B O S T O N L O N D O N

www.artechhouse.com

Include bar code:

ISBN-13: 978-1-60807-507-2ISBN-10: 1-60807-507-9

Randy Frank

Randy Frank

Frank

Now in its third edition, Understanding Smart Sensors is the most complete, up-to-date, and authoritative summary of the latest applications and developments impacting smart sensors in a single volume. This thoroughly expanded and revised edition of an Artech bestseller contains a wealth of new material, including:

• Critical coverage of sensor fusion and energy harvesting;

• The latest details on wireless technology;

• The roles and challenges involved with sensor apps and cloud sensing,

• Greater emphasis on applications throughout the book;

• Dozens of figures and examples of current technologies from over 50 companies.

Utilizing the latest in smart sensors, microelectromechanical systems (MEMS), and microelectronic research and development, readers get the technical and practical information they need to keep their designs and products on the cutting edge. Plus, engineers see how network (wired and wireless) connectivity continues to impact smart sensor development and the emerging need for trusted sensing.

By combining information on micromachining and microelectronics, this is the first book that links these two important aspects of smart sensor technology so professionals don’t have to keep multiple references on hand. This comprehensive resource also includes an extensive list of smart sensor acronyms and a glossary of key terms. With an effective blend of historical information and the latest content, the third edition of Understanding Smart Sensors provides a unique combination of foundational and future-changing information.

Randy Frank is the president of Randy Frank and Associates in Scottsdale, Arizona. A well-established author and holder of three patents, Mr. Frank received his B.S. and M.S. in electrical engineering, as well as his M.B.A. in management, from Wayne State University in Detroit, Michigan. He is a Society of Automotive Engineers Fellow, former chairman and a member of the SAE Sensors Standards Committee, an IEEE Fellow, and a former member of the IEEE 1451 Smart Transducer Interface standards committee.

SMARTSENSORS

SMA

RT SE

NSO

RS

SMART SENSORS

Understanding Understanding

Understanding

Third Edition

Third Edition

Third Edition

vii

Contents

Preface xvii

CHAPTER 1

SmartSensorBasics 1

1.1 Introduction 11.2 Mechanical-Electronic Transitions in Sensing 31.3 Nature of Sensors 41.4 Integration of Micromachining and Microelectronics 91.5 Application Example 111.6 Summary 13

References 13Selected Bibliography 14

CHAPTER 2

Micromachining 17

2.1 Introduction 172.2 Bulk Micromachining 182.3 Wafer Bonding 20

2.3.1 Silicon-on-Silicon Bonding 202.3.2 Silicon-on-Glass (Anodic) Bonding 212.3.3 Silicon Fusion Bonding 222.3.4 Wafer Bonding for More Complex Structures and Adding ICs 22

2.4 Surface Micromachining 242.4.1 Squeeze-Film Damping 262.4.2 Stiction 262.4.3 Particulate Control 262.4.4 Combinations of Surface and Bulk Micromachining 27

2.5 Other Micromachining Techniques 282.5.1 The LIGA Process 282.5.2 Dry Etching Processes 292.5.3 Micromilling 302.5.4 Lasers in Micromachining 31

2.6 Combining MEMS with IC Fabrication 322.7 Other Micromachined Materials 34

2.7.1 Diamond as an Alternate Sensor Material 34

viii Contents

2.7.2 Metal Oxides and Piezoelectric Sensing 352.7.3 Films on Microstructures 362.7.4 Micromachining Metal Structures 372.7.5 Carbon Nanotube MEMS 38

2.8 MEMS Foundry Services and Software Tools 382.9 Application Example 402.10 Summary 42

References 42 Selected Bibliography 45

CHAPTER 3

TheNatureofSemiconductorSensorOutput 47

3.1 Introduction 473.2 Sensor Output Characteristics 47

3.2.1 Wheatstone Bridge 483.2.2 Piezoresistivity in Silicon 493.2.3 Semiconductor Sensor Definitions 513.2.4 Static Versus Dynamic Operation 53

