# ANALOGUE ELECTRONICS

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- Versione italiana
- Academic year
- 2018/2019
- Teacher
- GIORGIO VANNINI
- Credits
- 9
- Didactic period
- Primo Semestre
- SSD
- ING-INF/01

#### Training objectives

- This is the first course in the field of analog electronics and is focused on different circuit components which are essential for the elaboration of analog electrical signals.

After the introduction of the electrical characteristics of the fundamental semiconductor devices, the main objective is to provide the student with the basic tools for linear and non-linear circuit analysis and synthesis. Emphasis is put on the most important circuit components in analog electronics.

The student will learn:

basic elements of semiconductor devices behavior;

analysis of analog electronic circuits;

network functions and frequency response of small-signal amplifiers;

elaboration of analog signals by means of operational amplifiers;

non-linear circuit analysis: amplifiers and oscillators;

basics of linear and switching power supplies.

The main acquired skills (i.e., the capability of applying what has been learnt) will be:

selection of semiconductor devices for the specific circuit application;

analysis of static and dynamic behavior of linear analog circuits;

evaluation of small-signal amplifier performance;

implementation of analog functions by means of operational amplifiers;

basic design of sinusoidal oscillators and class-A and class–B power amplifiers;

basic design of the main circuit components of power supplies. #### Prerequisites

- The knowledge of the concepts and tools dealt with in the following courses are mandatory (within brackets the most important topics are put in evidence):

Circuit Theory (circuit components and related models, Kirchhoff laws and their application, Thevenin and Norton theorems)

Foundations of Automatic (transfer and harmonic response functions, feedback and stability)

Signals and Communications (time- and frequency-domain signals – signal spectra, modulation) #### Course programme

- 90 hours of teaching are given, divided in lectures (70 hours), exercises and/or guided labs (20 hours).

Introduction and background (5 hours). A glimpse inside analog electronics. Circuit theory fundamentals. Power amplification and electron devices. Examples of non-linear elaboration of signals.

Diodes (4 hours). Basics on semiconductors, doping and pn junction behavior. Diode and related models. Analysis of diode circuits.

Power supplies (9 hours). Rectifiers and associated filters. Use of transformers. Linear and switching DC/DC regulators. Switching amplifier.

Bipolar transistor and bias (6 hours). Structure and behavior; Ebers-Moll model. Simplified models and DC analysis. MOS transistor equations. The transistor as an amplifier. Voltage bias; use of base and emitter resistances. Current mirror.

Small-signal amplifiers 11 hours). Linearization. BJT and diode small-signal models. Elementary single-stage amplifiers: bandwidth and in-band behavior. Analysis of common-emitter, -collector and -base amplifiers. Analogy with small-signal FET amplifiers.

Low- and high-frequency response of amplifiers. (5 hours). Decupling capacitances and harmonic function response. Lower and upper cutoff frequencies (short-circuit time-constants technique). Basics on parasitic capacitances in BJTs and FETs. Cutoff and transition frequencies. High-frequency response of the common-emitter amplifier (basics on common-collector and common-base). Open-circuit time-constants technique.

Differential elaboration of signals (3 hours). Multi-stage amplifiers: capacitance decoupling and direct coupling. Differential amplifier and its practical implementation.

Operational amplifiers (7 hours). Background on negative feedback and desensitization. Operational amplifier: ideal characteristics. Static and dynamic analysis. Circuits employing operational amplifiers. Non-idealities in operational amplifiers. CMRR. Bandwidth limitation. Dominant pole and compensation. Time-domain response and slew-rate.

Power amplifiers (10 hours). Distortion and efficiency. Different classes of operation (A, B and C). Static and dynamic load-line. Class-A and –B power amplifiers (efficiency, distortion and thermal design). Class-C power amplifiers (basics). Amplification of angularly modulated signals and analogy with switching PWM amplifier.

Oscillators (10 hours). Quasi-sinusoidal feedback oscillators: oscillation amplitude and frequency, self-starting condition. Examples of LC and RC oscillators. Three-points LC oscillators. Frequency stability (basics, electrical and quartz resonators).

Exercises: (20 hours). Analysis and synthesis exercises on different topics of the course and with emphasis on the final examination. Some subjects could be dealt with also trough lab exercises. #### Didactic methods

- The course is organized as follows:

frontal lectures on all the topics of the course;

classroom analysis and synthesis exercises with emphasis on the final examination; some subjects could be dealt with through exercises in the informatics and/or electronics labs. #### Learning assessment procedures

- The final examination is a written test composed of two parts. The examination can be carried out in English.

- One analysis exercise of a small-signal amplifier (typically includes static, dynamic and bandwidth analysis).

- Three theory questions on the course topics with the aim of evaluating the comprehension of the topics and the gained skills.

The two parts cannot be taken separately and the must be both sufficient. They contribute equally to the final score.

The evaluation of the theory questions is carried out on the two questions selected by the student. The answer to the third question is taken into account (only if the answers to the two questions selected are evaluated as sufficient) for score refinement and a possible laude.

It is clear that since the student can choose 2 of the 3 questions provided, at least two questions must be evaluated as sufficient to pass the examination.

If the examination score is sufficient, but the score is not accepted by the student it is possible to take an additional oral test.

The examination takes 3 hours (1:45 exercise + 1:15 theory).

It is not allowed consulting any textbook or document.

The examination list closes two days before the scheduled date.

Passing the exam is proof of having acquired the ability to apply knowledge related to semiconductor devices use and analysis and synthesis of electronic circuits for analog electrical signals elaboration. #### Reference texts

- Teaching material provided by the teacher.

Specific topics can be further developed in the following text:

R.C.Jaeger, T.N.Blalock, Microelettronics.

Additional texts:

Jacob Millman, Arvin Grabel, Microelectronics, Mc Graw-Hill.

Adel S. Sedra, Kenneth C. Smith, Microelectronic circuits, Oxford University Press.