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 12 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 35 2.2.1 pn Junction in Equilibrium 36 2.2.2 pn Junction Under Reverse Bias 41 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 55 2.3.2 Avalanche Breakdown 55 2.4 Chapter Summary 56 Problems 57 SPICE Problems 60   3 Diode Models and Circuits 61 3.1 Ideal Diode 62 3.1.1 Initial Thoughts 62 3.1.2 Ideal Diode 63 3.1.3 Application Examples 67 3.2 pn Junction as a Diode 72 3.3 Additional Examples 74 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 100 3.5.3 Limiting Circuits 103 3.5.4 Voltage Doublers 106 3.5.5 Diodes as Level Shifters and Switches 112 3.6 Chapter Summary 114 Problems 115 SPICE Problems 122 4 Physics of Bipolar Transistors 124 4.1 General Considerations 125 4.2 Structure of Bipolar Transistor 126 4.3 Operation of Bipolar Transistor in Active Mode 127 4.3.1 Collector Current 129 4.3.2 Base and Emitter Currents 133 4.4 Bipolar Transistor Models and Characteristics 135 4.4.1 Large-Signal Model 135 4.4.2 I/V Characteristics 137 4.4.3 Concept of Transconductance 139 4.4.4 Small-Signal Model 141 4.4.5 Early Effect 145 4.5 Operation of Bipolar Transistor in Saturation Mode 152 4.6 The PNP Transistor 155 4.6.1 Structure and Operation 155 4.6.2 Large-Signal Model 156 4.6.3 Small-Signal Model 159 4.7 Chapter Summary 162 Problems 163 SPICE Problems 170 5 Bipolar Amplifiers 172 5.1 General Considerations 173 5.1.1 Input and Output Impedances 173 5.1.2 Biasing 178 5.1.3 DC and Small-Signal Analysis 178 5.2 Operating Point Analysis and Design 180 5.2.1 Simple Biasing 181 5.2.2 Resistive Divider Biasing 183 5.2.3 Biasing with Emitter Degeneration 186 5.2.4 Self-Biased Stage 190 5.2.5 Biasing of PNP Transistors 192 5.3 Bipolar Amplifier Topologies 196 5.3.1 Common-Emitter Topology 197 5.3.2 Common-Base Topology 224 5.3.3 Emitter Follower 238 5.4 Summary and Additional Examples 246 5.5 Chapter Summary 253 Problems 253 SPICE Problems 267 6 Physics of Mos Transistors 269 6.1 Structure of MOSFET 270 6.2 Operation of MOSFET 272 6.2.1 Qualitative Analysis 272 6.2.2 Derivation of I-V Characteristics 279 6.2.3 Channel-Length Modulation 288 6.2.4 MOS Transconductance 290 6.2.5 Velocity Saturation 292 6.2.6 Other Second-Order Effects 292 6.3 MOS Device Models 293 6.3.1 Large-Signal Model 293 6.3.2 Small-Signal Model 295 6.4 PMOS Transistor 296 6.5 CMOS Technology 299 6.6 Comparison of Bipolar and MOS Devices 300 6.7 Chapter Summary 300 Problems 301 SPICE Problems 308 7 Cmos Amplifiers 309 7.1 General Considerations 310 7.1.1 MOS Amplifier Topologies 310 7.1.2 Biasing 310 7.1.3 Realization of Current Sources 313 7.2 Common-Source Stage 315 7.2.1 CS Core 315 7.2.2 CS Stage with Current-Source Load 318 7.2.3 CS Stage with Diode- Connected Load 319 7.2.4 CS Stage with Degeneration 320 7.2.5 CS Core with Biasing 323 7.3 Common-Gate Stage 325 7.3.1 CG Stage with Biasing 329 7.4 Source Follower 331 7.4.1 Source Follower Core 331 7.4.2 Source Follower with Biasing 333 7.5 Summary and Additional Examples 336 7.6 Chapter Summary 340 Problems 341 SPICE Problems 353 8 Operational Amplifier As a Black Box 355 8.1 General Considerations 356 8.2 Op-Amp-Based Circuits 358 8.2.1 Noninverting Amplifier 358 8.2.2 Inverting Amplifier 