CircuitsandAnalogElectronics電路與模擬電子技術(shù)

1、Circuits and Analog Electronics電路與模擬電子技術(shù)Prof. Li Chen, School of Information Science and Technology, Sun Yat-sen University中山大學(xué)信息科學(xué)與技術(shù)學(xué)院 陳立副教授Email: 10 級(jí)計(jì)算機(jī)科學(xué) 22References：W. H. Hayt, Jr., J. E. Kemmerly and S. M. Durbin, Engineering Circuit Analysis, McGraw-Hill, 2005, ISBN 978-7-121-01667-7.R. L.

2、Boylestad and L. Nashelsky, Electronic Devices and Circuit Theory, Pearson Education, 2007, ISBN 978-7-121-04396-3.高玉良, 電路與模擬電子技術(shù), 高教出版社, 2004, ISBN 7-04-014536-7. Circuits and Analog ElectronicsHandouts available at: H. Hayt, Jr., J. E. Kemmerly and S. M. Durbin, Engineering Circuit Analysis, McGra

3、w-Hill, 2005, ISBN 978-7-121-01667-7.R. L. Boylestad and L. Nashelsky, Electronic Devices and Circuit Theory, Pearson Education, 2007, ISBN 978-7-121-04396-3.高玉良, 電路與模擬電子技術(shù), 高教出版社, 2004, ISBN 7-04-014536-7. Circuits and Analog ElectronicsWeeksChaptersReferences1, 2Basis concepts and laws of electron

4、icsHayt: Ch 1 2 53, 4Basis analysis methods to circuitsHayt: Ch 3 45Basis RL & RC circuitsHayt: Ch 66, 7, 8Sinusoidal steady state analysisHayt: Ch 79Midterm10Diodes and diodes circuitsBoylestad: Ch 1 211, 12, 13Basic BJT amplifier circuitsBoylestad: Ch 3-614, 15, 16Operational amplifier and Op Amp

5、circuitsBoylestad: Ch 1117ReviewTeaching ScheduleCh1 Basic Concepts and Laws of Electric Circuits1.1 Basic Concepts and Electric Circuits1.2 Basic Quantities1.3 Circuit Elements 1.4 Kirchhoffs Current and Voltage Laws References: Hayt: Ch1, 2, 5; Gao: Ch1; Circuits and Analog Electronics Signal proc

6、essing and transmissionAmplifiers 1.1 Basic Concepts and Electric Circuits Electrical power conversion and transmissionPower Supplies TransmissionLoadsCircuitsKinescopeAntennaSpeakertransmitter1.1 Basic Concepts and Electric Circuits Electrical power conversion and transmission1.1 Basic Concepts and

7、 Electric CircuitsQuestion: What is the current through the bulb? Concept of AbstractionSolution:In order to calculate the current, we can replace the bulb with a resistor.R is the only subject of interest, which serves as an abstraction of the bulb.1.1 Basic Concepts and Electric CircuitsLumped cir

8、cuit abstraction!A resistor is a circuit element that transforms the electrical energy (e.g. electricity heat);Commonly used devices that are modeled as resistors include incandescent, heaters, wires and etc;A circuit consists of sources, resistors, capacitors, inductors and conductors;Elements are

9、lumped.Conductors are perfect.Resistance: R = V/I, 1 =1V/A, ohm;Conductance: G = 1/R = 1A/V, siemens (S);1S = 1A/V, i(t) = G v(t);Instantaneous current and voltage at time t;1.1 Basic Concepts and Electric CircuitsUnderstanding the AM radio requires knowledge of several concepts Communications/signa

10、l processing (frequency domain analysis) Electromagnetics (antennas, high-frequency circuits) Power (batteries, power supplies) Solid state (miniaturization, low-power electronics)The AM Radio SystemTransmitterReceiverExample 1: The AM audio systemExample 2: The telephone system1.1 Basic Concepts an

