Calibratable Multidimensional Magnetic Point Sensor
Description
The present invention relates to magnetic field sensors and, in particular, to Hall sensors
for detecting spatial components of a magnetic field in a reference point, the sensors being
in particular calibratable during measuring operation, and to the calibration and measuring
methods employed here
Apart from measuring magnetic fields as to magnitude and direction, Hall sensor elements
which are based on the Hall effect are frequently employed in technology for non-contact
contactless signal generators for detecting the position of switches or control elements in a
wear-free manner Another way of application is measuring a current, wherein a Hall
sensor element is placed close to a conductive trace and measures, in a non-contact
manner, the current in the conductive trace via detecting the magnetic field generated by
the current in the conductive trace In practical applications, Hall sensor elements excel, in
particular, by their relatively great insensitivity to external influences, such as, for
example, contaminations and the like
In technology, both so-called horizontal or lateral Hall sensor elements and vertical Hall
sensor elements are known, Fig 6a exemplanly illustrating a horizontal Hall sensor
element and Fig 6b illustrating a vertical Hall sensor element according to the prior art
A Hall sensor element is generally made up of a semiconductor wafer having four contact
terminals which are provided for an electrical connection to an external control circuit Of
the four contact terminals of a Hall sensor element, two contact terminals are provided for
impressing an operating current through an active semiconductor region, whereas the other
two contact terminals are provided for detecting the Hall voltage When the semiconductor
wafer through which the operating current flows is exposed to a magnetic field having an
induction B, the result will be a deflection in the current paths which is caused by the
"Lorenz force" acting on the moved charge carriers in the magnetic field The Hall voltage
will be perpendicular to the direction of the current flow and perpendicular to the magnetic
field applying in the active semiconductor region
As is basically illustrated in Fig 6a, a horizontal Hall sensor element 600 according to the
prior art is generally made up of an n-type doped semiconductor region 602 on a p-type
doped semiconductor substrate 604 A Hall sensor element which is arranged in parallel to
a chip surface (x-y plane) is referred to as horizontal

The n-type doped active region 602 is typically connected to external control or evaluation
logic via four contact electrodes 606a-d which are arranged in pairs opposite each other in
the active region 602 The control or evaluation logic is not illustrated in Fig 6 for clarity
reasons The four contact electrodes 606a-d are divided into two opposite control current
contact electrodes 606a and 606c which are provided to generate a current flow IH through
the active region 602, and additionally into two opposite voltage tapping contact electrodes
606b and 606d which are provided for tapping as a sensor signal a Hall voltage UH
occurring in a magnetic field B applying perpendicular to the current flow in the active
region 602 and the magnetic field applying By impressing the current flow IH between
different contact electrodes and correspondingly tapping the Hall voltage UH at the other
contact electrodes perpendicular to the current flow, compensation methods which allow
compensating tolerances which occur in the Hall sensors, for example, due to
manufacturing tolerances, etc , over several measuring cycles may be implemented
As can be seen from the horizontal Hall sensor element 600 illustrated in Fig 6a, the active
region between the contact terminals 606a-d is defined such that the active region has an
effective length L and an effective width W The horizontal Hall sensor elements 600
illustrated in Fig 6a are relatively easy to manufacture using conventional CMOS
(Complementary Metal Oxide Semiconductor) processes for manufacturing semiconductor
structures
Apart from the horizontal Hall sensor elements, realizations of so-called vertical Hall
sensor arrangements which also allow standard semiconductor manufacturing
technologies, such as, for example, CMOS processes to be used, are also known in the
prior art An example of a vertical Hall sensor element 620 is basically illustrated in Fig
6b, wherein vertical here means a plane perpendicular to the plane of the chip surface (X-Y
plane) In the vertical Hall sensor element 620 illustrated in Fig 6b, the preferably n-type
doped active semiconductor region 622 extends in the form of a well in a p-type doped
semiconductor substrate 624, the active semiconductor region 622 having a depth T As is
illustrated in Fig 6b, the vertical Hall sensor element comprises three contact regions
626a-c which are arranged in the semiconductor substrate 624 adjacent to the main surface
thereof, the contact terminals 626a-c being all arranged in the active semiconductor region
622 Due to the three contact regions, this variation of vertical Hall sensor elements is also
referred to as 3-pin sensor
The vertical Hall sensor element 620 illustrated in Fig 6b also comprises three contact
regions 626a-c along the main surface of the active semiconductor region 622, the contact

region 626a being connected to a contact terminal A, the contact region 626b being
connected to a contact terminal B and the contact region 626c being connected to a contact
terminal C When a voltage is applied between the two contact terminals A and C, the
result will be a current flow IH through the active semiconductor region 622 and a Hall
voltage UR which is oriented to be perpendicular to the current flow IH and to the magnetic
field B can be measured at the contact terminal B The effectively active regions of the
active semiconductor region 622 are predetermined by the depth T of the active
semiconductor region 622 and the length L corresponding to the distance between the
current feeding contact electrodes 626a and 626c
Horizontal and vertical Hall sensors and methods for reducing offsets which form due to
element tolerances, such as, for example, contaminations, asymmetries, piezoelectric
effects, aging phenomena, etc , like, for example, using the spinning-current method, are
already known in literature, such as, for example, in R S Popovic, "Hall Effect Devices,
Magnetic Sensors and Characterization of Semiconductors", Adam Hilger, 1991, ISBN 0-
7503-0096-5 Frequently, vertical sensors operated in a spinning-current manner are made
up of two or of four individual sensors, as is described, for example, in DE 101 50 955 and
DE 101 50 950
In addition, apart from the variation of 3-pin vertical Hall sensor elements, there are so-
called 5-pin vertical Hall sensor elements which are also described in DE 101 50 955 and
DE 101 50 950 In 5-pin Hall sensor elements, too, there is a way of performing a
measurement compensated for tolerances of individual elements by means of a
compensation method extending over several measuring phases, wherein exemplanily a
spinning-current method may also be employed here
Spinning-current technique means continuously cyclically turning the measurement
direction for detecting the Hall voltage at the Hall sensor element using a certain clock
frequency by, for example, 90° and summing over all the measuring signals of a complete
turn of 360° In a Hall sensor element comprising four contact regions of which two
respective contact regions are arranged in pairs to each other, each of the contact pairs is,
depending on the spinning-current phase, used both as a control current contact region for
feeding a current and as a measuring contact region for tapping the Hall signal Thus, in a
spinning-current phase or in a spinning-current cycle, the operating current (control current
IH) flows between two associated contact regions, the Hall voltage being tapped at the
other two contact regions associated to each other

In the next cycle, the measuring direction is turned by 90°, so that the contact regions
which, in the previous cycle, were used for tapping the Hall voltage, now serve for feeding
the control current By summing over all the four cycles or phases, the offset voltages due
to manufacturing or material approximately cancel out one another, so that only the
portions of the signal which really are dependent on the magnetic field will remain This
procedure is, of course, also applicable for a greater number of contact pairs, wherein
exemplanly, with four contact pairs (comprising eight contact regions), the spinning-
current phases are cyclically turned by 45° in order to be able to sum all the measuring
signals over a full 360° turn
In horizontal Hall sensors, four sensors are also frequently used, since, with a suitable
arrangement, the offset can additionally be reduced significantly by spatial spinning-
current operation, see, for example, DE 199 43 128
When a magnetic field is to be measured for several spatial directions, separate Hall sensor
elements are most frequently used Using separate sensors, for example for detecting the
three spatial directions of a magnetic field, generally entails the problem that the magnetic
field to be measured is not measured in one point, but in three different points Fig 7
makes this aspect clear, Fig 7 showing three Hall sensors 702, 704 and 706 The first Hall
sensor 702 serves for detecting a y spatial component, the second Hall sensor 704 serves
for detecting a z spatial component and the third Hall sensor 706 is provided for detecting
an x spatial component The individual sensors 702, 704 and 706 measure the
corresponding spatial components of a magnetic field approximately in the respective
central points of the individual sensors
An individual sensor, in turn, may be made up of several Hall sensor elements Fig 7
exemplanly shows three individual sensors which each comprise four Hall sensor
elements, wherein, in Fig 7, a horizontal Hall sensor 704 detecting a z component of the
magnetic field to be measured and one vertical Hall sensor 702 and 706 each for the y and
x components of the magnetic field to be measured are assumed The arrangement for
detecting the spatial magnetic field components, as is exemplanly illustrated in Fig 7,
entails the problem that the magnetic field cannot be measured in one point, but in the
respective central points of the individual sensors This inevitably entails corruption, since
an exact evaluation of the magnetic field based on the magnetic field components, detected
at different locations, of the magnetic field sensor, is not possible
Another aspect when detecting and evaluating magnetic fields by means of Hall sensor
elements is calibration of the individual elements According to the prior art, Hall sensor

