Fundamentals of microelectronics

1 INTRODUCTION TO MICROELECTRONICS 1 1.1 Electronics versus Microelectronics 1 1.2 Examples of Electronic Systems 2 1.2.1 Cellular Telephone 2 1.2.2 Digital Camera 5 1.2.3 Analog Versus Digital 7 1.3 Basic Concepts 8 1.3.1 Analog and Digital Signals 8 1.3.2 Analog Circuits 10 1.3.3 Digital Circuits 11 1.3.4 Basic Circuit Theorems 13 1.4 Chapter Summary 20 2 BASIC PHYSICS OF SEMICONDUCTORS 21 2.1 Semiconductor Materials and Their Properties 22 2.1.1 Charge Carriers in Solids 22 2.1.2 Modification of Carrier Densities 25 2.1.3 Transport of Carriers 28 2.2 pn Junction 36 2.2.1 pn Junction in Equilibrium 37 2.2.2 pn Junction Under Reverse Bias 42 2.2.3 pn Junction Under Forward Bias 46 2.2.4 I/V Characteristics 49 2.3 Reverse Breakdown 54 2.3.1 Zener Breakdown 54 2.3.2 Avalanche Breakdown 55 2.4 Chapter Summary 55 Problems 56 SPICE Problems 60 3 DIODE MODELS AND CIRCUITS 62 3.1 Ideal Diode 62 3.1.1 Initial Thoughts 62 3.1.2 Ideal Diode 64 3.1.3 Application Examples 68 3.2 pn Junction as a Diode 73 3.3 Additional Examples 75 3.4 Large-Signal and Small-Signal Operation 80 3.5 Applications of Diodes 89 3.5.1 Half-Wave and Full-Wave Rectifiers 89 3.5.2 Voltage Regulation 102 3.5.3 Limiting Circuits 104 3.5.4 Voltage Doublers 108 3.5.5 Diodes as Level Shifters and Switches 112 3.6 Chapter Summary 115 Problems 116 SPICE Problems 126 4 PHYSICS OF BIPOLAR TRANSISTORS 128 4.1 General Considerations 128 4.2 Structure of Bipolar Transistor 130 4.3 Operation of Bipolar Transistor in Active Mode 131 4.3.1 Collector Current 134 4.3.2 Base and Emitter Currents 137 4.4 Bipolar Transistor Models and Characteristics 139 4.4.1 Large-Signal Model 139 4.4.2 I/V Characteristics 141 4.4.3 Concept of Transconductance 143 4.4.4 Small-Signal Model 145 4.4.5 Early Effect 150 4.5 Operation of Bipolar Transistor in Saturation Mode 156 4.6 The PNP Transistor 159 4.6.1 Structure and Operation 160 4.6.2 Large-Signal Model 160 4.6.3 Small-Signal Model 163 4.7 Chapter Summary 167 Problems 167 SPICE Problems 178 5 BIPOLAR AMPLIFIERS 181 5.1 General Considerations 181 5.1.1 Input and Output Impedances 182 5.1.2 Biasing 186 5.1.3 DC and Small-Signal Analysis 186 5.2Operating Point Analysis and Design 188 5.2.1 Simple Biasing 189 5.2.2 Resistive Divider Biasing 192 5.2.3 Biasing with Emitter Degeneration 195 5.2.4 Self-Biased Stage 199 5.2.5 Biasing of PNP Transistors 202 5.3 Bipolar Amplifier Topologies 206 5.3.1 Common-Emitter Topology 207 5.3.2 Common-Base Topology 233 5.3.3 Emitter Follower 250 5.4 Summary and Additional Examples 258 5.5 Chapter Summary 264 Problems 264 SPICE Problems 285 6 PHYSICS OF MOS TRANSISTORS 288 6.1 Structure of MOSFET 288 6.2 Operation of MOSFET 291 6.2.1 Qualitative Analysis 291 6.2.2 Derivation of I/V Characteristics 297 6.2.3 Channel-Length Modulation 306 6.2.4 MOS Transconductance 308 6.2.5 Velocity Saturation 310 6.2.6 Other Second-Order Effects 310 6.3 MOS Device Models 311 6.3.1 Large-Signal Model 311 6.3.2 Small-Signal Model 313 6.4 PMOS Transistor 314 6.5 CMOS Technology 316 6.6 Comparison of Bipolar and MOS Devices 317 6.7 Chapter Summary 317 Problems 318 SPICE Problems 327 7 CMOS AMPLIFIERS 329 7.1 General Considerations 329 7.1.1 MOS Amplifier Topologies 329 7.1.2 Biasing 329 7.1.3 Realization of Current Sources 333 7.2 Common-Source Stage 