Abstract: A magnetic field sensor includes a plurality of magnetic field sensing elements configured to generate at least two measured magnetic field signals indicative of a magnetic field affected by an object and having a first predetermined phase difference with respect to each other and a controller responsive to the at least two measured magnetic field signals. The controller is configured to generate at least one virtual magnetic field signal having a second predetermined phase difference with respect to at least one of the measured magnetic field signals. In embodiments, the virtual magnetic field signal has the second predetermined phase difference with respect to each of the at least two measured magnetic field signals.

Abstract: A buffer amplifier comprises a source follower and a feedback amplifier. The feedback amplifier may be configured to control a drain current of the source follower to remain substantially constant independent of a load.

Abstract: A magnetoresistance structure includes a first magnetoresistance element and a second magnetoresistance element, wherein the first magnetoresistance element is formed on a surface of the second magnetoresistance element. The first magnetoresistance element comprises a free layer, a bias stack configured to bias a magnetic alignment of the free layer to a first direction in the absence of an external magnetic field, and a reference stack having a reference direction substantially orthogonal to the first direction. The magnetoresistance structure may be used to form a two- or three-dimensional magnetic field sensor.

Abstract: A material stack includes a first magnetoresistance element with a first direction of response to an external magnetic field and a second magnetoresistance element with second direction of response to the external magnetic field, opposite to the first direction of response. The first magnetoresistance element can be disposed under or over the second magnetoresistance element. An insulating layer separates the first and second magnetoresistance elements.

Abstract: In one aspect, an integrated circuit (IC) includes a magnetic field sensor to detect speed and direction of angular rotation of a rotating magnetic structure. The magnetic field sensor includes at least two magnetic field sensing elements configured to sense changes in a magnetic field caused by rotation of the magnetic structure. The IC also includes an output port configured to provide an output signal of the magnetic field sensor. The frequency of the output signal indicates the speed and the direction or indicates a fault.

Abstract: Systems and methods described herein provide a current sensor based on magnetic field detection having multiple sensor arrangements with multiple, different sensitivity ranges. The outputs of the multiple sensor arrangements can be combined to generate a single output signal. The current sensor can include two or more sensor arrangements, each having one or more magnetic field sensing elements, and configured to sense a magnetic field in different first measurement ranges corresponding to different ranges of currents through the conductor and further configured to generate different magnetic field signals indicative of the sensed magnetic field in the respective measurement range. The current sensor can include a circuit configured to generate an output signal indicative of a combination of the different magnetic field signals that corresponds to the current through the conductor.

Abstract: A substrate includes at least first, second, and third metal layers and adjacent substrate portions having rotated arrangements of signal traces provided by the metal layers. Each metal layer includes first and second spaced portions. The first portion of the first metal layer includes a first trace configured to carry a first signal and the second portion of the first metal layer includes a second trace configured to carry a second signal. The first portion of the second metal layer includes third and fourth spaced traces configured to carry the second signal and the second portion includes fifth and sixth spaced traces configured to carry the first signal. The first portion of the third metal layer includes a seventh trace configured to carry the first signal and the second portion includes an eighth trace configured to carry the second signal.

Abstract: Apparatus and methods provide a current sensor system including a plurality of current sensors positioned proximate a plurality of conductors. Each conductor is configured to carry a current to be measured. Each current sensor comprises one or more magnetic field sensing elements configured to generate a respective magnetic field signal indicative of a detected magnetic field. The plurality of current sensors includes a first number of current sensors and the plurality of conductors includes a second number of conductors such that the first number is at least one more than the second number. A controller is coupled to receive the magnetic field signal from each of the current sensors and, for each magnetic field sensing element, is configured to characterize a magnetic coupling between the magnetic field sensing element and each of the plurality of conductors.

Abstract: A method includes depositing on a substrate a magnetoresistance stack, depositing a first hard mask on the magnetoresistance stack, depositing a first photoresist on the first hard mask, patterning the first photoresist to expose portions of the first hard mask, and etching the exposed portions of the first hard mask to expose a portion of the magnetoresistance stack. The method further includes stripping the first photoresist, etching the exposed portions of the magnetoresistance stack and the first hard mask to form a first intermediate structure having a base and a pillar structure, depositing an etch barrier on the first intermediate structure, and depositing a second hard mask on the etch barrier. A second photoresist is deposited on the second hard mask.

Abstract: Methods and apparatus for providing an integrated circuit having a drive current source, a magnetic sensing element coupled to the drive current source, the magnetic sensing element having first and second differential outputs, and first and second current elements to provide respective currents in relation to the drive current source, wherein the first current element is coupled to the first differential output and the second current element is coupled to the second differential output. In illustrative embodiments, an IC output can output a voltage corresponding to the currents of the first and second current elements.

Abstract: A current sensor for sensing a direct magnetic field generated by a current through a conductor includes at least one first magnetic field sensing element spaced from at least one second magnetic field sensing element, with the magnetic field sensing elements configured to sense the direct magnetic field at different magnitudes. The direct magnetic field has a first direct coupling factor with respect to the at least one first magnetic field sensing element and a second direct coupling factor with respect to the at least one second magnetic field sensing element. A feedback conductor configured to carry a feedback current generates a feedback magnetic field that has a first feedback coupling factor with respect to the at least one first magnetic field sensing element and a second feedback coupling factor with respect to the at least one second magnetic field sensing element.

