# ELECTRONIC INSTRUMENTATION AND SENSORS + LABORATORY (UNIT 1)

## Learning outcomes of the course unit

At the end of this course, students will be able to:

1 - understand the principles on which the operation of quasi-sinusoidal oscillators is based,

2 - know the basic elements of signal conditioning and noise sources in electronic instrumentation,

3 - develop judgment of what response and architecture is appropriate in the filter design for different applications,

4 - analyze noise in electronic circuits and make a noise and static error budget

5 - know and understand the physical principles of sensors and select the right sensor for a given application

6 - represent by mathematical models some sensors and actuators which transduce energy between different domains

## Prerequisites

It is assumed that students are familiar with analog circuit analysis (transistor models, small signal circuit analysis, frequency compensation, etc.), building blocks (amplifiers, mirrors, etc.) as taught in Elettronica 2

## Course contents summary

To introduce students with the fundamentals of modern electronic instrumentation and sensor principles.

Topics include:

1. ELECTRONIC INSTRUMENTS

1.1. signal conditioning components such as:

1.1.1. electronic amplifiers

1.1.2. active filters

1.1.3. non-linear circuits

1.2. oscillators

1.3. electronic noise

2. SENSORS

2.1. sensors and actuators: lumped models,

2.2. energy-conserving transducers, linear and non-linear system dynamics

2.3. elasticity, stress and strain tensors, stiffness and compliance matrices. Elements of mechanical structures

2.4. physical principles of sensing, modeling and applications

2.4.1. thermal sensors

2.4.2. strain sensors

2.4.3. capacitive sensors

2.4.4. magnetic sensors

2.4.5. magnetostrictive sensors and actuators

2.4.6. piezoelectric sensors and actuators

## Course contents

1. ELECTRONIC INSTRUMENTATION (36 h)

1.1. signal conditioning components such as: (Total: 20 h)

1.1.1. electronic amplifiers (11 h)

1.1.1.1. voltage feedback amplifiers (VFA): complements about compensation to handle capacitive loads, photosensor and charge amplifiers, PCB layout issues for ultra-low leakage amplifiers in electrometers (2 h)

1.1.1.2. current feedback amplifiers (CFA): behavioural model and simplified circuit diagram, bandwidth, slew-rate, stability issues, basic circuits (VCVS, VCCS, CCVS, CCCS, integrators) (5 h)

1.1.1.3. transconductance operational amplifiers (OTA): characteristics (1 h)

1.1.1.4. isolation amplifiers, (1 h)

1.1.1.5. differential amplifiers and instrumentation amplifiers (common solutions using VFAs, CFAs and OTAs) (2 h)

1.1.2. active filters (6 h)

1.1.2.1. specifications

1.1.2.2. synthesis of Butterworth and Chebyshev low-pass filters

1.1.2.3. frequency transformations for the synthesis of high-pass and pass-band filters

1.1.2.4. synthesis by Bi-Lin and Bi-Quad sections

1.1.2.5. active RC synthesis

1.1.2.6. sensitivity

1.1.3. non-linear circuits (logarithmic amplifiers, multipliers) (3 ore)

1.2. oscillators (10 h)

1.2.1. positive feedback and negative resistance oscillator concepts

1.2.2. oscillator start-up requirement and transient

1.2.3. amplitude limits, frequency control

1.2.4. RC, LC, crystal oscillators

1.3. Electronic noise (6 h)

1.3.1. noise analysis in passive circuits; diode, BJT and FET noise; 1/f noise;

1.3.2. two-port noise analysis, role of source resistance, equiv. input noise voltage

1.3.3. noise figure, total input noise for cascaded blocks

2. SENSORS (30 h)

2.1. sensors and actuators: introductions, lumped modeling; (1 h)

2.2. energy-conserving transducers, linear and non-linear system dynamics: applications to elctrostatic and magnetic transducers (5 h)

2.3. Elasticity, stress and strain tensors, stiffness and compliance matrices. Elements of mechanical structures (4 h)

2.4. Physical principles of sensing, modeling and applications

2.4.1. Thermal sensors (3 h)

2.4.1.1. thermal expansion, heat transfer, Seebeck and Peltier effects

2.4.1.2. thermocouples,

2.4.1.3. pn junction sensors,

2.4.1.4. RTD (conductor sensors such as PT100), Thermistors NTC and PTC

2.4.1.5. Hot-wire anemometer

2.4.2. Strain sensors (4 h)

2.4.2.1. resistance and specific resistivity, strain sensitivity in conductors, piezoresistive effect

2.4.2.2. signal conditioning for resistive sensors (bridges, linearization)

2.4.3. capacitive sensors (1 h)

2.4.3.1. applications

2.4.4. magnetic sensors (5 h)

2.4.4.1. magnetism (Faraday, Ampère, induction laws),

2.4.4.2. applications (fluxgate, search-coil, LVDT), conditioning (synchronous detector for instance in the fluxgate)

2.4.4.3. Hall effect and magnetoresistors

2.4.5. magnetostriction, applications to actuators and linear, non-contact sensors (1 h)

2.4.6. piezoelectric sensors and actuators (6 h)

2.4.6.1. piezoelectric effect, models

2.4.6.2. signal conditioning at low-frequency and at resonance

## Recommended readings

Recommended:

A. S. Sedra, K. C. Smith, Microelectronic circuits, Oxford University Press, 6th Ed., 2011

J. Fraden, Handbook of modern sensors, Springer, 3a Ed.

Suggested References:

S. Franco, Design with operational amplifiers and analog integrated circuits, 3rd ed., McGrawHill, 2002 (ISBN: 0071207031)

S.D. Senturia, Microsystem Design, Springer, 2001, (ISBN: 978-0-7923-7246-2) Cap.5-10

R. Pallas-Areny, J. G. Webster, Sensors and signal conditioning, 2nd ed., J. Wiley & Sons Inc., 2001 (ISBN: 0-471-33232-1)

## Teaching methods

There will be 33 Lectures of 2 hours each.

In addition, 3 homework, with the aim of strengthening the theoretical knowledge, and one or two unannounced quizzes will be given throughout the semester.

The due dates for homework assignments will be given on the days that the assignments are given. Unannounced quizzes will be short, reflect recent lectures and/or homework/reading assignments.

Unannounced quizzes cannot be made up and late homework will not be accepted, unless due to an excused absence (illness, examination, etc...). Homework assignments must be submitted in a format that is organized, professional and legible (labeled axes, correct units, readable simulations, etc...)

Lesson handouts and assigned scientific articles will be periodically posted on Elly (http://elly.dii.unipr.it/).

In order to download handouts, homeworks, etc., students have to be registered by the Instructor.

Reading assignments include sections of the recommended textbook, distributed readings, and supplementary notes handed out in lecture.More details will be available during the semester in the Course website.

It is highly suggested the use of Matlab and Spice

## Assessment methods and criteria

Grading:

Homework assignments and quizzes: 20%

All homework assignments and quizzes are graded on a scale from 0 to 30 and will be weighted by a coefficient: 5% for homework and 2.5% (5%) for 2 (1) quizzes

Oral examination: 80%

The final exam will be in oral form. The knowledge, understanding and ability will be valued by 3 short parts:

1 - the presentation of a subject covered in the lessons (30%)

2 - the discussion of a technical problem in order to verify the autonomous capability to solve simple analysis or design issues (25%)

3 - the discussion of one of the technical reports which each team has prepared throughout the laboratory activity (Unit 2); the goal is to verify the accomplished ability to apply the theoretical knowledge (25%)

## Other informations

Address: http://elly.dii.unipr.it