The design and operation of a second-generation carrier-domain magnetometer device

The carrier-domain magnetometer generates an electrical output having a frequency proportional to an applied magnetic field, arising from the rotation of the current distribution in a circular bipolar transistor structure with its axis parallel to the field. An improved version of this silicon transducer has been designed and investigated, which has a sensitivity of about 100 kHz/T. The sensitivity depends on temperature and electrical bias conditions, and compensation techniques are described. If a magnetic field is applied parallel to the plane of the circle, its angular position can be monitored since the domain follows it.