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: Methods and apparatus for a sensor having non-ratiometric fault trip level setting. In embodiments, a sensor has a sensing element with a fixed gain. A signal processing module receives the fault trip level setting and maintains the fault trip level setting constant during changes in the supply voltage.

Abstract: The concepts, systems, circuits and techniques described herein are directed toward sensing a voltage transient within a magnetic field sensor integrated circuit, such as a current sensor. A magnetic field sensor integrated circuit includes a substrate having a first surface and a second opposing surface, at least one magnetic field sensing element supported by a first surface of the substrate, an electromagnetic shield layer disposed on a shielded region of the first surface of the substrate adjacent to an unshielded region of the first surface of the substrate and an electrode disposed in the unshielded region of the first surface of the substrate and configured to permit detection of the voltage transient. In some embodiments, the shielded region and/or the electrode can be omitted.

Abstract: A pressure sensor includes a chamber comprising a conductive portion and a deformable portion coupled to the conductive portion and susceptible to deformation in response to a pressure differential between an interior of the chamber and an exterior of the chamber; at least one coil responsive to an AC coil drive signal; at least one magnetic field sensing element disposed proximate to the at least one coil and to the conductive portion of the chamber and configured to generate a magnetic field signal in response to a reflected magnetic field generated by the at least one coil and reflected by the conductive portion; and a circuit coupled to the at least one magnetic field sensing element to generate an output signal of the pressure sensor indicative of the pressure differential between the interior of the chamber and the exterior of the chamber in response to the magnetic field signal.

Abstract: A magnetic field sensor includes at least one coil responsive to an AC coil drive signal; at least two spaced apart magnetic field sensing elements responsive to a sensing element drive signal and positioned proximate to the at least one coil; and a circuit coupled to the at least two magnetic field sensing elements to generate an output signal of the magnetic field sensor indicative of a difference between a distance of a conductive target with respect to each of the at least two spaced apart magnetic field sensing elements.

Abstract: A magnetic field sensor includes at least one coil responsive to an AC coil drive signal; at least one magnetic field sensing element responsive to a sensing element drive signal and configured to detect a directly coupled magnetic field generated by the at least one coil and to generate a magnetic field signal in response to the directly coupled magnetic field; a processor responsive to the magnetic field signal to compute a sensitivity value associated with detection of the directly coupled magnetic field and substantially independent of a reflected magnetic field reflected by a conductive target disposed proximate to the at least one magnetic field sensing element; and an output signal generator configured to generate an output signal of the magnetic field sensor indicative of the reflected magnetic field.

Abstract: An apparatus comprises one or more substrates and one or more coils. At least one of the coils is configured to produce a first magnetic field that induces eddy currents in a conductive target, which generates a reflected magnetic field. One or more magnetic field sensing elements supported by the one or more substrates detect the reflected magnetic field. A conductive support structure supports the one or more substrates. The support structure includes a gap in an area adjacent to the one or more coils so that the support structure does not generate a reflected magnetic field in response to the first magnetic field.

Abstract: An apparatus comprises a conductive material having varying thickness along its length, the varying thickness providing varying response along a length of the conductive material to a magnetic field having a non-zero frequency; wherein the magnetic field produces an eddy current in the conductive material which generates a reflected magnetic field, wherein the varying response causes the reflected magnetic field to vary in strength along the length of the conductive material. The apparatus may include one or more reference portions of conductive material.

Abstract: A magnetic field sensor for sensing external magnetic fields on multiple axes comprises a coil structure and a gain equalization circuit. The coil structure generates reference fields on magnetic field sensing elements in each axis. The gain equalization circuit measures and compares reference fields to generate gain-equalized output signals responsive to the external magnetic fields.

