Differential lateral magnetic field sensor system with offset cancelling and implemented using silicon-on-insulator technology

Abstract

A differential magnetic field sensor system () is provided, in which offset cancelling for differential semiconductor structures in magnetic field sensors arranged close to each other is realized. The system () comprises a first, a second and a third magnetic field sensor (), each of which is layouted substantially identically and comprises a, preferably silicon-on-insulator (SOI), surface layer portion () provided as a surface portion on a, preferably SOI, wafer and having a surface (). On the surface () is arranged a central emitter structure () formed substantially mirror symmetrical with respect to a symmetry plane () that is substantially perpendicular to the surface (), and a first and a second collector structure (), each of which is arranged spaced apart from the emitter structure () and which are arranged on opposite sides of the symmetry plane () so as to be substantially mirror images of each other. The first magnetic field sensor () is operated double-sided in that its first collector structure () and its emitter structure () are externally connected via a first read-out circuitry and its second collector structure () and its emitter structure () are externally connected via a second read-out circuitry. The second magnetic field sensor () is operated single-sided in that its first collector structure () and its emitter structure () are externally connected via a third read-out circuitry. The third magnetic field sensor () is operated single-sided in that its second collector structure () and its emitter structure () are externally connected via a fourth read-out circuitry.