elements are most frequently provided with so-called excitation lines which allow
generating a defined magnetic field in the measuring point of an individual sensor in order
to achieve the sensor to be calibrated subsequently by comparing and/or associating the
Hall voltage measured to the defined magnetic field
It is possible using excitation lines to generate an artificial magnetic field at a Hall sensor
by means of which a simple wafer test, 1 e a test directly on the substrate, and a self-test
and sensitivity calibration during operation are possible, compare Janez Trontelj,
"Optimization of Integrated Magnetic Sensor by Mixed Signal Processing, Proceedings of
the 16th IEEE Vol 1 This is of particular interest in safety-critical sectors, such as, for
example, in the automobile sector or also in medical engineering, since this allows the
sensors to monitor themselves even during operation
When exemplanily several individual sensors are used for detecting the spatial components
of a magnetic field, as is exemplanly shown in Fig 7, each individual sensor requires a
corresponding excitation line for calibration, wherein the individual sensors are still
calibrated individually This means that the calibration effort is scaled depending on the
number of individual sensor elements and, in the case of spatially detecting three magnetic
field components, is increased by three compared to the calibration effort of an individual
sensor
One approach of allowing a magnetic field to be evaluated, I e detecting a measurement in
one point, is a 3D sensor made by Ecole Polytechnique Federal Lausanne EPFL, compare
C Schott, R S Popovic, "Integrated 3D Hall Magnetic Field Sensor", Transducers '99,
June 7-10, Sensai, Japan, VOL 1, pages 168-171, 1999 Fig 8 is a schematic illustration of
such a Hall sensor 800 implemented on a semiconductor substrate 802 The 3D sensor
comprises four contact areas 804a-d via which currents can be impressed into the
semiconductor substrate 802 The 3D sensor additionally comprises four measuring contact
areas 806a-d via which the different magnetic field components can be detected Wiring
810 is illustrated on the right side of Fig 8 The wiring shown made up of four operational
amplifiers 812a-d evaluates the Hall voltages proportional to the individual magnetic field
components and outputs the corresponding components at the terminals 814a-c in the form
of signals Vx, Vy and Vz
The sensor illustrated entails the problem that it can only be calibrated by a defined
magnetic field generated externally and has no excitation line of its own Additionally, due
to its set-up and its mode of functioning, this sensor cannot be operated using a
compensation method, such as, for example, a spinning-current method Furthermore, a

problem of the arrangement shown in Fig 8 is that such a semiconductor element, due to
contaminations of the semiconductor material, asymmetries in contacting, variations in the
crystalic structure, etc, exhibits offset voltages which cannot be suppressed using a
corresponding compensation wiring suitable for spinning current The sensor measures
magnetic field components in a focused point, however, it exhibits a high offset and
consequently is suitable for precise measurements to a limited extent only Fig 9 shows a
compensation-enabled (spinning-current) 3D-sensor which detects spatial magnetic field
components in one measuring point and is discussed by Enrico Schunig in "Highly
Sensitive Vertical Hall Sensors in CMOS Technology", Hartung-Gorre Verlag Konstanz,
2005, Reprinted from EPFL Thesis No 3134 (2004), ISSN 1438-0609, ISBN 3-86628-
023-8 WW page 185ff In the top part of Fig 9, the 3D-sensor of Fig 7 made up of three
individual sensors is shown Fig 9, in the top part, shows three separate individual sensors
902, 904 and 906 for detecting the spatial magnetic field components In Fig 9, in the
bottom part, an alternative arrangement of the individual sensors is shown With this
arrangement, the sensor 904 is maintained unchanged since the measuring point of the
sensor 904 in Fig 9 is in the center of the arrangement 900, additionally the two individual
sensors 902 and 906 are made up of individual elements which are separable The sensor
902 is now divided into two sensor parts 902a and 902b and symmetrically arranged
around the central point of the sensor element 904 An analogue procedure is done for the
sensor 906 so that this one, too, is divided into two sensor parts 906a and 906b which are
symmetrically arranged around the central point of the sensor element 904, along the
corresponding spatial axis Due to the symmetrical arrangement of the individual sensor
elements, the magnetic field is then detected in one point which is in the geometrical center
of the arrangement
In summary, one might say that individual sensors which are symmetrical arranged around
a central point may be used in the field of conventional technology for measuring
multidimensional magnetic fields Arrangements of this kind can, in particular, be realized
in angular sensors where a magnetic field is to be measured in one point by all the sensors
Monitoring, calibration and testing of the sensors, however, are problematic in these
arrangements
It is the object of the present invention to provide a magnetic field sensor for a
multidimensional detection of magnetic field components in a reference point, the
tolerances of which are compensatable efficiently, which is calibratable in a both reliable
and simple manner, wherein calibration may be performed during measuring operation,
and which may be tested at low cost and efficiently both in an on-wafer test and during
operation

This object is achieved by a calibratable magnetic field sensor in accordance with claim 1
and a method for calibrating a magnetic field sensor during measuring operation in
accordance with claim 16
In one embodiment, the present invention provides a cahbratable magnetic field sensor for
sensing a first and a second spatial component of a magnetic field in a reference point,
wherein the magnetic field comprises a first and a second measurement field component
and/or a first and a second calibration field component, having a first sensor element
arrangement comprising at least a first and a second sensor element for sensing the first
magnetic field component, which comprises a first measurement field component and/or a
first calibration field component, with respect to a first spatial axis in the reference point
Furthermore, the magnetic filed sensor includes a second sensor element arrangement for
sensing the second magnetic field component, which comprises a second measurement
field component and/or a second calibration field component, with respect to a second
spatial axis in the reference point The magnetic filed sensor also includes an excitation
line arranged with respect to the first sensor element arrangement so that, when impressing
a default current into the excitation line, a pair of different asymmetrical default calibration
field components in the first sensor element and in the second sensor element is generated
with respect to the first spatial axis in the first sensor element arrangement, wherein the
two spatial axes pass along linearly independent position vectors
In another embodiment, the present invention provides a magnetic field sensor, cahbratable
during measuring operation, for detecting first, second and third spatial components Bz, By
and Bx of a magnetic field in a reference point, the magnetic field comprising first, second
and third measuring field components BMZ, BMy, BMX and/or first, second and third
calibration field components BKZ, Bjcy and BKX The magnetic field sensor includes a first
sensor element arrangement having at least two sensor elements, for detecting the first
magnetic field component Bz which comprises a first measuring field component BMZ
and/or a first calibration field component BKZ, relative to a first spatial axis z in the
reference point
Additionally, the magnetic field sensor includes a second sensor element arrangement
having at least two sensor elements, for detecting the second magnetic field component By
which comprises a second measuring field component BMy and/or a second calibration
field component Bky, relative to a second spatial axis y in the reference point The
magnetic field sensor additionally includes a third sensor element arrangement having at
least two sensor elements, for detecting the third magnetic field component Bx which

comprises a third measuring field component BMX and/or a third calibration field
component BKX relative to a third spatial axis x in the reference point Additionally, the
magnetic field sensor comprises an excitation line which is arranged relative to the first,
second and third sensor element arrangements such that when impressing a predetermined
current Iki into the excitation line, a first pair of different predetermined calibration field
component Bkza and BKzb is generated in the first sensor element arrangement relative to
the first spatial axis z, a second pair of different predetermined calibration field
components BKya and Bkyb is generated in the second sensor element arrangement relative
to the second spatial axis y and a third pair of different predetermined calibration field
components Bkxa and Bkxb is generated in the third sensor element arrangement relative to
the third spatial axis x, the three spatial axes z, y and x extending along linearly
independent position vectors
The present invention is based on the finding that preferably symmetrically arranged
sensor elements in pairs are able to provide a magnetic field sensor for a multidimensional
detection of a magnetic field, which becomes calibratable when using at least one
asymmetrical excitation line The excitation line thus is asymmetrical relative to the sensor
elements arranged in pairs in that the magnetic field which may be generated by applying a
current using the excitation line causes unequal calibration field components in the sensor
elements arranged in pairs Thus, sensor elements of equal sensitivity may be used here
because different calibration field components the difference of which is measurable and
cahbratable using the magnetic field sensors result due to the mentioned asymmetry When
using embodiments of inventive magnetic field sensors, two-dimensional and even three-
dimensional magnetic fields can be detected along two and three linearly independent
position vectors, respectively
Several excitation lines which, relative to the sensor elements arranged in pairs, may
comprise different or also mirrored or opposite asymmetries may also be used
Exemplanly, the excitation lines may form coils the magnetic fields of which are
superimposed onto one another and thus cause a resulting excitation field in the direction
of sensitivity of a sensor element This has an advantageous effect since the magnetic field
sensor may thus be implemented to be cahbratable and monitorable during measuring
operation
Another advantage of the inventive magnetic field sensor and method is that the magnetic
field sensor can be calibrated during operation and thus additional hardware cost or time
effort can be saved Exemplanly, the measuring results can be combined and/or evaluated
by a micro controller or processor such that additional effort is limited to only one

