In order to improve the temperature adaptability of MEMS accelerometer,frequency modulation and time-difference method are designed.This accelerometer utilizes the electrostatic stiffness effect to modulate the displacement change of the proof mass due to acceleration into the change of resonant frequency.This accelerometer combines the advantages of low temperature coefficient in displacement detection and less susceptibility to circuit noise interference in resonant frequency detection.And only one resonator is used,but differencing in time through stiffness switching,thus achieving a low zero bias with temperature.The experimental results show that,at 10 V tuning voltage,the zero bias stability is 76.79 μg at room temperature.The frequency difference obtained after the temporal difference is-0.072 Hz,which is reduced by about 99%compared with the resonant frequency variation of about 7.7 Hz under a single stiffness state.These results verify the effectiveness of electrostatic stiffness frequency modulation and temporal difference.
MEMS accelerometerelectrostatic stiffness frequency modulationtemporal difference
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