Noise contributions in a closed-loop MEMS gyroscope for automotive applications

This paper reports on zero-rate noise contributions in a closed-loop MEMS vibratory gyroscope. In particular, we are investigating sources and composition of bias instability noise. This 1/f-noise is the dominant error component when integrating the angular rate for durations on the order of one minute. It is demonstrated that mechanical quadrature is not responsible for the bulk of bias instability noise. We show experimentally that bias instability is strongly dependent on drive loop amplitude and sense mass frequency detuning. Potential sources and cross-coupling paths are discussed.