Abstract: Apparatus includes an ADC configured to convert an analog signal to a digital signal, a comparator having a first input responsive to the analog signal, a second input responsive to the digital signal, and an output at which a comparison signal is provided, and an output checker configured to process the comparison signal to generate a fault signal indicative of whether a fault has occurred in the ADC. The comparator can be an analog comparator in which case the digital signal is converted to an analog signal for the comparison or a digital comparator in which case an additional ADC is provided to convert the analog signal into a digital signal for the comparison. Embodiments include more than one ADC in which case summation elements are provided to sum the analog signals and the digital signals for the comparison.

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.

Abstract: Apparatus includes an ADC configured to convert an analog signal to a digital signal, a comparator having a first input responsive to the analog signal, a second input responsive to the digital signal, and an output at which a comparison signal is provided, and an output checker configured to process the comparison signal to generate a fault signal indicative of whether a fault has occurred in the ADC. The comparator can be an analog comparator in which case the digital signal is converted to an analog signal for the comparison or a digital comparator in which case an additional ADC is provided to convert the analog signal into a digital signal for the comparison. Embodiments include more than one ADC in which case summation elements are provided to sum the analog signals and the digital signals for the comparison.

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: 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: 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 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.

Abstract: A data storage circuit for storing data from volatile memory in response to a power loss, the data storage circuit including an input for receiving a power loss signal in response to a power loss from at least one power source, an input configured to receive data from a volatile memory, a single block of non-volatile matrix of memory cells and a driver circuit coupled to said single row of non-volatile matrix of memory cells. The driver circuit is configured to write data to and read data from said single block of non-volatile matrix of memory cells. The single block of non-volatile matrix of memory cells can be provided as a single row electrically erasable programmable read only memory (EEPROM).

Abstract: A magnetic field sensor is provided with improved stress compensation accounting for temperature. The magnetic field sensor includes a stress sensing, element, a temperature sensing element, a magnetic field sensing element, a memory, and an electronic circuitry. The memory is configured to store a first table. The first table identities a plurality of stress-to-sensitivity coefficients. Each of the plurality of stress-to-sensitivity coefficients is mapped to a different temperature value. The electronic circuitry is configured to use a temperature reading and a stress reading to calculate a stress difference between an expected stress and the stress reading.

Abstract: A magnetic field sensor includes an analog front end having first and second magnetic field sensing elements arranged at approximately 90-degrees with respect to each other, a pre-processor and an arctangent processor. The first and second magnetic field sensing elements are arranged in a sideshaft orientation with respect to a rotating object and offset with respect to an axis of rotation of the rotating object, the rotating object having a radial axis and a tangential axis. The pre-processor is configured to receive the first and second magnetic field signals from the analog front end and to apply a correction factor to one or both of the first and second magnetic field signals to produce first and second scaled magnetic field signals. The arctangent processor is configured to calculate an arctangent value of the first and second scaled magnetic field signals.

Abstract: A data storage circuit for storing data from volatile memory in response to a power loss, the data storage circuit including an input for receiving a power loss signal in response to a power loss from at least one power source, an input configured to receive data from a volatile memory, a single block of non-volatile matrix of memory cells and a driver circuit coupled to said single row of non-volatile matrix of memory cells. The driver circuit is configured to write data to and read data from said single block of non-volatile matrix of memory cells. The single block of non-volatile matrix of memory cells can be provided as a single row electrically erasable programmable read only memory (EEPROM).

Abstract: A magnetic field sensor includes an analog front end having first and second magnetic field sensing elements arranged at approximately 90-degrees with respect to each other, a pre-processor and an arctangent processor. The first and second magnetic field sensing elements are arranged in a sideshaft orientation with respect to a rotating object and offset with respect to an axis of rotation of the rotating object, the rotating object having a radial axis and a tangential axis. The pre-processor is configured to receive the first and second magnetic field signals from the analog front end and to apply a correction factor to one or both of the first and second magnetic field signals to produce first and second scaled magnetic field signals. The arctangent processor is configured to calculate an arctangent value of the first and second scaled magnetic field signals.