additional calculation operation The measuring field components and the calibration field
components may thus be made available at the same time and in a compensated manner
This is of particular advantage in safety-critical cases of application, such as, for example,
in automobile or medical engineering, since the magnetic field sensor can be calibrated
and/or adjusted continuously and at the same time its functionality can be monitored,
without having to put up with compromises as to quality or quantity of a measurement in
many cases
Preferred embodiments of the invention will be detailed subsequently referring to the
appended drawings, in which
Fig la shows a basic arrangement of Hall sensor elements and an excitation line in
accordance with an embodiment of the magnetic field sensor, calibratable during
measuring operation, for detecting first and second spatial magnetic field
components in accordance with the present invention,
Fig lb shows another basic arrangement of Hall sensor elements and an excitation line in
accordance with an embodiment of the magnetic field sensor, calibratable during
measuring operation, for detecting first and second spatial magnetic field
components in accordance with the present invention,
Fig lc shows a basic arrangement of Hall sensor elements and an excitation line in
accordance with an embodiment of the magnetic field sensor, calibratable during
measuring operation, for detecting first, second and third spatial magnetic field
components in accordance with the present invention,
Fig Id shows another basic arrangement of Hall sensor elements and an excitation line in
accordance with an embodiment of the magnetic field sensor, calibratable during
measuring operation, for detecting first, second and third spatial magnetic field
components in accordance with the present invention,
Fig 2 shows a basic arrangement of Hall sensor elements and an excitation line in
accordance with another embodiment of the magnetic field sensor calibratable
during measuring operation in accordance with the present invention,
Fig 3 a shows a basic arrangement of Hall sensor elements and an excitation line in
accordance with another embodiment of the magnetic field sensor calibratable
during measuring operation in accordance with the present invention,

Fig 3b shows a basic arrangement of Hall sensor elements and an excitation line in
accordance with another embodiment of the magnetic field sensor calibratable
during measuring operation in accordance with the present invention,
Fig 4 shows another embodiment of a magnetic field sensor,
Fig 5 shows another embodiment of a magnetic field sensor,
Fig 6a shows the basic setup of a horizontal Hall sensor element according to the prior
art,
Fig 6b shows the basic setup of a vertical Hall sensor element according to the prior art,
Fig 7 shows the basic arrangement of individual sensors for spatially detecting magnetic
field components in accordance with the prior art,
Fig 8 shows an alternative 3D sensor for detecting spatial components of a magnetic
field in accordance with the prior art, and
Fig 9 shows a basic arrangement of individual Hall sensor elements for detecting a
spatial magnetic field in one point
With reference to the following specifications it should be noted, that in the different
embodiments same or seemingly same functional elements have the same reference
numerals and are thus mutually interchangeable in the different embodiments illustrated in
the following
Fig la shows a cahbratable magnet field sensor 100 for detecting a first and a second
spatial component (By, Bz) of a magnet field in a reference point 101, wherein the
magnetic field comprises and first and a second measurement field component (BMy, BMZ)
and/or a first and second calibration field component (Bky, BKZ) The magnetic field sensor
100 includes a first sensor element arrangement 104 comprising at least a first and a
second sensor element (1041a, 104b) for detecting the first magnetic field component By
comprising a first measurement field component BMy and/or a first calibration field
component Bky, with reference to a first spatial axis y in the reference point 101

Further, the magnetic field sensor 100 includes a second sensor element arrangement 102
for detecting the second magnetic field component Bz comprising a second measurement
field component BMZ and/or a second calibration field component BKZ, with reference to a
second spatial axis z in the reference point 101 The magnetic field sensor 100 further
includes an excitation line 108 which is arranged with respect to the first sensor element
arrangement 104 such that with an impression of a predetermined current Iki into the
excitation line 108 a pair of different predetermined calibration field components Bkya in
the first sensor element 104a and Bkyb in the second sensor element 104b with reference to
the first spatial axis y is generated in the first sensor element arrangement 104, wherein the
two spatial axes y and z pass along linearly independent position vectors
Fig lb shows a further embodiment of a calibratable magnetic field sensor 100 for
detecting a first and a second spatial component (Bx, By) of a magnetic field in a reference
point 101, wherein the magnetic field comprises a first and a second magnetic field
component (BMX, BMy) and/or a first and a second calibration field component (BKX, Bky)
The magnetic field sensor 100 includes a first sensor element arrangement 106 comprising
at least a first and a second sensor element 106a and 106b for detecting the first magnetic
field component Bx comprising a first measurement field component BMX and/or a first
calibration field component BKX, with reference to the first spatial axis x in the reference
point 101
The magnetic field sensor illustrated in Fig lb further includes a second sensor element
arrangement 104 for detecting the second magnetic field component By comprising a
second measurement field component BMy and/or a second calibration field component
BKy, with reference to a second spatial axis y in the reference point 101
In the embodiment of Fig lb, the magnetic field sensor 100 further comprises an
excitation line 108 which is arranged with respect to the first sensor element arrangement
106 so that with an impression of a predetermined current IKI IN the excitation line 108 a
pair of different, predetermined calibration field components Bkxa in the first sensor
element 106a and BKxb in the second sensor element 106b with reference to the first spatial
axis x is generated in the first sensor element arrangement 106, wherein the two spatial
axes x and y pass along independent position vectors In a further embodiment, the sensor
elements may be arranged so that they relate to the two spatial axis x and z, wherein a such
an embodiment the first sensor element arrangement would correspond to the sensor
element arrangement 106 of Fig lb, and the second sensor element arrangement would
correspond to the sensor element arrangement 102 of Fig la In the general case, inventive
embodiments may be detect magnetic fields according to two spatial directions passing

along linearly independent position vectors, wherein the excitation line 108 is here
arranged so that it may generate calibration field components which are different at least
with regard to a sensor element arrangement of the magnetic field sensor comprising at
least two sensor elements Here, the directions of the linearly independent position vectors
are not fixed so that two random spatial directions may be realised
According to the embodiment illustrated in Fig lb, the calibratable magnetic field sensor
100 may include a second sensor element arrangement 104 also comprising at least a first
104a and a second sensor element 104b and wherein the excitation line is further arranged
with respect to the second sensor element arrangement 104 so that a second pair of
different predetermined calibration field components Bkya in the first sensor element 104a
and BKyb in the second sensor element 104b with reference to the second spatial axis y is
generated in the second sensor element arrangement 104
Apart from the magnetic field sensors described with reference to Fig la and lb, for
detecting at least two spatial dimensions, in embodiments also three spatial directions may
be detected Fig lc shows an embodiment of a cahbratable magnetic field sensor 100
which is further implemented to detect a third spatial component Bx or Bz of the magnetic
field in the reference point 100, wherein the magnetic field comprises a third measurement
field component BMX or BMZ and/or a third calibration field component BKX or BKZ
With reference to Fig la, by the embodiment of the magnetic field sensor which is
illustrated in Fig lc additionally a spatial magnetic component Bx is detected, with
reference to Fig lb the embodiment of the magnetic field sensor of Fig lc additionally
detects the spatial magnetic component Bz
The embodiment of the magnetic field sensor 100 of Fig lc further includes a third sensor
element arrangement 106 or 102 for detecting the third magnetic field component Bx or Bz
comprising the third measurement field component BMX or Bz and/or the third calibration
field component BKX or BKZ, with reference to a third spatial axis x or z in the reference
point 101, wherein the three spatial axes z, y and x pass along linearly independent
position vectors
A further embodiment of a magnetic field sensor 100 is illustrated in Fig Id In the
embodiment of Fig Id, the third sensor element arrangement 102 also includes a first and
a second sensor element 102a and 102b, wherein the excitation line 108 is arranged with
regard to the third sensor element arrangement 102 so that with an impression of a
predetermined current Iki into the excitation line 108 a pair of different predetermined

