A Test Setup for the Characterization of Lorentz-Force MEMS Magnetometers

Abstract

Lorentz-force MEMS magnetometers are interesting candidates for the replacement of magnetometers in consumer electronics products. Plenty of works in the literature propose MEMS magnetometers, their readout circuits and modulations. However, during the standalone characterization of such MEMS devices, a great variety of instruments and strategies are used, making it very complex to compare results from different works in the literature. For this reason, this article proposes a test setup to characterize Lorentz-force MEMS magnetometers. The proposed setup is based around the use of an impedance analyzer for the driving of voltage and Lorentz-current of the MEMS in-phase and in quadrature, which allows the device Amplitude Modulation and Frequency Modulation characterization. The proposed solution is validated by using the designed circuit to characterize two CMOS-MEMS magnetometers with very different characteristics.

Keywords

• Microelectromechanical systems
• MEMS
• magnetic sensor
• magnetometer
• Lorentz-force
• device characterization