01/07/2020 Circuitos Electrónicos I Unidad 1: Introducción a los circuitos electrónicos Ingeniería en Computación Facultad de Matemáticas Universidad Autónoma de Yucatán Agosto – Diciembre 2020 Electronic systems are everywhere… 1 01/07/2020 How did we get here? Triode (1907) ENIAC (1945) Integrated Circuit (1959) Transistor (1947) µp 4004 (1971) Where are we now? https://www.computerhistory.org/siliconengine/ Feature size trends in IC technology 2 01/07/2020 Block diagram of electronic system Analog Processing Sensor Physical System Amp Digital Processing A/D Conv Filter DSP/ µP Physical Electrical Signal Signal Course sequence in CE curriculum Analog Processing Sensor Physical System Physical Electrical Signal Signal In Computer Engineering CV: 1. Digital Design of Computers 2. Embedded Systems E&M Signals & Systems Amp Digital Processing A/D Conv Filter Analog & Mixed-Signal Design Electronic Circuits I Electronic Circuits II Embedded Systems DSP/ µP Digital Design Digital Systems I Digital Systems II Computer Arch. 3 01/07/2020 Technologies for electronic systems Discrete Circuit Integrated Circuit (IC) Printed Circuit Board (PCB) System-in-Package (SiP) System-on-Chip (SoC) What is a circuit? We define a circuit as the interconnection of electric/electronic devices (with at least a closed path) to perform some useful function. This course will introduce you to the analysis and design of linear circuits for signal processing. 2kΩ 220kΩ 10V 4V 4 01/07/2020 The concept of circuit abstraction A typical “circuit” may contain millions of devices. How do we deal with this level of complexity? • Hierarchy: Divide and conquer • Large circuit broken into sub-blocks • Sub-blocks broken into devices Basic circuit elements or devices Resistor Capacitor Inductor Battery AC source M Current Switch Diode Motor BJT Button Fuse MOSFET + LED Op Amp 5 01/07/2020 Passive and active devices Generally, we refer to devices that do not require an external power source in order to operate as passive devices; these include resistors, capacitors, and inductors. In contrast, an active device (such as a transistor or an IC) cannot function without a power source. Circuit terminology: nodes and branches A branch represents a single element. A node is an electrical connection point between two or more branches (elements). 1 1 3 2 3 2 6 01/07/2020 Circuit terminology: loop and mesh A loop in a circuit is a closed path with the same start and end node. A mesh is a loop that encloses no other loops. 1 3 2-1-3-2 is a loop (closed path) 2 Electric signals An electric signal is a waveform (voltage, current) that carries information about our physical world. Examples of signals To process the information contained in electric signals, we design electronic circuits. 7 01/07/2020 Analog signals (a) Analog signal and (b) effect of noise on analog signal. • Signals that occur in nature can assume all values in a given range. Called analog, such signals include voice, video, seismic, and music waveforms. Analog circuits o Analog circuits represent the signals as an electrical current/voltage o Typical analog circuits: Amplifiers (weak signals picked up by a receiver) Filters (remove unwanted components) Math operations (multiply, integrate, differentiate) o Very susceptible to noise and distortion o Analog circuits are “hand-crafted” by analog “designers” Very poor design automation achieved. 8 01/07/2020 Digital signals (a) Digital signal and (b) effect of noise on digital signal. • A digital signal assumes only a finite number of values at only certain points in time. Digital circuits o Represent quantities by discrete voltages –“1” and “0”– called bits o Perform logic operations (AND, OR, XOR) on the signals o Mathematical operations can be performed using logic o Digital memory can be created using regenerative circuits o Digital circuits are robust against noise in signals (levels are “regenerated” after digital functions) 9 01/07/2020 Analog-to-digital conversion v(t) t1 t 2 t3 t4 t5 t6 t7 t8 t9 t10 t You will learn more about these concepts in Signals & Systems and Embedded Systems courses. Independent signal sources An independent voltage (current) source is an ideal circuit element that maintains a prescribed voltage (current) independently of their current (voltage) in their terminals. 10 01/07/2020 v + - vs(t) t 0 Instantaneous voltage source v + - Vmcos(ωt) Vm t 0 AC voltage source v + VS VS t 0 – DC (constant) voltage source Dependent sources CCCS VCCS VCVS CCVS 11 01/07/2020 Constant signals (supply/reference) • A constant ideal and real signal. In addition to a tilt, the real signal is corrupted by noise and glitches Sinusoidal signals 12 01/07/2020 Real sinusoidal signals Frequency spectrum of signals Any signal can be characterized in the time domain or in terms of its frequency spectrum. Frequency spectrum of the square wave vt 4V 1 1 sen0t sen30t sen50t ... 3 5 13 01/07/2020 Symbol convention Amplitude Amplitude DC Component AC Component Time Time (a) Single AC and DC signals, (b) Signal combination (adding). International System’s Dimensions Dimension Unit Symbol Length Mass Time Electric charge Temperature Luminous intensity meter kilogram second coulomb kelvin candela m kg s C K Cd Current Voltage Resistance Power Frequency ampere volt ohm watt hertz A V Ω W Hz 14 01/07/2020 Prefixes Prefix Symbol Magnitude atto femto pico nano micro mili centi deci kilo mega giga tera peta exa a f p n μ m c d k M G T P E 10-18 10-15 10-12 10-9 10-6 10-3 10-2 10-1 103 106 109 1012 1015 1018 Reading • Looking behind: Sections 1-2, 1-3 from Circuit Analysis and Design. • Looking ahead: Sections 1-4, 1-5, 1-6 from Circuit Analysis and Design. 15
