Fundamentals of Electronics 1

Electronic Components and Elementary Functions

Pierre Muret

• Publisher: Wiley-ISTE
• Year: 2017
• Print ISBN: 9781786301819
• eBook ISBN: 9781119453406
• Edition: 1
• Topic: Technology & Engineering
• Subtopic: Power Resources
• Index: Technology & Engineering

Electronics has undergone important and rapid developments over the last 60 years, which have generated a large range of theoretical and practical notions.

This book presents a comprehensive treatise of the evolution of electronics for the reader to grasp both fundamental concepts and the associated practical applications through examples and exercises.

This first volume of the Fundamentals of Electronics series comprises four chapters devoted to elementary devices, i.e. diodes, bipolar junction transistors and related devices, field effect transistors and amplifiers, their electrical models and the basic functions they can achieve.

Volumes to come will deal with systems in the continuous time regime, the various aspects of sampling signals and systems using analog (A) and digital (D) treatments, quantized level systems, as well as DA and AD converter principles and realizations.

1
Diodes and Applications

1.1. Semiconductor physics and current transport in pn diodes

1.1.1. Energy and concentration of mobile Charge carriers (electrons and holes)

Studies of electrons’ physical properties indicate that they appear either as particles with a movement quantity (or impulse) of p and mass m, or as waves of wavelength λ and wave vector k. Between these values, De Broglie’s wave mechanics establishes the following relation:

, where h = 6.62 ×10^–34 J·s and ħ = h/2 π.

Figure 1.1. Silicon crystal lattice (Ångstrom distances, equal to 0.1 nm)

Here, kinetic energy is

, while potential energy corresponds to the work of the attractive force between 1 electron and 1 proton until they are approximately separated by the atomic radius, that is a₀ ≈ 0.2 nm; therefore,

(with e = 1.6×10^–19 Coulomb and ε ≈10^–10 Farad/m in a semiconductor such as Si) to the order of 10^–19 J, or a little less than 1 eV.

In an isolated atom, quantum mechanics makes a connection between energy and the wave frequency associated with each electron, so that the energy of each can only take certain values known as energy levels. When the atoms are in a solid such as silicon, which can hold a crystal shape where atoms are arranged in a regular and periodic manner in space (Figure 1.1), the potential in terms of the electrons is that determined by the atoms’ nuclei as well as other electrons, also becoming regular and periodic in space.

A consequence of this is the transformation of energy levels into allowed energy bands separated by a forbidden bandgap (Figure 1.2). These allowed bands are made up of as many energy levels as there are electrons in the solid, also known as energy states or quantum states, spread over an energy range of several electron volts.

Figure 1.2. Energy bands of a solid (full and empty quantum states in dark and hatched color, respectively)

Only a single electron can be placed in the allowed bands per quantum state, both for isolated atoms and in solids.

Conduction is only possible if electrons can change quantum state, as this allows them to acquire kinetic energy and movement. This change can occur in the case of metals, as the allowed band with the highest energy levels, known as the conduction band, is only ever partially filled; conversely, this can only occur when the temperature increases above...

Table of contents

• Cover
• Table of Contents
• Title
• Copyright
• Preface
• Introduction
• 1 Diodes and Applications
• 2 Bipolar Junction Transistors and Applications
• 3 Field Effect Transistors and Applications
• 4 Amplifiers, Comparators and Other Analog Circuits
• Appendix: Electrical Circuits
• Bibliography
• Index
• End User License Agreement