11、d Electric Circuits1.1 Basic Concepts and Electric CircuitsThe AM Radio System A signal is a quantity that may vary with time.* Voltage or current in a circuit* Sound (sinusoidal wave traveling through air)* Light or radio waves (electromagnetic energy traveling through free space) The analysis and

12、design of AM radios (and communication systems in general) is usually conducted in the frequency domain using Fourier analysis, which allows us to represent signals as combinations of sinusoids (sines and cosines).1.1 Basic Concepts and Electric CircuitsThe AM Radio SystemFrequency is the rate at wh

13、ich a signal oscillates.Duration of the signal T, frequency of the signal f = 1/T.High FrequencyLow Frequency1.1 Basic Concepts and Electric CircuitsThe AM Radio System Visible light is the electromagnetic energy with frequency between 380THz (Terahertz) and 860THz. Our visual system perceives the f

14、requency of the electromagnetic energy as color: is 460THz, is 570THz, and is 630THz. An AM radio signal has a frequency of between 500kHz and 1.8MHz.FM radio and TV uses different frequencies. Mathematical analysis of signals in terms of frequency Most commonly encountered signals can be represente

15、d as a Fourier series or a Fourier transform. A Fourier series is a weighted sum of cosines and sines.redgreenblue1.1 Basic Concepts and Electric CircuitsThe AM Radio SystemFourier Series: A Fourier series decomposes a periodic function (or signal) into the sum of a set of sines and cosines. Given f

16、unction f(t) with angular frequency and period T, its Fourier series can be written as:f(t) = A0 + A1msin(t + 1) + A2msin(2t + 2) + = 1.1 Basic Concepts and Electric CircuitsExample: Given function during a period: tFor the example :, k is even., k is odd.1.1 Basic Concepts and Electric CircuitsThe

17、AM Radio SystemExample-Fourier Series Signals can be represented in terms of their frequency components. The AM transmitter and receiver are analyzed in terms of their effects on the frequency components signals.1st series + 3rd series1st series (k = 1)3rd series (k = 3)1.1 Basic Concepts and Electr

18、ic CircuitsThe AM Radio SystemThe modulator converts the frequency of the input signal from the audio range (0-5kHz) to the carrier frequency of the station (i.e. 605kHz-615kHz)freq5kHzFrequency domain representation of inputFrequency domain representation of outputfreq610kHzModulatorSignalSourceMod

19、ulatorPowerAmplifierAntennaTransmitter Block Diagram1.1 Basic Concepts and Electric CircuitsThe AM Radio SystemInput SignalOutput SignalModulator: Time Domain1.1 Basic Concepts and Electric CircuitsThe AM Radio SystemA typical AM station broadcasts several kWUp to 50kW-Class I or Class II stationsUp

20、 to 5kW-Class III stationUp to 1kW-Class IV stationTypical modulator circuit can provide at most a few mWPower amplifier takes modulator output and increases its magnitudePower AmplifierThe antenna converts a current or a voltage signal to an electromagnetic signal which is radiated through the spac

21、e.Antenna1.1 Basic Concepts and Electric CircuitsThe AM Radio SystemRFAmplifierIFMixerIFAmplifierEnvelopeDetectorAudioAmplifierAntennaSpeakerReceiver Block Diagram1.1 Basic Concepts and Electric CircuitsThe AM Radio SystemThe antenna captures electromagnetic energy and converts it to a small voltage

22、 or current.In the frequency domain, the antenna output is 0frequencyUndesired SignalsDesired SignalCarrier Frequencyof desired stationAntennainterferencesinterferences1.1 Basic Concepts and Electric CircuitsThe AM Radio SystemRF Amplifier amplifies small signals from the antenna to voltage levels a

23、ppropriate for transistor circuits.RF Amplifier also performs as a Bandpass filter for the signalBandpass filter attenuates the other components outside the frequency range that contains the desired stationRF (Radio Frequency) Amplifier0frequencyUndesired SignalsDesired SignalCarrier Frequency of de

