Design and performance of CMOS micromechanical resonator oscillators

A completely monolithic high-Q oscillator, fabricated via a combined CMOS plus surface micromachining technology, is described, for which the oscillation frequency is controlled by a polysilicon micromechanical resonator to achieve high stability. It is shown that the closed-loop, steady-state oscillation amplitude of this oscillator can be controlled through the dc-bias voltage applied to the capacitively driven and sensed /spl mu/resonator. Brownian motion and mass loading phenomena are shown to have a greater influence on short-term stability in this micro-scale.<
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