11. Chapter: Amplitude stabilization of the harmonic oscillator

Save this PDF as:
 WORD  PNG  TXT  JPG

Size: px
Start display at page:

Download "11. Chapter: Amplitude stabilization of the harmonic oscillator"

Transcription

1 Punčochář, Mohylová: TELO, Chapter Chapter: Amplitude stabilization of the harmonic oscillator Time of study: 3 hours Goals: the student should be able to define basic principles of oscillator amplitude stabilization describe low distortion oscillator (spot sinus) Text Two basic oscillator structures you can see in the 6.Chapter. A positive-feedback loop is formed by an amplifier A and a frequency-selective network β. The amplifier produces a 0 or 180 voltage phase shift, as does the feedback network. This results in a combined 0 voltage phase shift around the loop, which is the same thing as a 360 phase shift. In order to oscillate, the loop gain (return ration) Aβ must be equal to unity. Because circuit components and transistors change characteristics (drift) with age, temperature, voltage, etc., the Aβ =1 condition could not be permanently satisfied. The product will become either less or larger than unity. In the former case the oscillation simply stops, and in the latter case nonlinearity is required in order to limit the amplitude. An oscillator in which the loop gain is exactly unity is an abstraction completely unrealizable in practice. In every practical oscillator the loop gain is slightly larger than unity, and the amplitude of the oscillations is limited by the onset of nonlinearity. The distortion is low if the amplitude of oscillation remains within the linear region of the amplifier. It must not be allowed to go into a full-swing oscillation. An amplitude-limiting mechanism is basically an automatic gain control (AGC) circuit that forces the amplifier gain to decrease when the amplitude of the oscillation increases. Wien bridge oscillator The positive feedback network (RC + RC) is frequency selective, and at the most favored frequency passes a maximum of 1/3 of the output swing back to the + input Fig.1. The negative feedback (560Ω + lamp; R lamp grows with current - positive temperature coefficient (PTC) thermistor) adjusts the gain (noninverting amplifier, 1+560/R lamp ). The incan-

2 Punčochář, Mohylová: TELO, Chapter 10 2 descent lamp is used as a variable-resistance element (with a long time-constant of response; the lamp is rated at 14 ma and 10V). The initial gain (not yet oscillation, the lamp is cold, R lamp is small) is greater than 3 the oscillator begins to oscillate. As the output level rises, the lamp heats slightly, reducing the gain to 3. Fig.1: Wien bridge oscillator amplitude stabilization (LAMP) Figure 2 shows Wien-bridge oscillators with diode amplitude limiting mechanisms; when the diodes are off, the gain is 1 + R2 R1; and when a diode is on, the gain is reduced to 1 + (R2 R3 )/R1. The start up condition requires a gain slightly greater than 3 or The inequality above can be satisfied by making it equal to a value between 2.1 to 2.2. When a diode is on, the gain should be slightly less than 3, or The inequality above can be satisfied by making it equal to a value between 1.8 to 1.9. When a diode is conducting, the amplitude of the output voltage is limited. Since v + = v = v o /3, a nodal equation gives or

3 Punčochář, Mohylová: TELO, Chapter 10 3 where V D» 0.5V for an actual diode. Fig.2: Wien bridge oscillator amplitude stabilization (diodes) Fig.3: Wien bridge oscillator another amplitude stabilization (diodes) Another Wien-bridge oscillator with a diode amplitude-limiting circuit is shown in Figure 3. In this oscillator the amplitude-limiting circuit consists of the diodes D1 and D2, and the resistors R3, R4, R5, and R6. To understand the operation of the amplitude-limiting circuit, observe that as v o increases, the voltage at node v y will exceed the voltage v 1, forcing D2 to conduct. When D2 conducts, the value of v y is v y = v , and v o is clamped at the value v o(max), given by (superposition theorem)

4 Punčochář, Mohylová: TELO, Chapter 10 4 Since v 1 is approximately v o /3, it follows from equation above that Similarly, as v o decreases, the voltage v x will drop below v 1, forcing D1 to conduct. When D1 conducts, the voltage v x is v x = v 1 0.7, and v o is clamped at the value v o(min), given by The simultaneous solution of equations gives the value of the resistors that limit the output voltage to v o(min) < v o < v o(max). In order to obtain a symmetrical sinusoidal voltage, the selection R3 = R6 and R4 = R5 is usually made. Example 1 -Design the Wien-bridge oscillator shown in Fig. 3 to oscillate at 5 khz. - Design an amplitude-limiting circuit. The amplitude of the sinusoidal output voltage is to be limited to v o = 5V. Solution A practical value of 0.01 μ F for the capacitors can be selected. Then, using the value of R is A practical value of 3 kω can be used in series with a trimming potentiometer to set the frequency of oscillation at 5 khz. To start the oscillation, a value of A vo = 3.2 is used. From a gain of 3.2 is obtained with R 2 = 22 kω and R 1 = 10 kω. The supply voltages of the op amp can be selected as 12V and 12V.Tthe output voltage will reach saturation producing a clipping in the output waveform and, therefore, a significant amount of distortion. This occurs because the starting condition requires A vo > 3, and the gain of the amplifier changes when its output reaches saturation. Some sort of amplitude-limiting mechanism is needed to reduce the harmonic distortion. With v o(max) = 5V and v o(min) = -5V, it follows from