calibration field components BKZB and Bkzb in the first sensor element 102a and in the
second sensor element 102b with respect to the first spatial axis z is generated in the third
sensor element arrangement
Generally, embodiments include calibratable magnetic field sensors for detecting two or
three spatial magnetic field components Figs la to Id here show different variants,
wherein the individual spatial directions are interchangeable here Thus, for example, to a
magnetic field sensor according to Fig la, a third sensor element arrangement 106
according to Fig lc may be added
In the following, embodiments of the present invention are explained in detail In order to
avoid repetitions, in the following embodiments it is assumed that the respective magnetic
field sensors detect a magnetic field towards three spatial directions, wherein the three
spatial directions pass along linearly independent position vectors Generally, however, all
embodiments described in the following are also possible for only detecting two spatial
directions of magnetic fields Thus, in the embodiments explained in the following, one
sensor element arrangement 102, 104 or 106 each may be omitted The explained concept
then unrestrictedly also apply to the remaining two sensor element arrangements for
detecting a magnetic field along two linearly independent spatial directions and/or the
following embodiments may be applied, with respect to the sensor elements and their
implementations, equally also to the embodiments of Fig la and lb
Fig Id shows an embodiment of a magnetic field sensor 100 calibratable in the
measurement operation for detecting a first, second and third spatial component Bz, By and
Bx of a magnetic field in a reference point 101, wherein the magnetic field comprises a
first, second and third measurement field component BMZ, BMy, BMZ and/or a first, second
and third calibration field component BKZ, BKy and BRX
The magnetic field sensor 100 includes a first sensor element arrangement 102 comprising
at least two sensor elements 102a and 102b for detecting the first magnetic field
component Bz comprising a first measurement field component BMZ and/or a first
calibration field component BKZ, with reference to a first spatial axis z in the reference
point 101 The magnetic field sensor 100 further includes a second sensor element
arrangement 104 comprising at least two sensor elements 104a and 104b for detecting the
second magnetic field component By comprising a second measurement field component
BMy and/or a second calibration field component Bky, with reference to a second spatial
axis y in the reference point 101 The magnetic field sensor 100 also includes a third sensor
element arrangement 106 comprising at least two sensor elements 106a and 106b for

detecting the third magnetic field component Bx comprising a third measurement field
component BMX and/or a third calibration field component BKX with respect to a third
spatial axis x in the reference point 101
The magnetic field sensor 100 further includes an excitation line 108 which is arranged
with respect to the first 102, second 104 and third sensor element arrangement 106 so that
with an impression of a predetermined current Iki into the excitation line 108, a first pair of
different predetermined calibration field components Bkza in the sensor element 102a and
Bkzb in the sensor element 102b of the first spatial axis z is generated in the first sensor
element arrangement 102, a second pair of different predetermined calibration field
components Bkya in the sensor element 104a and BKyb in the sensor element 104b with
respect to the second spatial axis y is generated in the second sensor element arrangement
104, and a third pair of different predetermined calibration field components Bkza in the
sensor element 106a and Bkzb in the sensor element 106b with respect to the first spatial
axis x is generated in the third sensor element arrangement 106, wherein the three spatial
axes z, y and x pass along linearly independent position vectors
Fig Id shows an embodiment of a magnetic field sensor 100 comprising an
asymmetrically arranged excitation line 108 The pairs of different, predetermined
calibration field components with respect to the at least two sensor elements each (e g,
102a, 102b, 104a, 104b, 106a, 106b) of a sensor element arrangement (e g , 102, 104, 106)
are here achieved by the asymmetry of the excitation line with respect to the reference
point 101 The excitation line 108 may here be arranged such according to the embodiment
of Fig Id, that it forms a coil with at least one winding
Geometrically seen, the excitation line 108 may be arranged in embodiments such that the
coil with the at least one winding comprises shortest distances to the at least two sensor
elements (e g , 102a, 102b, 104a, 104b, 106a, 106b) of a sensor element arrangement (e g ,
102, 104, 106), which are different Due to shorter distances of the excitation line 108 to
the sensor element arrangements (e g, 104, 106), when a current flows in the excitation
line 108, stronger calibration field components are generated than with greater distances A
shortest distance of the excitation line 108 to a sensor element (e g, 104a, 104b, 106a,
106b) may here relate to a mean effective distance
For example, here the sensor elements (e g, 104a, 104b, 106a, 106b) may preferably be
implemented paired symmetrically with regard to the excitation line 108, with reference to
the example of Fig Id, sensor elements 104a and 106a and/or 104b and 106b Generally,
however, also any "asymmetrical" geometries may be realised in which a defined

asymmetry is generated with respect to the calibration field components in the different
sensor elements (e g , 104a, 104b, 106a, 106b) or sensor element arrangements (e g, 104,
106) The asymmetry may also be accomplished via differently strong excitation currents
The paired symmetrical arrangement allows a simple evaluation, whereas between the
sensor elements (eg, 104 and 104b and/or 106a and 106b) due to different distances a
defined asymmetry and thus also a defined asymmetry with respect to the calibration field
components that may be generated may exist This may, for example, according to Fig 1 a
to Id, be achieved by a geometrical shift or asymmetry of the excitation line 108 with
respect to the reference point 101 The excitation line 108 in the embodiments of Fig lc
and Id passes directly above the sensor elements 104b and 106b, however, laterally to the
sensor elements 104a and 106a Insofar, the different shortest distances of the excitation
line 108 to the sensor elements (eg, 104a, 104c, 106a, 106b) of a sensor element
arrangement (e g , 104, 106) may be regarded in such a way that the excitation line 108
shows different distances to two sensor elements each (e g, 104a and 104b and/or 106a
and 106b) of a sensor element arrangement (eg, 104 and/or 106), so that the magnetic
field components caused in the sensor elements (eg, 104a and 104b and/or 106a and
106b) of a sensor element arrangement (eg, 104 and/or 106) due to a current Iki in the
excitation line 108 are also different
As already explained above, in the explained embodiments one sensor element
arrangement 102, 104 or 106 respectively may also be omitted The explained concepts
then apply unrestrictedly also for the remaining two sensor element arrangements for
detecting a magnetic field along two linearly independent spatial directions and/or the
explanations with regard to the sensor elements and their implementations equally apply
also to the embodiments of Figs la and lb
In other embodiments, the excitation line 108 may also be arranged symmetrically with
regard to the reference point 101 Such an embodiment is illustrated in Fig 2 Fig 2 shows
a further embodiment of a magnetic field sensor 100 comprising the same components
which were already illustrated and explained with reference to Fig Id The difference to
Fig Id is now the arrangement of the excitation line 108, which is implemented in Fig 2
as a coil with 1 5 windings Generally, in embodiments coil implementations with any
number of windings are possible, the already mentioned asymmetry may, however, also be
achieved by incomplete windings and/or partial windings, as it is illustrated schematically
in Fig 2 Generally, here also one individual partial winding would be possible, see Fig la
and lb In these cases, a partial winding may thus also be realized by a conductive trace
according to Fig la and lb, which is arranged asymmetrically with respect to the sensor
elements of a sensor element arrangement

Embodiments may also comprise excitation lines 108, which are not implemented
symmetrically with respect to the reference point 101 and comprise a non-integer number
of windings Accordingly, the excitation line 108 may be implemented such that it
comprises one complete winding and one partial winding Also here, a paired symmetrical
arrangement of the excitation line 108 is possible with respect to the sensor elements (e g
104a, 104b, 106a, 106b), wherein the general case is not restricted to this symmetry and in
embodiments any arrangements may occur, which may generate defined "asymmetrical"
calibration field components
As already explained above, in the mentioned embodiments also one sensor arrangement
each 102, 104, or 106 may be omitted The explained concepts then also apply
unrestrictedly to the remaining two sensor element arrangements for detecting a magnetic
field along two linearly independent spatial directions and/or the embodiments with respect
to the sensor elements and their implementations are each equally applicable also to the
embodiments of Fig la and lb
A further embodiment of a magnetic field sensor 100 is illustrated in Fig 3a The magnetic
field sensor 100 of Fig 3a comprises the same components as those which were illustrated
and explained with reference to Fig la to d and 2 Additionally, in the embodiment of Fig
3a a second excitation line 109 exists According to Fig 3a, the second excitation line 109
is shifted with respect to the excitation line 108, I e the excitation line 108 passes directly
above the sensor elements 104b and 106b, however, laterally to the sensor elements 104a
and 106a The second excitation line 109 passes directly above the sensor elements 104a
and 106a, however, laterally to the sensor elements 104b and 106b
Also here, in the explained embodiments, one sensor element arrangement 102, 104 or 106
may each also be omitted The explained concepts then unrestrictedly also apply to the
remaining two sensor element arrangements for detecting a magnetic field along two
linearly independent spatial directions and/or the explanations with respect to the sensor
elements and their implementations are each equally applicable also to the embodiments of
Fig la and lb
In embodiments, the second excitation line 109 may be arranged with regard to the first
102, second 104 and third sensor element arrangement 106, so that with an impression of a
further predetermined current lk2 into the second excitation line 109, a first further pair of
different predetermined calibration field components BKza2 in the sensor element 102a and
BKzb2 in the sensor element 102b is generated with respect to the first spatial axis z in the

