Introduction to Electronic Circuits and Devices

1. Presenter : Engr. Cezar N. Velasco Jr. Introduction to Electronic Circuits and Devices

2. Learning Outcomes • Describe the historical development of electronics • Describe the design process of electronic circuits and systems • Describe electronic systems and their classifications

3. Introduction Radios Televisions Audio equipments Computers Industrial Control and Automation The field of electronics deals with the design and applications of electronic devices

5. History of Electronics Integrated Circuits (ICs) 1958 1956 1947 1925 1906 1904 Thyristor Power Electronics Transistor Color Television Unipolar field effect transistor Field Effect device FM radio, Radar Solid-state point contact diode First radio circuits: Superheterodyne receiver, Television Triode vacuum tube

6. Moore’s Law Diagram Growth in number of Transistors

7. Levels of Integration 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.

8. 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

9. Example of Electronic System Antenna Speaker 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 Temperature sensor Electronic system Display Temperature display instrument

10. 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

11. 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.

12. 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.

13. 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.

14. 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.

15. Analog-to-Digital Converters An A/D converter converts an analog signal to digital form and provides an interface between analog and digital signals

16. 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.

17. Notation

18. Example A iA vAB 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 vab 2sinwt VDC vAB VDC t 0 B

19. 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

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

21. Cont….Transient Specifications Delay time tdis the time before the circuit can respond to any input signal. Rise time tris the time required for the output to rise from 10% to 90% of its final (high) value. On time tonis the time during which the circuit is fully turned on and is functioning in its normal mode. Fall time tfis the time required for the output to decrease from 90% to 10% of its initial (high) value. Off time toffis the time during which the circuit is completely off, not operating.

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

23. Frequency Specifications The 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

24. Cont…Frequency Specifications

25. DC and small-signal Specifications The 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).

26. 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

27. 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.

28. 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.

29. 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.

30. 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.

31. 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)

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

33. Circuit-level Design Process

34. End of first Topic