5 Punčochář, Mohylová: TELO, Chapter 10 5 that R3 = R6 = 10.9 kω and R4 = R5 = 2 kω. In the circuit in Fig.4, an amplitude discriminator consisting of the diodes and RC adjusts the AC gain by varying the resistance of the JFET, which behaves like a voltagevariable resistance for small voltages. The LM103 is a two-terminal monolithic reference diode electrically equivalent to a breakdown diode. The long time constant is used (2s) to avoid distortion, since fast feedback will distort the wave by attempting to control the amplitude within the time of one cycle. 1 μf 2N5457 A 1N914 LM103 6,8 k 2,2 μf Fig.4: Wien bridge oscillator JFET amplitude stabilization The small amplitude generates a small voltage (negative) JFET is open (small resistor in parallel with 6,8 kω) small JFET resistance determines the maximum gain of more than 3. As the amplitude grows, the voltage (negative, on RC) grows too and JFET closes the minimum amplifier gain is about 1+ 10/6,8 = 2,47. We can add a buffer (voltage gain of 1) to isolate the non-linear effects of rectifier (diodes) from the oscillator output Fig. 5 and thus reduce the distortion of the oscillator.

6 Punčochář, Mohylová: TELO, Chapter 10 6 A output BUFFER 1 to 1N914 Fig.5: Wien bridge oscillator JFET amplitude stabilization; buffer reduces distortion of the oscillator Phase shift oscillator Phase-shift oscillators usually use RC networks in the feedback path. The op amp is used in an inverting configuration with a gain of -R 2 /R 1. Thus, the signal experiences a phase shift of -180 through the amplifier, and the phase shift from each RC section is 60 at the frequency of oscillation, for a total phase shift in the feedback path of 180. In this oscillator the RC sections are connected without isolation and, therefore, there is loading. In the last stage the resistors R and R 1 appear in parallel. The loading of R 1 can be neglected if R 1 R» R, or in some cases by removing R in the third stage and letting R1 = R. To summarize, the phase-shift oscillator in Fig. 6 will oscillate at the frequency ω o given by if the gain is A vo = R 2 /R 1 > 29. The loading of the op amp is minimized by making R1 > 10R. Fig.6: Phase shift oscillator amplitude stabilization (diodes)

7 Punčochář, Mohylová: TELO, Chapter 10 7 The harmonic distortion can be significantly reduced with an amplitude-limiting circuit. The amplitude-limiting circuit is designed using (see Fig. 3) and with v 1 set equal to zero (i.e., v y = 0.7V and v x = -0.7V). Example 2 -Design the phase shift oscillator shown in Fig. 3 to oscillate at 1 khz. - Design an amplitude-limiting circuit. The amplitude of the sinusoidal output voltage is to be limited to v o = 5V. Solution A practical value of 0.01 μ F for the capacitors can be selected. Then, using The resistors R 1 and R 2 must provide the gain A vo > 29 in order to prevent loading R 1 R R. Letting R 1 = 15 kω, then R 2 = 29R 1 = 435 kω. A 495-kΩ resistor was used to implement R 2. This will allow for some extra gain to satisfy the start of oscillation condition (i.e., A vo > 29). From (supply voltage ± 12 V) with v 1 = 0 and v o(max) = 5V, we obtain which can be satisfied with R 5 = 2 kω and R 6 = 5.9 kω. From for symmetry, we obtain R 3 = R 6 = 5.9 kω and R 4 = R 5 = 2 kω.

8 Punčochář, Mohylová: TELO, Chapter 10 8 Band pass filter comparator oscillator (spot sinus) The basic idea of low THD BPF-based oscillators is to incorporate a bandpass filter (BPF) along with a limiter and a comparator, in a positive feedback loop Fig.7. The oscillation frequency is set by the center frequency of the filter while the amplitude is set by the limiter (this filter has independent control of frequency, amplitude and distortion of the output). Fig.7: Bandpass filter comparator oscillator Input of BPF is roughly a square wave. According to its Fourier series, a 50% duty-cycle square wave consists of odd order harmonic sine waves with the fundamental at the same frequency as the square wave. Fourier Series for a Square Wave where k = peak amplitude of the square wave. Thus THD is dominated by lower order harmonics. The THD is directly proportional to the quality factor of the loop filter Fig.8. Fig.9 shows the THD of the oscillator versus the quality factor (Q) of a second-order filter. Achieving linearity better than 62 db requires very high-q filter (Q > 70). Implementing such high-q filter requires large op-amp gain bandwidth product as well as a large spread of the capacitor values, and will end up with larger silicon area. Fig.8: The Fourier series versus Q of BPF

9 Punčochář, Mohylová: TELO, Chapter 10 9 Fig.9: The third harmonic versus Q Notice that although the filter has unity gain, the amplitude of the sine wave output signal is greater than that of the square wave. This is because the fundamental has an amplitude of 4/π times that of the square wave as shown by the Fourier series. The bandpass filter will also filter out any DC component of the square wave input. The very simple (only limiter is used) circuit is shown in Fig. 10, for example. The limiter is a pair of diodes (and R 1 ) to have a squarewave at v 2. The active filter (other circuit elements) selects the fundamental frequency and provides the sinus output at v 1 (any filter circuit with positive gain can be used to implement the bandpass filter). Fig.10: Bandpass filter the limiter used only

10 Punčochář, Mohylová: TELO, Chapter Basic texts Other text Questions Answers you find in this text 1. Why isn t an input signal (to the oscillator) needed to obtain an output voltage signal? 2. Compare the operation of the described oscillator circuits. 3. Why does a harmonic oscillator need an amplitude control circuit? 4. Explain the function of the buffer on Fig.4 5. How can we get the sinusoidal voltage from the square wave voltage? 6. Why we need high-q band pass filter on Fig.7? Problems 1. Redesign the circuit of Fig. 3 for operation at 1 khz. The amplitude of the sinusoidal output voltage is to be limited to v o = 2V. 2. Redesign the circuit of Fig. 3 for operation at 5 khz. The amplitude of the sinusoidal output voltage is to be limited to v o = 2V. 3. Determine the needed Q of BPF (Fig.7) if we need HD 3-40 DB. Problems key See example 1 and example 2 and Fig

