3-D silicon vector sensor based on a novel parallel-field Hall microdevice

摘要

A single-chip 3-D silicon vector sensor for magnetic-field measurement is presented. This triaxial device functionally integrates in a common transducer region two novel five-contacts parallel-field Hall elements for in-plane components B-x and B-y and four cross-coupled orthogonal triple Hall elements for the B-z component, perpendicular to the chip surface. The effective sensor volume is 150 mum x 150 mum x 100 mum. The main advantage of this 3-D vector magnetometer is the strongly reduced (with about 45%) channel cross-sensitivities. This is achieved by amperometric output mode of operation using an original read-out circuitry, keeping equal voltage conditions on the top of the chip with and without magnetic field. The sensitivities per channel reaches S-A(B-x)=S-A(B-y)=356 muA/T and S-A(B-z)=260 muA/T at a supply current 10 mA, the measured equivalent offsets of the three channel outputs are 25/35 mT and the low frequency noise is mainly a 1/f. The lowest detected magnetic induction of the three output channels is about 15/20 muT in the range 1 less than or equal to f less than or equal to 10(2) Hz and the frequency response of the 3-D device together with the read-out electronics is at least 30 kHz. (C) 2003 Elsevier B.V. All rights reserved. [References: 26]