first sensor element arrangement 102, a second further pair of different predetermined
calibration field components BKya2 in the sensor element 104a and Bkyb2 in the sensor
element 104b with respect to the second spatial axis y is generated in the second sensor
element arrangement 104, and a third pair of different predetermined calibration field
components BKxa2 in the sensor element 106a and Bkxb2 in the sensor element 106b with
respect to the third spatial axis x is generated in the third sensor element arrangement 106
According to Fig 3 a, via the second excitation line also additional calibration field
components may be generated Also here, a paired symmetrical arrangement of the second
excitation line 109 is possible with respect to the sensor elements (e g 104a, 104b, 106a,
106b), wherein the general case is not limited to this symmetry and in embodiments any
arrangements may occur, which may generate defined calibration field components
Here, in embodiments, the first excitation line 108 and the second excitation line 109 may
be arranged such that the first further pair of different predetermined calibration field
components is in a reversed relation to each other compared to the first pair of calibration
field components, that the second further pair of different predetermined calibration field
components is in a reversed relation to each other compared to the second pair of
calibration field components and that the third further pair of different predetermined
calibration field components is in a reversed relation to each other compared to the third
pair of calibration field components This is illustrated in Fig 3 a as an example by the
geometry of the first 108 and second excitation line 109
As an example, a current flows through the first excitation line 108, while no current flows
through the second excitation line Accordingly, the first excitation line 108 in the sensor
elements 104b and 106b generates strong calibration field components BKyb and BKxb, and
weak calibration field components BKya and BKxa in the sensor elements 104a and 106a If
the energization and/or current flow is reversed, so that the first excitation line 108 is
current-less and the second excitation line carries the current lk2, which previously has
flown in the first excitation line, then the second excitation line 108 generates weak
calibration field components Bkyb2 and Bkxb2 in the sensor elements 104b and 106b and
strong calibration field components Bkya2 and BkXa2 in the sensor elements 104a and 106a
In embodiments, the excitation lines 108 and 109 may be arranged so that the following
may apply in such an example



In embodiments, the first sensor element arrangement 102 may comprise a horizontal Hall
sensor element 102a or 102b with respect to a main surface of the magnetic field sensor
Generally, in embodiments any magnetic field sensors may be used which comprise
corresponding sensitivities for the different magnetic field components (Bx, By, Bz) For
example, also the use of magneto-resistive sensor elements is possible In the following,
embodiments of the present invention are described as an example by realizations of Hall
sensor elements The first sensor element arrangement 102 may further comprise a
plurality of Hall sensor elements horizontal with regard to a main surface of the magnetic
field sensor, wherein the geometric arrangement of the plurality of horizontal Hall sensor
elements (e g 102a, 102b) may be symmetrical in pairs with respect to the reference point
101, and the Hall sensor elements are coupled to each other such that the magnetic field
component may be detectable in an offset-compensated way
In embodiments, the second sensor element arrangement 104 may comprise two Hall
sensor elements (e g 104a, 104b) vertical with respect to a main surface of the magnetic
field sensor, wherein the geometrical arrangement of the at least two vertical Hall sensor
elements may be symmetrical in pairs with respect to the reference point 101, and the
sensor elements may be coupled to each other such that the magnetic field component
becomes detectable in an offset-compensated way Generally, in embodiments also here
any magnetic field sensors may be used which comprise a corresponding sensitivity for the
different magnetic field components (Bx, By, Bz)
In embodiments , the third sensor element arrangement 106 may comprise at least two Hall
sensor elements (e g 106a, 106b) vertical with respect to a main surface of the magnetic
field sensor, wherein the geometrical arrangement of the at least two vertical Hall sensor
elements may be symmetrical in pairs with respect to the reference point 101, and the same
are coupled to each other such that the magnetic field component is detected in an offset
compensated way In further embodiments, the first 102, second 104 or third sensor
element arrangement 106 may also be operable in the spinning current mode Generally, in
embodiments also here any magnetic field sensors may be used
A further embodiment is illustrated in Fig 3 b As already explained above, in the
explained embodiments, one sensor element arrangement 102, 104 or 106 each may also

be omitted The explained concepts then unrestrictedly also apply to the remaining two
sensor element arrangements for detecting a magnetic field along two linearly independent
spatial directions and/or the embodiments with respect to the sensor elements and their
implementations are equally applicable also to the embodiments of Fig la and lb
The magnetic field sensor 100 of Fig 3b comprises the same components as those which
were illustrated and explained with reference to Fig 1, 2 and 3a In the embodiment of Fig
3b, also a second excitation line 109 exists which is implemented as a dashed line
According to Fig 3b, the second excitation line 109 is shifted with respect to the excitation
line 108, I e the excitation line 108 passes directly above the sensor elements 104b and
106b, however laterally to the sensor elements 104a and 106a The second excitation line
109 passes directly above the sensor elements 104a and 106a, however laterally to the
sensor elements 104b and 106b In Fig 3b, the sensor elements (eg 102a, 102b, 104a,
104b, 106a, 106b) are combined from two individual sensors each, which are designated
according to their measurement alignment
As an example, it is assumed in Fig 3b, that the sensor element arrangement 102 includes
two sensor elements 102a and 102b, wherein the sensor element 102a comprises two
individual sensors Zl and Z2 and the sensor element 102b comprises two individual
sensors Z3 and Z4 According to the schematically illustrated coordinate cross in the top
right corner of Fig 3b, the sensor element arrangement 102 is arranged such that magnetic
field components may be detected in the z-direction For example, the individual sensors
Z1-Z4 may be realized by horizontal Hall sensors Analogously, in Fig 3b the sensor
elements arrangement 104 consists of the sensor elements 104a and 104b, which again
include the individual sensorsYl-Y4 for detecting magnetic field components in the y-
direction For detecting magnetic field components in the x-direction, the sensor element
arrangement 106 is accordingly aligned with the sensor elements 106a and 106b and the
individual sensors XI-X4 The individual sensors XI-X4 and Y1-X4 may, for example,
also be realized by vertical Hall sensors
In embodiments, the magnetic field sensors may be excited by only one coil and/or
excitation line 108 In the following, thus, the second excitation line 109 and/or coil is
disregarded and is explained in more detail in further embodiments, which are regarded
later In the case that only one excitation line 108 and/or a coil exists, the sensor element
arrangement 102, which, for example, detects the magnetic field in the z-direction, may be
excited with a magnetic field, which is then of only half the size like e g when using two
coils In the sensor element arrangements 104 and 106, for example, detecting magnetic
fields of the x-direction and the y-direction, the excitation works in a different way

The sensor element arrangement 104 and 106 may consist of four partial sensors each, as it
is, for example, illustrated in Fig 3 b In this embodiment, two partial sensors each detect
the complete field of a coil (eg XI, X2, Yl, Y2), the respectively other ones (e g X3, X4,
Y3, Y4) only detect the substantially weaker approximately also vanishing stray field
pointing into the other direction By a corresponding connection (e g parallel connection)
of the partial sensors (e g XI-X4, Y1-Y4), an averaging of the output signals of the partial
sensors results Two partial sensors in this embodiment each show the complete signal (e g
XI, X2, Yl, Y2), the respective other two partial sensors (eg X3, X4, Y3, Y4) detect
virtually no signal This means that in summation in this embodiment an output signal with
comparatively half the intensity is generated
In this embodiment, the sensor elements arrangement 104 and 106 consequently detect, in
comparison with an embodiment having two excitation lines, half the signal by exciting
half the partial sensors (eg XI,X2, Yl, Y2) with the full magnetic field The sensor
element arrangement 102, which in this embodiment detects the magnetic field in the z-
direction, compared to an embodiment with two excitation lines, detects half the signal by
an equal excitation of all partial sensors with half the field, as only one coil is used
In comparison with embodiments having two excitation lines, then half the signal hub
results, I e also half the signal/noise ratio For achieving the same quality as with an
excitation with two excitation lines, thus a filtering of the measurement and/or a longer
measurement may be executed Further, in the sensor elements arrangements 104 and 106
(eg X and Y sensors) not all partial sensors (eg XI-X4, Y1-Y4) are excited As an
example, in the embodiment according to Fig 3b the individual sensors X3, X4, Y3 and
Y4 are not and/or only marginally magnetically excited with only one excitation line 108
Thus, a magnetic test of the sensitivity of those individual sensors seems not possible at
first, as the same are of the same setup as the respectively opposite sensor elements, a
count-back and/or conclusion from the same may be executed Based on a symmetrical
arrangement of the sensor elements arrangements (e g 104, 106) then first of all a break in
of a calibration field component to one sensor element each (e g 104b) may be executed
Due to the defined calibration field component, this sensor element may then be calibrated
Further, based on the given symmetry and the use of the same sensor elements 104a and
104b, in an analog way for the sensor elements 106a and 106b, a calibration of the sensor
element which is not directly excited with the calibration field component may be
concluded