Precision Rectifier Circuits

Precision Rectifier Circuits Precision Rectifier Circuits Rectifier circuits are used in the design of power supply circuits. In such applications, the voltage being rectified are usually much greater than the diode voltage drop,

More information

BENE 2163 ELECTRONIC SYSTEMS

BENE 2163 ELECTRONIC SYSTEMS UNIVERSITI TEKNIKAL MALAYSIA MELAKA FAKULTI KEJURUTERAAN ELEKTRONIK DAN KEJURUTERAAN KOMPUTER BENE 263 ELECTRONIC SYSTEMS LAB SESSION 3 WEIN BRIDGE OSCILLATOR Revised: February 20 Lab 3 Wien Bridge Oscillator

More information

EE 368 Electronics Lab. Experiment 10 Operational Amplifier Applications (2)

EE 368 Electronics Lab. Experiment 10 Operational Amplifier Applications (2) EE 368 Electronics Lab Experiment 10 Operational Amplifier Applications (2) 1 Experiment 10 Operational Amplifier Applications (2) Objectives To gain experience with Operational Amplifier (Op-Amp). To

More information

EMT212 Analog Electronic II. Chapter 4. Oscillator

EMT212 Analog Electronic II. Chapter 4. Oscillator EMT Analog Electronic II Chapter 4 Oscillator Objectives Describe the basic concept of an oscillator Discuss the basic principles of operation of an oscillator Analyze the operation of RC, LC and crystal

More information

1) Consider the circuit shown in figure below. Compute the output waveform for an input of 5kHz

1) Consider the circuit shown in figure below. Compute the output waveform for an input of 5kHz ) Consider the circuit shown in figure below. Compute the output waveform for an input of 5kHz Solution: a) Input is of constant amplitude of 2 V from 0 to 0. ms and 2 V from 0. ms to 0.2 ms. The output

More information

Oscillators. An oscillator may be described as a source of alternating voltage. It is different than amplifier.

Oscillators. An oscillator may be described as a source of alternating voltage. It is different than amplifier. Oscillators An oscillator may be described as a source of alternating voltage. It is different than amplifier. An amplifier delivers an output signal whose waveform corresponds to the input signal but

More information

Sine-wave oscillator

Sine-wave oscillator Sine-wave oscillator In Fig. 1, an op-'amp can be made to oscillate by feeding a portion of the output back to the input via a frequency-selective network, and controlling the overall voltage gain. For

More information

Applied Electronics II

Applied Electronics II Applied Electronics II Chapter 4: Wave shaping and Waveform Generators School of Electrical and Computer Engineering Addis Ababa Institute of Technology Addis Ababa University Daniel D./Getachew T./Abel

More information

Summer 2015 Examination

Summer 2015 Examination Summer 2015 Examination Subject Code: 17445 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

UNIVERSITI MALAYSIA PERLIS

UNIVERSITI MALAYSIA PERLIS UNIVERSITI MALAYSIA PERLIS ANALOG ELECTRONICS II EMT 212 2009/2010 EXPERIMENT # 3 OP-AMP (OSCILLATORS) 1 1. OBJECTIVE: 1.1 To demonstrate the Wien bridge oscillator 1.2 To demonstrate the RC phase-shift

More information

Homework Assignment 03 Solution

Homework Assignment 03 Solution Homework Assignment 03 Solution Question 1 Determine the h 11 and h 21 parameters for the circuit. Be sure to supply the units and proper sign for each parameter. (8 points) Solution Setting v 2 = 0 h

More information

Assume availability of the following components to DESIGN and DRAW the circuits of the op. amp. applications listed below:

Assume availability of the following components to DESIGN and DRAW the circuits of the op. amp. applications listed below: ========================================================================================== UNIVERSITY OF SOUTHERN MAINE Dept. of Electrical Engineering TEST #3 Prof. M.G.Guvench ELE343/02 ==========================================================================================

More information

Assignment 11. 1) Using the LM741 op-amp IC a circuit is designed as shown, then find the output waveform for an input of 5kHz

Assignment 11. 1) Using the LM741 op-amp IC a circuit is designed as shown, then find the output waveform for an input of 5kHz Assignment 11 1) Using the LM741 op-amp IC a circuit is designed as shown, then find the output waveform for an input of 5kHz Vo = 1 x R1Cf 0 Vin t dt, voltage output for the op amp integrator 0.1 m 1

More information

Test Your Understanding

Test Your Understanding 074 Part 2 Analog Electronics EXEISE POBLEM Ex 5.3: For the switched-capacitor circuit in Figure 5.3b), the parameters are: = 30 pf, 2 = 5pF, and F = 2 pf. The clock frequency is 00 khz. Determine the

More information

UNIT I. Operational Amplifiers

UNIT I. Operational Amplifiers UNIT I Operational Amplifiers Operational Amplifier: The operational amplifier is a direct-coupled high gain amplifier. It is a versatile multi-terminal device that can be used to amplify dc as well as

More information

The steeper the phase shift as a function of frequency φ(ω) the more stable the frequency of oscillation

The steeper the phase shift as a function of frequency φ(ω) the more stable the frequency of oscillation It should be noted that the frequency of oscillation ω o is determined by the phase characteristics of the feedback loop. the loop oscillates at the frequency for which the phase is zero The steeper the

