Feedback.

Slides:



Advertisements
Similar presentations
Ref:080130HKNEE3110 Feedback Amplifiers1 Lecture 2 Feedback Amplifier Introduction of Two-Port Network Negative Feedback (Uni-lateral Case) Feedback Topology.
Advertisements

Chapter 6 Feedback Amplifiers
Feedback of Amplifier Circuits I
Chapter 3 Feedback Amplifiers
ELECTRONIC PRINCIPLES
Subject : Advance Electronics
Review 0、introduction 1、what is feedback?
Feedback Section 8.1. Topics General Feedback Examples of Feedback Circuits – Bandwidth Extension – Gain Sensitivity – Input and Output Impedance Types.
D. De Venuto,Politecnico di Bari 0 (a) ideal structure; (b) equivalent circuit. The series-series feedback amplifier.
ECE 352 Electronics II Winter 2003 Ch. 8 Feedback 1 *Feedback circuit does not load down the basic amplifier A, i.e. doesn’t change its characteristics.
Non-Ideal Characteristics Input impedance Output impedance Frequency response Slew rate Saturation Bias current Offset voltage.
The four basic feedback topologies: (a) voltage-sampling series-mixing (series-shunt) topology; (b) current-sampling shunt-mixing (shunt-series) topology;
Low Noise Amplifier Design
The General Feedback Structure
Microelectric Circuits by Meiling CHEN 1 Lecture 14 Feedback.
1 Figure 8.1 General structure of the feedback amplifier. This is a signal-flow diagram, and the quantities x represent either voltage or current signals.
Lecture 31 Electrical Instrumentation. Lecture 32 Electrical Instrumentation Electrical instrumentation is the process of acquiring data about one or.
Lecture161 Instrumentation Prof. Phillips March 14, 2003.
Chapter 8 - Feedback 1 - Desensitize The Gain 2 - Reduce Nonlinear Distortions 3 - Reduce The Effect of Noise 4 – Control The Input And Output Impedances.
Lecture 25 ANNOUNCEMENTS OUTLINE
Chapter 8 - Feedback 1 - Desensitize The Gain 2 - Reduce Nonlinear Distortions 3 - Reduce The Effect of Noise 4 – Control The Input And Output Impedances.
Frequency Response of Amplifier
Differential Amplifier
Sensitivity System sensitivity is defined as the available input signal level Si for a given (SNR)O Si is called the minimum detectable signal An expression.
Microelectronic Circuits, Sixth Edition Sedra/Smith Copyright © 2010 by Oxford University Press, Inc. C H A P T E R 10 Feedback.
ECE 352 Electronics II Winter 2003 Ch. 8 Feedback 1 Feedback *What is feedback?Taking a portion of the signal arriving at the load and feeding it back.
Chapter-9 Feedback Amplifier
General Characteristics of Negative-Feedback Amplifiers
ECE 342 – Jose Schutt-Aine 1 ECE 342 Solid-State Devices & Circuits 18. Operational Amplifiers Jose E. Schutt-Aine Electrical & Computer Engineering University.
1 Feedback. Microelectronic Circuits - Fifth Edition Sedra/Smith2 Copyright  2004 by Oxford University Press, Inc. Figure 8.1 General structure of the.
Microelectronic Circuits SJTU Yang Hua Chapter 8 Feedback Introduction 8.1 The general feedback structure 8.2 Some properties of negative feedback 8.3.
ECE 352 Electronics II Winter 2003 Ch. 8 Feedback 1 *Feedback circuit does not load down the basic amplifier A, i.e. doesn’t change its characteristics.
Chapter 5: FEEDBACK IN AMPLIFIER Dr. Gopika Sood, PG Govt. College For Girls, Sector -11, Chandigarh.
General Characteristics of Negative-Feedback Amplifiers
ECE 352 Electronics II Winter 2003 Ch. 8 Feedback 1 *Feedback circuit does not load down the basic amplifier A, i.e. doesn’t change its characteristics.
The College of New Jersey (TCNJ) – ELC251 Electronics I Based on Textbook: Microelectronic Circuits by Adel S. Sedra.
TELECOMMUNICATIONS Dr. Hugh Blanton ENTC 4307/ENTC 5307.
Feedback. 8.4 The Series-Shunt Feedback Amplifier The Ideal Situation.
Chapter 9. Feedback.
Chapter 3 Feedback Circuits BY: PN NORIZAN BINTI MOHAMED NAWAWI EKT 214 – Analog Electronic CIRCUIT II.
Chapter 9. Feedback.
Solid-State Devices & Circuits
Lecture VIII Operational Amplifiers DMT 231/3 Electronic II.
Exam 3 information Open book, open notes, bring a calculator Eligible topics (1 of 9) (not an exhaustive list) Generic amplifiers Amplifier basics voltage.
1 CHAPTER 20 OPERATIONAL AMPLIFIERS (OP-AMPS). 2 Introduction to operational amplifiers Symbol and Terminals.
CHAPTER 20 OPERATIONAL AMPLIFIERS (OP-AMPS). Introduction to operational amplifiers Symbol and Terminals.
Guided by - Prof. N A Gajjar Prepared by : Hemaxi Halpati : Priyank Hirani : Manish Jatiya : Rakesh.
Feedback Amplifier By : Mohanish R. Chaubal –
7/9/2016 HANSABA COLLEGE OF ENGINEERING AND TECHNOLOGY, SIDDHPUR.
Feedback Amplifiers. Outline Introduction The general feedback structure Some properties of negative feedback The four basic feedback topologies The series-shunt.
FEEDBACK CIRCUITS CLASSIFICATION OF AMPLIFIER CONCEPT OF FEEDBACK
E212 – Analog Electronic II
SAFFRONY INSTITUTE TECHNOLOGY
Feedback Xs Xi Xo + - Xf βf
Effect of feedback on amplifier poles
Feedback Amplifier RAi HIMANSHU ER NO
Feedback Xs Xi Xo + - Xf βf
C H A P T E R 10 Feedback Microelectronic Circuits, Sixth Edition
General Characteristics of Negative Feedback Amplifiers
Feedback Introduction 8.1 The general feedback structure
Control and Feedback Introduction Open-loop and Closed-loop Systems
Feedback Amplifiers.
Subject Name: Electronic Circuits Subject Code: 10CS32
EC16403 ELECTRONIC CIRCUITS II
Chapter 6 Feedback Circuits
Lecture 25 ANNOUNCEMENTS OUTLINE
Feedback Amplifiers By Dr. Vaibhav Jain Associate Professor, Dept. of Physics, D.A.V (PG) College, Bulandshahr, U.P., India.
Analysis of Single Stage Amplifiers
Unit –III Feedback Amplifiers
ECE 352 Electronics II Winter 2003 Ch. 8 Feedback 1 Feedback *What is feedback?Taking a portion of the signal arriving at the load and feeding it back.
Presentation transcript:

