Electronic oscillators using an electromechanical device as a frequency reference are irreplaceable components of systems-on-chip for time-keeping, carrier frequency generation and digital clock generation. With their excellent frequency stability and very large quality factor Q, quartz crystal resonators have been the dominant solution for more than 70 years. But new possibilities are now offered by micro-electro-mechanical (MEM) resonators, that have a qualitatively identical equivalent electrical circuit.
Low-Power Crystal and MEMS Oscillators concentrates on the analysis and design of the most important schemes of integrated oscillator circuits. It explains how these circuits can be optimized by best exploiting the very high Q of the resonator to achieve the minimum power consumption compatible with the requirements on frequency stability and phase noise. The author has 40 years of experience in designing very low-power, high-performance quartz oscillators for watches and other battery operated systems and has accumulated most of the material during this period. Some additional original material related to phase noise has been added. The explanations are mainly supported by analytical developments, whereas computer simulation is limited to numerical examples. The main part is dedicated to the most important Pierce circuit, with a full design procedure illustrated by examples. Symmetrical circuits that became popular for modern telecommunication systems are analyzed in a last chapter.
About the Author
Table of ContentsPreface. List of Symbols.
1Introduction. 1.1 Applications of Quartz Oscillators. 1.2 Historical Notes. 1.3 The Book Structure. 1.4 Basics on Oscillators.
2 Quartz and MEMs Resonators. 2.1 The Quartz Crystal resonator. 2.2 Equivalent Circuit. 2.3 Figure of Merit. 2.4 Mechanical Energy and Power Dissipation. 2.5 Various Types of Quartz Resonators. 2.6 MEMs Resonators.
3 General Theory of High-Q Oscillators. 3.1 General Form of the Oscillator. 3.2 Stable Oscillation. 3.3 Critical Condition for Oscillation and Linear Approximation. 3.4 Amplitude Limitation. 3.5 Start-up of Oscillation. 3.6 Duality. 3.7 Basic Considerations on Phase Noise. 3.8 Model of the MOS Transistor.
4 Theory of the Pierce Oscillator. 4.1 Basic Circuit. 4.2 Linear Analysis. 4.3 Nonlinear Analysis. 4.4 Phase Noise. 4.5 Design Procedure.
5 Implementations of the Pierce Oscillator. 5.1 Grounded-Source Oscillator. 5.2 Amplitude Regulation. 5.3 Extraction of the Oscillatory Signal. 5.4 CMOS-Inverter Oscillator. 5.5 Grounded Drain Oscillator.
6 Alternative Architectures. 6.1 Introduction. 6.2 Symmetrical Oscillator for Parallel Resonance. 6.3 Symmetrical Oscillator for Series Resonance. 6.4 Van den Homberg Oscillator. 6.5 Comparison of Oscillators.