More information

Homework Assignment 01

Homework Assignment 01 Homework Assignment 01 In this homework set students review some basic circuit analysis techniques, as well as review how to analyze ideal op-amp circuits. Numerical answers must be supplied using engineering

More information

An Oscillator is a circuit which produces a periodic waveform at its output with only the dc supply voltage at the input. The output voltage can be

An Oscillator is a circuit which produces a periodic waveform at its output with only the dc supply voltage at the input. The output voltage can be An Oscillator is a circuit which produces a periodic waveform at its output with only the dc supply voltage at the input. The output voltage can be either sinusoidal or non sinusoidal depending upon the

More information

Figure 1: Closed Loop System

Figure 1: Closed Loop System SIGNAL GENERATORS 3. Introduction Signal sources have a variety of applications including checking stage gain, frequency response, and alignment in receivers and in a wide range of other electronics equipment.

More information

Homework Assignment 06

Homework Assignment 06 Question 1 (2 points each unless noted otherwise) Homework Assignment 06 1. True or false: when transforming a circuit s diagram to a diagram of its small-signal model, we replace dc constant current sources

More information

21/10/58. M2-3 Signal Generators. Bill Hewlett and Dave Packard s 1 st product (1939) US patent No HP 200A s schematic

21/10/58. M2-3 Signal Generators. Bill Hewlett and Dave Packard s 1 st product (1939) US patent No HP 200A s schematic M2-3 Signal Generators Bill Hewlett and Dave Packard s 1 st product (1939) US patent No.2267782 1 HP 200A s schematic 2 1 The basic structure of a sinusoidal oscillator. A positive feedback loop is formed

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

Physical Limitations of Op Amps

Physical Limitations of Op Amps Physical Limitations of Op Amps The IC Op-Amp comes so close to ideal performance that it is useful to state the characteristics of an ideal amplifier without regard to what is inside the package. Infinite

More information

University of Pittsburgh

University of Pittsburgh University of Pittsburgh Experiment #6 Lab Report Active Filters and Oscillators Submission Date: 7/9/28 Instructors: Dr. Ahmed Dallal Shangqian Gao Submitted By: Nick Haver & Alex Williams Station #2

More information

Applied Electronics II

Applied Electronics II Applied Electronics II Chapter 3: Operational Amplifier Part 1- Op Amp Basics School of Electrical and Computer Engineering Addis Ababa Institute of Technology Addis Ababa University Daniel D./Getachew

More information

OSCILLATORS AND WAVEFORM-SHAPING CIRCUITS

OSCILLATORS AND WAVEFORM-SHAPING CIRCUITS OSILLATORS AND WAVEFORM-SHAPING IRUITS Signals having prescribed standard waveforms (e.g., sinusoidal, square, triangle, pulse, etc). To generate sinusoidal waveforms: o Positive feedback loop with non-linear

More information

EXPERIMENT 2.2 NON-LINEAR OP-AMP CIRCUITS

EXPERIMENT 2.2 NON-LINEAR OP-AMP CIRCUITS 2.16 EXPERIMENT 2.2 NONLINEAR OPAMP CIRCUITS 2.2.1 OBJECTIVE a. To study the operation of 741 opamp as comparator. b. To study the operation of active diode circuits (precisions circuits) using opamps,

More information

C H A P T E R 02. Operational Amplifiers

C H A P T E R 02. Operational Amplifiers C H A P T E R 02 Operational Amplifiers The Op-amp Figure 2.1 Circuit symbol for the op amp. Figure 2.2 The op amp shown connected to dc power supplies. The Ideal Op-amp 1. Infinite input impedance 2.

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

Lecture # 11 Oscillators (RC Circuits)

Lecture # 11 Oscillators (RC Circuits) December 2014 Benha University Faculty of Engineering at Shoubra ECE-312 Electronic Circuits (A) Lecture # 11 Oscillators (RC Circuits) Instructor: Dr. Ahmad El-Banna Agenda Introduction Feedback Oscillators

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

EE301 ELECTRONIC CIRCUITS CHAPTER 2 : OSCILLATORS. Lecturer : Engr. Muhammad Muizz Bin Mohd Nawawi

EE301 ELECTRONIC CIRCUITS CHAPTER 2 : OSCILLATORS. Lecturer : Engr. Muhammad Muizz Bin Mohd Nawawi EE301 ELECTRONIC CIRCUITS CHAPTER 2 : OSCILLATORS Lecturer : Engr. Muhammad Muizz Bin Mohd Nawawi 2.1 INTRODUCTION An electronic circuit which is designed to generate a periodic waveform continuously at

More information

55:041 Electronic Circuits

55:041 Electronic Circuits 55:041 Electronic Circuits Oscillators Sections of Chapter 15 + Additional Material A. Kruger Oscillators 1 Stability Recall definition of loop gain: T(jω) = βa A f ( j) A( j) 1 T( j) If T(jω) = -1, then

More information

Basic Operational Amplifier Circuits

Basic Operational Amplifier Circuits Basic Operational Amplifier Circuits Comparators A comparator is a specialized nonlinear op-amp circuit that compares two input voltages and produces an output state that indicates which one is greater.