Embodiments with a second excitation line 109 according to Fig 3b are explained in the
following As already explained above, in the explained embodiments, one sensor element
arrangement 102, 104 or 106 may also be omitted The explained concepts then
unrestrictedly also apply to the remaining two sensor element arrangements for detecting a
magnetic field along two linearly independent spatial directions and/or implementations
with regard to the sensor elements and their implementations are each applicable in the
same way also to the embodiments of Figs la and lb
In Fig 4, a further embodiment is illustrated Fig 4 shows a first sensor element
arrangement 102, which may, for example be realized by four horizontal Hall sensors
102a, 102b, 102c and 102d Further, Fig 4 shows a second sensor element arrangement
104, which may be realized by four vertical Hall sensors 104a, 104b, 104c, and 104d
Further, Fig 4 shows a third sensor element arrangement 106, which may be realized by
four vertical Hall sensors 106a, 106b, 106c, 106d Additionally, in Fig 4 a first excitation
line 108 is illustrated as coil A and a second excitation line 109 as coil B Here, for
example, sensor elements 102a-d, 104a-d or 106a-d of the same sensitivity may be used
As illustrated in Fig 4, in such an embodiment two excitation lines 108 and 109 may be
realized as two coils geometrically shifted with respect to each other
Embodiments according to Fig 4 allow for superimposing two magnetic fields of the coils
A and B and thus generating a resulting excitation or calibration field in a sensitivity
direction For example, a coil may here be arranged on one side of the arrangement directly
above the sensor elements, for example, such as coil A with respect to the sensor elements
104a, 104c, 106b and 106d, and/or the coil B with respect to the sensor elements 104b,
104d, 10,6a and 106c in Fig 4 Furthermore, the coils may here pass on another side next to
the sensors, such as coil B with respect to the sensor elements 104a, 104c, 106b and 106d,
and/or the coil A with respect to the sensor elements 104b, 104d, 106a and 106c in Fig 4
In embodiments, the coils thus may be placed or arranged so as to be opposite As already
mentioned above, the excitation lines (eg 108, 109) or coils may also preferably be
arranged symmetrically in pairs with respect to the sensor elements here, but this does not
necessarily has to be the case, with arbitrary geometries generally being conceivable,
allowing to generate defined different calibration field components within a sensor element
arrangement
If a coil passes directly above vertical sensor elements, its influence thereon is significantly
greater than the influence of an adjacent or laterally offset coil, wherein this influence may
also be negligible in one embodiment Thus, the coil A in Fig 4 mainly excites the vertical
sensor elements 104a, 104b, 106b and 106d, and/or the coil B mainly excites the sensor

elements 104b, 104d, 106a and 106c Both coils excite the horizontal sensor elements
102a/d at the center of the arrangement The following table is to represent, once again,
separately for both coils, how the excitation direction behaves depending on the direction
of an excitation current, broken down according to the sensor element arrangements 102,
104 and 106 The current arrows in Fig 4 here each indicate the positive current direction,
I e a positive current Ik1 in the coil A at first flows laterally past the sensor elements 106a,
106c, 104d and 104b and then directly above the sensor element 106d, 106b, 104a and
104c, a positive current Ik2 in the coil B at first flows above the sensor elements 106a,
106c, 104d and 104b and then laterally past the sensor elements 106d, 106b, 104a and
104c

Fig 5 shows another embodiment of a magnetic field sensor 100 The embodiment of Fig
5 comprises the same sensor elements (eg 102a-d, 104a-d, 106a-d) and the same
geometry of the sensor elements and sensor element arrangements as Fig 4, so that
repeated description will be omitted The magnetic field sensor 100 of Fig 5 comprises
only one excitation line 108, which is embodied as a coil having 1 5 windings and passing
directly above the vertical sensor elements A current Ik1 through the excitation line 108 in
Fig 5 thus flows across the sensor elements 106a, 106c, 104b and 104d twice and across
the sensor elements 106d, 106b, 104a and 104c only once, whereby the difference or
asymmetry of the calibration field components in the pairs of sensor elements is achieved
In further embodiments, the magnetic field sensor may also compnse a second excitation
line also having 1 5 windings and may be arranged so as to be opposite, corresponding to
the above description In general, excitation lines are conceivable with various numbers of
windings, which in the end comprise a partial winding for producing asymmetry of the
calibration field components
In embodiments, there are obtained various measurement processes that can be realized
with one or also two excitation lines 108, 109 For example, if current is applied to a coil,

c f Figs 1, 2, 3, 5 as well as the above table, all three sensor arrangements 102, 104 and
106 can be excited On the basis of the embodiments from Figs 3b, 4 and the table,
positive excitation of all sensor elements results from a positive current Ik1 through the coil
A Here, all horizontal sensor elements 102a-d are excited, but only the sensor elements on
the left (eg 106b, 106d) and at the bottom (eg 104a, 104c) out of the vertical sensor
elements The horizontal sensor elements 102a-d are excited with the full magnetic field of
the coil A, the vertical sensor elements (eg 104a, 104c, 106b, 106d) only with half the
magnetic field, however, since only two out of four sensor elements are excited each
In comparison thereto, if only the coil B is excited, the vertical sensor elements (e g 104a,
104b, 104d, 106a, 106c) experience negative excitation, and the horizontal sensor elements
(e g 102a-d) positive excitation Similar to the above, all horizontal sensor elements (e g
102a-d) are excited and thus sense the full magnetic field of the coil B Correspondingly,
only half (e g 104a, 104b, 104d, 106a, 106c) of the vertical sensor elements (e g 104a-d,
106a-d) are excited and thereby only sense half the magnetic field of the coil B
By combining the controls of the coils A and B, the magnetic field sensors can be
monitored and calibrated, in embodiments For example, also both coils can be controlled
in a positive current direction Thereby, the horizontal sensor elements (e g 102a-d) are
excited with twice the magnetic field, and the field may cancel itself out in the vertical
sensor elements (e g 104a-d, 106a-d)
If both coils are excited in opposite directions, the vertical sensor elements (e g 104a-d,
106a-d) may be excited with the twice the field, wherein the field cancels itself out in the
horizontal sensor elements (eg 102a-d) In further embodiments, differently strong
currents may also be applied to the coils For example, when applying current in positive
direction to both coils, but with twice the current strength in the first coil A, three times the
magnetic field results for the horizontal sensor elements (e g 102a-d), but only the single
magnetic field for the vertical sensor elements (eg 106d, 106b, 104a, 104c) Such
excitation may also be achieved by coils having partial windings, as shown in Fig 5, for
example, in other embodiments In Fig 5, the right-hand side of the magnetic field sensor
100 then would be excited in a dually negative way, whereas the left-hand side would be
excited in a single positive way, thus amounting to three times the magnetic field The
excitation ratio of 2 1 would not be realized by way of two coils in such an embodiment,
but way of one coil having 1 5 windings In general, the coils having arbitrary numbers of
windings, which allow for generating an asymmetric calibration field, are possible in
embodiments, wherein arbitrary non-integer numbers of windings capable of generating an
"unsymmetncal" excitation ratio are possible, for example

