Lecture

Negative Feedback: Properties & Configurations

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In course

EE-336: Electronic circuits and systems

L'objectif de ce cours est l'étude approfondi des circuits et systèmes électroniques utilisant le concept fondamental de la réaction (feedback), en mettant l'accent sur les applications pratiques. Le cours aborde aussi les principes fondamentaux des conver ...

Description

This lecture covers the concept of negative feedback, including its introduction, definition, and basic relationships. It explores the ideal and non-ideal aspects of negative feedback, with examples of real-world analysis. The properties discussed include bandwidth expansion, gain stabilization, and noise reduction. The lecture also delves into the four fundamental configurations of negative feedback, such as unidirectional gain amplifiers and quadrupoles. It explains how negative feedback affects loop gain, precision, and linearization of transfer characteristics. The impact on input and output impedances is also examined, along with the reduction of harmonic distortions. The lecture concludes by summarizing the key performance parameters of negative feedback systems.

Instructors (2)

Maher Kayal

Maher Kayal received M.S. and Ph.D degrees in electrical engineering from the Ecole Polytechnique Fédérale de Lausanne (EPFL, Switzerland) in 1983 and 1989 respectively. He has been with the Electronics laboratories of the Ecole Polytechnique Fédérale de Lausanne (EPFL, Switzerland) since 1990, where he is currently a professor and director of the Energy Management and Sustainability" section. He has published many scientific papers, coauthor of three text books dedicated to mixed-mode CMOS design and he holds eleven patents. His technical contributions have been in the area of analog and Mixed-signal circuits design including highly linear and tunable sensors microsystems, signal processing and green energy management. Prizes and Honors Electronics Letters journal Premium Award 2013, Outstanding Paper Award? IEEE Mixdes 2013 Basil Papadias paper Award, IEEE Powertech 2013 Best Paper Awards, Mixdes 2013 Best Paper Awards, ICCAS 2012 Outstanding Paper Award- IEEE Mixdes 2012. Poland Section IEEE ED Chapter special award in 2011. Credit Suisse Award for Best Teaching- 2009. The William M. Portnoy Award at the Energy Conversion Congress and Exposition , California Sept 2009. Best Paper Award - IEEE-Mixdes 2009. High Quality Paper - IEEE Power Tech Conference June 2009. Best Paper Award - IEEE-Mixdes 2007. Best Paper Award - IEEE-TTTC International Conference on Automation, Quality and Testing, Robotics - 2006. Best Application Specific Integrated Circuit at the International European Design and Test Conference ED&TC - 1997. Ascom Award for the Best Work in Telecommunication Fields 1990. Publications Books. Books: Methodology for the Digital Calibration of Analog Circuits and Systems, Marc Pastre & Maher Kayal. Springer Publisher- (ISBN 1-4020-4252-3)-2006. Structured Analog CMOS Design, Danica Stefanovic & Maher Kayal. Springer Publisher-(ISBN 978-1-4020-8572-7)-2008. Linear CMOS RF Amplifiers for Wireless Applications, Maher Kayal, Springer Publisher. (ISBN 978-90-481-9360-8)-2010. Coeditor of Microelectronics Education Kluwer Academic Publishers. (ISBN 1-4020-2072-4). -2004.

Anisoara Ionescu

Teaching & PhD PhD Students Sebastian Mayr, Dario Sciacca, Hojjat Karami Past EPFL PhD Students as codirector Abolfazl Soltani, Gaëlle Prigent Courses Electronic circuits and systems EE-336 The objective of this course is an in-depth study of electronic circuits and systems using the fundamental concept of feedback, with an emphasis on practical applications. The course also covers the fundamental principles of A/D and D/A converters and their architectures. Sensors in medical instrument

Official source

Ontological neighbourhood

Physics

Electromagnetism: Electrical networks

Related concepts (32)

Input impedance

The input impedance of an electrical network is the measure of the opposition to current (impedance), both static (resistance) and dynamic (reactance), into a load network that is external to the electrical source network. The input admittance (the reciprocal of impedance) is a measure of the load network's propensity to draw current. The source network is the portion of the network that transmits power, and the load network is the portion of the network that consumes power.

Output impedance

The output impedance of an electrical network is the measure of the opposition to current flow (impedance), both static (resistance) and dynamic (reactance), into the load network being connected that is internal to the electrical source. The output impedance is a measure of the source's propensity to drop in voltage when the load draws current, the source network being the portion of the network that transmits and the load network being the portion of the network that consumes.

Impedance matching

In electronics, impedance matching is the practice of designing or adjusting the input impedance or output impedance of an electrical device for a desired value. Often, the desired value is selected to maximize power transfer or minimize signal reflection. For example, impedance matching typically is used to improve power transfer from a radio transmitter via the interconnecting transmission line to the antenna. Signals on a transmission line will be transmitted without reflections if the transmission line is terminated with a matching impedance.

Impedance parameters

Impedance parameters or Z-parameters (the elements of an impedance matrix or Z-matrix) are properties used in electrical engineering, electronic engineering, and communication systems engineering to describe the electrical behavior of linear electrical networks. They are also used to describe the small-signal (linearized) response of non-linear networks. They are members of a family of similar parameters used in electronic engineering, other examples being: S-parameters, Y-parameters, H-parameters, T-parameters or ABCD-parameters.

Open-loop gain

The open-loop gain of an electronic amplifier is the gain obtained when no overall feedback is used in the circuit. The open-loop gain of many electronic amplifiers is exceedingly high (by design) – an ideal operational amplifier (op-amp) has infinite open-loop gain. Typically an op-amp may have a maximal open-loop gain of around , or 100 dB. An op-amp with a large open-loop gain offers high precision when used as an inverting amplifier.

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