Abstract: A data storage circuit for storing data from volatile memory in response to a power loss, the data storage circuit including an input for receiving a power loss signal in response to a power loss from at least one power source, an input configured to receive data from a volatile memory, a single block of non-volatile matrix of memory cells and a driver circuit coupled to said single row of non-volatile matrix of memory cells. The driver circuit is configured to write data to and read data from said single block of non-volatile matrix of memory cells. The single block of non-volatile matrix of memory cells can be provided as a single row electrically erasable programmable read only memory (EEPROM).

Abstract: A method is provided comprising: obtaining a temperature reading by using a temperature sensing element that is part of a magnetic field sensor; obtaining a stress reading by using a stress sensing element that is part of the magnetic field sensor; calculating a stress difference using the temperature reading and the stress reading, the stress difference including a difference between an expected stress associated with the temperature reading and the stress reading obtained from the stress sensing element; and adjusting a gain of a sensing element signal based on the stress difference, the sensing element signal being generated at least in part by a magnetic field sensing element that is part of the magnetic field sensor.

Abstract: A magnetic field sensor that detects an angle of a target includes a first channel having first and second magnetic field sensing elements that are orthogonal with respect to each other and produce first and second magnetic field signals, and a second channel having third and fourth magnetic field sensing elements that are orthogonal with respect to each other and produce third and fourth magnetic field signals. The third sensing element is positioned at an angle (e.g., 45-degrees) with respect to the first sensing element. The magnetic field sensor includes a low power mode circuit that uses comparators to compare the first, second, third, and fourth magnetic field signals to a first, second, third, and fourth threshold, respectively. A processor is configured to use an output of the low power mode circuit to determine the angle of the target.

Abstract: A data storage circuit for storing data from volatile memory to non-volatile memory is powered by a low power charge pump circuit that is independent of the power for the volatile memory and that is activated upon power loss. The low power charge pump circuit includes an amplifier, a voltage-controlled oscillator, a charge pump core, and a voltage divider. The amplifier outputs a current according to a voltage difference between a reference input voltage and a feedback voltage output from the voltage divider. The current is converted to a voltage that controls the oscillator, which outputs a series of pulses to power the charge pump core. The charge pump core in turn provides the output voltage, which may be used to power an attached load. The attached load may be a programming port for an EEPROM.

Abstract: A magnetic field sensor that detects an angle of a target includes a first channel having first and second magnetic field sensing elements that are orthogonal with respect to each other and produce first and second magnetic field signals, and a second channel having third and fourth magnetic field sensing elements that are orthogonal with respect to each other and produce third and fourth magnetic field signals. The third sensing element is positioned at an angle (e.g., 45-degrees) with respect to the first sensing element. The magnetic field sensor includes a low power mode circuit that uses comparators to compare the first, second, third, and fourth magnetic field signals to a first, second, third, and fourth threshold, respectively. A processor is configured to use an output of the low power mode circuit to determine the angle of the target.

Abstract: The systems and methods described can reduce high order temperature coefficients on the Hall plate sensitivity. A temperature coefficient circuit may include a first amplifier to receive a first reference voltage generated in conjunction with a proportional to absolute temperature (PTAT) device and a second amplifier to receive a second reference voltage generated in conjunction with a complementary to absolute temperature (CTAT) device, the second amplifier having a second output node. A plurality of resistors may be disposed in a signal path between output node of the first amplifier and an output node of the second amplifier. The plurality of resistors may be coupled to at least one voltage-to-current converter through one or more resistors taps. The voltage-to-current converter may generate at least one current signal that can be operable to apply a multiplication factor or a division divisor to an amplifier coupled to the voltage-to-current converter.

Abstract: A sensor integrated circuit can include sensors with differing levels of sensitivity, a first processing channel that responds to a first analog signal generated by a first sensor to generate a first processed signal, and a second processing channel that responds to a second analog signal generated by the second sensor to generate a second processed signal. Where the first sensor can include a pressure or optical sensing element, and the second sensor can include a pressure or optical sensing element. A checker circuit uses the processed signals to detect faults in the sensor integrated circuit.

Abstract: A sensor integrated circuit can include sensors with differing levels of sensitivity, a first processing channel that responds to a first analog signal generated by a first sensor to generate a first processed signal, and a second processing channel that responds to a second analog signal generated by the second sensor to generate a second processed signal. Where the first sensor can include a pressure or optical sensing element, and the second sensor can include a pressure or optical sensing element. A checker circuit uses the processed signals to detect faults in the sensor integrated circuit.