24、sired stationThe AM Radio System0frequencyUndesired SignalsDesired Signal455 kHzIF (Intermediate Frequency) MixerThe IF Mixer shifts its input in the frequency domain from the carrier frequency to an intermediate frequency of 455kHzThe IF amplifier bandpass filters the output of the IF mixer, elimin

25、ating all of the undesired signals.IF Amplifier0frequencyDesired Signal455 kHz1.1 Basic Concepts and Electric CircuitsThe AM Radio SystemComputes the envelope of its input signalEnvelope DetectorOutput SignalInput Signal1.1 Basic Concepts and Electric CircuitsThe AM Radio SystemAudio AmplifierAmplif

26、ies signal from envelope detectorProvides power to drive the speakerHierarchical System ModelsModelling at different levels of abstractionHigher levels of the model describe overall function of the systemLower levels of the model describe necessary details to implement the systemIn the AM receiver,

27、the input is the antenna voltage and the output is the sound energy produced by the speaker.In EE, a system is an electrical and/or mechanical device, a process, or a mathematical model that relates one or more inputs to one or more outputs.SystemInputsOutputs1.1 Basic Concepts and Electric Circuits

28、The AM Radio SystemTop Level ModelAM ReceiverInput SignalSoundSecond Level ModelRFAmplifierIFMixerIFAmplifierEnvelopeDetectorAudioAmplifierAntennaSpeakerPower Supply1.1 Basic Concepts and Electric CircuitsThe AM Radio SystemHalf-waveRectifierLow-passFilterLow Level Model Envelope Detector.Circuit Le

29、vel Model Envelope Detector+-RC+-VoutVin1.1 Basic Concepts and Electric CircuitsThe Telephone SystemThe modern telephone system is developed from the following Electrical Engineering sub-disciplines:Signal processing: Speech compression, noise reduction, A/D and D/A conversion. E.g. channel coding +

30、 equalisation.Communications and networking: transmission technologies, network architectures and protocols.Digital and computer: configurable switching hardware.Electromagnetics: microwave transmission hardware.Solid state: miniaturization, integration of complex systems onto a single chip. E.g. bu

31、ilding a signal processing chips , called very-large-scale integration(VLSI)Power Electronics: extremely reliable power supplies.1.1 Basic Concepts and Electric CircuitsThe Telephone SystemAn Early Phone SystemTelephoneTelephoneSpeakerMic.TelephoneSpeakerMic.Central OfficeSwitchboardSpeakerMic.Power

32、 Supply1.1 Basic Concepts and Electric CircuitsThe Telephone SystemThe major components include a carbon microphone and a speaker made from an electromagnet and a paramagnetic diaphragm.Telephones were connected to the central office by twisted-pair wires.At the central office, calls were completed

33、by a human operator at a switchboard-a physical connection between two telephones was made.An Early Phone SystemAn Early Phone CircuitTelephone HandsetCarbon MicrophoneEarphoneCentral OfficeBatteryTelephone HandsetCarbon MicrophoneEarphone1.1 Basic Concepts and Electric CircuitsThe Telephone SystemT

34、he Modern Telephone SystemPCM EncoderPCM DecoderSwitching NetworkPCM DecoderPCM EncoderAnalogAnalogDigitalA similar network structure .There are very significant differences:Data, video, and other signals are transmitted along with speech.Calls are routed automatically under software control.Most tr

35、ansmission is digital.1.1 Basic Concepts and Electric CircuitsThe Telephone SystemAnalog Vs. DigitalAn analog signal is a continuous signal represented over time domain:A digital signal is a sequence of 1s and 0s:1101001010011100100110001001110timeBPSKInput 1 , =0Input 0 , =1801.1 Basic Concepts and

36、 Electric CircuitsThe Telephone SystemWhy Digital?Analogue signal is prone to interference and degradation. Digital signal easily be retreated and repeat without any signal distortion - long distance transmission.Can carry many types of information (phone, video, data, etc.)Digital hardware is less

37、expensive.Digital data can be encrypted.PCM-Pulse Code ModulationA PCM encoder converts an analog signal into a digital signal with a particular format.A PCM decoder converts a digital signal into an analog signal.PCM is a form of quantization.PCM is a form of analog-to-digital (A/D) conversion.1.1

