| dc.description.abstract | This design allows control of 2-axis simultaneous operation or single-axis enhanced operation of the magnetometer. This magnetometer uses UMC 0.18 μm CMOS process. The circuitry is integrated within the chip, resulting in a single-chip system-on-chip (SoC) solution. The MEMS structure has dimensions of 995 × 932 μm² and is capable of measuring both DC and AC magnetic fields.
When measuring DC magnetic fields, an AC driving current is required. In simultaneous mode, the device can measure the magnetic field vector of a single plane, making it suitable for use in position detection feedback systems. With a driving AC current of 60 mA, the sensitivity for the Y-axis magnetic field is 18.5 V/T, and for the Z-axis magnetic field, it is 2.9 V/T. In superimposed mode, simply adjusting the frequency and phase of the driving current can increase the Y-axis magnetic field sensitivity to 37.5 V/T, approximately doubling it. This enhancement allows for clear measurement of the geomagnetic field, enabling applications in orientation detection.
When measuring AC magnetic fields, a DC driving current of 1 mA is required. This allows for the measurement of the rotational speed and direction of a BLDC motor, which can be used for motor control. | en_US |