If twice the current Ik1 is applied to the first coil A and current in opposite direction to the
second coil B in the above example, the horizontal sensor elements (e.g. 102a-d)
experience the single magnetic field, but the vertical sensors (e.g. 104a-d, 106a-d) the three
times the same. According to the examples considered, many other combinations or
controls to enhance and/or suppress individual magnetic field components may still be
found in further embodiments.
Each of these controls has advantages, depending on which component is to be extracted or
suppressed. For example, if only the vertical sensor elements (e.g. 104a-d, 106a-d) are
monitored or calibrated, applying current in opposite direction to the coils could be
employed. For example, if only the horizontal sensor elements (e.g. 102a-d) are excited,
current in the same direction could be applied to the coils. If both, the horizontal (e.g.
102a-d) and the vertical sensor elements (e.g. 104a-d, 106a-d), are of interest, current could
be applied to the individual coils successively or with different current strengths, according
to the above examples.
As already explained above, one sensor element arrangement 102, 104 or 106 each may
also be omitted in the embodiment explained. The concepts explained then also apply,
without limitation, for the remaining two sensor element arrangements for sensing a
magnetic field along two linearly independent spatial directions. What has been said with
respect to the sensor elements and their embodiments each also equally applies to the
embodiments of Figs, la and lb.
An additional advantage may be obtained if all sensor elements (e.g. XI-X4, Y1-Y4) are
excited. This can be achieved by a second excitation line 109, c.f. Figs. 3b, to which a
current then is applied in a temporally offset manner, for example, as already mentioned
above. The following table summarizes the effects of applying current to the excitation line
108 and/or coil A and the excitation line 109 and/or coil B on the basis of the example of
the magnetic field sensor shown in Fig. 3b. A "+" here indicates application of current
and/or magnetomotive force in positive direction, a "- " in negative direction, and a "0"
designates no signal at all.


In the above summary, it is further assumed that the current through both coils is equal In
other embodiments, as already mentioned in the previous sections, various currents and/or
numbers of windings could also be used In one embodiment, an advantage is obtained in
the alternating operation of the coils Then, signal proportions in all sensor element
arrangements 102, 104 and 106 can be sensed, this being represented in the three columns
on the right in the above table
According to the above statements, not all sensor elements of a sensor element
arrangement can be tested at the same time in the alternating operation In the simultaneous
operation of the coils, however, a signal that may be twice as high in comparison is
obtained, wherein all sensor elements of a sensor element arrangement can be tested at the
same time Different sensor element arrangements, eg 104-106 (e g X,Y sensors) and 102
(e g Z sensors), can only be calibrated or tested alternately
In summary, with respect to the inventive concept of the magnetic multi-dimensional point
sensor cahbratable during measurement operation, it can be stated that magnetic sensors
according to the embodiments of the present invention thus can manage with only one
excitation line, but offer additional monitoring and calibration possibilities with a second
excitation line They offer the advantage that all three field components can be measured in
very good approximation in one point, wherein offsets, which are caused by component
tolerances, contaminations in the semiconductor matenal, structural inhomogeneities in the
semiconductor material, etc, for example, can be compensated for and the measurement
values thus be made available with little offset Through the use of the excitation loop,
which may also comprise an arbitrary number of windings and/or partial windings, a

simple wafer test is made possible, 1 e an on-chip test of all three sensors Furthermore, by
combining the measurement signals from the individual excitations, it is possible to allow
for a self-test with the measurement operation running, because both, measurement signal
proportions originating from the measurement field components on the one hand and
measurement signal proportions originating from calibration field components on the other
hand, can be reduced significantly Thus, it is possible to perform sensitivity calibration on
such a magnetic field sensor during operation The excitation loop itself may also be tested,
because failure of three sensors with separate evaluation electronics is very unlikely
In particular, it is pointed out that, depending on the conditions, the inventive scheme may
also be implemented in software The implementation may be on a digital storage medium,
particularly a disk or a CD with electronically readable control signals capable of
cooperating with a programmable computer system and/or microcontroller so that the
corresponding method is executed In general, the invention thus also consists in a
computer program product with a program code stored on a machine-readable carrier for
executing the inventive method, when the computer program is executed on a computer
and/or microcontroller In other words, the invention may thus be realized as a computer
program with a program code for performing the method, when the computer program is
executed on a computer and/or microcontroller

we CLAIM:
1 Calibratable magnetic field sensor (100) for sensing a first and a second spatial
component (By, Bz, Bx, By) of a magnetic field in a reference point (101), wherein the
magnetic field comprises a first and a second measurement field component (BMy,
BMZ, BMX, BMy) and/or a first and a second calibration field component (Bky, BKZ, BRX,
Bicy), comprising
a first sensor element arrangement (104, 106) comprising at least a first and a second
sensor element (104a, 104b, 106a, 106b) for sensing the first magnetic field
component (By, Bx), which comprises a first measurement field component (BMy,
BMX) and/or a first calibration field component (BKy, BKX), with respect to a first
spatial axis (y, x) in the reference point (101),
a second sensor element arrangement (102, 104) for sensing the second magnetic
field component (Bz, By), which comprises a second measurement field component
(BMZ BMy) and/or a second calibration field component (BKZ, BKY-), with respect to a
second spatial axis (z, y) in the reference point (101), wherein the two spatial axes (y,
z, x, z, x, y) pass along linearly independent position vectors,
an excitation line (108) arranged with respect to the first sensor element arrangement
(104, 106) so that, when impressing a default current (Ik1) into the excitation line
(108), a pair of different asymmetrical default calibration field components (BKya,
Bkxa) in the first sensor element (104a, 106a) and (Bkyb, BKxb) in the second sensor
element (104b, 106b) is generated with respect to the first spatial axis (y, x)
2 Cahbratable magnetic field sensor (100) according to claim 1, wherein the second
sensor element arrangement (102, 104) comprises at least a first and a second sensor
element (102a, 102b, 104a, 104b), and the excitation line (108) further is arranged
with respect to the second sensor element arrangement (102, 104) so that a second
pair of different asymmetrical default calibration field components (Bkzb, BKya) in the
first sensor element (102a, 104a) and (Bkzb, BKyb) in the second sensor element
(102b, 104b) is generated with respect to the second spatial axis (z, y) in the sensor
element arrangement (102, 104)
3 Cahbratable magnetic field sensor (100) according to one of claims 1 or 2, further
formed to sense a third spatial component (Bx, Bz) of the magnetic field in the
reference point (101), wherein the magnetic field further comprises a third

measurement field component (BMX, BMZ) and/or a third calibration field component
(BKX, BKZ), and the magnetic field sensor (100) further comprises a third sensor
element arrangement (106, 102) for sensing the third magnetic field component (Bx,
Bz), which comprises the third measurement field component (BMXI BMZ) and/or the
third calibration field component (BKX, BKA), with respect to a third spatial axis (x, z)
in the reference point (101), wherein the three spatial axes (z, y, x) pass along
linearly independent position vectors
4 Calibratable magnetic field sensor (100) according to claim 3, wherein the third
sensor element arrangement (106, 102) comprises at least a first and a second sensor
element (106a, 106b, 102a, 102b), and wherein the excitation line (108) is arranged
with respect to the third sensor element arrangement (106, 102) so that, when
impressing a default current (Ik1) into the excitation line (108), a pair of different
asymmetrical default calibration field components (BKXa, Bkxb, BKZa, BKZB) in the first
sensor element (106a, 102a) and in the second sensor element (106b, 102b) is
generated with respect to the third spatial axis (x, z) in the third sensor element
arrangement (106, 102)
5 Magnetic field sensor (100) according to one of claims 1 to 4, wherein the excitation
line (108) is formed such that it comprises a partial winding
6 Magnetic field sensor (100) according to claim 5, wherein the excitation line (108) is
arranged such that the coil with the at least one winding comprises shortest distances
to the at least two sensor elements (102a, 102b, 104a, 104b, 106a, 106b) of a sensor
element arrangement (102, 104, 106), which are different
7 Magnetic field sensor (100) according to claim 5, wherein the excitation line (108) is
arranged symmetrically with respect to the reference point (101) and sweeps the
sensor elements (102a, 102b, 104a, 104b, 106a, 106b) of a sensor element
arrangement (102, 104, 106) a different number of times
8 Magnetic field sensor (100) according to one of claims 1 to 7, wherein the excitation
line (108) is arranged such that it comprises a coil with at least one complete
winding
9 Magnetic field sensor (100) according to one of claims 1 to 8, further comprising a
second excitation line (109)