38、Basic Concepts and Electric CircuitsThe Telephone SystemPCM-Pulse Code ModulationPCM EncoderA continuous signal is converted into a bit stream:0 1 1Involves three operations: Sampling, Quantization and EncodingtimeThe Telephone SystemPCM-Pulse Code ModulationSampling: Value of the signal is obtained

39、 at equally spaced points in time:timeQuantization: each sample is quantized to one of a finite number of values. 1.1 Basic Concepts and Electric CircuitstimeTs sampling time .Fs=1/Ts sampling frequency .The Telephone SystemPCM-Pulse Code ModulationEncoding: a pattern of bits is used to represent di

40、fferent output level of the quantizer;n bits can represent 2n quantizer output levels.PCM decoder is one type of digital-to-analog (D/A) converter.00000101000000001111111.1 Basic Concepts and Electric CircuitsWe have 5 output levels , we need at least 3 bits to represent them.00000000110000101101100

41、0.010Telephone NetworkA house or business is called a subscriber.Typically, phone lines to houses or small businesses are analog twisted-pair wire connections.Subscribers analog lines are connected to a Regional Terminal (RT) or to a Central Office (CO).At the RT or CO, the analog signal is converte

42、d to a digital signal.The Telephone SystemRTRTSubscriberSubscriberSubscriberSubscriberCOLong-distanceNetwork1.1 Basic Concepts and Electric Circuits1.2 Basic QuantitiesUnitsStandard SI Prefixes10-12 pico (p)10-9 nano (n)10-6 micro ()10-3 milli (m)103 kilo (k)106 mega (M)109 giga (G)1012 tera (T)Elec

43、tric charge (q)in Coulombs (C)Current (I)in Amperes (A)Voltage (V)in Volts (V)Energy (W)in Joules (J)Power (P)in Watts (W) CurrentTime rate of change of chargeConstant currentTime varying currentUnit(1 A = 1 C/s)1.2 Basic QuantitiesNotation: Current flow represents the flow of positive chargeAlterna

44、ting versus direct current (AC vs DC)i(t)i(t)ttDCACTime varying currentSteady current A mount of electric charges flowing through the surface per unit time.CurrentPositive versus negative current2 A-2 AP1.1, In the wire electrons moving left to right to create a current of 1 mA. Determine I1 and I2.

45、Ans: I1 = -1 mA; I2 = +1 mA.1.2 Basic QuantitiesCurrent is always associated with arrows (directions)Negative charge of -2C/s moving Positive charge of 2C/s moving orNegative charge of -2C/s moving Positive charge of 2C/s moving orVoltage(Potential)VoltageUnits: 1 V = 1 J/CPositive versus negative v

46、oltage+2 V-2 V1.2 Basic Quantities Energy per unit charge. It is an electrical force drives an electric current.+/- of voltage (V) tell the actual polarity of a certain point .DNTwo “Do Not (DN)”+/- of current (I) tell the actual direction of particles movement .DNVoltage (Potential)aba、b, which poi

47、nts potential is higher？ baVab = ?ab+Q from point b to point a get energy ，Point a is Positive? or negative ?1.2 Basic QuantitiesExample Voltage (Potential)abccdd1.2 Basic QuantitiesExample IVoltage (Potential)K OpenK CloseVa=?1.2 Basic QuantitiesExample III1.2 Basic QuantitiesExample IPower One jou

48、les of energy is expanded per second.Rate of change of energyP = W/tUsed to determine the electrical power is being absorbed or suppliedif P is positive (+), power is absorbedif P is negative (), power is supplied+v(t)i(t)p(t) = v(t) i(t)v(t) is defined as the voltage with positive reference at the

49、same terminal that the current i(t) is entering.1.2 Basic QuantitiesPowerExample1.2 Basic Quantities2A+-5VPower is supplied. delivered power to external element.+5V2APower is absorbed. Power delivered toNote :+5V+-5V2A-2APower absorbed .PowerPower absorbed by a resistor:1.2 Basic QuantitiesPower1234

