A digital demodulation solution to achieve stable driving for a micro-machined gyroscope with an AGC mechanism

This paper presents a digital solution to restrain the impact of the unwanted low-frequency signal on the practical driving signal, i.e. carrier signal, in a MEMS gyroscope with automatic gain control (AGC) mechanism. For this purpose, an ASIC has been designed and fabricated. With digital signal processing (DSP) techniques, the digital demodulated angular rate signal is adjusted by using a self-multiplied practical carrier signal after LPF in a digital divider. The simulation gives an SNR of better than 70 dB, which indicates that good device performance can be possibly achieved with this principle even though the driving is not ideal.