A 0.1°/HR bias drift electronically matched tuning fork microgyroscope

This paper presents an architecture that utilizes the often ignored residual quadrature error in a gyroscope to achieve and maintain perfect mode-matching, i.e., ~ 0 Hz split between the drive and sense mode frequencies, as well as electronically control the sensor bandwidth. A 6 mW, 3 V CMOS ASIC and control algorithm have been interfaced with a 60 mum thick mode-matched tuning fork gyroscope (M²-TFG) to implement an angular rate sensor with bias drift as low as 0.15deg/radichr and angle random walk (ARW) of 0.003deg/radichr - the lowest recorded to date for a silicon MEMS gyro. The maximum scale factor of the gyroscope is 88 m V/deg/s and the microsystem bandwidth can be configured between 1 to 10 Hz.