Feedback

8 Feedback Why Feedback? Desensitize the gain: make the value of the gain less sensitive to variations in the value of circuit components, such as might be caused by changes in temperature Reduce nonlinear distortion: make the output proportional to the input Reduce the effect of noise: minimize the contribution to the output of unwanted electric signals generated, either by the circuit components themselves, or by extraneous interference Control the input and output impedances: raise or lower the input and output impedance by the selection of an appropriate feedback topology Extend the bandwidth of the amplifier

8 Feedback 8.1 The General Feedback Structure

8.2 Some Properties of Negative Feedback 8.2.1 Gain Desensitivity Assume  is constant. Taking differentials of both sides results in desensitivity factor

8.2 Some Properties of Negative Feedback 8.2.2 Bandwidth Extension Midband Gain: 3-dB Frequency:

8.2 Some Properties of Negative Feedback 8.2.3 Noise Reduction Signal-to-Noise Ratio

8.2 Some Properties of Negative Feedback 8.2.3 Reduction in Nonlinear Distortion  = 0.01 Open Gain: 1000 Open Gain: 100

8.3 The Four Basic Feedback Topologies 8.3.1 Voltage Amplifiers Sample Voltage Mix Feedback Input: Voltage Output: Voltage Voltage-mixing voltage sampling Series - shunt feedback

8.3 The Four Basic Feedback Topologies 8.3.2 Current Amplifiers Sample Current Mix Feedback Input: Current Output: Current Current-mixing current sampling Shunt - series feedback

8.3 The Four Basic Feedback Topologies 8.3.3 Transconductance Amplifiers Sample Current Mix Feedback Input: Voltage Output: Current Voltage-mixing current sampling Series - series feedback

8.3 The Four Basic Feedback Topologies 8.3.4 Transresistance Amplifiers Sample Voltage Mix Feedback Input: Current Output: Voltage Current-mixing Voltage sampling Shunt - shunt feedback

8.4 The Series-Shunt Feedback Amplifier 8.4.1 The Ideal Situation

8.4 The Series-Shunt Feedback Amplifier 8.4.1 The Ideal Situation (cont.) Series mixing

8.4 The Series-Shunt Feedback Amplifier 8.4.1 The Ideal Situation (cont.) Shunt sampling

8.5 The Series-Series Feedback Amplifier 8.5.1 The Ideal Situation Series mixing

8.5 The Series-Series Feedback Amplifier 8.5.1 The Ideal Situation (cont.) Series sampling

8.6 The Shunt-Shunt and Shunt-Series Feedback Amplifier 8.6.1 The Shunt-Shunt Configuration

8.6 The Shunt-Shunt and Shunt-Series Feedback Amplifier 8.6.3 The Shunt-Series Configuration

8.6 The Shunt-Shunt and Shunt-Series Feedback Amplifier 8.6.3 Summary Ri  Rif: Mixing Voltage (series) mixing always increases the input resistance. Current (shunt) mixing always reduces it. Ro  Rof: Sampling Voltage (shunt) sampling always reduces the output resistance Current (series) sampling increases it

Homework: 10.1, 10.3, 10.8, 10.16, 10.24, 10.26, 10.31, 10.32