Abstract: One example discloses a security device, including: a bulk security capacitance, including a first endpoint and a second endpoint, and having, a first layer including a first set of conductive elements, the first endpoint, and the second endpoint; and a second layer including a second set of conductive elements; wherein the first set of conductive elements and the second set of conductive elements together form at least two bulk capacitors in series; wherein the first and second layers are separated by a distance; and wherein the first and second endpoints are configured to be coupled to a tamper detection circuit configured to detect a change in the bulk security capacitance.

Abstract: A method for digital-to-analog signal conversion with distributed reconstructive filtering includes receiving a digital code synchronous to a clock signal having a first frequency, determining next states of a plurality of digital-to-analog current elements based on the digital code, combining a plurality of currents to generate an output current, and generating the plurality of currents. Each of the plurality of currents is based on a corresponding control signal of a plurality of control signals. The method includes generating the plurality of control signals based on the next states of the plurality of digital-to-analog current elements. Each of the plurality of control signals selects a first voltage level, a second voltage level, or a transitioning voltage level for use by a corresponding digital-to-analog current element. The transitioning voltage level linearly transitions from the first voltage level to the second voltage level over a predetermined number of periods of the clock signal.

Abstract: An integrated circuit (IC) includes an input/output (I/O) circuitry with a first circuitry section including I/O pins and a second circuitry section including I/O pins. The first and second circuitry sections are mutually exclusive sections of the I/O ring. The first circuitry section includes a first I/O pin configured to receive an input voltage from a first energy source and a second I/O pin connectable to an external startup capacitor. A startup circuit is coupled to the first I/O pin and the second I/O pin. Upon receiving the input voltage from the first energy source, the startup circuit enters a during the startup phase and isolates the first circuitry section from the second circuitry section, and provides charge to the external startup capacitor. In response to achieving a predetermined minimum charge on the external startup capacitor, the first circuitry section is connected to the second circuitry section, and the startup phase ends and the IC transitions to a functional mode of operation.

Abstract: A controller for a DC-DC converter that includes an inductor. The DC-DC converter has three phases of operation: a first phase, in which an input voltage charges the inductor; a second phase, in which the inductor discharges to a load; and a third phase, in which the inductor is disconnected from the load and in which the input voltage does not charge the inductor. The controller is configured to set a control-factor based on the input voltage of the DC-DC converter, and set the duration of the third phase based on the control-factor and the sum of the duration of the first phase and the second phase.

Abstract: A resistive sensor system includes resistive sensor pairs formed of first and second sensors of opposite sensitivity directions to a measured property. Each resistive sensor pair includes one of the first sensors having a first terminal and a second terminal, and one of the second sensors having a third terminal and a fourth terminal. The fourth terminal is coupled to the second terminal of the first sensor. The system further includes multiple noninverting switch elements, each having a noninverting output coupled to the first terminal of one the first sensors, and multiple inverting switch elements, each having an inverting output coupled to the third terminal of one of the second sensors. For each resistive sensor pair, the noninverting and inverting switch elements receive a switch signal for controlling the noninverting and inverting switch elements such that the first and second sensors are biased in opposition to one another.

Abstract: A resistive sensor system includes resistive sensor pairs formed of first and second sensors of opposite sensitivity directions to a measured property. Each resistive sensor pair includes one of the first sensors having a first terminal and a second terminal, and one of the second sensors having a third terminal and a fourth terminal. The fourth terminal is coupled to the second terminal of the first sensor. The system further includes multiple noninverting switch elements, each having a noninverting output coupled to the first terminal of one the first sensors, and multiple inverting switch elements, each having an inverting output coupled to the third terminal of one of the second sensors. For each resistive sensor pair, the noninverting and inverting switch elements receive a switch signal for controlling the noninverting and inverting switch elements such that the first and second sensors are biased in opposition to one another.

Abstract: A system includes a magnet having an axis of rotation, the magnet being configured to produce a magnetic field. The system further includes a plurality of magnetoresistive sensor elements, each of the magnetoresistive sensor elements having a magnetic free layer configured to generate a vortex magnetization pattern in the magnetic free layer, and the magnetoresistive sensor elements being configured to produce output signals in response to the magnetic field. A rotation angle of a rotating element to which the magnet is coupled may be determined using the plurality of output signals.

