Monolithic and top-down clock synthesis with micromachined radio frequency reference

This dissertation explores the techniques by which clock synthesis for embedded processors can be achieved in monolithic form while maintaining high frequency accuracy and stability. Motivation for this work includes the potential for substantial reductions in overall microelectronic system power dissipation, size, and cost through complete integration of the clock synthesis function.; A thorough treatment of phase noise and jitter is presented in this work. The effects of frequency translation on stability are also analyzed and a new systemic top-down clock synthesis approach is presented as a consequence of this analysis. Harmonic oscillators are identified as the best solution for stable and accurate top-down clock synthesis. Consequently, micromachining techniques for RF passive devices are explored in an effort to develop a precision harmonic reference for this work. A maskless post-process for fabricating RF MEMS components in commercial CMOS is presented successfully. Both micro-mechanical varactors and suspended inductors are shown. The tuning range of the developed micromechanical varactors is shown to be up to 20%. Additionally, the inductor quality factor is shown to improve by up to 13% using the techniques shown here.; A successful prototype of a complete monolithic harmonic clock synthesizer is demonstrated with these passive devices. The synthesizer generates frequencies from 28MHz to 900MHz in increments of 2. The maximum RMS jitter for all frequencies is shown to be less than 300ppm while the power dissipation is less than 15mW. Tuning of up to 2.2% is also demonstrated using a novel frequency-pulling approach.; The remainder of this dissertation focuses on implementation of the developed clock synthesizer into an embedded system. Advances in the area of design automation and IP-based design have been developed throughout this effort. A top-down microsystems methodology has been proposed and a software tool has been developed for the synthesis of MEMS devices related to this research. The clock synthesizer is demonstrated successfully as the sole clock reference for an embedded processor where the clock frequencies can be switched nearly instantaneously between any two frequencies in the range of 2kHz to 66MHz.