360 8.2.3 Integrator and Differentiator 363 8.2.4 Voltage Adder 371 8.3 Nonlinear Functions 373 8.3.1 Precision Rectifier 373 8.3.2 Logarithmic Amplifier 374 8.3.3 Square-Root Amplifier 375 8.4 Op Amp Nonidealities 376 8.4.1 DC Offsets 376 8.4.2 Input Bias Current 379 8.4.3 Speed Limitations 382 8.4.4 Finite Input and Output Impedances 387 8.5 Design Examples 388 8.6 Chapter Summary 390 Problems 391 SPICE Problems 397 9 Cascode Stages and Current Mirrors 398 9.1 Cascode Stage 399 9.1.1 Cascode as a Current Source 399 9.1.2 Cascode as an Amplifier 405 9.2 Current Mirrors 414 9.2.1 Initial Thoughts 414 9.2.2 Bipolar Current Mirror 416 9.2.3 MOS Current Mirror 425 9.3 Chapter Summary 429 Problems 430 SPICE Problems 441 10 Differential Amplifiers 443 10.1 General Considerations 444 10.1.1 Initial Thoughts 444 10.1.2 Differential Signals 446 10.1.3 Differential Pair 449 10.2 Bipolar Differential Pair 452 10.2.1 Qualitative Analysis 452 10.2.2 Large-Signal Analysis 458 10.2.3 Small-Signal Analysis 463 10.3 MOS Differential Pair 469 10.3.1 Qualitative Analysis 469 10.3.2 Large-Signal Analysis 473 10.3.3 Small-Signal Analysis 478 10.4 Cascode Differential Amplifiers 481 10.5 Common-Mode Rejection 485 10.6 Differential Pair with Active Load 489 10.6.1 Qualitative Analysis 490 10.6.2 Quantitative Analysis 492 10.7 Chapter Summary 496 Problems 497 SPICE Problems 509 11 Frequency Response 511 11.1 Fundamental Concepts 512 11.1.1 General Considerations 512 11.1.2 Relationship Between Transfer Function and Frequency Response 515 11.1.3 Bode’s Rules 518 11.1.4 Association of Poles with Nodes 519 11.1.5 Miller’s Theorem 521 11.1.6 General Frequency Response 525 11.2 High-Frequency Models of Transistors 529 11.2.1 High-Frequency Model of Bipolar Transistor 529 11.2.2 High-Frequency Model of Mosfet 531 11.2.3 Transit Frequency 532 11.3 Analysis Procedure 534 11.4 Frequency Response of CE and CS Stages 535 11.4.1 Low-Frequency Response 535 11.4.2 High-Frequency Response 536 11.4.3 Use of Miller’s Theorem 537 11.4.4 Direct Analysis 539 11.4.5 Input Impedance 543 11.5 Frequency Response of CB and CG Stages 544 11.5.1 Low-Frequency Response 544 11.5.2 High-Frequency Response 544 11.6 Frequency Response of Followers 547 11.6.1 Input and Output Impedances 550 11.7 Frequency Response of Cascode Stage 553 11.7.1 Input and Output Impedances 557 11.8 Frequency Response of Differential Pairs 558 11.8.1 Common-Mode Frequency Response 559 11.9 Additional Examples 561 11.10 Chapter Summary 564 Problems 565 SPICE Problems 573 12 Feedback 575 12.1 General Considerations 577 12.1.1 Loop Gain 579 12.2 Properties of Negative Feedback 582 12.2.1 Gain Desensitization 582 12.2.2 Bandwidth Extension 584 12.2.3 Modification of I/O Impedances 586 12.2.4 Linearity Improvement 589 12.3 Types of Amplifiers 591 12.3.1 Simple Amplifier Models 591 12.3.2 Examples of Amplifier Types 593 12.4 Sense and Return Techniques 595 12.5 Polarity of Feedback 598 12.6 Feedback Topologies 600 12.6.1 Voltage–Voltage Feedback 600 12.6.2 Voltage–Current Feedback 605 12.6.3 Current–Voltage Feedback 608 12.6.4 Current–Current Feedback 613 12.7 Effect of Nonideal I/O Impedances 616 12.7.1 Inclusion of I/O Effects 617 12.8 Stability in Feedback Systems 628 12.8.1 Review of Bode’s Rules 