Abstract: A single-package power meter is disclosed for measuring the power consumed by a load connected to an electrical conductor. The power meter is galvanically isolated from the electrical conductor through the use of magnetic sensors or through the combination of magnetic sensors and capacitors. Instantaneous power consumed at the load and other desired parameters are determined by measuring the voltage of the load and current flowing through the electrical conductor. Current is measured using a magnetic sensor to detect the magnetic field associated with the current flowing through the electrical conductor. Voltage is measured by one of two possible techniques involving magnetic sensors to measure the current flowing through a coil connected in parallel with a load, or through the use of a capacitively coupled voltage divider connected in parallel with the load.

Abstract: A transducer is disclosed for detecting the AC and DC voltage difference between two nodes in an electrical circuit and electronically transmitting the measured voltage difference to an electrical system that is electrically isolated from the common mode potential of the two nodes. The voltage drop between two points in a circuit under test is determined by detecting the current flowing through a resistive shunt coil connected in parallel to the test points. Current through the resistive shunt coil is linearly proportional to the voltage difference between the test points, and it is detected by using a magnetic sensor that is separated from the shunt coil by an insulating dielectric barrier. The transducer can be packaged in a standard integrated circuit package in order to provide a small and low cost voltage transducer for test, measurement, control, and signal-isolation applications.

Abstract: A single package magnetoresistive angle sensor for use in measuring rotation angle of a magnet is disclosed. The magnetoresistive angle sensor comprises a pair of magnetoresistive sensor chips, wherein one of the chips is rotated by 180-degree rotation relative to the other. The magnetoresistive sensor chips are attached to a standard semiconductor package lead frame to form a single-axis push-pull full-bridge sensor. Each of the magnetoresistive sensor chips comprises a pair of magnetoresistance sensor arms. Each magnetoresistive sensor arm comprises one or more GMR or MTJ sensor elements. The GMR of MTR sensor elements utilize a pined layer. The element blocks of the magnetoresistive sensor electrically are interconnected and connected to the package leads by wirebonding. The magnetoresistive angle sensor can be packaged into various standard semiconductor package designs.

Abstract: A spin dependent tunneling device includes an electrically insulative material intermediate layer, a magnetization reference layer on one of the opposite major surfaces of the intermediate layer, and a memory film of a magnetostrictive, anisotropic ferromagnetic material on the other of the opposite major surfaces of the intermediate layer. The memory film material has a magnetization directed at an angle with respect to the relatively fixed direction of the magnetization reference layer, due to an effective magnetic bias field being present, in a first kind of stress condition with unequal coercivities for external magnetic fields applied in opposite directions. In one kind of stress condition the device has a coercivity with a magnitude exceeding that of the effective magnetic bias field, and in another kind of stress condition, the device has a coercivity with a magnitude less than that of the effective magnetic bias field.

Abstract: The present invention discloses a single-chip referenced full-bridge magnetoresistive magnetic-field sensor. The single-chip sensor is a Wheatstone bridge arrangement of magnetoresistive sensing elements and reference elements. The sensing elements and reference elements are formed from either magnetic tunnel junctions or giant magnetoresistive materials. The sensitivity of the reference and sensor elements is controlled through one or a combination of magnetic bias, exchange bias, shielding, or shape anisotropy. Moreover, the bridge output is tuned by setting the ratio of the reference and sensor arm resistance values to a predetermined ratio that optimizes the bridge output for offset and symmetry. The single-chip referenced-bridge magnetic field sensor of the present invention exhibits excellent temperature stability, low offset voltage, and excellent voltage symmetry.

Abstract: A single-package power meter is disclosed for measuring the power consumed by a load connected to an electrical conductor. The power meter is galvanically isolated from the electrical conductor through the use of magnetic sensors or through the combination of magnetic sensors and capacitors. Instantaneous power consumed at the load and other desired parameters are determined by measuring the voltage of the load and current flowing through the electrical conductor. Current is measured using a magnetic sensor to detect the magnetic field associated with the current flowing through the electrical conductor. Voltage is measured by one of two possible techniques involving magnetic sensors to measure the current flowing through a coil connected in parallel with a load, or through the use of a capacitively coupled voltage divider connected in parallel with the load.

Abstract: The present invention discloses a single-chip referenced full-bridge magnetoresistive magnetic-field sensor. The single-chip sensor is a Wheatstone bridge arrangement of magnetoresistive sensing elements and reference elements. The sensing elements and reference elements are formed from either magnetic tunnel junctions or giant magnetoresistive materials. The sensitivity of the reference and sensor elements is controlled through one or a combination of magnetic bias, exchange bias, shielding, or shape anisotropy. Moreover, the bridge output is tuned by setting the ratio of the reference and sensor arm resistance values to a predetermined ratio that optimizes the bridge output for offset and symmetry. The single-chip referenced-bridge magnetic field sensor of the present invention exhibits excellent temperature stability, low offset voltage, and excellent voltage symmetry.

Abstract: A single package magnetoresistive angle sensor for use in measuring rotation angle of a magnet is disclosed. The magnetoresistive angle sensor comprises a pair of magnetoresistive sensor chips, wherein one of the chips is rotated by 180-degree rotation relative to the other. The magnetoresistive sensor chips are attached to a standard semiconductor package lead frame to form a single-axis push-pull full-bridge sensor. Each of the magnetoresistive sensor chips comprises a pair of magnetoresistance sensor arms. Each magnetoresistive sensor arm comprises one or more GMR or MTJ sensor elements. The GMR of MTR sensor elements utilize a pined layer. The element blocks of the magnetoresistive sensor electrically are interconnected and connected to the package leads by wirebonding. The magnetoresistive angle sensor can be packaged into various standard semiconductor package designs.

