Intrinsic feedthrough current cancellation in a seesaw CMOS-MEMS resonator for integrated oscillators

The parasitic feedthrough capacitance that inherently appears in capacitive transduced MEMS resonators presents two main drawbacks: it partially, or even totally, masks the magnitude of the resonance peak; and also, it reduces the π-phase transition produced by the resonance peak. This reduction in the phase transition not only complicates to meet the Barkhausen's phase condition in oscillator systems, but also it reduces the quality factor, deteriorating in this way the phase noise performance of oscillator systems. In this paper, we report on the initial experimental demonstration of a dual-mode seesaw CMOS-MEMS resonator that intrinsically mitigates the effect of the parasitic current on the magnitude and phase of the resonance frequency. Finally, a dual-clock application with the presented dual-mode resonator is proposed and experimentally demonstrated.