Continuous-time lowpass and bandpass ΔΣ-modulators for closed-loop readout circuits of capacitive MEMS gyroscopes

This paper presents the design and implementation of electro-mechanical continuous-time bandpass and lowpass ΔΣ-modulators for closed-loop readout of vibratory MEMS gyroscopes. These concepts improve the performance of the readout system in terms of susceptibility to temperature and sensor parameter variations compared to open-loop solutions. Additionally, the linearity and the dynamic range are improved while the power consumption is low. Measurement results are shown of both readout concepts, which demonstrate the competitiveness and the functionality of the readout interfaces.