Operational Amplifiers (LECTURE) Chapter 5 CHAPTER 5 Nonlinear Signal Processing Circuits INTRODUCTION ELT 215 Operational Amplifiers (LECTURE) In this chapter, we shall present several nonlinear circuits using op-amps, which include those situations

More information

Exercise 2: Collector Current Versus Base Current

Exercise 2: Collector Current Versus Base Current Exercise 2: Collector Current Versus Base Current EXERCISE OBJECTIVE When you have completed this exercise, you will be able to demonstrate the relationship of collector current to base current by using

More information

I C I E =I B = I C 1 V BE 0.7 V

I C I E =I B = I C 1 V BE 0.7 V Guide to NPN Amplifier Analysis Jason Woytowich 1. Transistor characteristics A BJT has three operating modes cutoff, active, and saturation. For applications, like amplifiers, where linear characteristics

More information

Transistor Characteristics

Transistor Characteristics Transistor Characteristics Introduction Transistors are the most recent additions to a family of electronic current flow control devices. They differ from diodes in that the level of current that can flow

More information

ITT Technical Institute. ET215 Devices 1. Unit 6 Chapter 3, Sections

ITT Technical Institute. ET215 Devices 1. Unit 6 Chapter 3, Sections ITT Technical Institute ET215 Devices 1 Unit 6 Chapter 3, Sections 3.7-3.9 Chapter 3 Section 3.7 The Bipolar Transistor as a Switch Objectives: Explain how a transistor can be used as a switch 1. Compute

More information

Biasing of BJT IENGINEERS- CONSULTANTS LECTURE NOTES SERIES ELECTRONICS ENGINEERING 1 YEAR UPTU. Page 1

Biasing of BJT IENGINEERS- CONSULTANTS LECTURE NOTES SERIES ELECTRONICS ENGINEERING 1 YEAR UPTU. Page 1 HTTP://NGNS.N/ NGNS- ONSULTANTS LTU NOTS SS LTONS NGNNG 1 YA UPTU iasing of JT As we know that JT can be operated in three regions: active, saturation and cutoff by applying proper voltage condition. n

More information

LM389 Low Voltage Audio Power Amplifier with NPN Transistor Array

LM389 Low Voltage Audio Power Amplifier with NPN Transistor Array LM389 Low Voltage Audio Power Amplifier with NPN Transistor Array General Description The LM389 is an array of three NPN transistors on the same substrate with an audio power amplifier similar to the LM386

More information