Three-dimensional magnetometer based on subsequent measurement principle

Abstract

A novel single-chip 3-D multidimensional Hall device for subsequent measurement of the three orthogonal magnetic-field components using one and the same transducer zone is presented. The magnetometer includes n-Si microsensor and simple and reliable interface circuitry which contains power supply and original signal extraction and conditioning circuitry. In the 3-D microsensor, six ohmic planar contacts on silicon substrate are implemented. Two of them are used for power supply. The other four are used to obtain the full information about the magnetic field vector components, by three successive coupling arrangements realizing two in-plane sensitive and one orthogonal Hall effect devices. The proposed approach employs the same element, but at different time. The sensor operation is determined by the direction of individual parts of nonlinear carriers’ trajectory in the substrate and the Lorentz force action on them. The effective sensor minimum operational volume is 90μm×60μm×30μm. The respective channel-magnetosensitivities consist Sx≈35V/AT, Sy≈26V/AT, and Sz≈18V/AT, the channel cross-talk at induction B≤1T reaches no more than 3% and the lowest detected magnetic field of the three channels is about 10μT in the frequency range f≤102Hz. The instrument ensures the measurement of the full magnetic field vector with rate 20,000Hz and the output signal is in range [−5V, 5V].