Hall Sensor Readout System with Offset Determination Using the Hall Element Itself

Method for offset determination in a Hall sensor for measuring a magnetic field,

• the Hall sensor comprising:
• at least one Hall element having a plate-shaped sensor element made of a doped semiconductor material, the Hall sensor being embedded in a semiconductor chip further comprising storage means storing on-chip, in a non-volatile form, calibration data obtained from a calibration procedure,
• the method comprising:
• i) obtaining a first readout signal (VH) from the at least one Hall element by using a first technique which yields a result that is substantially dependent on the magnetic field to be measured including an offset (VO) to be determined,
• ii) obtaining a second readout signal (VP) from the at least one Hall element by using a second technique which yields a result that is substantially independent of the magnetic field but is correlated to said offset (VO), and
• iii) using the second readout signal (VP) for obtaining a prediction ({circumflex over (V)}O) of the offset (VO) on the first readout signal (VH) as a linear function of the second readout signal (VP), expressed as {circumflex over (V)}O=a+b VP, a and b being parameters in the linear function based on the calibration data stored in the on-chip storage means.

A semiconductor chip comprising a Hall sensor, the Hall sensor comprising:

• at least one Hall element, each Hall element having a plate-shaped sensor element made of a doped semiconductor material,
• storage means storing on-chip, in a non-volatile form, calibration data obtained from a calibration procedure;
• sensor means for obtaining a first readout signal (VH) from the at least one Hall element using a first technique that yields a result which is substantially dependent on the magnetic field and has an offset (VO) to be determined,
• sensor means for obtaining a second readout signal (VP) from the at least one Hall element using a second technique that yields a result which is substantially independent of the magnetic field but is correlated to said offset (VO), and
• means for obtaining a prediction ({circumflex over (V)}O) of the offset (VO) on the first readout signal (VH) as a linear function of the second readout signal (VP), expressed as {circumflex over (V)}O=a+b VP, a and b being parameters in the linear function based on the calibration data stored in the on-chip storage means,
• means for compensating the offset (VO) on the first readout signal (VH) based on the prediction signal ({circumflex over (V)}O).