The Magnetic Field Sensitive Transistor-A New Sensor for Crankshaft Angle Position

A semiconductor sensor is described, suitable for indicating crankshaft angle or more generally any position which can be related to changes in a magnetic field. The sensor is based on a lateral P-N-P transistor which is sensitive to magnetic fields. Devices made in a standard analog IC process are presented and show the voltage sensitivity to magnetic fields to be up to Z orders of magnitude larger than for a comparable Hall-element.

The parameters most interesting for use in automobiles are discussed: sensitivity, zero field offset, temperature effects and mechanical stress effects.