Abstract: A chopper-stabilized amplifier has switching networks arranged to support a high frequency clocking signal and to provide a high common mode rejection and a high rejection of an offset component of an input signal. A magnetic field sensor includes a Hall effect element coupled to a modulation circuit. The modulation circuit provides a signal to the chopper-stabilized amplifier. The chopper-stabilized amplifier provides an output signal to a low pass filter, which provides an output signal from the magnetic field sensor.

Abstract: An integrated circuit current sensor includes a lead frame having at least two leads coupled to provide a current conductor portion, and a substrate having a first surface in which is disposed one or more magnetic field sensing elements, with the first surface being proximate to the current conductor portion and a second surface distal from the current conductor position. In one particular embodiment, the substrate is disposed having the first surface of the substrate above the current conductor portion and the second surface of the substrate above the first surface. In this particular embodiment, the substrate is oriented upside-down in the integrated circuit in a flip-chap arrangement. The current sensor can also include an electromagnetic shield disposed between the current conductor portion and the magnetic field sensing elements.

Abstract: Apparatus for detecting vibration of an object adapted to rotate includes one or more vibration processors selected from: a direction-change processor adapted to detect changes in a direction of rotation of the object, a direction-agreement processor adapted to identify a direction of rotation of the object in at least two channels and identify an agreement or disagreement in direction of rotation identified by the at least two channels, a phase-overlap processor adapted to identify overlapping signal regions in signals associated with the rotation of the object, and a running mode processor adapted to identify an unresponsive output signal from at least one of the at least two channels.

Abstract: In one aspect, a control circuit to control a speed of a motor includes a PWM oscillator configured to generate a PWM output signal having a duty cycle. The speed of the motor is controlled by the PWM output signal to be proportional to the duty cycle. The control circuit also includes a duty cycle control circuit responsive to a duty cycle selection signal and coupled to the PWM oscillator. The duty cycle control circuit is configured to compare a voltage reference and a supply voltage. The duty cycle control circuit controls the duty cycle of the PWM output signal to be inversely proportional to the supply voltage.

Abstract: A time delay fault device includes an integrated circuit (IC) having an electronic circuit having a fault indicator signal output and a time delay circuit having an input connected to the fault indicator signal output and an output to provide a delayed fault indicator signal output, the time delay circuit being responsive to an external voltage from a resistor capacitor network coupled to the delayed fault indicator signal output to set the time delay of the delayed fault indicator signal.

Abstract: A magnetic sensor comprises a plurality of layers including a substrate having circuitry, at least one conductive layer to interconnect the circuitry, and an insulator layer to electrically insulate the at least one conductive layer. First and second conductive layers are disposed above the substrate with a dielectric layer disposed between the first and second conductive layers such that the first and second conductive layers and the dielectric layer form a capacitor. A first terminal is electrically connected to the first conductive layer and a second terminal is electrically connected to the second conductive layer.

Abstract: An integrated circuit includes a monitor node adapted to receive a monitored signal. The integrated circuit also includes a multi-purpose node. The integrated circuit is adapted to receive and store a threshold presented at the multi-purpose node during a first time period. The integrated circuit is also adapted to output a fault signal from the multi-purpose node at a time after the predetermined time period. The fault signal is indicative of a relationship between the monitored signal and the threshold. With this arrangement, the multi-purpose node achieves at least two functions.

Abstract: Apparatus and methods for detecting passing magnetic articles using a first, True Power On State (TPOS) detector during a first time interval and transitioning to a second, running mode detector after the first time interval, when the output of the second detector is accurate. A phase comparator is responsive to the output signal of the first and second detectors and provides a control signal indicative of a change in the phase relationship between the two output signals. An output switch controlled by the phase comparator provides, as the detector output signal, the first detector output signal during the first time interval and the second detector output signal thereafter.

Abstract: A track-and-hold peak detector circuit, which can operate at low input signal frequencies, includes a capacitor to hold a peak voltage of the input signal and logic circuitry that reduces an effect of leakage current into or out of the capacitor, and therefore, provides protection against self-switching of an output signal of the peak detector circuit.

Abstract: An electronic circuit includes a first substrate having a first substrate surface and a device supported by the first substrate surface. The device is selected from among a passive electronic component and an active electronic component. The electronic circuit also includes a second substrate having a second substrate surface and a conductor proximate to the second substrate. The electronic circuit also includes a magnetic field transducer disposed over the conductor and coupled to the device and an insulating layer disposed between the conductor and the second substrate. The conductor is adapted to carry an electrical current to generate a first magnetic field. The electronic circuit is responsive to the first magnetic field. In some embodiments, the conductor is a secondary conductor and the circuit further includes a primary conductor disposed proximate to the magnetic field transducer and an insulating layer disposed between the primary conductor and the second substrate.

