Richard B. Brown - Research
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MEMS-Based Monolithic Clock Generation
Graduate Student Researcher: Michael S. McCorquodale

 This work is focused at leveraging previous work in RF micromachining to develop a high-performance, digital, monolithic clock generation circuit for application in embedded processors. A high-Q and CMOS-compatible MEMS LC-tank (pictured) oscillator has been developed to synthesize a high-frequency reference which is then divided in frequency to meet the specifications for the application. This architecture further reduces the relative jitter and phase noise from the reference through frequency division. In contrast, clock generation systems that employ frequency multiplication, such as PLLs and DLLs, accumulate noise and increase the jitter and phase noise from the reference. We have shown that this architecture achieves similar stability performance when compared to PLL and DLL systems for common embedded applications. Prototypes have been developed and fabricated in TSMC 0.18µm CMOS and IBM 0.13µm SOI-CMOS. These circuits have been post-processed in the University of Michigan Solid State Electronics Laboratory and are capable of synthesizing clock signals from 1GHz to 31.25MHz. The contributions of this work include potentially the highest performance on-chip clock generation circuit, a fully commercially-compatible microsystems manufacturing process, and an efficient design methodology for microsystems and mixed-signal development. This project is funded by the Engineering Research Centers Program of the National Science Foundation under Award Number EEC-9986866.