Magnetic field sensor transmission factor variation compensation circuit uses correlator for comparing auxiliary signal with detected corresponding field coupled to series regulation circuit

摘要

The compensation circuit has a coil device (5a,5b) coupled to an auxiliary current generator (3) via a voltage/current converter (4) for providing an auxiliary magnetic field (Bt,-Bt) superimposed on the measured magnetic field, a sum element (12a) determining the component of the magnetic field sensor output voltage resulting from the auxiliary magnetic field, supplied to a correlator (6) for correlation with the voltage output (Vg) of the auxiliary current generator. The circuit is provided by an IC, the correlator output fed to a series circuit with an A/D converter (14), a digital regulator (28) and a D/A converter (17) providing a variable setting component for compensation of the transmission factor variation. An Independent claim is also made for a method for compensation of the transmission factor variation of a magnetic field sensor.