# ELECTRONIC INSTRUMENTATION AND SENSORS

## 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.

Finally, thanks to lab practice, students should

1. demonstrate software, hardware and equipment skills:

1.1. Demonstrate the ability of modeling electronic circuit and sensor/ actuator systems with Matlab or Spice

1.2. Demonstrate the safe and proper use of basic laboratory equipment

1.3. Demonstrate proper techniques for debugging/troubleshooting an experimental setup

1.4. Design, build, and characterize a custom set of signal conditioning circuits and transducers to make engineering and/or scientific measurements

2. demonstrate experimental and analytical skills:

2.1. Demonstrate the design/planning and completion of safe experiments,

2.2. Demonstrate manipulation and presentation of experimentally-obtained data,

2.3. Analyze and compare the results of mathematical and computer modeling of an experiment with actual experimental results

3. demonstrate the beginnings of professional practice:

3.1. Effectively communicate in written form the design, completion, and analysis of experiments,

3.2. Effectively communicate by oral presentation the design, completion, and analysis of experiments

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.

Finally, thanks to lab practice, students should

1. demonstrate software, hardware and equipment skills:

1.1. Demonstrate the ability of modeling electronic circuit and sensor/ actuator systems with Matlab or Spice

1.2. Demonstrate the safe and proper use of basic laboratory equipment

1.3. Demonstrate proper techniques for debugging/troubleshooting an experimental setup

1.4. Design, build, and characterize a custom set of signal conditioning circuits and transducers to make engineering and/or scientific measurements

2. demonstrate experimental and analytical skills:

2.1. Demonstrate the design/planning and completion of safe experiments,

2.2. Demonstrate manipulation and presentation of experimentally-obtained data,

2.3. Analyze and compare the results of mathematical and computer modeling of an experiment with actual experimental results

3. demonstrate the beginnings of professional practice:

3.1. Effectively communicate in written form the design, completion, and analysis of experiments,

3.2. Effectively communicate by oral presentation the design, completion, and analysis of experiments

## Prerequisites

Familiarity with analog circuit analysis (transistor models, small signal circuit analysis, frequency compensation, etc.), building blocks (amplifiers, mirrors, etc.) as taught in Elettronica 2.

Familiarity with analog circuit analysis (transistor models, small signal circuit analysis, frequency compensation, etc.), building blocks (amplifiers, mirrors, etc.) as taught in Elettronica 2.

Familiarity with electronic instruments.

## Course contents summary

To introduce students with the fundamentals of modern electronic instrumentation and sensor principles. 9 CFU will be dedicated to lessons and 3 CFU to laboratory projects.

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

2.4.7 photodetectors

The lab project will be designed to provide students with an opportunity to consolidate their theoretical knowledge of electronics and sensors and to acquaint them with the art and practice of circuit and product design.

Projects include electric, magnetic and piezo sensors, electronic instrumentation such oscillators and signal-conditioning circuits. A specification or functional description will be provided, and the students will design the circuit, select all components, construct a breadboard or a PCB, and test. The objective will be functional, pragmatic, cost-effective designs.

Software: LTSPICE and Matlab

To introduce students with the fundamentals of modern electronic instrumentation and sensor principles. 9 CFU will be dedicated to lessons and 3 CFU to laboratory projects.

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

The lab project will be designed to provide students with an opportunity to consolidate their theoretical knowledge of electronics and sensors and to acquaint them with the art and practice of circuit and product design.

Projects include electric, magnetic and piezo sensors, electronic instrumentation such oscillators and signal-conditioning circuits. A specification or functional description will be provided, and the students will design the circuit, select all components, construct a breadboard or a PCB, and test. The objective will be functional, pragmatic, cost-effective designs.

Software: LTSPICE and Matlab

## Course contents

Lessons:

1. ELECTRONIC INSTRUMENTATION (38 h)

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

1.1.1. electronic amplifiers

- voltage feedback amplifiers (VFA): complements about compensation to handle capacitive loads, photo-sensor and charge amplifiers, PCB layout issues for ultra-low leakage amplifiers in electrometers

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

- transconductance operational amplifiers (OTA): characteristics

- isolation amplifiers,

- differential amplifiers and instrumentation amplifiers (common solutions using VFAs, CFAs and OTAs)

1.1.2. active filters

- specifications

- synthesis of Butterworth and Chebyshev low-pass filters

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

- synthesis by Bi-Lin and Bi-Quad sections

- active RC synthesis

- sensitivity

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

1.2. oscillators (12 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 (34 h)

2.1. sensors and actuators: introductions, lumped modeling; (2 h)

2.2. energy-conserving transducers, linear and non-linear system dynamics: applications to electrostatic and magnetic transducers. (6 h)

2.3. Elasticity, stress and strain tensors, stiffness and compliance matrices. Elements of mechanical structures (2 h)

2.4. Physical principles of sensing, modeling and applications

2.4.1. Thermal sensors (thermal expansion, heat transfer, Seebeck and Peltier effects; thermocouples, pn junction sensors, RTD (conductor sensors such as PT100), Thermistors NTC and PTC; Hot-wire anemometer) (10 h)

2.4.2. Strain sensors (2 h) (resistance and specific resistivity, strain sensitivity in conductors, piezoresistive effect, signal conditioning for resistive sensors (bridges, linearization)).

2.4.3. capacitive sensors: applications

2.4.4. magnetic sensors (magnetism: Faraday, Ampère, induction laws; induction sensors fluxgate, search-coil, LVDT; conditioning (synchronous detector for instance in the fluxgate); Hall effect and magneto-resistors; non-contact position magnetostrictive sensors) (6 h)

2.4.6. piezoelectric sensors and actuators (6 h) (piezoelectric effect, models, signal conditioning at low-frequency and at resonance)

Laboratory: (12 x 3 hours)

The lab project will be designed to provide students with an opportunity to consolidate their theoretical knowledge of electronics and sensors and to acquaint them with the art and practice of circuit and product design.

