Device for generating a magnetic field of calibration and built-in self-calibration magnetic sensor and calibration method using the same

A built-in self-calibration magnetic sensor, comprising:

• a first magnetic field generating device, comprising a first conducting structure, a second conducting structure, and a conducting coil having a top surface, a bottom surface, an inner surface close to the first conducting structure and an outer surface that is opposite to the inner surface, wherein the first conducting structure generates a first magnetic field through a first electric current, the second conducting structure is substantially parallel to the first conducting structure and generates a second magnetic field with respect to a second axis substantially orthogonal to the first axis through a second electric current, and the conducting coil is peripherally arranged around the first and second conducting structures and generates a third magnetic field with respect to a third axis substantially orthogonal to the first and second axes through a third electric current, wherein the first conducting structure has a bottom plane with respect to the first axis and the second axis, the second conducting structure has a top plane with respect to the first axis and the second axis, the top plane has a distance apart from the bottom plane along the third axis, and is substantially parallel to the bottom plane;
• a magnetic field sensing unit, generating a sensing information in response to detection of the first, second and third magnetic fields;
• and
• a control module, electrically coupled to the magnetic field sensing unit for receiving the sensing information and comparing the sensing information corresponding to each axis with a predetermined magnetic field of the corresponding axis, respectively, for determining a calibration information associated with the first, second and third magnetic fields.

A method for calibrating magnetic field, utilized to perform a self-calibration procedure, comprising steps of:

• providing a magnetic sensor comprising a device for generating a calibration magnetic field, the device comprising a magnetic field sensing unit, wherein the device comprises a first conducting structure having a bottom plane with respect to a first axis and the a second axis, a second conducting structure having a top plane with respect to the first axis and the second axis, and a conducting coil having a top surface, a bottom surface, an inner surface close to the first conducting structure and an outer surface that is opposite to the inner surface, wherein the top plane has a distance apart from the bottom plane along a third axis, and is substantially parallel to the bottom plane;
• generating, by the device, three different magnetic fields respectively along the first axis, the second axis, and the third axis, wherein each magnetic field has a predetermined magnitude and the three different magnetic fields are substantially orthogonal to each other;
• sensing, by the magnetic field sensing unit, the three different magnetic fields respectively along the first axis, the second axis, and the third axis, and generating a sensing information respectively corresponding to each axis;
• and
• comparing the sensing information of each axis with the predetermined magnitude of each magnetic field along the corresponding axis for determining a calibration information associated with each axis.