Phase correction in digital self-oscillation drive circuit for improve silicon MEMS gyroscope bias stability

To further improve the performance of the bias stability which is the key character for MEMS gyroscope in navigation application, a new digital self-oscillation based drive circuit with drive phase correction is proposed. Started with the gyroscope working principle, analyzed the factors that may affect the bias output. Compared with drive amplitude control which already got a higher precision, the drive phase drift has become the main factor affects the bias stability. Consider the linear phase response character of the digital signal processing this paper gives out a linear phase compensation method to reduce the phase drift. Experiment results indicate that the bias stability has improved from 56°/h to 24°/h.