Abstract: In one aspect, a magnetic field sensor includes a chopper stabilized amplifier and a plurality of Hall-type elements in parallel and connected to the chopper stabilized amplifier. In another aspect, a magnetic field sensor includes a chopper stabilized amplifier and a plurality of Hall quad elements in parallel and connected to the chopper stabilized amplifier. In a further aspect, a current sensor has a bandwidth of 1 MHz and includes a chopper stabilized amplifier and a plurality of Hall quad elements, fabricated in silicon, in parallel and connected to the chopper stabilized amplifier.

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.

Abstract: Methods and apparatus for a sensor having non-ratiometric fault trip level setting. In embodiments, a sensor has a sensing element with a fixed gain. A signal processing module receives the fault trip level setting and maintains the fault trip level setting constant during changes in the supply voltage.

Abstract: In one aspect, a magnetic field sensor includes a chopper stabilized amplifier and a plurality of Hall-type elements in parallel and connected to the chopper stabilized amplifier. In another aspect, a magnetic field sensor includes a chopper stabilized amplifier and a plurality of Hall quad elements in parallel and connected to the chopper stabilized amplifier. In a further aspect, a current sensor has a bandwidth of 1 MHz and includes a chopper stabilized amplifier and a plurality of Hall quad elements, fabricated in silicon, in parallel and connected to the chopper stabilized amplifier.

Abstract: The concepts, systems, circuits and techniques described herein are directed toward sensing a voltage transient within a magnetic field sensor integrated circuit, such as a current sensor. A magnetic field sensor integrated circuit includes a substrate having a first surface and a second opposing surface, at least one magnetic field sensing element supported by a first surface of the substrate, an electromagnetic shield layer disposed on a shielded region of the first surface of the substrate adjacent to an unshielded region of the first surface of the substrate and an electrode disposed in the unshielded region of the first surface of the substrate and configured to permit detection of the voltage transient. In some embodiments, the shielded region and/or the electrode can be omitted.

Abstract: Systems and methods described herein are directed towards integrating a shield layer into a current sensor to shield a magnetic field sensing element and associated circuitry in the current sensor from electrical, voltage, or electrical transient noise. In an embodiment, a shield layer may be disposed along at least one surface of a die supporting a magnetic field sensing element. The shield layer may be disposed in various arrangements to shunt noise caused by a parasitic coupling between the magnetic field sensing element and the current carrying conductor away from the magnetic field sensing element.

Abstract: Systems and methods are described herein for creating a high isolation integrated current sensor whereby a portion of a current to be sensed by a magnetic field sensing circuit is split within the current sensor. The current sensor includes a primary conductor configured to carry a first portion of a primary current and a semiconductor substrate having a first surface and a second opposing surface. The first surface supports a magnetic field sensing circuit. The current sensor includes a first insulation layer disposed over the first surface, a conductive layer disposed over the first insulation layer and at least two interconnects coupled between the primary conductor and the conductive layer. A second portion of the primary current can flow through the conductive layer and the magnetic field sensing circuit is configured to sense the second portion of primary current.

Abstract: Methods and apparatus for bi-directional communication between first and second die of a signal isolator for feedback and/or diagnostic signals. In embodiments, the first and second die can be matched.

Abstract: Methods and apparatus for a signal isolator having first and second dies separated by a voltage barrier region, wherein transmit and receive paths of the first and second dies provide bi-directional transfer of feedback and/or diagnostic signals between the first and second die. In embodiments, transmitter refresh signals and receiver refresh signals are exchanged to detect fault conditions.

Abstract: A magnetic field sensor for sensing external magnetic fields on multiple axes comprises a coil structure and a gain equalization circuit. The coil structure generates reference fields on magnetic field sensing elements in each axis. The gain equalization circuit measures and compares reference fields to generate gain-equalized output signals responsive to the external magnetic fields.

Abstract: Method and apparatus for a current sensing device including a magnetoresistive magnetic field sensing element positioned with respect to a shaped conductor such that an applied field generated by current through the shaped conductor forms an offset angle theta defined by the applied field and a field of a pinning layer of the magnetoresistive element. The offset angle increases a linearity of the device output for current in the shaped conductor flowing in a first direction. A further sensor can increase linearity in the opposite direction.