INTRODUCTION TO

ELECTRONIC CIRCUITS AND DEVICES

Presenter :Engr. Cezar N. Velasco Jr.

Learning Outcomes

Describe the historical development of electronics

Describe the design process of electronic circuits and systems

Describe electronic systems and their classifications

Introduction

The field of electronics deals with the design and applications of electronic devices

RadiosTelevisionsAudio equipmentsComputersIndustrial Control and Automation

History of Electronics 1958

1956

1947

1925

1906

1904

Triode vacuum

tube

Solid-state point

contact diode

Field Effect device

First radio circuits:Superheterodyne receiver,Television

Transistor

FM radio,Radar

Thyristor

Integrated Circuits

(ICs)

Color Television

Unipolar field effect

transistor

Power Electroni

cs

Moore’s Law Diagram

Growth in number of Transistors

Levels of IntegrationDate Degree of Integration Number of

Components

1950s Discrete Components 1 to 2

1960s Small-scale Integration (SSI) Fewer than 102

1966 Medium-scale Integration (MSI)

From 102 to 103

1969 Large-scale Integration From 103 to 104

1975 Very-large-scale Integration From 104 to 109

1990s Ultra-large-scale Integration More than 109

The degree of device integration continues to follow Moore’s

Law, which is an observation made by Gordon E. Moore that the

number of Transistors inside an IC could be doubled every 24

months at a density that also minimizes the cost of a transistor.

Electronic System

An electronic system is an arrangement of electronic

devices and components with a defined set of inputs

and outputs.

Electronic system may be categorized/classified

according to the type of application such as

communication system, medical electronics, instrumentation,

control system, computer system, mechatronics, office electronics,

consumer electronics, automobile electronics

Example of Electronic System

Electronic systems often use sensors and actuators. Sensors and actuators are often called transducers.A loudspeaker is an example of a transducer.

Electronic system

Radio receiver

AntennaSpeaker

Electronic system

DisplayTemperatur

esensor

Temperature display instrument

Types of Sensor Thermistors and thermocouples to measure

temperature Photransistors and photodiodes to measure

light Strain gauges and piezoelectric materials to

measure force Potentiometers, inductive sensors, and absolute

position encoders to measure displacement Microphones to measure sound Tachogenerators, accelerometers, and Doppler

effect sensors to measure motion Anemometer to measure the wind speed

Types of Actuators

Resistive heaters to produce heat Light-emitting diodes (LEDs) and light

dimmers to control the amount of light Solenoids to produce force Meters to indicate displacement Electric motors to produce motion or

speed Speakers and ultrasonic transducers to

produce sound.

The field of electronics can be classified into three areas:

Analog electronics deals primarily with the operation and applications of transistors as amplifying devices

Digital electronics deals primarily with the operation and applications of transistors as “on” and “off” switching devices.

Power electronics deals with the operation and applications of power semiconductor devices, including power transistors, as “on” and “off” for the control and conversion of electric power.

Advantages and disadvantages of Analog and Digital electronics

Noise is usually present in electronic circuits, added directly to analog signals and hence affect the signals. Noise will not affect the digital output and can effectively removed be removed from digital signals.

An analog circuit requires fewer individual components than a digital circuit to perform a given function. However, an analog circuit often requires large capacitors or inductors that cannot be manufactured in ICs.

A digital circuit tends to be easier to implement than an analog circuit in ICs, although it can be more complex than an analog circuit. Digital circuits, however, generally offer much higher quality and speed of signal processing.

Advantages and disadvantages of Analog and Digital electronics

Analog systems are designed to perform specific functions or operations, whereas digital systems are adaptable to a variety of tasks or uses.

Signals from sensors and actuators in electronic systems are generally analog. If an input signal has a low magnitude and must be processed at very high frequencies, then analog technique is required. For optimal performance and design, both analog and digital approaches are often used.

Analog-to-Digital Converters

An A/D converter converts an analog signal to digital form and provides an interface between analog and digital signals

Digital-to-Analog Converters

A D/A converter takes an input signal in binary form and produces an output voltage or current in an analog (or continuous) form.

