Precision Temperature Sensors in CMOS Technology

ISBN-13: 9789048173259 / Angielski / Miękka / 2010 / 292 str.

Micheal A. P. Pertijs; Johan H. Huijsing

Opis

The low cost and direct digital output of CMOS smart temperature sensors are important advantages compared to conventional temperature sensors. This book addresses the main problem that nevertheless prevents widespread - plication of CMOS smart temperature sensors: their relatively poor absolute accuracy. Several new techniques are introduced to improve this accuracy. The effectiveness of these techniques is demonstrated using three prototypes. ? The ?nal prototype achieves an inaccuracy of 0.1 C over the military t- perature range, which is a signi?cant improvement in the state of the art. Since smart temperature sensors have been the subject of academic and industrial research for more than two decades, an overview of existing knowledge and techniques is also provided throughout the book. Inthisintroductorychapter, themotivationandobjectivesofthisworkare- scribed. ThisisfollowedbyareviewofthebasicoperatingprinciplesofCMOS smart temperature sensors, and a brief overview of previous work. The ch- lenges are then described that need to be met in order to improve the accuracy of CMOS smart temperature sensors while maintaining their cost advantage. Finally, the structure of the rest of the book is introduced."

Spis treści

Acknowledgment.

1. INTRODUCTION. 1.1 Motivation and Objectives. 1.2 Basic Principles. 1.3 Context of the Research. 1.4 Challenges. 1.5 Organization of the Book. References.

2. CHARACTERISTICS OF BIPOLAR TRANSISTORS. 2.1 Introduction. 2.2 Bipolar Transistor Physics. 2.3 Temperature Characteristics of Bipolar Transistors. 2.4 Bipolar Transistors in Standard CMOS Technology. 2.5 Processing Spread. 2.6 Sensitivity to Mechanical Stress. 2.7 Effect of Series Resistances and Base-Width Modulation. 2.8 Effect of Variations in the Bias Current. 2.9 Conclusions. References.

3. RATIOMETRIC TEMPERATURE MEASUREMENT USING BIPOLAR TRANSISTORS. 3.1 Introduction. 3.2 Generating an Accurate Current-Density Ratio. 3.3 Generating an Accurate Bias Current. 3.4 Trimming. 3.5 Curvature Correction. 3.6 Compensation for Finite Current-Gain. 3.7 Series-Resistance Compensation. 3.8 Conclusions. References.

4. SIGMA-DELTA ANALOG-TO-DIGITAL CONVERSION. 4.1 Introduction. 4.2 Operating Principles of Sigma-Delta ADCs. 4.3 First-Order Sigma-Delta Modulators. 4.4 Second-Order Sigma-Delta Modulators. 4.5 Decimation Filters. 4.6 Filtering of Dynamic Error Signals. 4.7 Conclusions. References.

5. PRECISION CIRCUIT TECHNIQUES. 5.1 Introduction. 5.2 Continuous-Time Circuitry. 5.3 Switched-Capacitor Circuitry. 5.4 Advanced Offset Cancellation Techniques. 5.5 Conclusions. References.

6. CALIBRATION TECHNIQUES. 6.1 Introduction. 6.2 Conventional Calibration Techniques. 6.3 Batch Calibration. 6.4 Calibration based on DV_BE Measurement. 6.5 Voltage Reference Calibration. 6.6 Conclusions. References.

7. REALIZATIONS. 7.1 A Batch-Calibrated CMOS Smart Temperature Sensor. 7.2 A CMOS Smart Temperature Sensor with a 3s Inaccuracy of ±0.5° C from -50° C to 120° C. 7.3 A CMOS Smart Temperature Sensor with a 3s Inaccuracy of ±0.1° C from -55° C to 125° C. 7.4 Benchmark. References.

8. CONCLUSIONS. 8.1 Main Findings. 8.2 Other Applications of this Work. 8.3 Future Work. References.

Appendices. A Derivation of Mismatch-Related Errors. A.1 Errors in DV_BE

B Resolution Limits of Sigma-Delta Modulators with a DC Input. B.1 First-Order Modulator. B.2 Second-Order Single-Loop Modulator. References.

C Non-Exponential Settling Transients. C.1 Problem Description. C.2 Settling Transients from V_BE1 ¹ 0 to V_BE2 . C.3 Settling Transients from V_BE1 = 0 to V_BE2 . Summary.

About the Authors. Index.

O autorze

Prof. Johan Huijsing has (co) authored and edited over 20 books with Springer / Kluwer.

Dr. Michiel Pertijs graduated "cum laude" for his PhD work on the Temperature Sensor