More information

Lesson number one. Operational Amplifier Basics

Lesson number one. Operational Amplifier Basics What About Lesson number one Operational Amplifier Basics As well as resistors and capacitors, Operational Amplifiers, or Op-amps as they are more commonly called, are one of the basic building blocks

More information

Wien-Bridge oscillator has simplified frequency control

Wien-Bridge oscillator has simplified frequency control Wien-Bridge oscillator has simplified frequency control High-quality audio signal generators mae extensive use of the Wien-Bridge oscillator as a basic building bloc. The number of frequency decades covered

More information

AUDIO OSCILLATOR DISTORTION

AUDIO OSCILLATOR DISTORTION AUDIO OSCILLATOR DISTORTION Being an ardent supporter of the shunt negative feedback in audio and electronics, I would like again to demonstrate its advantages, this time on the example of the offered

More information

AE103 ELECTRONIC DEVICES & CIRCUITS DEC 2014

AE103 ELECTRONIC DEVICES & CIRCUITS DEC 2014 Q.2 a. State and explain the Reciprocity Theorem and Thevenins Theorem. a. Reciprocity Theorem: If we consider two loops A and B of network N and if an ideal voltage source E in loop A produces current

More information

Homework Assignment 10

Homework Assignment 10 Homework Assignment 10 Question The amplifier below has infinite input resistance, zero output resistance and an openloop gain. If, find the value of the feedback factor as well as so that the closed-loop

More information

CHAPTER 3 OSCILOSCOPE AND SIGNAL CONDITIONING

CHAPTER 3 OSCILOSCOPE AND SIGNAL CONDITIONING CHAPTER 3 OSCILOSCOPE AND SIGNAL CONDITIONING OUTLINE Introduction to Signal Generator Oscillator Requirement for Oscillation Positive Feedback Amplifier Oscillator Radio Frequency Oscillator Introduction

More information

AN increasing number of video and communication applications

AN increasing number of video and communication applications 1470 IEEE JOURNAL OF SOLID-STATE CIRCUITS, VOL. 32, NO. 9, SEPTEMBER 1997 A Low-Power, High-Speed, Current-Feedback Op-Amp with a Novel Class AB High Current Output Stage Jim Bales Abstract A complementary

More information

Infrared Communications Lab

Infrared Communications Lab Infrared Communications Lab This lab assignment assumes that the student knows about: Ohm s Law oltage, Current and Resistance Operational Amplifiers (See Appendix I) The first part of the lab is to develop

More information

Thursday, 1/23/19 Automatic Gain Control As previously shown, 1 0 is a nonlinear system that produces a limit cycle with a distorted sinusoid for

Thursday, 1/23/19 Automatic Gain Control As previously shown, 1 0 is a nonlinear system that produces a limit cycle with a distorted sinusoid for Thursday, 1/23/19 Automatic Gain Control As previously shown, 1 0 is a nonlinear system that produces a limit cycle with a distorted sinusoid for x(t), which is not a very good sinusoidal oscillator. A

More information

For the filter shown (suitable for bandpass audio use) with bandwidth B and center frequency f, and gain A:

For the filter shown (suitable for bandpass audio use) with bandwidth B and center frequency f, and gain A: Basic Op Amps The operational amplifier (Op Amp) is useful for a wide variety of applications. In the previous part of this article basic theory and a few elementary circuits were discussed. In order to

More information

Homework Assignment 07

Homework Assignment 07 Homework Assignment 07 Question 1 (Short Takes). 2 points each unless otherwise noted. 1. A single-pole op-amp has an open-loop low-frequency gain of A = 10 5 and an open loop, 3-dB frequency of 4 Hz.

More information

BME/ISE 3512 Bioelectronics. Laboratory Five - Operational Amplifiers

BME/ISE 3512 Bioelectronics. Laboratory Five - Operational Amplifiers BME/ISE 3512 Bioelectronics Laboratory Five - Operational Amplifiers Learning Objectives: Be familiar with the operation of a basic op-amp circuit. Be familiar with the characteristics of both ideal and

More information

LINEAR IC APPLICATIONS

LINEAR IC APPLICATIONS 1 B.Tech III Year I Semester (R09) Regular & Supplementary Examinations December/January 2013/14 1 (a) Why is R e in an emitter-coupled differential amplifier replaced by a constant current source? (b)

More information

Operational Amplifiers

Operational Amplifiers Questions Easy Operational Amplifiers 1. Which of the following statements are true? a. An op-amp has two inputs and three outputs b. An op-amp has one input and two outputs c. An op-amp has two inputs

More information

Dimensions in inches (mm) .021 (0.527).035 (0.889) .016 (.406).020 (.508 ) .280 (7.112).330 (8.382) Figure 1. Typical application circuit.

Dimensions in inches (mm) .021 (0.527).035 (0.889) .016 (.406).020 (.508 ) .280 (7.112).330 (8.382) Figure 1. Typical application circuit. Dimensions in inches (mm) Linear Optocoupler FEATURES Couples AC and DC signals.% Servo Linearity Wide Bandwidth, > khz High Gain Stability, ±.%/C Low Input-Output Capacitance Low Power Consumption,

More information

ELEC207 LINEAR INTEGRATED CIRCUITS

ELEC207 LINEAR INTEGRATED CIRCUITS Concept of VIRTUAL SHORT For feedback amplifiers constructed with op-amps, the two op-amp terminals will always be approximately equal (V + = V - ) This condition in op-amp feedback amplifiers is known

More information

Friday, 1/27/17 Constraints on A(jω)

Friday, 1/27/17 Constraints on A(jω) Friday, 1/27/17 Constraints on A(jω) The simplest electronic oscillators are op amp based, and A(jω) is typically a simple op amp fixed gain amplifier, such as the negative gain and positive gain amplifiers

More information

Homework Assignment 07

Homework Assignment 07 Homework Assignment 07 Question 1 (Short Takes). 2 points each unless otherwise noted. 1. A single-pole op-amp has an open-loop low-frequency gain of A = 10 5 and an open loop, 3-dB frequency of 4 Hz.