334 7.2.1 CS Core 334 7.2.2 CS Stage With Current-Source Load 337 7.2.3 CS Stage With Diode-Connected Load 338 7.2.4 CS Stage With Degeneration 340 7.2.5 CS Core With Biasing 343 7.3 Common-Gate Stage 345 7.3.1 CG Stage With Biasing 350 7.4 Source Follower 351 7.4.1 Source Follower Core 352 7.4.2 Source Follower With Biasing 354 7.5 Summary and Additional Examples 356 7.6 Chapter Summary 360 Problems 360 SPICE Problems 378 8 OPERATIONAL AMPLIFIER AS A BLACK BOX 380 8.1 General Considerations 381 8.2 Op-Amp-Based Circuits 383 8.2.1 Noninverting Amplifier 383 8.2.2 Inverting Amplifier 385 8.2.3 Integrator and Differentiator 388 8.2.4 Voltage Adder 395 8.3 Nonlinear Functions 396 8.3.1 Precision Rectifier 396 8.3.2 Logarithmic Amplifier 397 8.3.3 Square-Root Amplifier 398 8.4 Op Amp Nonidealities 399 8.4.1 DC Offsets 399 8.4.2 Input Bias Current 402 8.4.3 Speed Limitations 405 8.4.4 Finite Input and Output Impedances 410 8.5 Design Examples 411 8.6 Chapter Summary 413 Problems 414 SPICE Problems 423 9 CASCODE STAGES AND CURRENT MIRRORS 425 9.1 Cascode Stage 425 9.1.1 Cascode as a Current Source 425 9.1.2 Cascode as an Amplifier 432 9.2 Current Mirrors 441 9.2.1 Initial Thoughts 441 9.2.2 Bipolar Current Mirror 442 9.2.3 MOS Current Mirror 451 9.3 Chapter Summary 454 Problems 455 SPICE Problems 470 10 DIFFERENTIAL AMPLIFIERS 473 10.1 General Considerations 473 10.1.1 Initial Thoughts 473 10.1.2 Differential Signals 475 10.1.3 Differential Pair 478 10.2 Bipolar Differential Pair 479 10.2.1 Qualitative Analysis 479 10.2.2 Large-Signal Analysis 484 10.2.3 Small-Signal Analysis 488 10.3 MOS Differential Pair 494 10.3.1 Qualitative Analysis 495 10.3.2 Large-Signal Analysis 499 10.3.3 Small-Signal Analysis 503 10.4 Cascode Differential Amplifiers 507 10.5 Common-Mode Rejection 511 10.6 Differential Pair with Active Load 515 10.6.1 Qualitative Analysis 516 10.6.2 Quantitative Analysis 518 10.7 Chapter Summary 523 Problems 524 PICE Problems 541 11 FREQUENCY RESPONSE 544 11.1 Fundamental Concepts 544 11.1.1 General Considerations 544 11.1.2 Relationship Between Transfer Function and Frequency Response 547 11.1.3 Bode's Rules 550 11.1.4 Association of Poles with Nodes 551 11.1.5 Miller's Theorem 553 11.1.6 General Frequency Response 556 11.2 High-Frequency Models of Transistors 559 11.2.1 High-Frequency Model of Bipolar Transistor 559 11.2.2 High-Frequency Model of MOSFET 561 11.2.3 Transit Frequency 563 11.3 Analysis Procedure 564 11.4 Frequency Response of CE and CS Stages 565 11.4.1 Low-Frequency Response 565 11.4.2 High-Frequency Response 566 11.4.3 Use of Miller's Theorem 566 11.4.4 Direct Analysis 569 11.4.5 Input Impedance 572 11.5 Frequency Response of CB and CG Stages 573 11.5.1 Low-Frequency Response 573 11.5.2 High-Frequency Response 574 11.6 Frequency Response of Followers 576 11.6.1 Input and Output Impedances 580 11.7 Frequency Response of Cascode Stage 583 11.7.1 Input and Output Impedances 587 11.8 Frequency Response of Differential Pairs 588 11.8.1 Common-Mode Frequency Response 590 11.9 Additional Examples 591 11.10 Chapter Summary 595 Problems 596 SPICE Problems 607 12 FEEDBACK 610 12.1 General Considerations 610 12.1.1 Loop Gain 613 12.2 Properties of Negative Feedback 614 12.2.1 Gain Desensitization 614 12.2.2 Bandwidth Extension 616 12.2.3 Modification of I/O