新編模擬電路分析與設(shè)計(jì)英文ch1精選課件

1、Huazhong University of Science and TechnologyThe Department of Electronics and Information EngineeringFirst Term 08/09Electronic Circuit Analysis and DesignDr. Tianping DengEmail: PART 1SEMICONDUCTOR DEVICES AND BASIC APPLICATIONSChapter 1Semiconductor Materials and DiodesChapter 2Diod

2、e CircuitsChapter 3The Field-Effect TransistorChapter 4Basic FET AmplifiersChapter 5The Bipolar Junction TransistorChapter 6Basic BJT AmplifiersChapter 7Frequency ResponseChapter 8Output Stages and Power AmplifiersPART 2ANALOG ELECTRONICSChapter 9Ideal Operational Amplifiers and Op-Amp CircuitsChapt

3、er 10Integrated Circuit Biasing and Active LoadsChapter 11Differential and Multistage AmplifiersChapter 12Feedback and StabilityChapter 13Operational Amplifier CircuitsChapter 14Nonideal Effects in Operational Amplifier CircuitsChapter 15Applications and Design of Integrated CircuitsContentsChapter

4、1Semiconductor Materials and DiodesCh1. Semiconductor Materials and Diodes1.1 Semiconductor Materials and Properties1.2 The PN Junction1.4 Diode Circuits AC Equivalent Circuit1.3 Diode Circuits DC Analysis and Models1.5 Other Diode Types1.6 Design Application: Diode Thermometer1.7 Summary1.1 Semicon

5、ductor Materials and Properties1.1.1 Intrinsic Semiconductor1.1.2. Extrinsic SemiconductorN-type semiconductorP-type semiconductorCh1. Semiconductor Materials and Diodes 1.1 Semiconductor Materials and PropertiesMaterialsConductorInsulatorSemiconductor: conduction electrons_electrical conductivity:

6、electrons in bonding mechanism _cannot move: silicon, germanium, gallium arsenide1.1.1. Intrinsic SemiconductorSilicon Valley1.1.1 Intrinsic Semiconductor1. Silicon, germanium_single-crystal structureAt temperature T=0oK, silicon is an insulator.1.1.1 Intrinsic SemiconductorEach Si atom shares one e

7、lectron with each of its four closest neighbors so that its valence band will have a full 8 electrons.+4+4+4+41.1.1 Intrinsic Semiconductor2. When T increases, free electrons and “holes”are created In pure semiconductor, the concentration of electrons and holes are equal, and very small, so it has v

8、ery small conductivity.Increasing temperature, generating electron-hole pairsFree electronproduced by thermal ionization. It can move freely in the lattice structure so as to form current.Holeempty position in broken covalent bond. It can be filled by free electron (recombination) and can also “move

9、” freely to form current.CarriersA free electron is negative charge and a hole is positive charge. 1.1.1 Intrinsic SemiconductorA hole can be regarded as a positive charge carrierDoes the hole can move through the crystal freely?1.1.2. Extrinsic Semiconductor1. phosphorus+silicon=N-type semiconducto

10、rHoles present because of thermal energyWhat are the majority carriers in n-type materials? What are the minority carriers in n-type materials?RedundantelectronN-type semiconductorDonor ImpurityPositive charge N-type semiconductor material (phosphorus) donor: provide free electrons majority carrier

11、electrons minority carrier holesDoped Semiconductorn type SiSiSiSiSiSiSiSiSi PDonorFree Ebound charge Donor pentavalent impurity provides free electrons, usually entirely ionized.Positive bound charge-impurity atom donating electron gives rise to positive bound charge.Majority carriers-free electron

12、s (mostly generated by ionized donor and a very tiny portion by thermal ionization) .Minority carriers-holes (only generated by thermal ionization) .n type Semiconductor1.1.2. Extrinsic SemiconductorP-type semiconductorMotion of holesHoleAcceptor ImpurityNegative chargeWhat are the majority carriers

13、 in P-type materials? What are the minority carriers in P-type materials?2. boron+silicon=P-type semiconductor P-type semiconductor material (Boron) acceptor: accept an extra electrons majority carrier holes minority carrier electronsDoped Semiconductorp type Boundcharge SiSiSiSiSiSiSiSiSiAlAlHoleAc