More information

GOVERNMENT OF KARNATAKA KARNATAKA STATE PRE-UNIVERSITY EDUCATION EXAMINATION BOARD II YEAR PUC EXAMINATION MARCH-2013 SCHEME OF VALUATION

GOVERNMENT OF KARNATAKA KARNATAKA STATE PRE-UNIVERSITY EDUCATION EXAMINATION BOARD II YEAR PUC EXAMINATION MARCH-2013 SCHEME OF VALUATION GOVERNMENT OF KARNATAKA KARNATAKA STATE PRE-UNIVERSITY EDUCATION EXAMINATION BOARD II YEAR PUC EXAMINATION MARCH-03 SCHEME OF VALUATION Subject Code: 0 Subject: PART - A 0. What does the arrow mark indicate

More information

BME 3512 Bioelectronics Laboratory Five - Operational Amplifiers

BME 3512 Bioelectronics Laboratory Five - Operational Amplifiers BME 351 Bioelectronics Laboratory Five - Operational Amplifiers Learning Objectives: Be familiar with the operation of a basic op-amp circuit. Be familiar with the characteristics of both ideal and real

More information

Homework Assignment 03

Homework Assignment 03 Homework Assignment 03 Question 1 (Short Takes), 2 points each unless otherwise noted. 1. Two 0.68 μf capacitors are connected in series across a 10 khz sine wave signal source. The total capacitive reactance

More information

ECE3204 D2015 Lab 1. See suggested breadboard configuration on following page!

ECE3204 D2015 Lab 1. See suggested breadboard configuration on following page! ECE3204 D2015 Lab 1 The Operational Amplifier: Inverting and Non-inverting Gain Configurations Gain-Bandwidth Product Relationship Frequency Response Limitation Transfer Function Measurement DC Errors

More information

ECE-342 Test 1: Sep 27, :00-8:00, Closed Book. Name : SOLUTION

ECE-342 Test 1: Sep 27, :00-8:00, Closed Book. Name : SOLUTION ECE-342 Test 1: Sep 27, 2011 6:00-8:00, Closed Book Name : SOLUTION All solutions must provide units as appropriate. Use the physical constants and data as provided on the formula sheet the last page of

More information

Oscillator Principles

Oscillator Principles Oscillators Introduction Oscillators are circuits that generates a repetitive waveform of fixed amplitude and frequency without any external input signal. The function of an oscillator is to generate alternating

More information

CHAPTER 3: OSCILLATORS AND WAVEFORM-SHAPING CIRCUITS

CHAPTER 3: OSCILLATORS AND WAVEFORM-SHAPING CIRCUITS CHAPTER 3: OSCILLATORS AND WAVEFORM-SHAPING CIRCUITS In the design of electronic systems, the need frequently arises for signals having prescribed standard waveforms (e.g., sinusoidal, square, triangle,

More information

ELC224 Final Review (12/10/2009) Name:

ELC224 Final Review (12/10/2009) Name: ELC224 Final Review (12/10/2009) Name: Select the correct answer to the problems 1 through 20. 1. A common-emitter amplifier that uses direct coupling is an example of a dc amplifier. 2. The frequency

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

OPERATIONAL AMPLIFIER PREPARED BY, PROF. CHIRAG H. RAVAL ASSISTANT PROFESSOR NIRMA UNIVRSITY

OPERATIONAL AMPLIFIER PREPARED BY, PROF. CHIRAG H. RAVAL ASSISTANT PROFESSOR NIRMA UNIVRSITY OPERATIONAL AMPLIFIER PREPARED BY, PROF. CHIRAG H. RAVAL ASSISTANT PROFESSOR NIRMA UNIVRSITY INTRODUCTION Op-Amp means Operational Amplifier. Operational stands for mathematical operation like addition,

More information

Common mode rejection ratio

Common mode rejection ratio Common mode rejection ratio Definition: Common mode rejection ratio represents the ratio of the differential voltage gaina d tothecommonmodevoltagegain,a cm : Common mode rejection ratio Definition: Common

More information

Dev Bhoomi Institute Of Technology Department of Electronics and Communication Engineering PRACTICAL INSTRUCTION SHEET REV. NO. : REV.

Dev Bhoomi Institute Of Technology Department of Electronics and Communication Engineering PRACTICAL INSTRUCTION SHEET REV. NO. : REV. Dev Bhoomi Institute Of Technology Department of Electronics and Communication Engineering PRACTICAL INSTRUCTION SHEET LABORATORY MANUAL EXPERIMENT NO. ISSUE NO. : ISSUE DATE: July 200 REV. NO. : REV.

More information

Integrated Circuit: Classification:

Integrated Circuit: Classification: Integrated Circuit: It is a miniature, low cost electronic circuit consisting of active and passive components that are irreparably joined together on a single crystal chip of silicon. Classification:

More information

EECE251 Circuit Analysis I Set 5: Operational Amplifiers

EECE251 Circuit Analysis I Set 5: Operational Amplifiers EECE251 Circuit Analysis I Set 5: Operational Amplifiers Shahriar Mirabbasi Department of Electrical and Computer Engineering University of British Columbia shahriar@ece.ubc.ca 1 Amplifiers There are various

More information

Lecture #3: Voltage Regulator

Lecture #3: Voltage Regulator Lecture #3: Voltage Regulator UNVERSTY OF CALFORNA, SAN DEGO Voltage regulator is a constant voltage source with a high current capacity to drive a low impedance load. A full-wave rectifier followed by

More information

Başkent University Department of Electrical and Electronics Engineering EEM 311 Electronics II Experiment 8 OPERATIONAL AMPLIFIERS

Başkent University Department of Electrical and Electronics Engineering EEM 311 Electronics II Experiment 8 OPERATIONAL AMPLIFIERS Başkent University Department of Electrical and Electronics Engineering EEM 311 Electronics II Experiment 8 Objectives: OPERATIONAL AMPLIFIERS 1.To demonstrate an inverting operational amplifier circuit.

