A high-performance single-chip timing and inertial measurement unit with robust mode-matched gyroscopes

Abstract

This paper presents a single-chip timing and inertial measurement unit (TIMU) with high-frequency modematched gyroscopes, high-bandwidth accelerometers, and a high-frequency high-Q bulk acoustic wave (BAW) timing resonator integrated on a 4.5mm∗5.5mm platform using the HARPSS+ process, which enables vertical, horizontal, and 54°-slanted electrodes with scalable nano-gaps. The TIMU is the first single-chip IMU featuring 3-axis high-frequency quadrature-compensated resonant (i.e. mode-matched) gyroscopes. The 3-axis gyroscopes have high shock and vibration resistance and present sub-1°/√h angle random walk (ARW) and ∼10°/h bias instability (BI) limited by discrete electronics. The 3-axis accelerometers show sub-300μg/√Hz velocity random walk (VRW) and sub-100μg BI. The timing resonator has a high Q of 47k with a high frequency of 85MHz. Further improvements can be achieved with optimized interface electronics to meet high-end application requirements.