Abstract: A system includes a magnet configured to produce a magnetic field, the magnet having an asymmetric magnetization configuration that produces a distinct feature in the magnetic field. The asymmetric magnetization configuration can be produced via an asymmetric physical characteristic, nonuniform magnetization strengths, nonuniform magnetization distributions, off-centered magnet, and so forth. Magnetic field sensors are configured to produce output signals in response to the magnetic field, the output signals being indicative of the distinct feature in the magnetic field. A processing circuit receives the output signals and determines a rotation angle for the magnet using the output signals, the rotation angle having a range of 0-360°.

Abstract: A system for determining angular position includes a magnet having at least four poles and an axis of rotation, wherein the magnet produces a magnetic field. A first magnetic field sensor produces a first output signal and a second magnetic field sensor produces a second output signal in response to the magnetic field. The magnetic field sensors are operated in a saturation mode in which the magnetic field sensors are largely insensitive to the field strength of the magnetic field. Thus, the first output signal is indicative of a first direction of the magnetic field and the second output signal is indicative of a second direction of the magnetic field. Methodology performed by a processing circuit entails combining the first and second output signals to obtain a rotation angle value of the magnet in which angular error from a stray magnetic field is at least partially canceled.

Abstract: An integrated circuit includes a load circuit having multiple functional modules, a first voltage regulator configured to provide a supply voltage to the multiple functional modules, and a supply current monitoring circuit including a second voltage regulator and a current monitor, the second voltage regulator being configured to provide a test supply voltage. A switch matrix is interconnected between the first voltage regulator, the supply current monitoring circuit, and the functional modules. Each of the functional modules in successive order is a module under test, and the switch matrix is configured to disconnect the first voltage regulator from the module under test and connect the supply current monitoring circuit to the module under test such that the second voltage regulator provides the test supply voltage to the module under test and the current monitor measures a supply current of the module under test in response to the test supply voltage.

Abstract: A system for determining angular position includes a dipole magnet having an axis of rotation, wherein the dipole magnet produces a magnetic field. A first magnetic field sensor produces a first output signal and a second magnetic field sensor produces a second output signal in response to the magnetic field. The magnetic field sensors are operated in a saturation mode in which the magnetic field sensors are largely insensitive to the field strength of the magnetic field. Thus, the first output signal is indicative of a first direction of the magnetic field and the second output signal is indicative of a second direction of the magnetic field. Methodology performed by a processing circuit entails combining the first and second output signals to obtain a rotation angle value of the magnet in which angular error from a stray magnetic field is substantially cancelled.

Abstract: A system includes a magnetic sense element for detecting an external magnetic field along a sensing axis and a magnetic field source proximate the magnetic sense element for providing an auxiliary magnetic field along the sensing axis. The magnetic sense element produces a first output signal having a magnetic field signal component, responsive to the external magnetic field, that is modulated by an auxiliary magnetic field signal component responsive to the auxiliary magnetic field. A processing circuit identifies from the first output signal an influence of a magnetic interference field on the auxiliary magnetic field signal component, the magnetic interference field being directed along a non-sensing axis of the magnetic sense element, and applies a correction factor to the magnetic field signal component to produce a second output signal in which the influence of the magnetic interference field is substantially removed.

Abstract: A system includes a magnet having an axis of rotation, the magnet being configured to produce a magnetic field. The system further includes a plurality of magnetoresistive sensor elements, each of the magnetoresistive sensor elements having a magnetic free layer configured to generate a vortex magnetization pattern in the magnetic free layer, and the magnetoresistive sensor elements being configured to produce output signals in response to the magnetic field. A rotation angle of a rotating element to which the magnet is coupled may be determined using the plurality of output signals.

Abstract: A system includes a magnet configured to produce a magnetic field, the magnet having an asymmetric magnetization configuration that produces a distinct feature in the magnetic field. The asymmetric magnetization configuration can be produced via an asymmetric physical characteristic, nonuniform magnetization strengths, nonuniform magnetization distributions, off-centered magnet, and so forth. Magnetic field sensors are configured to produce output signals in response to the magnetic field, the output signals being indicative of the distinct feature in the magnetic field. A processing circuit receives the output signals and determines a rotation angle for the magnet using the output signals, the rotation angle having a range of 0-360°.

