A magnetic sensor includes at least one sensor main body; a detection circuit provided on the at least one sensor main body, the detection circuit including a magnetic detection element; and a plurality of sensor terminals provided on the at least one sensor main body. The plurality of sensor terminals include a plurality of signal terminals and a plurality of power supply terminals. The plurality of signal terminals are all disposed on a side of one end of the at least one sensor main body. The plurality of power supply terminals include at least one first terminal disposed on the side of the one end of the at least one sensor main body, and a plurality of second terminals disposed on a side of another end of the at least one sensor main body.

A magnetic sensor includes an insulating layer, a first MR element, and a second MR element. The insulating layer includes a protruding surface including first and second inclined surfaces. Each of the first and second MR elements includes a magnetization pinned layer and a free layer. The magnetization pinned layer and the free layer of the first MR element are disposed on the first inclined surface. The magnetization pinned layer and the free layer of the second MR element are disposed on the second inclined surface. The dimension of the protruding surface in a direction parallel to the Z direction is in the range of 1.4 .Math.m to 3.0 .Math.m.

A system and method that can automatically select a frequency of a magnetic field in a magnetic tracking system. A magnetic tracking system emits an alternating magnetic field using a set of three frequencies. In the present approach, a transmitter is capable of generating multiple sets of three frequencies. A processor selects a first set of frequencies to use and causes the receiver to measure the amplitude of the magnetic field at those frequencies. In one embodiment, the frequency set having the lowest energy is selected. The processor then compares an estimated jitter at those frequencies to the actual jitter experienced using the frequencies. If the actual jitter exceeds the estimated jitter by a predetermined amount, the processor switches to a different set of frequencies and causes the receiver to measure the magnetic field at the new set of frequencies. The process may repeat using the additional sets of frequencies.

An exemplary embodiment of a sensor system includes a magnet system which is designed to generate a magnetic field. Furthermore, the sensor system includes a first magnetic field sensor which is movable in a first direction relative to the magnet system and has a first distance from the magnet system in a second direction perpendicular to the first direction. The sensor system also includes a second magnetic field sensor which is movable in the first direction relative to the magnet system and has a second distance from the magnet system in the second direction, the second distance being greater than the first distance.

A magnetic sensor may include a comparator to receive a first signal indicating a strength of a magnetic field sensed by a first sensing component of the magnetic sensor, receive a second signal indicating a strength of a magnetic field sensed by a second sensing component of the magnetic sensor, perform an error check associated with the first sensing component and the second sensing component, the error check being performed based on the first signal and the second signal, and provide an indication of a result of the error check. The magnetic sensor may include a protocol encoder to receive the first signal, receive the indication of the result of the error check, and provide an output that includes the indication of the result of the error check.

In one aspect, bridge circuitry includes a first magnetoresistance (MR) element; a second MR element connected in series with the first MR element at a first node; a third MR element; a fourth MR element connected in series with the third MR element at a second node; a first switch connected at one end to a supply voltage and connected at the other end to the third MR element; a second switch connected at one end to ground and connected at the other end to the fourth MR element; a third switch connected at one end to ground and connected at the other end to the third MR element and the first switch; and a fourth switch connected at one end to the supply voltage and the other end to the fourth MR element and the second switch. The first and second MR elements are in parallel with the third and fourth MR elements.

A gain-controllable magnetoresistive analog amplifier comprises a substrate located in an X-Y plane, an output signal magnetoresistive sensor located on the substrate, and an input signal coil and a gain adjustment coil. The input signal coil and the gain adjustment coil are respectively located on two side surfaces of the output signal magnetoresistive sensor. The gain adjustment coil is used to input a gain signal by the generation of a gain magnetic field, in order to set the gain the magnetic field is applied along a magnetization direction of a free layer of the output signal magnetoresistive sensor, thereby adjusting the slope of the input resistance-magnetic field transfer curve of the output signal magnetoresistive sensor. The input signal coil is used for inputting a current signal to generate an input magnetic field, in order to apply the input magnetic field to a magnetization direction of a pinned layer of the output signal magnetoresistive sensor, thereby controlling the gain signal to adjust a gain factor of an output signal after the current signal passes through the output signal magnetoresistive sensor. This magnetoresistive analog amplifier provides isolation between input signals, output signals, and controllable gain signals.

A method for detecting an error in a bridge sensor which is adapted for measuring a physical parameter. The method comprises biasing a first contact pair of the bridge sensor at least two times in a first direction and at least one time in a second direction opposite to the first direction; while biasing the first contact pair, measuring an output signal on a different contact pair of the bridge sensor, thus obtaining at least three output measurements which are representative for the physical parameter and which are separated by time intervals; combining the output measurements to obtain an output value which is indicative for an error in the bridge sensor, wherein the output measurements which are combined are only those output measurements which are measured when biasing the first contact pair.

A method and apparatus for reducing magnetic tracking error in the position and orientation determined in a magnetic tracking system having a magnetic field generator. In some embodiments, the measured position and orientation of a sensor is compared to an expected theoretical position and orientation. Any error is assumed to be from “floor distortion,” i.e., eddy currents in the floor caused by the magnetic field generated by the magnetic field transmitter. The floor distortion is modeled as being caused by eddy currents caused by a second magnetic field transmitter that is a reflection of the actual transmitter. An algorithm iteratively searches over a parameter space to minimize the difference between the measured position and orientation and the theoretical position and orientation, and applies a correction to the measured position and orientation. The measurements and corrections of the position and orientation run in real-time with no additional hardware or calibration required.

A multi-contact Hall plate having four contacts or a multiple of four contacts, wherein each of the contacts is arranged substantially equally distributed along an edge region of the Hall plate, and each of the contacts is connected to one of the four terminals.