Notation

Definition Quantity Subscript Example

DC value of the signalUppercase

Uppercase

VD

AC value of the signalLowercase

Lowercase

vd

Total instantaneous value of the signal (DC and AC)

Lowercase

Uppercase

vD

Complex variable, phasor, or rms value of the signal

Uppercase

Lowercase

Vd

Example

VDC and IDC are DC values

vab and ia are the instantaneous AC values

vAB and iA are total instantaneous values

Vab and Ia are total rms values

vab

B

A

vAB

VDC

iA vAB

t

VDC

vab

0

2sinwt

Specifications of Electronic Systems

An electronic system is normally designed to

perform certain functions or operations. The

performance of an electronic system is specified

or evaluated in terms of voltage , current, impedance, power, time, and frequency

at the input and output of the system

Transient SpecificationsTransient Specifications refer to the output signal of a circuit generated in response to a specified input signal, usually a repetitive pulse signal

Cont….Transient Specifications

Delay time td is the time before the circuit can respond to

any input signal.Rise time tr is the time required for the output to rise from

10% to 90% of its final (high) value.On time ton is the time during which the circuit is fully turned on

and is functioning in its normal mode.Fall time tf is the time required for the output to decrease from

90% to 10% of its initial (high) value.Off time toff is the time during which the circuit is completely

off, not operating.

DistortionDistortion may take many forms and can alter the shape, amplitude, frequency, or phase of a signal

Frequency SpecificationsThe range of signal frequencies of electronic signals varies

widely, depending on the applications. For frequencies less than fL

and greater than fH, the output is attenuated. But for the frequencies

between fL

and fH, the output remains almost constant. The frequency range from

fL to fH is called bandwidth of the circuit

Cont…Frequency Specifications

DC and small-signal SpecificationsThe DC and small-signal specifications include the DC power supply VCC , DC biasing currents (required to

activate and operate internal transistor), and power dissipation PD (power requirement from the DC power

supply).

Signal Amplification Types are classified by the types of input and output signals

Voltage Amplifier produces an amplified output voltage in response to an input voltage signal

Transconductance amplifier produces an amplified output current in response to an input voltage signal

Current Amplifier produces an amplified output current in response to an input current signal

Impedance amplifier produces an amplified output voltage and delivers power to a low resistance load signal

Power amplifier produces amplified output voltage and deliver power to a low resistance load in response to an input voltage signal

Functional types are classified by their function or output characteristics

Linear amplifier produces an output signal in response to an input signal without introducing significant distortion on the output signal, whereas a nonlinear amplifier does introduce distortion.

Audio amplifier is a power amplifier in the audio frequency (AF) range.

Operational amplifier performs some mathematical functions for instruments and for signal processing.

Wideband amplifier amplifies an input signal over a wide range of frequencies to boost signal levels, whereas a narrowband amplifier amplifies a signal over a specific narrow range of frequencies.

Radio frequency (RF) amplifier amplifies a signal for use over the RF range.

Servo amplifier uses a feedback loop to control the output at the desired level.

Interstage coupling types are classified by the coupling method of the signal at the input, at the output, or between stages

RC-coupled amplifier uses a network of resistors and capacitors to connect it to the following and preceding amplifier stages.

LC-coupled amplifier uses a network of inductors and capacitors to connect it to the following and preceding amplifier stages.

Transformer-coupled amplifier uses transformer to match impedances to the load side and input side.

Direct-coupled amplifier uses no interstage elements, and each stage is connected directly to the following and preceding amplifier stages.

Frequency types are classified in accordance to the frequency range

DC amplifier is capable of amplifying signals from zero frequency (DC) and above.

AF amplifier is capable of amplifying signals from 20 Hz to 20 kHz.

Video amplifier is capable of amplying signals up to a few hundred megahertz (< 10 MHz for TV).

Ultra-high frequency (UHF) amplifier is capable of amplifying signals up to a few gigahertz.

Load types are classified in accordance to the type of load

Audio amplifier has an audio type of load Video amplifier has a video type of load Tuned amplifier amplifies a single RF or band of

frequencies.

Engineering Design

Engineering design is the process of devising a system,

component, or process to meet desired needs. It is a decision making process (often iterative), in which the basic

sciences and mathematics and engineering sciences are

applied to convert resources optimally to meet these stated

needs.

Source:From the definition of ABET (Accreditation Board for Engineering and Technology)

Elements of Design Process

Analysis is the process of finding the unique specifications or properties of a given circuit.Design is the creative process of developing a solution to a problem.

Circuit-level Design Process

End of first Topic