Abstract: A magnetic field angle sensor is provided having two or more bridge structures of magnetoresistance elements, with each bridge structure configured to measure a projection of a magnetic field along a different axis such that an angle of direction of the magnetic field can be measured with greater accuracy. The angle sensor includes a first bridge structure configured to generate a first sinusoidal signal indicative of the magnetic field along a first axis and a first cosinusoidal signal indicative of the magnetic field along a second axis that is orthogonal with respect to the first axis and a second bridge structure configured to generate a second sinusoidal signal indicative of the magnetic field along a third axis and a second cosinusoidal signal indicative of the magnetic field along a fourth axis that is orthogonal with respect to the third axis, wherein an angle between the first axis and the third axis is a factor of 90°.

Abstract: A magnetic field sensor includes a substrate having a surface and a plurality of magnetoresistance elements supported by the surface of the substrate. Each magnetoresistance element has a respective width parallel to the surface, and each width may be a smallest dimension parallel to the surface. A first width of a first magnetoresistance element of the plurality of magnetoresistance elements may be different from a second width of a second magnetoresistance element of the plurality of magnetoresistance elements. A processing circuit may be coupled to the plurality of magnetoresistance elements to receive a signal representing a detected magnetic field from at least one of the magnetoresistance elements.

Abstract: Methods and apparatus for a magnetic field sensor for measuring movement of a target including a substrate and a magnet. A first bridge structure has first and second pluralities of magnetic field sensing elements spaced from each other. An axis of sensitivity of the magnetic field sensing elements is rotated at a predetermined angle with respect to an axis of rotation of the target to generate an output signal corresponding to the position of the target and a change in a property of the magnetic field generated by the magnet.

Abstract: Methods and apparatus for a magnetic field sensor integrated circuit including a lead frame having a first surface, a second opposing surface, and a plurality of leads. A substrate has a first surface supporting a magnetic field sensing element and a second surface attached to the first surface of the lead frame. A magnet has a first surface and a second, opposing surface, and is configured to generate a magnetic field. A spacer is positioned between the first surface of the magnet and the second surface of the lead frame with a thickness selected to establish a predetermined distance between the first surface of the magnet and the magnetic field sensing element, the predetermined distance selected to provide the magnetic field signal as a sinusoidal signal.

Abstract: An integrated circuit including a first multiplexor configured to receive one of a plurality of diagnostic signals from circuitry under test (DUT), the first multiplexor responsive to diagnostic signals provided thereto and configured to selectively output one of the diagnostic signals in response to a control signal, a second multiplexor configured to receive one of a plurality of reference signals from one of a plurality of nodes on a reference circuit, the second multiplexor configured to selectively output one of the diagnostic signals in response to a control signal, and a comparator configured to compare the diagnostic signal elicited from the first multiplexor with the reference signal elicited from the second multiplexor, the comparator further configured to output the result of the comparison between the diagnostic signal and the reference signal.

Abstract: A magnetoresistance assembly can include a substrate and a first GMR element disposed over the substrate, the first GMR element having a bottom surface and top surface. The magnetoresistance assembly can further include a first TMR element disposed over the substrate, the first TMR element having a top surface and a bottom surface, wherein a line perpendicular to and intersecting the top or bottom surface of the first TMR element intersects the first GMR element. The first GMR element and the first TMR element are in electrical communication.

Abstract: A motor drive circuit for driving an electric motor includes a plurality of driver circuits, each one of the plurality of driver circuit comprising a high side transistor coupled to a low side transistor in a half bridge arrangement, wherein each one of the high side transistors and each one of the low side transistors has a respective control node and respective first and second current passing nodes, wherein the second current passing node of each of the high side transistors is coupled to the first current passing node of a respective one of the low side transistors at a respective junction node, wherein each one of the plurality of driver circuits is operable to drive a respective current out of a respective junction node into a respective winding of the electric motor. The motor drive circuit further includes a capacitor coupled to the first current passing node of each one of the high side transistors, the capacitor operable to hold a capacitor voltage.

Abstract: A sensor includes an output circuit configured to generate a sensor output signal based on an input signal having a logic high or low level, as may be provided by a Schmitt trigger circuit. During normal operation, the output switches between a first percentage of the supply voltage for logic high and a second percentage of the supply voltage for logic low. To convey a failure at the output, an output signal is output as either ground or the supply voltage when a fault is detected. As such, a fault can be communicated any time the output voltage is not equal to the first percentage or the second percentage of the supply voltage.

Abstract: Systems and methods described herein are directed towards differential current sensing a current sensor having two or more magnetic field sensing elements that are oriented to sense a magnetic field generated by a current through an external conductor in the same direction. The current sensor can be positioned such that at least one first magnetic field sensing element is vertically aligned with the external conductor and at least one second magnetic field sensing element is not vertically aligned with the external conductor. The magnetic field sensing elements may be spaced from each to measure a gradient field and can generate a magnetic field signal indicative of a distance between the respective magnetic field sensing element and the current carrying external conductor. A difference between the magnetic field signals can be determined that is indicative of the current through the external conductor.