High sensitivity, low cost, low power, and direct integration with MEMS inertial sensors, such as accelerometers and gyroscopes, make the MEMS magnetic sensor a very attractive option in consumer electronic devices. The goal of this project is to develop a low-power three axis MEMS magnetic sensor suitable for use as an electronic compass in smart phones and portable electronics. Our objective is to achieve a resolution of 100 nT/rt-Hz and power consumption of 0.1 mW/axis with DC power supply of 1.8 V. Although past devices designed by our group have demonstrated that our resolution goal is reachable, these devices suffered from dc offset larger than Earth's field and required an external programmable oscillator for operation. Here, we aim to reduce offset by two orders of magnitude for improving the long-term stability of the magnetic sensor and to develop self-oscillation loops to excite the sensor either at resonance or off-resonance.
Project end date: 08/10/17