14、ceptorAcceptor trivalent impurity provides holes, usually entirely ionized.Negative bound charge- impurity atom accepting hole give rise to negative bound chargeMajority carriers-holes (mostly generated by ionized acceptor and a tiny small portion by thermal ionization) Minority carriers- free elect

15、rons (only generated by thermal ionization.)p type Semiconductor1.1.2. Extrinsic Semiconductor2. boron+silicon=P-type semiconductor1. phosphorus+silicon=N-type semiconductorPositive Charges + holes =electronsNegative Charges + electrons = holesmajority carrierminority carrierDoping Temperaturemajori

16、ty carrierDopingminority carrier TemperatureMajority carrier is only determined by the impurity, but independent of temperature.Minority carrier is strongly affected by temperature.If the temperature is high enough, characteristics of doped semiconductor will decline to the one of intrinsic semicond

17、uctor.Conclusion on the doped semiconductor 1.1.2. Extrinsic Semiconductor Diffusion: a concentration of charge carriers tends to spread with time1.1.2. Extrinsic Semiconductor Diffusion: a concentration of charge carriers tends to spread with timeDrift: The average motion of the charge carriers due

18、 to an applied electric field.1.2 The PN Junction1.2.1 The Equilibrium PN Junction1.2.2 Forward-Biased PN Junction1.2.3 Reverse-Biased PN Junction1.2.4 PN Junction Diode1.2 The PN Junction1.2.1 The Equilibrium PN Junction NPholeElectronHoles diffuse from P- to N-region.Electrons diffuse from N- to P

19、-region1.2 The PN Junction1.2.1 The Equilibrium PN Junction1. Depletion region(space-charge region)_PN junctionDepletion regionPN JunctionElectric field2. Electric fieldNP1.2.1 The Equilibrium PN Junction3. Drift current IDR = diffusion current IDF _Balance1. Depletion region(space-charge region)_PN

20、 junction2. Electric fieldIDFIDRNP1.2.1 The Equilibrium PN JunctionThe procedure of forming pn the dynamic equilibrium of drift and diffusion movements for carriers in the silicon. In detail, there are 4 steps: DiffusionSpace charge regionDriftEquilibrium1.2.2 Forward-Biased PN JunctionPositive volt

21、age is applied to P, forward-biased PN.1. Depletion region is reduced, low resistance. 2. Majority carriers flow across PN junction more easily. IDFIDR , iD=IDFIDRvDD-region electric fieldApplied electric fieldiDvDThe two fields are opposite. The results are:1.2.2 Forward-Biased PN Junction1.2.2 For

22、ward-Biased PN Junction3. The current-voltage (v-i) characteristicThe current is an exponential function of voltage. 4. V _turn-on, cut-in voltageIS_reverse-bias saturation currentVT _thermal voltage at room temperature VT =0.026VvD1.2.3 Reverse-Biased PN JunctionPositive voltage is applied to N, re

23、verse-biased PN.1. Depletion region is increased, high resistance. 2. Majority carriers cannot cross the junction. Minority carriers sweep across PN easily. IDF T0T1 T0IS and VT are functions of T.T increasesrequired forward-bias voltage decrease1.2.4 PN Junction Diode3. Switching Transient Storage

24、time ts Turn-off time tfWhen forward-bias, excess carrier is stored in both regions. When switching from forward to reverse, it need time to remove.1.3 Diode Circuits DC Analysis and Models1.3.1 Models1.3.2 DC Analysis1.3 Diode Circuits_DC Analysis and Models1.3.1 Models1. Ideal modelDescribing i-v

25、characteristic, when analyzing circuit(a) (b) (c)Case 2Case 11.3.1 Models2. Piecewise modelTwo linear approximations1.3.2 DC Analysis E.g.1.1 Determine the diode voltage and current for the circuit shown in figure, AssumeSol: For diodeFor R and VPS branch(a) Diode circuit(b) Conventional circuitPSPS