Abstract: An integrated sensor has a magnetic field sensing element and first and second relatively high magnetically permeable members forming a gap, wherein the magnetic field element is disposed within the gap. The magnetically permeable members provide an increase in the flux experienced by the magnetic field sensing element in response to a magnetic field. The integrated sensor can be used as a current sensor, a proximity detector, or a magnetic field sensor.

Abstract: An integrated circuit current sensor includes a lead frame having at least two leads coupled to provide a current conductor portion, and a substrate having a first surface in which is disposed one or more magnetic field sensing elements, with the first surface being proximate to the current conductor portion and a second surface distal from the current conductor portion. In one particular embodiment, the substrate is disposed having the first surface of the substrate above the current conductor portion and the second surface of the substrate above the first surface. In this particular embodiment, the substrate is oriented upside-down in the integrated circuit in a flip-chap arrangement. The lead frame also includes a shunt conductor portion formed as a coupling of the at least two leads.

Abstract: Apparatus and methods for processing a clock input signal with a clock regeneration circuit to provide a clock output signal for coupling to a cascaded device. The clock output signal has a period substantially equal to the period of the clock input signal and a duty cycle independent of the duty cycle of the clock input signal. In one embodiment, the clock regeneration circuit includes a one-shot and a buffer. Also described are apparatus and methods for aligning a data output signal of a cascaded device to non-clock-triggering edges of a selected one of the clock input signal and the clock output signal.

Abstract: A chopped Hall effect sensor topology includes a switched Hall plate, an amplifier responsive to an output of the switched Hall plate and a filter stage responsive to the output of the amplifier and including an anti-aliasing filter and a selective filter that is tuned to the modulation frequency. The switched Hall plate includes a Hall element and a Hall plate modulation circuit that modulates the Hall offset signal component or the magnetic signal component. In embodiments in which the Hall offset signal component is modulated by the switched Hall plate, the amplifier, if chopped, includes an even number of additional modulation circuits. In embodiments in which the magnetic signal component is modulated by the switched Hall plate, the amplifier contains an odd number of modulation circuits. The described topology provides a low noise, fast response time Hall effect sensor.

Abstract: A proximity detector includes a fine DAC and a coarse DAC, outputs of which are summed to provide a tracking signal for tracking a magnetic field signal. The proximity detector provides two mode of operation. In a first mode of operation the coarse and fine DACs operate in combination as one higher order DAC. In a second mode of operation, the coarse DAC is provided with one or more extra counts, allowing the tracking signal to move more rapidly to track a rapidly changing magnetic field signal. In another embodiment, the proximity detector also includes an offset circuit for bringing at least one of the magnetic field signal and the tracking signal towards the other one of the magnetic field signal and the tracking signal.

Abstract: Apparatus for detecting vibration of an object adapted to rotate includes one or more vibration processors selected from: a direction-change processor adapted to detect changes in a direction of rotation of the object, a direction-agreement processor adapted to identify a direction of rotation of the object in at least two channels and identify an agreement or disagreement in direction of rotation identified by the at least two channels, a phase-overlap processor adapted to identify overlapping signal regions in signals associated with the rotation of the object, and a running mode processor adapted to identify an unresponsive output signal from at least one of the at least two channels.

Abstract: Apparatus and methods for detecting passing magnetic articles using a first, True Power On State (TPOS) detector during a first time interval and transitioning to a second, running mode detector after the first time interval, when the output of the second detector is accurate. A phase comparator is responsive to the output signal of the first and second detectors and provides a control signal indicative of a change in the phase relationship between the two output signals. An output switch controlled by the phase comparator provides, as the detector output signal, the first detector output signal during the first time interval and the second detector output signal thereafter.

Abstract: Fabrication of a semiconductor package includes placing a conductive material on a protrusion from a leadframe to form a first assembly, forming a non-conductive mask about the protrusion, and placing a die on the first assembly, the die having an active area. Fabrication can further include reflowing the conductive material to form a second assembly such that a connection extends from the die active area, through the conductive material, to the protrusion. A semiconductor package includes a leadframe having a protrusion, a conductive material reflowed to the protrusion, and a die having an active area coupled to the protrusion by the reflowed solder.

Abstract: A method and apparatus provide a substrate having a depression into which a magnetic material is disposed, forming a magnetic flux concentrator and/or a permanent magnet. A magnetic field sensing element can be disposed proximate to the depression.

Abstract: A switch which is magnetic pole insensitive is described. The switch includes a Hall effect sensor coupled to a threshold circuit which provides an output signal indicative of the proximity of a magnet, and hence a magnetic field, to the Hall effect sensor regardless of the orientation of the magnet to the Hall effect sensor.