Abstract: A system includes first and second magnetic sense elements for producing first and second output signals, respectively, in response to an external magnetic field along a sensing axis parallel to a plane of the first sense element, a magnetization direction of the second element being rotated in the plane relative to a magnetization direction of the first element. The second output signal differs from the first output signal in dependency to a magnetic interference field along a non-sensing axis of the first magnetic field. A processing circuit, receives the first and second output signals, identifies from a relationship between the first and second output signals an influence of the magnetic interference field on the first output signal, and applies a correction factor to the first output signal to produce a resultant output signal in which the influence of the magnetic interference field is substantially removed.

Abstract: A system for determining angular position includes a dipole magnet having an axis of rotation, wherein the dipole magnet produces a magnetic field. A first magnetic field sensor produces a first output signal and a second magnetic field sensor produces a second output signal in response to the magnetic field. The magnetic field sensors are operated in a saturation mode in which the magnetic field sensors are largely insensitive to the field strength of the magnetic field. Thus, the first output signal is indicative of a first direction of the magnetic field and the second output signal is indicative of a second direction of the magnetic field. Methodology performed by a processing circuit entails combining the first and second output signals to obtain a rotation angle value of the magnet in which angular error from a stray magnetic field is substantially cancelled.

Abstract: A system for determining angular position includes a magnet having at least four poles and an axis of rotation, wherein the magnet produces a magnetic field. A first magnetic field sensor produces a first output signal and a second magnetic field sensor produces a second output signal in response to the magnetic field. The magnetic field sensors are operated in a saturation mode in which the magnetic field sensors are largely insensitive to the field strength of the magnetic field. Thus, the first output signal is indicative of a first direction of the magnetic field and the second output signal is indicative of a second direction of the magnetic field. Methodology performed by a processing circuit entails combining the first and second output signals to obtain a rotation angle value of the magnet in which angular error from a stray magnetic field is at least partially canceled.

Abstract: A system includes first and second magnetic sense elements for producing first and second output signals, respectively, in response to an external magnetic field along a sensing axis parallel to a plane of the first sense element, a magnetization direction of the second element being rotated in the plane relative to a magnetization direction of the first element. The second output signal differs from the first output signal in dependency to a magnetic interference field along a non-sensing axis of the first magnetic field. A processing circuit, receives the first and second output signals, identifies from a relationship between the first and second output signals an influence of the magnetic interference field on the first output signal, and applies a correction factor to the first output signal to produce a resultant output signal in which the influence of the magnetic interference field is substantially removed.

Abstract: A system includes a magnetic sense element for detecting an external magnetic field along a sensing axis and a magnetic field source proximate the magnetic sense element for providing an auxiliary magnetic field along the sensing axis. The magnetic sense element produces a first output signal having a magnetic field signal component, responsive to the external magnetic field, that is modulated by an auxiliary magnetic field signal component responsive to the auxiliary magnetic field. A processing circuit identifies from the first output signal an influence of a magnetic interference field on the auxiliary magnetic field signal component, the magnetic interference field being directed along a non-sensing axis of the magnetic sense element, and applies a correction factor to the magnetic field signal component to produce a second output signal in which the influence of the magnetic interference field is substantially removed.

Abstract: A resistive sensor includes a current input sigma-delta converter that uses a switched offset voltage source to provide scalable gain and more linear operation. The sigma-delta converter includes an integrator, a quantizer, and a decimator. In one embodiment, the resistive sensor and offset voltage source are coupled to provide an input current at a first node. The integrator has a first input terminal coupled to the first node, and an output terminal. The quantizer has a first input terminal coupled to the output terminal of the integrator, a second input terminal for receiving a clock signal, and an output terminal coupled to provide a feedback signal to control the offset voltage source. The decimator has an input terminal coupled to the output terminal of the quantizer, and an output terminal for providing an output signal. The switched offset voltage source provides scalable gain and good linearity.