26、VPS=5V , R=2kFind two special points (5V,0mA) and (0V, 2.5mA) (1) using the graphical analysis.Intersection_quiescent point or Q-pointVDID1.3.1 Models3. Small signal model_AC model When a diode is operating in the small range，it can be a small-signal incremental resistance.That is: small-signal cond

27、uctanceRoom T（T=300K）1.3.2 DC Analysis (2) using the model analysis. Ideal Model Piecewise model_1（Silicon Diode）(a) Diode circuit(b) ConventionPSPS Piecewise model_2Assume（Silicon Diode）VD=V + ID rf =1.09V1.4 Diode Circuits_AC Equivalent Circuit1.4.1 Sinusoidal Analysis1.4.1 Sinusoidal AnalysisE.g.

28、1.2. Determine the output voltage in Fig. 1.31. Assume circuit and parameter of VPS=5V , R=2k, Vr=0.6V ,and vi =0.1sinwt(V).Sol: because(1) For the DC analysis, we set vi =0, then(2) For the AC analysis, we set VPS =0, thenFig. 1.311.5 Other Diode Types1.5.1 Solar Cell1.5.2 Photodiode1.5.3 Light-Emi

29、tting Diode (LED)1.5.4 Schottky Barrier Diode1.5.5 Zener Diode1.5 Other Diode Types1.5.1 Solar CellIt gets power from the solar array and can be used eitherto power an electric motor or to charge a battery pack.1.5 Other Diode Types1.5.2 PhotodiodeIt converts optical signals into electrical signals.

30、155Mbps622Mbps2.5Gbps10Gbps40GbpsTrunk- lineMetro- coreMetro-accessData- comAccessDFB/MODCW+LockerCoaxial LD&PDAPD+ampOSA10G-APD+TIA10G-PIN+TIAUncooled 10G-LD40G-PIN(R&D)Can LD1.5 Other Diode Types1.5.3 Light-Emitting Diode(LED)It converts current into light. E/O1.5 Other Diode Types1.5.4 Schottky B

31、arrier Diode There is no minority carrier storage in the Schottky diode, so the switching time from a forward bias to a reverse bias is very short compared to the pn junction diode.1.5.5 Zener Diode 1. Symbol and I-V characteristic(a) symbol(b) I-V characteristic Zener diodes can be operated in the

32、breakdown region by limiting the current to the capabilities of the diodes.1.5.5 Zener Diode 2. ParametersVZ _ Zener breakdown voltagerZ =VZ /IZ rZ _Incremental resistance IZ _ Reverse-bias current when the diode is operating in the breakdown region.3. Zener Diode Circuits E.g.1.3 Assume Zener diode

33、 VZ =5.6V, rZ =0 and IZ max=3mA, find the value of resistance. Sol:Question:Can we eliminate the R? Why?If VPS is replaced by sinusoidal input voltage vi =15sinwt(V) , plot output voltage vO versus vi .If VI is the sinwave, and VomVZ.VO=?Think about:Does the output voltage can equal 6V?Sol:Which is

34、bigger between UO and UZ?AssumeThe output voltage cant equal 6VUO UZIf we want the output is 6V, R 4. Ideal Voltage Reference Circuit(1) Zener diode is useful in a voltage regulator, or a constant-voltage reference circuit.(3) When IL is a max, and VPS is a min, IZ is a min.When IL is a min, and VPS

35、 is a max, IZ is a max. Due toWe obtain and (2) Ri limits Iz and drops the “excess” voltage between VPS and VZ .4. Ideal Voltage Reference CircuitEquating these two expressions, we know VPS(min) and VPS(max), and assume IZ (min)=0.1IZ (max).Then we can determine Ri and max power rating PZ(max) of Ze

36、ner diode.E.g.1.4 (page 66)Sol: from Equation (3) IL(min)=0, IL(max)=100mA, VPS =11-13.6V, VZ =9V. Design Ri and PZ(max).from Equation (2)Max power dissipated in Ri isDiode CharacteristicDiode CharacteristicIntrinsic Semiconductor Doped Semiconductor Carriers Diffusion ,Drift SummaryGain a basic understanding of semiconductor material properties Two types of charged carriers Two mechanisms that generate currentsDetermine the properties of a pn jun