Abstract: Methods and apparatus for nonuniformity correction (NUC) for a sensor having an avalanche photodiode (APD) array and an integrated circuit. The sensor can include anode bias control module, a passive mode module, and an active mode module. DC photocurrent from the APD array can be measured and used for controlling an anode reverse bias voltage to each element in the APD to achieve a nonuniformity correction level less than a selected threshold.

Abstract: Methods and apparatus for a detector system having a photodetector and an amplifier to amplify the photodetector signal. A discriminator generates an active output signal when the output from the amplifier is greater than a threshold. An injection circuit is coupled to the input of the amplifier. The injection circuit is configured to selectively inject a test pulse that mimics a pulse from the photodetector for verifying operation of the detector system.

Abstract: Methods and apparatus for nonuniformity correction (NUC) for a sensor having an avalanche photodiode (APD) array and an integrated circuit. The sensor can include anode bias control module, a passive mode module, and an active mode module. DC photocurrent from the APD array can be measured and used for controlling an anode reverse bias voltage to each element in the APD to achieve a nonuniformity correction level less than a selected threshold.

Abstract: A magnetic field angle sensor includes a coil configured to generate a magnetic field that induces an eddy current in a rotatable target, a first magnetic field sensing structure positioned proximate to the coil and configured to detect a reflected magnetic field generated by the eddy current induced in the target, a second magnetic field sensing structure positioned proximate to the coil and configured to detect the reflected magnetic field generated by the eddy current induced in the target, wherein the first and second magnetic field sensing structures are configured to detect quadrature components of the reflected magnetic field, and a processing module configured to process the reflected magnetic field detected by the first and second magnetic field sensing structures for determining an angular position of the target.

Abstract: Methods and apparatus for a controlling a stimulus source to direct photons to a pixel in a pixel array contained in a detector system, analyzing a response of the pixel in the pixel array; and generating an alert based on the response of the pixel in the pixel array. Example stimulus sources include a conductive trace, a PN junction, and a current source.

Abstract: A method includes receiving a signal that is generated at least in part by one or more magnetic field sensing elements in response to a magnetic field associated with a rotating target, the rotating target a changing feature that changes with target rotation angle, the one or more magnetic field sensing elements being part of a sensor; detecting a current value of the signal; and identifying a current angular position of the rotating target relative to the sensor based on: (i) the current value of the signal and (ii) a map that maps each of a plurality of values of the signal to a different respective angular position of the rotating target.

Abstract: A current sensor including: a sensing unit including one or more sensing elements, the sensing unit being arranged to generate, at least in part, an internal signal, the internal signal being generated in response to a magnetic field, the magnetic field being produced, at least in part, by an electrical current that is sensed with the sensing unit; a first signal processing path coupled to the sensing unit, the first signal processing path including a first compensation unit for adjusting the internal signal, the first signal processing path being configured to generate a first signal based on the internal signal; a second signal processing path coupled to the sensing unit, the second signal processing path including a second compensation unit for adjusting the internal signal, the second path having a different sensitivity than the first path.

Abstract: In one aspect, an electronic device includes a switching circuit connected to a resistance circuit and ground, the resistance circuit connected to a port and the port configured to be connected in series to an external resistor and a supply voltage. A voltage at the port is a first voltage that is less than the supply voltage if the switching circuit is enabled to be a closed circuit and the voltage at the port is a second voltage that is equal to the supply voltage if the switching circuit is enabled to be an open circuit.

Abstract: A method for use in a sensor includes generating a first signal by a first sensing module in response to a magnetic field associated with a rotating target, generating a base word based on the first signal, the base word including a first base bit that is generated by comparing respective components of the first signal, reversing a respective polarity of the first signal and offsetting the first signal, generating a test word based on the first signal, the test word being generated after the respective polarity of the first signal is reversed and the first signal is offset, the test word including a first test bit that is generated by comparing the respective components of the first signal, and setting a value of an error signal based on whether the test word matches the base word.

Abstract: In one aspect, a magnetic-field sensor includes main coil circuitry configured to generate a first magnetic field signal at a first frequency. A reflected signal is generated from a target caused by the first signal generated by the main coil circuitry. The magnetic field sensor also includes magnetoresistance circuitry configured to receive an error signal. The error signal is formed from a combination of the reflected signal and a second magnetic field signal. The magnetic-field sensor further includes analog circuitry configured to receive an output signal from the magnetoresistance circuitry, digital circuitry configured to receive an output signal from the analog circuitry, a mixer configured to receive a feedback signal from one of the digital circuitry or the analog circuitry, and secondary coil circuitry configured to receive a driver signal from the mixer causing the secondary coil circuitry to generate the second magnetic field signal at the first frequency.

Abstract: A method for testing a signal path in a sensor, the signal path including a filter circuit and a comparator circuit, the method including: closing a first signal line that is arranged to bypass a first capacitor in the filter circuit; injecting a test signal into the signal path after the first signal line is closed; and detecting whether a signal that is output by the comparator circuit in response to the test signal satisfies a predetermined condition.

