Abstract:
A magnetic field sensing system includes one or more magnetoresistive random access memory (MRAM) cells, and may be configured to determine one or more of a presence, a magnitude, and a polarity of an external magnetic field incident upon an MRAM cell. In some examples, a control module of the system controls a write current source, or another device, to provide a write current through a write line associated with the MRAM cell to induce a magnetic field proximate to the MRAM cell. The magnetic field may be less than a magnetic switching threshold of the MRAM cell. After initiating the provision of the write current through the write line, the control module may determine a magnetic state of the MRAM cell, and determine a presence of an external magnetic field incident upon the MRAM cell based at least in part on the magnetic state of the MRAM cell.
Abstract:
A system may include circuitry and a magnetoresistive random access memory (MRAM) die including at least one MRAM cell. The circuitry may be configured to detect attempted tampering with the MRAM die and generate a signal based on the detected attempted tampering. The signal may be sufficient to damage or destroy at least one layer of the at least one MRAM cell or a fuse electrically connected to a read line of the at least one MRAM cell.
Abstract:
This disclosure is directed to techniques for generating a reference current based on a combinational logic function that is to be performed by a magnetic logic device. A comparator circuit may compare an amplitude of a read current that flows through the magnetic logic device and the reference current to generate a logic output value that corresponds to the logic output value when combinational logic function is applied to the input values. By selecting appropriate amplitudes for the reference current the magnetic logic device may be caused to implement different combinational logic functions.
Abstract:
This disclosure is directed to a magnetic logic device for implementing a combinational logic function. The magnetic logic device may include a chain of at least two magnetoresistive devices electrically coupled in series comprising a first terminal located at a first end of the chain and a second terminal located at a second end of the chain. The magnetic logic device may further include a voltage source configured to apply a voltage between the first terminal and the second terminal of the chain of at least two magnetoresistive devices electrically coupled in series. The magnetic logic device may further include a logic output generator configured to generate a logic output value for a logic function based on a magnitude of a current produced at the second terminal of the chain in response to the applied voltage.
Abstract:
A magnetic device is provided in one example that comprises a free layer having a magnetic anisotropy. The magnetic anisotropy is at least partially non-uniform. The magnetic device further comprises an antiferromagnetic layer adjacent to and weakly exchange coupled with the free layer, wherein the weak exchange coupling reduces the non-uniformity of the magnetic anisotropy of the free layer.
Abstract:
This disclosure is directed to a magnetic logic device for implementing a combinational logic function. The magnetic logic device may include a network of at least two magnetoresistive devices electrically coupled in parallel. The magnetic logic device may further include a voltage source configured to apply a voltage between a first terminal and a second terminal of the network of at least two magnetoresistive devices electrically coupled in parallel. The magnetic logic device may further include a logic output generator configured to generate a logic output value for a logic function based on a magnitude of a current produced at the second terminal of the network in response to the applied voltages.
Abstract:
A magnetic shield is presented. The shield may be used to protect a microelectronic device from stray magnetic fields. The shield includes at least two layers. A first layer includes a magnetic material that may be used to block DC magnetic fields. A second layer includes a conductive material that may be used to block AC magnetic fields. Depending on the type of material that the first and second layers include, a third layer may be inserted in between the first and second layers. The third layer may include a non-conductive material that may be used to ensure that separate eddy current regions form in the first and second layers.
Abstract:
An improved MRAM cell may include a first, second, and third contact, a first MTJ between the first and second contact, and a MTJ between the second and third contact. The MRAM cell is nonconductive between the first and second MTJ. The first MTJ may include a first free layer with a first switching field, and the second MTJ may include a second free layer with a second switching field. If the first switching field is substantially higher than the second switching field, the first MTJ may be a reference element for the second MTJ. If the first switching field is adequately higher than the second switching field, the first and second MTJ may each contain a data bit. If the first switching field is substantially similar to the second switching field, the first and second MTJs may contain identical data bits connected in series.
Abstract:
A giant magnetoresistive memory device includes a magnetic sense layer, a magnetic storage layer, a non-magnetic spacer layer between the magnetic sense layer and the magnetic storage layer, and an antiferromagnetic layer formed in proximity to the magnetic storage layer. The antiferromagnetic layer couples magnetically in a controlled manner to the magnetic storage layer such that the magnetic storage layer has uniform and/or directional magnetization. Additionally or alternatively, an antiferromagnetic layer may be formed in proximity to the magnetic sense layer. The antiferromagnetic layer in proximity to the magnetic sense layer couples magnetically in a controlled manner to the magnetic sense layer such that the magnetic sense layer has uniform and/or directional magnetization.
Abstract:
A magnetic shield is presented. The shield may be used to protect a microelectronic device from stray magnetic fields. The shield includes at least two layers. A first layer includes a magnetic material that may be used to block DC magnetic fields. A second layer includes a conductive material that may be used to block AC magnetic fields. Depending on the type of material that the first and second layers include, a third layer may be inserted in between the first and second layers. The third layer may include a non-conductive material that may be used to ensure that separate eddy current regions form in the first and second layers.