10 Magnetic field sensor (100) according to claim 9, wherein the second excitation line
(109) is arranged with respect to the first (102), second (104) or third sensor element
arrangement (106) so as to generate a first further pair of different asymmetrical
default calibration field components (BKZa2, Bkzb2) in the first sensor element (102a)
and in the second sensor element (102b) with respect to the first spatial axis (z) in the
first sensor element arrangement (102) when impressing a further default current (la)
into the second excitation line (109), to generate a second further pair of different
asymmetrical default calibration field components (BKya2, BRyb2) in the first sensor
element (104a) and in the second sensor element (104b) with respect to the second
spatial axis (y) in the second sensor element arrangement (104), or to generate a third
further pair of different asymmetrical default calibration field components (Bksa2,
Bkxb2) in the first sensor element (106a) and in the second sensor element (106b)
with respect to the third spatial axis (x) in the third sensor element arrangement
(106)
11 Magnetic field sensor (100) according to claim 10, wherein the first excitation line
(108) and the second excitation line (109) are arranged so that the first further pair of
different asymmetrical default calibration field components is in an inverse relation
with respect to each other relative to the first pair of calibration field components, the
second further pair of different asymmetrical default calibration field components is
in an inverse relation with respect to each other relative to the second pair of
calibration field components, and the third further pair of different asymmetrical
default calibration field components is in an inverse relation with respect to each
other relative to the third pair of calibration field components
12 Magnetic field sensor (100) according to one of claims 1 to 11, wherein the second
or third sensor element arrangement (102) comprises a hall sensor element horizontal
with respect to a main surface of the magnetic field sensor
13 Magnetic field sensor (100) according to one of claims 1 to 10, wherein the second
or third sensor element arrangement (102) comprises a plurality of hall sensor
elements horizontal with respect to a main surface of the magnetic field sensor,
wherein the geometrical arrangement of the plurality of horizontal hall sensor
elements with respect to the reference point (101) is symmetrical in pairs, and the
hall sensor elements are coupled to each other such that the magnetic field
component can be sensed in an offset-compensated manner

14 Magnetic field sensor (100) according to one of claims 1 to 13, wherein the first,
second or third sensor element arrangement (104, 102) comprises at least two hall
sensor elements vertical with respect to a main surface of the magnetic field sensor
(100), wherein the geometrical arrangement of the at least two vertical hall sensor
elements with respect to the reference point (101) is symmetrical in pairs, and the
same are coupled to each other such that the magnetic field components can be
sensed in an offset-compensated manner
15 Magnetic field sensor (100) according to one of claims 1 to 14, wherein the first
(102), second (104) or third sensor element arrangement (106) can be operated in the
spinning current mode
16 Method for sensing a first and a second spatial component (By, Bz, Bx, By) of a
magnetic field in a reference point (101), wherein the magnetic field comprises a first
and a second measurement field component (BMy, BMZ, BMX, BMy) and/or a first and a
second calibration field component (BKy, BKZ, BKX, Bky), comprising
sensing, in a first and a second sensor element (104a, 104b, 106a, 106b) of a first
sensor element arrangement (104, 106), a first pair of magnetic field components
(Bya, Byb, Bxa, BXb), which comprise first measurement field components (BMya, BMyb,
BMXB, BMxb) and/or first calibration field components (Bkya, BKyb, BKxa, BKxb), with
respect to a first spatial axis (y, x) in the reference point (101),
sensing, in a second sensor element arrangement (102, 104), second magnetic field
components (Bz, By), which comprise second measurement field components (BMZ,
BMy) and/or second calibration field components (BKZ, BKy), with respect to a second
spatial axis (z, y) in the reference point (101), wherein the two spatial axes (y, z, x,
y) pass along linearly independent position vectors, and
generating a first pair of different asymmetrical calibration field components (BKya,
BKyb, BKxa, BKxb) with respect to the first spatial axis (y, x) in the first and the second
sensor element (104a, 104b, 106a, 106b) of the first sensor element arrangement
(104, 106)
17 Method according to claim 16, further comprising
sensing a second pair of magnetic field components (Bza, BZb, Bya, Byb), which
comprise second magnetic field components (BMZa, BMZb, BMya, BMyb) and/or second

calibration field components (BkZa Bkzb, BKya, BRyb), with respect to the second
spatial axis (z, y) in the reference point (101), and
generating a second pair of different asymmetrical calibration field components
(Bkza, Bkzb BKya, Bkyb) with respect to the second spatial axis (z, y)
18 Method according to one of claims 16 or 17, further comprising
sensing a third spatial component (Bx, Bz) of the magnetic field in the reference point
(101), wherein the magnetic field further comprises a third measurement field
component (BMX, BMZ) and/or a third calibration field component (BKX, BRZ), and
generating third calibration field components (BKX, BKZ) with respect to the third
spatial axis (x, z), wherein the three spatial axes (z, y, x) pass along linearly
independent position vectors
19 Method according to claim 18, further comprising
sensing a third pair of magnetic field components (Bxa, BXb, Bza, BZb), which
comprise three measurement field components (BMXB, BMxb. BMZ3, BMzb) and/or third
calibration field components (BKX3, Bkxb, Bkza, Bkzb) with respect to the third spatial
axis (x, z) in the reference point (101), and
generating the third pair of different asymmetrical calibration field components
(BKX3, Bkxb, Bkza, Bkzb) with respect to the third spatial axis (x, z)
20 Method according to one of claims 16 to 19, further comprising generating the first,
second and third further calibration field components (BKZ2, BKy2, BKX2) with respect
to the first, second and third spatial axes (z, y, x) and sensing the first, second and
third further magnetic field components (Bz2, By2, Bx2), which comprises the first,
second and third further measurement field components (BMZ2, BMy2, BMXZ) and/or
first, second and third calibration field components (BKZ2, BKy2, BKX2)
21 Method according to one of claims 16 to 20, further comprising
first linearly combining the measurement signals of a magnetic field component,
which are associated with the magnetic field components, to a first total

measurement value, in order to reduce the influence of the measurement field
component in the first total measurement value, or
second linearly combining the measurement signals of a magnetic field component,
which are associated with the further magnetic field components, to a second total
measurement value, in order to reduce the influence of the calibration field
component in the second total measurement value
22 Method according to claim 21, wherein first linearly combining the measurement
signals of a measurement field component, which is associated with the magnetic
field components or the further magnetic field components, to a first total
measurement value takes place such that a proportion of the measurement field
component in the first total measurement value is reduced to less than 10%, 1% or
0 1% of the first total measurement value
23 Method according to claim 21, wherein second combining of the measurement
signals of a magnetic field component, which are associated with the magnetic field
components or the further magnetic field components, to a second total measurement
value takes place such that the proportion of the calibration field component in the
second total measurement value is reduced to less than 10%, 1% or 0 1% of the
second total measurement value
24 Method according to one of claims 16 to 23, further comprising combining the
measurement signals of a magnetic field component, which are associated with the
magnetic field components or the further magnetic field components, so that the
magnetic field component is sensed in an offset-compensated manner
25 Method according to one of claims 16 to 24, wherein operating phases are performed
in accordance with to a spinning current method
26 Method according to one of claims 16 to 25, further comprising
storing excitation current strengths, measurement field components or calibration
field components for calibration,
associating the excitation current strengths with calibration field components or
magnetic field strengths, and

providing value pairs of measurement field components and magnetic field strengths
27 Computer program with a program code for performing all of the steps of one of the
methods of claims 16 to 26, when the program code is executed on a computer

Calibratable Multidimensional Magnetic Point Sensor

Abstract

A calibratable magnetic field sensor (100) for sensing a first and a second spatial
component (By, Bz, Bx, By) of a magnetic field in a reference point (101), wherein the
magnetic field comprises a first and a second measurement field component (BMy, BMZ,
BMX, BMy) and/or a first and a second calibration field component (Bky, BKZ, BKX, BKy) The
magnetic filed sensor (100) includes a first sensor element arrangement (104, 106)
comprising at least a first and a second sensor element (104a, 104b, 106a, 106b) for
sensing the first magnetic field component (By, Bx), which comprises a first measurement
field component (BMy, BMX) and/or a first calibration field component (BKy, BKX), with
respect to a first spatial axis (y, x) in the reference point (101) Furthermore, the magnetic
field sensor (100) includes a second sensor element arrangement (102, 104) for sensing the
second magnetic field component (Bz, By), which comprises a second measurement field
component (BMZ, BMY) and/or a second calibration field component (BKZ, BKy), with respect
to a second spatial axis (z, y) in the reference point (101) The magnetic filed sensor (100)
also includes an excitation line (108) arranged with respect to the first sensor element
arrangement (104, 106) so that, when impressing a default current (Ik1) into the excitation
line (108), a pair of different asymmetrical default calibration field components (BKya,
Bkxa) in the first sensor element (104a, 106a) and (Bkyb, Bkxb) in the second sensor element
(104b, 106b) is generated with respect to the first spatial axis (y, x) in the first sensor
element arrangement (104, 106), wherein the two spatial axes (y, z, x, z, x, y) pass along
linearly independent position vectors