3.3 Other Sensing Technologies 533.3.1 Capacitive Sensing 533.3.2 Piezoelectric Sensing 543.3.3 The Hall-Effect 553.3.4 Chemical Sensors 563.3.5 Improving Sensor Characteristics 56

3.4 Digital Output Sensors 573.4.1 Incremental Optical Encoders 573.4.2 Digital Techniques 59

3.5 Noise/Interference Aspects 593.6 Low Power, Low Voltage Sensors 60

3.6.1 Impedance 613.7 Analysis of Sensitivity Improvement 61

3.7.1 Thin Diaphragm 613.7.2 Increase Diaphragm Area 613.7.3 Improve Topology 61

3.8 Application Example 623.9 Summary 64

References 64

CHAPTER 4

GettingSensorInformationIntotheMicrocontroller 67

4.1 Introduction 674.2 Amplification and Signal Conditioning 68

4.2.1 Instrumentation Amplifiers 694.2.2 Sleep-Mode Circuitry for Reducing Power 704.2.3 Rail to Rail Operational Amplifiers 714.2.4 Switched-Capacitor Amplifier 72

Contents ix

4.2.5 Barometer Application Circuit 734.2.6 4- to 20-mA Signal Transmitter 734.2.7 Schmitt Trigger 74

4.3 Separate Versus Integrated Signal Conditioning 754.3.1 Integrated Signal Conditioning 754.3.2 External Signal Conditioning 76

4.4 Digital Conversion 764.4.1 A/D Converters 774.4.2 Performance of A/D Converters 794.4.3 Implications of A/D Accuracy and Errors 80

4.5 On-Line Tool for Evaluating a Sensor Interface Design 814.6 Application Example 814.7 Summary 81

References 83Selected Bibliography 84

CHAPTER 5

UsingMCUs/DSPstoIncreaseSensorIQ 85

5.1 Introduction 855.1.1 Other IC Technologies 855.1.2 Logic Requirements 86

5.2 MCU Control 865.3 MCUs for Sensor Interface 87

5.3.1 Peripherals 875.3.2 Memory 885.3.3 Input/Output 895.3.4 On-Board A/D Conversion 905.3.5 Power Saving Capability 905.3.6 Local Voltage or Current Regulation 92

5.4 DSP Control 925.4.1 Digital Signal Controllers 935.4.2 Field Programmable Gate Arrays 935.4.3 Algorithms Versus Look-Up Tables 93

5.5 Techniques and Systems Considerations 955.5.1 Linearization 955.5.2 PWM Control 965.5.3 Autozero and Autorange 965.5.4 Diagnostics 985.5.5 Reducing EMC/RFI 985.5.6 Indirect (Computed not Sensed) Versus Direct Sensing 98

5.6 Software, Tools, and Support 995.6.1 Design-in Support 99

5.7 Sensor Integration 1005.8 Application Example 1015.9 Summary 102

References 103

x Contents

CHAPTER 6

CommunicationsforSmartSensors 107

6.1 Introduction 1076.2 Background and Definitions 107

6.2.1 Definitions 1086.2.2 Background 108

6.3 Sources (Organizations) and Standards 1096.4 Automotive Protocols 112

6.4.1 CAN Protocol 1136.4.2 LIN Protocol 1156.4.3 Media Oriented Systems Transport 1156.4.4 FlexRay 1166.4.5 Other Automotive Protocol Aspects 116

6.5 Industrial Networks 1176.5.1 Example Industrial Protocols 117

6.6 Protocols in Other Applications 1176.7 Protocols in Silicon 118

6.7.1 MCU with Integrated CAN 1186.7.2 LIN Implementation 1206.7.3 Ethernet Controller 120

6.8 Transitioning Between Protocols 1206.9 Application Example 1216.10 Summary 123

References 123Additional References 124

CHAPTER 7

ControlTechniques 125

7.1 Introduction 1257.1.1 Programmable Logic Controllers 1257.1.2 Open- Versus Closed-Loop Systems 1267.1.3 PID Control 126

7.2 State Machines 1287.3 Fuzzy Logic 1297.4 Neural Networks 1327.5 Combined Fuzzy Logic and Neural Networks 1347.6 Adaptive Control 134