629 12.8.2 Problem of Instability 630 12.8.3 Stability Condition 633 12.8.4 Phase Margin 636 12.8.5 Frequency Compensation 638 12.8.6 Miller Compensation 641 12.9 Chapter Summary 642 Problems 643 SPICE Problems 654 13 Oscillators 656 13.1 General Considerations 656 13.2 Ring Oscillators 659 13.3 LC Oscillators 664 13.3.1 Parallel LC Tanks 664 13.3.2 Cross-Coupled Oscillator 667 13.3.3 Colpitts Oscillator 670 13.4 Phase Shift Oscillator 672 13.5 Wien-Bridge Oscillator 675 13.6 Crystal Oscillators 677 13.6.1 Crystal Model 678 13.6.2 Negative-Resistance Circuit 679 13.6.3 Crystal Oscillator Implementation 681 13.7 Chapter Summary 683 Problems 684 SPICE Problems 688 14 Output Stages and Power Amplifiers 690 14.1 General Considerations 690 14.2 Emitter Follower as Power Amplifier 691 14.3 Push-Pull Stage 694 14.4 Improved Push-Pull Stage 697 14.4.1 Reduction of Crossover Distortion 697 14.4.2 Addition of CE Stage 701 14.5 Large-Signal Considerations 704 14.5.1 Biasing Issues 704 14.5.2 Omission of PNP Power Transistor 705 14.5.3 High-Fidelity Design 708 14.6 Short-Circuit Protection 708 14.7 Heat Dissipation 709 14.7.1 Emitter Follower Power Rating 710 14.7.2 Push-Pull Stage Power Rating 711 14.7.3 Thermal Runaway 713 14.8 Efficiency 714 14.8.1 Efficiency of Emitter Follower 714 14.8.2 Efficiency of Push-Pull Stage 715 14.9 Power Amplifier Classes 716 14.10 Chapter Summary 717 Problems 718 SPICE Problems 723 15 Analog Filters 725 15.1 General Considerations 725 15.1.1 Filter Characteristics 726 15.1.2 Classification of Filters 727 15.1.3 Filter Transfer Function 730 15.1.4 Problem of Sensitivity 734 15.2 First-Order Filters 735 15.3 Second-Order Filters 738 15.3.1 Special Cases 738 15.3.2 RLC Realizations 742 15.4 Active Filters 747 15.4.1 Sallen and Key Filter 747 15.4.2 Integrator-Based Biquads 753 15.4.3 Biquads Using Simulated Inductors 756 15.5 Approximation of Filter Response 761 15.5.1 Butterworth Response 762 15.5.2 Chebyshev Response 766 15.6 Chapter Summary 771 Problems 772 SPICE Problems 776 16 Digital Cmos Circuits 778 16.1 General Considerations 778 16.1.1 Static Characterization of Gates 779 16.1.2 Dynamic Characterization of Gates 786 16.1.3 Power-Speed Trade-Off 789 16.2 CMOS Inverter 791 16.2.1 Initial Thoughts 791 16.2.2 Voltage Transfer Characteristic 793 16.2.3 Dynamic Characteristics 799 16.2.4 Power Dissipation 804 16.3 CMOS NOR and NAND Gates 808 16.3.1 NOR Gate 808 16.3.2 NAND Gate 811 16.4 Chapter Summary 812 Problems 813 SPICE Problems 818 17 Cmos Amplifiers 819 17.1 General Considerations 819 17.1.1 Input and Output Impedances 820 17.1.2 Biasing 824 17.1.3 DC and Small-Signal Analysis 825 17.2 Operating Point Analysis and Design 826 17.2.1 Simple Biasing 828 17.2.2 Biasing with Source Degeneration 830 17.2.3 Self-Biased Stage 833 17.2.4 Biasing of PMOS Transistors 834 17.2.5 Realization of Current Sources 835 17.3 CMOS Amplifier Topologies 836 17.4 Common-Source Topology 837 17.4.1 CS Stage with Current-Source Load 842 17.4.2 CS Stage with Diode- Connected Load 843 17.4.3 CS Stage with Source Degeneration 844 17.4.4 Common-Gate Topology 856 17.4.5 Source Follower 867 17.5 Additional Examples 874 17.6 Chapter Summary 878 Problems 879 SPICE Problems 891 Appendix A Introduction To Spice A- 1 Index I- 1