Abstract: Methods and apparatus for a current sensor having an elongate current conductor having an input and an output and a longitudinal axis. First, second, third and fourth magnetic field sensing elements are coupled in a bridge configuration and positioned in a plane parallel to a surface of the current conductor such that the second and fourth magnetic field sensing elements comprise inner elements and the first and third magnetic field sensing elements comprise outer elements. Embodiments of the sensor reduce the effects of stray fields on the sensor.

Abstract: In one aspect, an integrated circuit (IC) includes a magnetic-field sensor. The magnetic-field sensor includes digital circuitry that includes a first and second analog-to-digital converter (ADC). The digital circuitry is configured to receive a first and second analog output signals and, using the first and second ADC, configured to convert the first and second analog output signals to a first and second digital signals. The magnetic-field sensor also includes diagnostic circuitry configured to receive, from the digital circuitry, an input signal related to the first and/or the second digital signals and configured to provide a test signal at a pin of the IC. In response to a range parameter, the diagnostic circuitry is further configured to provide the test signal comprising a range of codes from the first and/or the second ADC corresponding to the range parameter.

Abstract: A method includes forming a plurality of identical arrays on a semiconductor wafer, each array having a plurality of detectors, screening each of the plurality of arrays to determine an operational status of each of the plurality of arrays, and selecting one of the plurality of arrays for use based on the determination of the operational status of the plurality of arrays. Also described is a focal plane array including a circuit having a plurality of electrical contacts and a die including a plurality of identical arrays, each including a plurality of detectors. The plurality of identical arrays includes at least one selected array that is fully functional and at least one non-selected array that is not fully functional and the selected array is positioned with respect to the circuit so that the detectors of the selected array contact the plurality of electrical contacts of the circuit.

Abstract: According to some embodiments, a device includes: a magnetic field current sensor magnetically coupled to a conductor and configured to generate a magnetic field signal having a magnitude responsive to a current flowing through the conductor; a shunt interface having first and second input terminals electrically coupled to ends of a shunt disposed along the conductor, the shunt interface configured to generate a shunt signal having a magnitude responsive to the current flowing through the conductor; and a diagnostic circuit configured to receive the magnetic field signal and the shunt signal and to generate a fault signal based on a comparison between the magnitude of the magnetic field signal and the magnitude of the shunt signal.

Abstract: An electronic circuit can have a first plurality of vertical Hall elements and a second plurality of vertical Hall elements all disposed on a substrate having a plurality of crystal unit cells, wherein the first plurality of vertical Hall elements have longitudinal axes disposed within five degrees of parallel to an edge of the crystal unit cells, and wherein the second plurality of vertical Hall elements have longitudinal axes disposed between eighty-five and ninety-five degrees relative to the longitudinal axes of the first plurality of vertical Hall elements.

Abstract: A magnetic field sensor configured to sense a parameter associated with a rotatable target that affects a magnetic field includes at least one magnetic field sensing element that is arranged to generate a signal that is indicative of the magnetic field, a magnitude calculator responsive to the signal and configured to generate a magnitude signal indicative of a magnitude of the magnetic field, and a harmonic compensator responsive to the magnitude signal and configured to generate an estimate of a harmonic error of the signal and apply the estimate of the harmonic error of the signal to the signal to generate a corrected signal.

Abstract: In one aspect, a magnetic-field sensor includes main coil circuitry configured to generate a first magnetic field signal at a first frequency. A reflected signal is generated from a target caused by the first signal generated by the main coil circuitry. The magnetic field sensor also includes magnetoresistance circuitry configured to receive an error signal. The error signal is formed from a combination of the reflected signal and a second magnetic field signal. The magnetic-field sensor further includes analog circuitry configured to receive an output signal from the magnetoresistance circuitry, digital circuitry configured to receive an output signal from the analog circuitry, feedback circuitry configured to receive a feedback signal from one of the digital circuitry or the analog circuitry, and secondary coil circuitry configured to receive a driver signal from the feedback circuitry causing the secondary coil circuitry to generate the second magnetic field signal at the first frequency.

Abstract: A low dropout (LDO) voltage regulator includes a first LDO stage that receives a first supply voltage and is active during a first time interval and a second LDO stage that receives a second supply voltage and is active during a second time interval. An operational amplifier receives a feedback voltage based on the LDO output voltage and has an output at which an amplified feedback signal is provided to both the first and second LDO stages. A compensation capacitor is selectively coupled between the operational amplifier and either the first LDO stage or the second LDO stage. A current limit circuit includes a sense FET having a gate coupled to the gate of the LDO pass FET, a drain voltage replication circuit coupled between the drains of the pass FET and sense FET to replicate the pass FET drain voltage so that the sense current is indicative of load current when the pass FET is in a linear region, and a current comparator to compare the sense current to a predetermined current level.

Abstract: A sensor system and method use channel information to generate redundant angle measurements for sensing rotation of magnets about a given axis of rotation. It was observed that magnetic field strength on a circle, centered on the axis of rotation but in a plane perpendicular to it, have a component parallel to the axis that varies sinusoidally as a function of the angle around the circle. By placing magnetic field sensors equiangularly around such a circle, and summing their field strengths with appropriate weights, the angle of magnet rotation may be computed in a manner that is immune to the presence of stray fields. Moreover, fewer than all channels of sense data may be combined to form redundant estimates of the angle of rotation, to permit continued operation when one of the sensors has failed.