50、5I1I2I3+-+-+-+-P1.5 Find the power absorbed by each element in the circuit.1.2 Basic QuantitiesSupply energy : element 1、3、4 .Absorb energy : element 2、5 Open CircuitR=I=0, V=E , P=0ER0Short CircuitR=0ER0R01.2 Basic QuantitiesLoaded CircuitER0RI1.2 Basic Quantities1.3 Circuit ElementsKey Words: Resi

51、stors, Capacitors, Inductors, voltage source, current source Passive elements (cannot generate energy)e.g., resistors, capacitors, inductors, etc.Active elements (capable of generating energy)batteries, generators, etc.Important active elementsIndependent voltage sourceIndependent current sourceDepe

52、ndent voltage sourcevoltage dependent and current dependentDependent current sourcevoltage dependent and current dependent1.3 Circuit ElementsResistors Dissipation Elements v=iR P=vi=Ri2=v2/R 0 ， v-i relationshipvi1.3 Circuit ElementsResistors connected in series:Equivalent Resistance is found by Re

53、q= R1 + R2 + R3 + R1R2R3Resistors connected in parallel 1/Req=1/R1 + 1/R2 + 1/R3 + R1R2R3CapacitorsCapacitance occurs when two conductors (plates) are separated by a dielectric (insulator).Charge on the two conductors creates an electric field that stores energy.The voltage difference between the tw

54、o conductors is proportional to the charge: q = C vThe proportionality constant C is called capacitance.Units of Farads (F) - C/V1F= one coulomb of charge of each conductor causes a voltage of one volt across the device. 1F=106F, 1F=106PF 1.3 Circuit ElementsCapacitors store energy in an electric fi

55、eld v-i relationshipi(t)+-v(t)TherestofthecircuitEnergy stored 1.3 Circuit ElementsCapacitors connected in series:Equivalent capacitance is found by 1/Ceq=1/C1 + 1/C2 + 1/C3 + seriesparallelCapacitors connected in parallel Ceq= C1 + C2 + C3 + vC(t+) = vC(t-)Capacitorsti(t)1A-1A1s2si(t)+-v(t)circuit0

56、.2FP1.71.3 Circuit Elementstv(t)5V1s2s(1)For (1) :Capacitorsti(t)1A-1A1s2si(t)+-v(t)circuit0.2FP1.71.3 Circuit Elementstw (t)2.5J1s2s(2)For (2) :For (1)、(2) :Inductors store energy in a magnetic field that is created by electric passing through it. v-i relationshipi(t)+-v(t)circuitLInductors connect

57、ed in series: Leq= L1 + L2 + L3 + Inductors connected in parallel: 1/Leq=1/L1 + 1/L2 + 1/L3 + 1.3 Circuit ElementsEnergy stored: iL(t+) = iL(t-)Independent voltage source+VSRS0viVSIdealpractical1.3 Circuit ElementsIndependent current sourceIviISRS Idealpractical1.3 Circuit ElementsVoltage source con

58、nected in series:Voltage source connected in parallel:1.3 Circuit ElementsVoltage controlled (dependent) voltage source (VCVS)+_+Current controlled (dependent) voltage source (CCVS)+_Q: What are the units for and r?1.3 Circuit ElementsVoltage controlled (dependent) current source (VCCS)Current contr

59、olled (dependent) current source (CCCS)_+Q: What are the units for and g?1.3 Circuit ElementsIndependent sourcedependent sourceCan provide power to the circuit;Excitation to circuit ; Output is not controlled by external.Can provide power to the circuit; No excitation to circuit;Output is controlled

60、 by external.1.3 Circuit ElementsSo far, we have talked about two kinds of circuit elements:Sources (independent and dependent)active, can provide power to the circuit.Resistorspassive, can only dissipate power.ReviewThe energy supplied by the active elements is equivalent to the energy absorbed by