7.6.1 Observers for Sensing 1357.7 Other Control Areas 137

7.7.1 RISC Versus CISC 1387.8 Impact of Artificial Intelligence 1397.9 Application Example 1417.10 Summary 142

References 143

Contents xi

CHAPTER 8

WirelessSensing 147

8.1 Introduction 1478.1.1 The RF Spectrum 1488.1.2 Spread Spectrum 149

8.2 Wireless Data and Communications 1508.3 Wireless Sensing Networks 151

8.3.1 ZigBee 1528.3.2 ZigBee-Like Wireless 1528.3.3 ANT+ 1528.3.4 6LoWPAN 1538.3.5 Near Field Communication (NFC) 1538.3.6 Z-Wave 1538.3.7 Dust Networks 1548.3.8 Other RF Wireless Solutions 1548.3.9 Optical Signal Transmission 154

8.4 Industrial Wireless Sensing Networks 1548.5 RF Sensing 155

8.5.1 Surface Acoustic Wave Devices 1558.5.2 Radar 1568.5.3 Light Detection and Ranging (LIDAR) 1578.5.4 Global Positioning System 1588.5.5 Remote Emissions Sensing 1598.5.6 Remote Keyless Entry 1598.5.7 Intelligent Transportation System 1608.5.8 RF-ID 1628.5.9 Other Remote Sensing 163

8.6 Telemetry 1638.7 RF MEMS 1668.8 Application Example 1678.9 Summary 168

References 169Selected Bibliography 171

CHAPTER 9

MEMSBeyondSensors 173

9.1 Introduction 1739.2 MEMS Actuators 174

9.2.1 Microvalves 1749.2.2 Micromotors 1769.2.3 Micropumps 1779.2.4 Microdynamometer 1799.2.5 Microsteam Engine 1809.2.6 Actuators in Other Semiconductor Materials 180

xii Contents

9.3 Other Micromachined Structures 1819.3.1 Cooling Channels 1829.3.2 Microoptics 1839.3.3 Microgripper 1839.3.4 Microprobes 1859.3.5 Micromirrors 1869.3.6 Heating Elements 1879.3.7 Thermionic Emitters 1879.3.8 Field Emission Devices 1889.3.9 Unfoldable Microelements 1889.3.10 Micronozzles 1909.3.11 Interconnects for Stacked Wafers 1919.3.12 Nanoguitar 191

9.4 Application Example 1929.5 Summary 194

References 194

CHAPTER 10

Packaging,Testing,andReliabilityImplicationsofSmarterSensors 197

10.1 Introduction 19710.2 Semiconductor Packaging Applied to Sensors 197

10.2.1 Increased Pin Count 20010.3 Hybrid Packaging 201

10.3.1 Ceramic Packaging and Ceramic Substrates 20110.3.2 Multichip Modules 20110.3.3 Dual-Chip Packaging 20210.3.4 BGA Packaging 202

10.4 Common Packaging for Sensors 20310.4.1 Plastic Packaging 20410.4.2 Surface-Mount Packaging 20410.4.3 Flip-Chip 20510.4.4 Wafer-Level Packaging 20610.4.5 3-D Packaging 207

10.5 Reliability Implications 20910.5.1 The Physics of Failure 21110.5.2 Wafer-Level Sensor Reliability 212

10.6 Testing Smarter Sensors 21410.7 Application Example 21410.8 Summary 215

References 216

CHAPTER 11

MechatronicsandSensingSystems 219

11.1 Introduction 21911.1.1 Integration and Mechatronics 219

Contents xiii

11.2 Smart-Power ICs 22011.3 Embedded Sensing 222

11.3.1 Temperature Sensing 22211.3.2 Current Sensing in Power ICs 22511.3.3 Diagnostics 22511.3.4 MEMS Relays 228

11.4 Other System Aspects 22811.4.1 Batteries 22911.4.2 Field Emission Displays 23011.4.3 System Voltage Transients, Electrostatic Discharge, and Electromagnetic Interference 230