Projects include electric, magnetic and piezo sensors, electronic instrumentation such oscillators and signal-conditioning circuits. A specification or functional description will be provided, and the students will design the circuit, select all components, possibly construct a breadboard or a PCB, and test. The objective will be functional, pragmatic, cost-effective designs.

Lessons:

1. ELECTRONIC INSTRUMENTATION (38 h)

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

1.1.1. electronic amplifiers

- voltage feedback amplifiers (VFA): complements about compensation to handle capacitive loads, photo-sensor and charge amplifiers, PCB layout issues for ultra-low leakage amplifiers in electrometers

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

- transconductance operational amplifiers (OTA): characteristics

- isolation amplifiers,

- differential amplifiers and instrumentation amplifiers (common solutions using VFAs, CFAs and OTAs)

1.1.2. active filters

- specifications

- synthesis of Butterworth and Chebyshev low-pass filters

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

- synthesis by Bi-Lin and Bi-Quad sections

- active RC synthesis

- sensitivity

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

1.2. oscillators (12 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 (34 h)

2.1. sensors and actuators: introductions, lumped modeling; (2 h)

2.2. energy-conserving transducers, linear and non-linear system dynamics: applications to electrostatic and magnetic transducers. (6 h)

2.3. Elasticity, stress and strain tensors, stiffness and compliance matrices. Elements of mechanical structures (2 h)

2.4. Physical principles of sensing, modeling and applications

2.4.1. Thermal sensors (thermal expansion, heat transfer, Seebeck and Peltier effects; thermocouples, pn junction sensors, RTD (conductor sensors such as PT100), Thermistors NTC and PTC; Hot-wire anemometer) (10 h)

2.4.2. Strain sensors (2 h) (resistance and specific resistivity, strain sensitivity in conductors, piezoresistive effect, signal conditioning for resistive sensors (bridges, linearization)).

2.4.3. capacitive sensors: applications

2.4.4. magnetic sensors (magnetism: Faraday, Ampère, induction laws; induction sensors fluxgate, search-coil, LVDT; conditioning (synchronous detector for instance in the fluxgate); Hall effect and magneto-resistors; non-contact position magnetostrictive sensors) (6 h)

2.4.6. piezoelectric sensors and actuators (6 h) (piezoelectric effect, models, signal conditioning at low-frequency and at resonance)

Laboratory: (12 x 3 hours)

The lab project will be designed to provide students with an opportunity to consolidate their theoretical knowledge of electronics and sensors and to acquaint them with the art and practice of circuit and product design.

Projects include electric, magnetic and piezo sensors, electronic instrumentation such oscillators and signal-conditioning circuits. A specification or functional description will be provided, and the students will design the circuit, select all components, possibly construct a breadboard or a PCB, and test. The objective will be functional, pragmatic, cost-effective designs.

## 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

V. Kaajakari, Practical MEMS, Small Gear Pub., 2009, (ISBN: 978-0-9822991-0-4)

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

Practical design techniques for sensor signal conditioning, Analog Devices, http://www.analog.com/

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

V. Kaajakari, Practical MEMS, Small Gear Pub., 2009, (ISBN: 978-0-9822991-0-4)

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

Practical design techniques for sensor signal conditioning, Analog Devices, http://www.analog.com/

## Teaching methods

There will be 36 Lectures of 2 hours each and up to 5 laboratory assignments to be developed preferably in groups of 2 or 3 students during 12 weeks (3 consecutive hours per week).

Laboratory projects consist of

- design of an active filter by means of Matlab and Spice

- design of a sinusoidal oscillator with Spice

- design of a signal conditioning circuit for a NTC sensor

- analysis with Spice or Matlab of a self-balancing bridge described in a scientific paper

- analysis with Spice or Matlab of a conditioning circuit for a Rogowski coil described in a scientific paper

The due dates for laboratory assignments will be given on the web page.

Homework assignments must be submitted in a concise (4 page maximum) 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

Lessons will be trasmitted on-line: they will be recordered and recording will be available for a week.

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 LTSpice

There will be 36 Lectures of 2 hours each and 2 laboratory assignments to be developed in groups of 2 or 3 students during 12 weeks (3 consecutive hours per week).

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.

The due dates for laboratory assignments will be given on the web page.

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.dia.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 LTSpice

## Assessment methods and criteria

Grading:

Homework assignments and quizzes: 30%

All homework assignments and quizzes are graded on a scale from 0 to 30 and will be weighted by a coefficient of the 6%

Oral examination: 70%

The final exam will be in oral form. The knowledge, understanding and ability will be valued by 4 short parts:

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

2. the analysis of an electronic circuit similar to those analysed during the course (15%)

3. the technical discussion of one of the assigned scientific papers, in order to verify criticism and autonomous capability to read an english paper facing a new technical problem (15%)

4. the discussion of one of the technical reports which each team has prepared throughout the laboratory activity; the goal is to verify the accomplished ability to apply the theoretical knowledge (10%)

Grading:

Homework assignments and quizzes: 30%

All homework assignments and quizzes are graded on a scale from 0 to 30 and will be weighted by a coefficient: 8% for homework and 3% (6%) for 2 (1) quizzes

Oral examination: 70%

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 (20%)

3. the discussion of one of the technical reports which each team has prepared throughout the laboratory activity; the goal is to verify the accomplished ability to apply the theoretical knowledge (20%)

## Other informations

See web site Elly

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