Temperature and 3D magnetic field measurement using the same sensing zone

A novel functional multisensor for temperature and subsequent measurement of three orthogonal magnetic-field components using the same transducer zone is presented. One central emitter, two symmetrically positioned base contacts and two pairs of output ohmic terminals on a silicon substrate, close to the bases, are implemented. Three subsequent coupling arrangements of the four output terminals use the same sensor region at different times. Temperature is measured through the voltage on the forward biased p+-n emitter junction at a constant supply current. The obtained channel sensitivities are Sx = 7 V/AT, Sy = 9 V/AT and Sz = 11.3 V/AT. The thermo-sensitivity is KEB = −1.82 mV/°C at a current of 1 mA. Magnetic induction does not perturb thermometric voltage within a wide range, −0.8 T ≤ B ≤ 0.8 T. The spatial resolution is high reaching about 110 × 90 × 40 μm3 and the channel cross-sensitivities are no more than 2.6% at induction B = 1.0 T. The mean lowest detected magnetic field at a frequency range f ≤ 100 Hz and a supply current 3 mA is Bmin ≈13 μT for the channels.