Abstract: A transducer is disclosed for detecting the AC and DC voltage difference between two nodes in an electrical circuit and electronically transmitting the measured voltage difference to an electrical system that is electrically isolated from the common mode potential of the two nodes. The voltage drop between two points in a circuit under test is determined by detecting the current flowing through a resistive shunt coil connected in parallel to the test points. Current through the resistive shunt coil is linearly proportional to the voltage difference between the test points, and it is detected by using a magnetic sensor that is separated from the shunt coil by an insulating dielectric barrier. The transducer can be packaged in a standard integrated circuit package in order to provide a small and low cost voltage transducer for test, measurement, control, and signal-isolation applications.

Abstract: A tamper sensing system mounted with respect to a protected structure so as to have corresponding stress changes occur therein in response to selected kinds of tamperings with said protected structure comprising a first pair of stress affected magnetoresistive memory devices each capable of having a magnetic material layer therein established in a selected one of a pair of alternative magnetization states if in a first kind of stress condition and of being established in a single magnetization state if in an alternative second kind of stress condition, and the magnetic material layer in each having a magnetization in a first direction in one of the pair of alternative magnetization states and in a second direction in that remaining one of the pair of magnetization states.

Abstract: A tamper sensing system mounted with respect to a protected structure so as to have corresponding stress changes occur therein in response to selected kinds of tamperings with said protected structure comprising a first pair of stress affected magnetoresistive memory devices each capable of having a magnetic material layer therein established in a selected one of a pair of alternative magnetization states if in a first kind of stress condition and of being established in a single magnetization state if in an alternative second kind of stress condition, and the magnetic material layer in each having a magnetization in a first direction in one of the pair of alternative magnetization states and in a second direction in that remaining one of the pair of magnetization states.

Abstract: A ferromagnetic thin-film based device that transitioned between alternative magnetic states thereof through having electrical currents established therethrough and has both a reference magnetization and a free layer magnetization provided therein by vortex magnetizations.

Abstract: An MRAM device includes an array of magnetic memory cells having an upper conductive layer and a lower conductive layer separated by a barrier layer. To reduce the likelihood of electrical shorting across the barrier layers of the memory cells, spacers can be formed around the upper conductive layer and, after the layers of the magnetic memory cells have been etched, the memory cells can be oxidized to transform any conductive particles that are deposited along the sidewalls of the memory cells as byproducts of the etching process into nonconductive particles. Alternatively, the lower conductive layer can be repeatedly subjected to partial oxidation and partial etching steps such that only nonconductive particles can be thrown up along the sidewalls of the memory cells as byproducts of the etching process.

Abstract: A ferromagnetic thin-film based digital memory system having memory cells interconnected in a grid that are selected through voltage values supplied coincidently on interconnections made thereto for changing states thereof and determining present states thereof through suitable biasing of grid interconnections.

Abstract: A ferromagnetic thin-film based digital memory system having memory cells interconnected in a grid that are selected through voltage values supplied coincidently on interconnections made thereto for changing states thereof and determining present states thereof through suitable biasing of grid interconnections.

Abstract: A method is provided for fabricating a fixed layer for a MRAM device. The method includes providing the fixed layer. The fixed layer includes an antiferromagnetic pinning layer over a substrate and a ferromagnetic pinned layer over the pinning layer, the pinned layer having a first thickness. The fixed layer further includes a spacer layer over the pinned layer, and a ferromagnetic reference layer over the spacer layer, the reference layer having a second thickness. The method further includes annealing the fixed layer using a temporal temperature/magnetic field profile, the profile having a maximum magnetic field magnitude (Hanneal). The profile is selected based on the first thickness of the pinned layer and the second thickness of the reference layer.

Abstract: The present invention provides a method of forming an MRAM cell which minimizes the occurrence of electrical shorts during fabrication. A first conductor in a trench is provided in an insulating layer and an upper surface of the insulating layer and the first conductor is planarized. Then, a dielectric layer is deposited to a thickness slightly greater than the desired final thickness of a sense layer, which is formed later. The dielectric layer is then patterned and etched to form an opening for the cell shapes over the first conductor. Then, a permalloy is electroplated in the cell shapes to form the sense layer. The sense layer and dielectric layer are flattened and then a nonmagnetic tunnel barrier layer is deposited. Finally, the pinned layer is formed over the tunnel barrier layer.

Abstract: A ferromagnetic thin-film based device that transitioned between alternative magnetic states thereof through having electrical currents established therethrough and has both a reference magnetization and a free layer magnetization provided therein by vortex magnetizations.

Abstract: A tamper detecting enclosure arrangement for enclosures containing an interior space in which a protected item is positioned having a magnetoresistive sensing memory storage cell positioned in or near the protected item in the enclosure having a two state offset magnetoresistance versus externally applied magnetic field. A magnet is positioned at a selected separation distance from the magnetoresistive sensing memory storage cell to thereby provide a magnetic field about the magnetoresistive sensing memory storage cell if said enclosure has not been opened in such a manner as to result in substantially increasing said separation distance.

Abstract: A tamper sensing system mounted with respect to a protected structure so as to have corresponding stress changes occur therein in response to selected kinds of tamperings with said protected structure comprising a first pair of stress affected magnetoresistive memory devices each capable of having a magnetic material layer therein established in a selected one of a pair of alternative magnetization states if in a first kind of stress condition and of being established in a single magnetization state if in an alternative second kind of stress condition, and the magnetic material layer in each having a magnetization in a first direction in one of the pair of alternative magnetization states and in a second direction in that remaining one of the pair of magnetization states.