11.5 Application Example 23211.6 Summary 233

References 233

CHAPTER 12

StandardsforSmartSensing 235

12.1 Introduction 23512.2 Setting the Standards for Smart Sensors and Systems 23512.3 IEEE 1451.1 237

12.3.1 Network-Capable Application Processor 23712.3.2 Network Communication Models 240

12.4 IEEE 1451.2 24112.4.1 STIM 24112.4 2 Transducer Electronic Data Sheet 24312.4.3 TII 24512.4.4 Calibration/Correction Engine 24512.4.5 Sourcing Power to STIMs 24712.4.6 Representing Physical Units in the TEDS 248

12.5 IEEE 1451.3 24912.6 IEEE 1451.4 25012.7 IEEE 1451.5 25012.8 IEEE P1451.6 25212.9 IEEE 1451.7 25212.10 Extending the System to the Network 25212.11 Application Example 25212.12 Summary 254

References 255 Selected Bibliography 256

CHAPTER 13

MoreStandardsImpactingSensors 257

13.1 Introduction 25713.2 Sensor Plug and Play 25713.3 Universal Serial Bus 259

xiv Contents

13.4 Development Tools Establish De Facto Standards 26013.5 Alternate Standards 261

13.5.1 Airplane Networks 26113.5.2 Automotive Safety Network 26213.5.3 Another Automotive Safety Network 26313.5.4 Automotive Sensor Protocol 264

13.6 Consumer/Cell Phone Apps 26713.7 Application Example 26813.8 Summary 269

References 269

CHAPTER 14

SensorFusion 271

14.1 Introduction 27114.2 Sensor and Other Fusion Background 27114.3 Automotive Applications 273

14.3.1 Ranging and Vision 27414.3.2 Sensor Fusion for Virtual Sensors 27514.3.3 Autonomous Driving 276

14.4 Industrial (Robotic) Applications 27714.5 Consumer Applications 278

14.5.1 Fusion Software in the Sensor 27814.5.2 Separate Fusion Software 27914.5.3 Flexible Fusion Software 27914.5.4 Agnostic Sensor Fusion 27914.5.5 Simulation and Testing 280

14.6 Application Example 28114.7 Summary 282

References 282 Selected Bibliography 284

CHAPTER 15

EnergyHarvestingforWirelessSensorNodes 285

15.1 Introduction 28515.2 Applications Drive Technology Implementation and Development 285

15.2.1 Structural Health Monitoring 28515.2.2 Building Automations Systems 28615.2.3 Industrial Applications 28615.2.4 Automotive 28615.2.5 Aircraft 28615.2.6 Portable Consumer 28715.2.7 Remote Distributed Applications 287

15.3 Complete System Consideration 287

Contents xv

15.4 EH Technologies 28815.4.1 Thermoelectric EH 28815.4.2 Piezoelectric EH 29115.4.3 Photovoltaic EH 29315.4.4 Electromagnetic EH 29415.4.5 RF EH 29415.4.6 Electromechanical EH 29415.4.7 Multiple Energy Sources 29515.4.8 Future Concepts 296

15.5 Energy Storage 29715.5.1 Batteries 29715.5.2 Ultracapacitors 298

15.6 Energy Budget 29815.6.1 Power Management ICs 29815.6.2 MCUs 29915.6.3 Wireless Transmission 30015.6.4 Sensor Power Consumption 301

15.7 Development Systems 30215.8 Application Example 30415.9 Summary 304

References 306 Selected Bibliography 308

CHAPTER 16

TheNextPhaseofSensingSystems 309

16.1 Introduction 30916.2 Future Sensor Plus Semiconductor Capabilities 310

16.2.1 Monolithic Versus Package-Level Integration 31116.3 Future System Requirements 313

16.3.1 Sensing in Automobiles 31316.3.2 Sensing in Smart Phones 31516.3.3 Health Care Sensors 316

16.4 Software, Sensing, and the System 31616.4.1 Sensor Apps 31716.4.2 Cloud Sensing 319

16.5 Trusted Sensing 32016.6 Alternate Views of Smart Sensing 32116.7 The Smart Loop 32216.8 Application Example 32316.9 Summary 324 Acknowledgment 325

References 325 Selected Bibliography 327