More information

ECE4902 C Lab 5 MOSFET Common Source Amplifier with Active Load Bandwidth of MOSFET Common Source Amplifier: Resistive Load / Active Load

ECE4902 C Lab 5 MOSFET Common Source Amplifier with Active Load Bandwidth of MOSFET Common Source Amplifier: Resistive Load / Active Load ECE4902 C2012 - Lab 5 MOSFET Common Source Amplifier with Active Load Bandwidth of MOSFET Common Source Amplifier: Resistive Load / Active Load PURPOSE: The primary purpose of this lab is to measure the

More information

Project Report Designing Wein-Bridge Oscillator

Project Report Designing Wein-Bridge Oscillator Abu Dhabi University EEN 360 - Electronic Devices and Circuits II Project Report Designing Wein-Bridge Oscillator Author: Muhammad Obaidullah 03033 Bilal Arshad 0929 Supervisor: Dr. Riad Kanan Section

More information

High Speed BUFFER AMPLIFIER

High Speed BUFFER AMPLIFIER High Speed BUFFER AMPLIFIER FEATURES WIDE BANDWIDTH: MHz HIGH SLEW RATE: V/µs HIGH OUTPUT CURRENT: 1mA LOW OFFSET VOLTAGE: 1.mV REPLACES HA-33 IMPROVED PERFORMANCE/PRICE: LH33, LTC11, HS APPLICATIONS OP

More information

Dimensions in inches (mm) .021 (0.527).035 (0.889) .016 (.406).020 (.508 ) .280 (7.112).330 (8.382) Figure 1. Typical application circuit.

Dimensions in inches (mm) .021 (0.527).035 (0.889) .016 (.406).020 (.508 ) .280 (7.112).330 (8.382) Figure 1. Typical application circuit. IL Linear Optocoupler Dimensions in inches (mm) FEATURES Couples AC and DC signals.% Servo Linearity Wide Bandwidth, > khz High Gain Stability, ±.%/C Low Input-Output Capacitance Low Power Consumption,

More information

LM675 Power Operational Amplifier

LM675 Power Operational Amplifier LM675 Power Operational Amplifier General Description The LM675 is a monolithic power operational amplifier featuring wide bandwidth and low input offset voltage, making it equally suitable for AC and

More information

Chapter 9: Operational Amplifiers

Chapter 9: Operational Amplifiers Chapter 9: Operational Amplifiers The Operational Amplifier (or op-amp) is the ideal, simple amplifier. It is an integrated circuit (IC). An IC contains many discrete components (resistors, capacitors,

More information

Lecture 2: Non-Ideal Amps and Op-Amps

Lecture 2: Non-Ideal Amps and Op-Amps Lecture 2: Non-Ideal Amps and Op-Amps Prof. Ali M. Niknejad Department of EECS University of California, Berkeley Practical Op-Amps Linear Imperfections: Finite open-loop gain (A 0 < ) Finite input resistance

More information

DEPARTMENT OF ELECTRICAL ENGINEERING AND COMPUTER SCIENCE MASSACHUSETTS INSTITUTE OF TECHNOLOGY CAMBRIDGE, MASSACHUSETTS 02139

DEPARTMENT OF ELECTRICAL ENGINEERING AND COMPUTER SCIENCE MASSACHUSETTS INSTITUTE OF TECHNOLOGY CAMBRIDGE, MASSACHUSETTS 02139 DEPARTMENT OF ELECTRICAL ENGINEERING AND COMPUTER SCIENCE MASSACHUSETTS INSTITUTE OF TECHNOLOGY CAMBRIDGE, MASSACHUSETTS 019.101 Introductory Analog Electronics Laboratory Laboratory No. READING ASSIGNMENT

More information

AN174 Applications for compandors SA570/571 SA571

AN174 Applications for compandors SA570/571 SA571 RF COMMUNICATIONS PRODUCTS Applications for compandors SA570/571 SA571 1997 Aug 20 Philips Semiconductors APPLICATIONS The following circuits will illustrate some of the wide variety of applications for

More information

An active filter offers the following advantages over a passive filter:

An active filter offers the following advantages over a passive filter: ACTIVE FILTERS An electric filter is often a frequency-selective circuit that passes a specified band of frequencies and blocks or attenuates signals of frequencies outside this band. Filters may be classified

More information

Dimensions in inches (mm) .268 (6.81).255 (6.48) .390 (9.91).379 (9.63) .045 (1.14).030 (.76) 4 Typ. Figure 1. Typical application circuit.