Impedances 618 12.2.4 Linearity Improvement 622 12.3 Types of Amplifiers 622 12.3.1 Simple Amplifier Models 623 12.3.2 Examples of Amplifier Types 624 12.4 Sense and Return Techniques 626 12.5 Polarity of Feedback 629 12.6 Feedback Topologies 631 12.6.1 Voltage-Voltage Feedback 631 12.6.2 Voltage-Current Feedback 636 12.6.3 Current-Voltage Feedback 639 12.6.4 Current-Current Feedback 644 12.7 Effect of Nonideal I/O Impedances 647 12.7.1 Inclusion of I/O Effects 648 12.8 Stability in Feedback Systems 660 12.8.1 Review of Bode's Rules 660 12.8.2 Problem of Instability 662 12.8.3 Stability Condition 665 12.8.4 Phase Margin 668 12.8.5 Frequency Compensation 670 12.8.6 Miller Compensation 673 12.9 Chapter Summary 674 Problems 675 SPICE Problems 691 13 OUTPUT STAGES AND POWER AMPLIFIERS 694 13.1 General Considerations 694 13.2 Emitter Follower as Power Amplifier 695 13.3 Push-Pull Stage 698 13.4 Improved Push-Pull Stage 701 13.4.1 Reduction of Crossover Distortion 701 13.4.2 Addition of CE Stage 705 13.5 Large-Signal Considerations 708 13.5.1Biasing Issues 708 13.5.2Omission of PNP Power Transistor 709 13.5.3High-Fidelity Design 712 13.6 Short-Circuit Protection 713 13.7 Heat Dissipation 713 13.7.1 Emitter Follower Power Rating 13.7.2 Push-Pull Stage Power Rating 13.7.3 Thermal Runaway 716 13.8 Efficiency 718 13.8.1 Efficiency of Emitter Follower 13.8.2 Efficiency of Push-Pull Stage 719 13.9 Power Amplifier Classes 720 13.10 Chapter Summary 721 Problems 722 SPICE Problems 728 14 ANALOG FILTERS 731 14.1 General Considerations 731 14.1.1 Filter Characteristics 732 14.1.2 Classification of Filters 733 14.1.3 Filter Transfer Function 737 14.1.4 Problem of Sensitivity 740 14.2 First-Order Filters 741 14.3 Second-Order Filters 744 14.3.1 Special Cases 744 14.3.2 RLC Realizations 748 14.4 Active Filters 753 14.4.1 Sallen and Key Filter 753 14.4.2 Integrator-Based Biquads 758 14.4.3 Biquads Using Simulated Inductors 762 14.5 Approximation of Filter Response 768 14.5.1 Butterworth Response 768 14.5.2 Chebyshev Response 772 14.6 Chapter Summary 777Problems 778SPICE Problems 784 15 DIGITAL CMOS CIRCUITS 786 15.1 General Considerations 786 15.1.1 Static Characterization of Gates 787 15.1.2 Dynamic Characterization of Gates 794 15.1.3 Power-Speed Trade-Off 797 15.2 CMOS Inverter 799 15.2.1 Initial Thoughts 799 15.2.2 Voltage Transfer Characteristic 801 15.2.3 Dynamic Characteristics 807 15.2.4 Power Dissipation 812 15.3 CMOS NOR and NAND Gates 816 15.3.1 NOR Gate 816 15.3.2 NAND Gate 819 15.4 Chapter Summary 820 Problems 821 SPICE Problems 827 16 CMOS AMPLIFIERS 829 16.1 General Considerations 829 16.1.1 Input and Output Impedances 830 16.1.2 Biasing 834 16.1.3 DC and Small-Signal Analysis 835 16.2 Operating Point Analysis and Design 836 16.2.1 Simple Biasing 838 16.2.2 Biasing with Source Degeneration 840 16.2.3 Self-Biased Stage 843 16.2.4 Biasing of PMOS Transistors 844 16.2.5 Realization of Current Sources 845 16.3 CMOS Amplifier Topologies 846 16.4 Common-Source Topology 847 16.4.1 CS Stage with Current-Source Load 852 16.4.2 CS Stage with Diode-Connected Load 853 16.4.3 CS Stage with Source Degeneration 854 16.4.4 Common-Gate Topology 866 16.4.5 Source Follower 877 16.5 Additional Examples 883 16.6 Chapter Summary 887 Problems 888 SPICE Problems 906 Appendix A Introduction to SPICE Index