AN AUTOMATIC MODE MATCHING SYSTEM FOR A HIGH Q-FACTOR MEMS GYROSCOPE USING A DECOUPLED PERTURBATION SIGNAL

2015-06-25
Yesil, F.
Alper, S. E.
Akın, Tayfun
This paper reports a closed-loop controller system developed for in-run automatic matching of the drive and sense mode resonance frequencies of a MEMS gyroscope with a high quality factor (Q). This is achieved by injecting a perturbation signal to the quadrature cancellation loop, while keeping it decoupled from the angular rate control loop. The new controller is implemented in a CMOS ASIC together with the other sensor control loops, and it is verified to maintain matched-mode state under changing environmental conditions. The system reduces the overall output noise of the tested MEMS gyroscope by a factor of 6; truly reaching down to the thermo-mechanical noise floor of 0.4 (degrees/hr)/Hz(1/2).