Learning objectives
The course provides an introduction to bipolar and MOS analogue electronic circuits, with emphasis on linear amplifiers.
Prerequisites
Analisi matematica 1 e 2. Fisica generale 1 e 2. Principi e Applicazioni dell’Ingegneria Elettrica . Elettronica 1
Course unit content
Introduction Analogue and digital signals. Linearity, conditions for avoiding linear distortion. Linearization.
Small signal equivalent circuit for a p-n diode. Small-signal BJT model in active zone, common emitter (CE) connection. Small signal MOSFET model in saturation.
Linear amplifiers. Network functions. Elementary amplifiers: The common emitter (CE) amplifier: bias point, small signal DCanalysis, large signal analysis. Bias point stability. Emitter follower (CC). Common base amplifier (CB). Common source, drain and gate amplifiers.
Multi-stage amplifiers: CC+CE, CE+CC, cascode. Darlington connection. BJT differential pair. Active loads and current mirrors.
Frequency response of amplifiers. Frequency response of the CE amplifier, Bode plots. Feedback in electronic circuits. Block schemes for the representation of linear systems. Positive and negative feedback in amplifiers. Properties of negative feedback: desensitization, bandwidth, . Pointing out feedback in electronic circuits. The Op-Amp concept. Stability of feedback systems:Nyquist and Bode criteria, analysis of the poles of the transfer function, root loci.
Operational amplifiers. Definition, virtual short-circuit concept. Applications: inverting and non-inverting amplifier, follower, sum-difference amplifier, integrator, I-V converters, negative impedance converters, girators, precision rectifiers, peak detectors. Compensation of op-amp circuits: by gain reduction, lag compensation, lead compensation. Limitations: offset, input currents and slew rate.
Large-signal analysis of output stages.
Distortion, conversion efficiency, power gain and normalized power handling capability. Class A output stages: common collector/drain, common emitter/source. Stress of output devices (Imax, Vmax).Heat transmission in electronic devices. Safe Operating Area. Definition of class A,B,C and D operation. Class AB push-pull operation. Class C operation. Class D operation with resonant load or with wide band signals (PWM).
An introduction to oscillators and multivibrators. Stability of the bias point. Natural frequencies of a linear network. One single rest point, two complex conjugate, positive real part natural frequencies: examples of circuits potentially capable of sustaining quasi-sinusoidal oscillations. A single rest point, real positive natural frequencies: astable multivibrator examples. Transient behavior analysis using servo switches. Two stable and one unstable rest points: examples of bistable multivibrators. Examples of monostable multivibrators.
Bibliography
P. R. Gray, P.J. Hurst, S.H. Lewis, R. G. Meyer, “Analysis and Design of Analog Integrated Circuits”, 5th Edition, Wiley.
C. Morandi, “Elettronica C”, available on Lea, corsi on line.
Additional Books
S. Franco, “Design with Operational Amplifiers and Analog Integrated Circuits” McGraw-Hill
Teaching methods
Lectures.
Exercises are solved in the classroom and deal with the analysis and design of simple analogue circuits.
Assessment methods and criteria
The exam includes a written and an oral part.
To gain access to the oral discussion, students have to get through the written part of the exam.
The written and the oral parts of the exam must be successfully completed within the same exam session (summer, fall or winter).
If the student does not pass the oral part of the exam, the result gained in the written part expires.
To be accepted to the written part of the exam, students have to register themselves in the web page of the exam.