Dimensions in inches (mm) .268 (6.81).255 (6.48) .390 (9.91).379 (9.63) .045 (1.14).030 (.76) 4 Typ. Figure 1. Typical application circuit. LINEAR OPTOCOUPLER FEATURES Couples AC and DC signals.% Servo Linearity Wide Bandwidth, > KHz High Gain Stability, ±.%/C Low Input-Output Capacitance Low Power Consumption, < mw Isolation Test Voltage,

More information

Difference between BJTs and FETs. Junction Field Effect Transistors (JFET)

Difference between BJTs and FETs. Junction Field Effect Transistors (JFET) Difference between BJTs and FETs Transistors can be categorized according to their structure, and two of the more commonly known transistor structures, are the BJT and FET. The comparison between BJTs

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

PHYS 536 The Golden Rules of Op Amps. Characteristics of an Ideal Op Amp

PHYS 536 The Golden Rules of Op Amps. Characteristics of an Ideal Op Amp PHYS 536 The Golden Rules of Op Amps Introduction The purpose of this experiment is to illustrate the golden rules of negative feedback for a variety of circuits. These concepts permit you to create and

More information

2. SINGLE STAGE BIPOLAR JUNCTION TRANSISTOR (BJT) AMPLIFIERS

2. SINGLE STAGE BIPOLAR JUNCTION TRANSISTOR (BJT) AMPLIFIERS 2. SINGLE STAGE BIPOLAR JUNCTION TRANSISTOR (BJT) AMPLIFIERS I. Objectives and Contents The goal of this experiment is to become familiar with BJT as an amplifier and to evaluate the basic configurations

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 8: Field Effect Transistors

Chapter 8: Field Effect Transistors Chapter 8: Field Effect Transistors Transistors are different from the basic electronic elements in that they have three terminals. Consequently, we need more parameters to describe their behavior than

More information

Project 6: Oscillator Circuits

Project 6: Oscillator Circuits : Oscillator Circuits Ariel Moss The purpose of this experiment was to design two oscillator circuits: a Wien-Bridge oscillator at 3 khz oscillation and a Hartley Oscillator using a BJT at 5 khz oscillation.

More information

EE LINEAR INTEGRATED CIRCUITS & APPLICATIONS

EE LINEAR INTEGRATED CIRCUITS & APPLICATIONS UNITII CHARACTERISTICS OF OPAMP 1. What is an opamp? List its functions. The opamp is a multi terminal device, which internally is quite complex. It is a direct coupled high gain amplifier consisting of

More information

About the Tutorial. Audience. Prerequisites. Copyright & Disclaimer. Linear Integrated Circuits Applications

About the Tutorial. Audience. Prerequisites. Copyright & Disclaimer. Linear Integrated Circuits Applications About the Tutorial Linear Integrated Circuits are solid state analog devices that can operate over a continuous range of input signals. Theoretically, they are characterized by an infinite number of operating

More information

ES250: Electrical Science. HW6: The Operational Amplifier

ES250: Electrical Science. HW6: The Operational Amplifier ES250: Electrical Science HW6: The Operational Amplifier Introduction This chapter introduces the operational amplifier or op amp We will learn how to analyze and design circuits that contain op amps,

More information

designideas Soft limiter for oscillator circuits uses emitter-degenerated differential pair

designideas Soft limiter for oscillator circuits uses emitter-degenerated differential pair Edited By brad thompson and Fran Granville readers SOLVE DESIGN PROBLEMS Soft limiter for oscillator circuits uses emitter-degenerated differential pair Herminio Martínez and Encarna Garcia, Technical

More information

For input: Peak to peak amplitude of the input = volts. Time period for 1 full cycle = sec

For input: Peak to peak amplitude of the input = volts. Time period for 1 full cycle = sec Inverting amplifier: [Closed Loop Configuration] Design: A CL = V o /V in = - R f / R in ; Assume R in = ; Gain = ; Circuit Diagram: RF +10V F.G ~ + Rin 2 3 7 IC741 + 4 6 v0-10v CRO Model Graph Inverting

More information

LM675 Power Operational Amplifier

LM675 Power Operational Amplifier Power Operational Amplifier General Description The LM675 is a monolithic power operational amplifier featuring wide bandwidth and low input offset voltage, making it equally suitable for AC and DC applications.

More information

ECEN 325 Lab 5: Operational Amplifiers Part III

ECEN 325 Lab 5: Operational Amplifiers Part III ECEN Lab : Operational Amplifiers Part III Objectives The purpose of the lab is to study some of the opamp configurations commonly found in practical applications and also investigate the non-idealities

More information

Module 4 Unit 4 Feedback in Amplifiers

Module 4 Unit 4 Feedback in Amplifiers Module 4 Unit 4 Feedback in mplifiers eview Questions:. What are the drawbacks in a electronic circuit not using proper feedback? 2. What is positive feedback? Positive feedback is avoided in amplifier

More information

Laboratory 9. Required Components: Objectives. Optional Components: Operational Amplifier Circuits (modified from lab text by Alciatore)

Laboratory 9. Required Components: Objectives. Optional Components: Operational Amplifier Circuits (modified from lab text by Alciatore) Laboratory 9 Operational Amplifier Circuits (modified from lab text by Alciatore) Required Components: 1x 741 op-amp 2x 1k resistors 4x 10k resistors 1x l00k resistor 1x 0.1F capacitor Optional Components:

More information

Q Multiplication in the Wien-bridge Oscillator

Q Multiplication in the Wien-bridge Oscillator Multiplication in the Wien-bridge Oscillator The Wien-bridge oscillator earns its name from the typical bridge arrangement of the feedbac loops (fig.). This configuration is capable of delivering a clean

More information

Chapter 9: Operational Amplifiers

Chapter 9: Operational Amplifiers Chapter 9: Operational Amplifiers The Operational Amplifier (or op-amp) is the ideal, simple amplifier. It is an integrated circuit (IC). An IC contains many discrete components (resistors, capacitors,

More information

EE301 Electronics I , Fall

EE301 Electronics I , Fall EE301 Electronics I 2018-2019, Fall 1. Introduction to Microelectronics (1 Week/3 Hrs.) Introduction, Historical Background, Basic Consepts 2. Rewiev of Semiconductors (1 Week/3 Hrs.) Semiconductor materials

More information