An apparatus and a method for detecting a phase delay of a resolver are provided. The apparatus includes a resolver configured to output a signal corresponding to a rotation angle of a motor, an excitation signal generator configured to generate an excitation signal using a square wave signal, and a controller configured to differentiate the signal to obtain a differential signal, detect a time when the differential signal meets a reference voltage as a peak time of the signal, and detect a phase delay time of the signal based on the peak time of the signal and an edge time of the square wave signal.

According to some embodiments, a method implemented in electronic circuitry includes: receiving a first signal having a sinusoidal waveform; receiving a second signal having a sinusoidal waveform; generating a composite signal responsive to the first and second signals; determining an orthogonality adjustment coefficient based on a duty cycle of the composite signal; and applying the orthogonality adjustment coefficient to generate an adjusted second signal that is substantially orthogonal to the first signal.

A method for calibrating a position measurement system includes receiving measurement data from the position measurement system and determining that the measurement data includes periodic distortion data. The position measurement system includes a nonius track and a master track. The method also includes modifying the measurement data by decomposing the periodic distortion data into periodic components and removing the periodic components from the measurement data.

Implementations of a resolver sensor system may include a signal amplifier portion configured to be coupled to a magnetoresistive sensor coupled with a movable element where the signal amplifier portion configured to receive a sine signal and a cosine signal from the magnetoresistive sensor; and a sensor offset canceling portion coupled with a signal amplifier portion. The sensor offset canceling portion may be configured to generate a direct current offset correction signal to the signal amplifier portion which uses two or more amplifiers included in the signal amplifier portion to receive the sine signal and the cosine signal and to generate corresponding adjusted digital sine and cosine signals. The signal amplifier portion may be configured to provide the adjusted digital sine signal and the adjusted digital cosine signal to one of the servo signal processor or the system controller for use in determining a position of the movable element.

A method for authorizing an update of a switching threshold of a magnetic-field sensor for an internal combustion engine of a motor vehicle, in order to ensure an immunity of the sensor to external magnetic disturbances. The sensor detects magnetic-field variations induced by a passage of the teeth of a target in proximity to the sensor, by generating a magnetic signal exhibiting oscillations, certain of which may be due to magnetic disturbances and be not to be taken into account in the update by the sensor of the switching threshold, which is recomputed depending on a detected amplitude of at least two consecutive oscillations of the magnetic field. An update of the switching threshold is suspended when an oscillation frequency computed between the at least two consecutive oscillations is higher than a maximum oscillation frequency computed from a predetermined speed of rotation of the engine and from the number of teeth on the target.

An encoder and a signal processing method are disclosed. The method includes: receiving an analog signal, and generating a filtered analog signal by an analog filter according to the input signal and a first frequency indication signal; generating a digital signal by an analog-to-digital converter according to the filtered analog signal; generating a filtered digital signal by a digital filter according to the digital signal and a second frequency indication signal; generating a seventh signal and an eighth signal by a dynamic offset calibration unit according to the filtered digital signal and a period indication signal; and generating a position information by a position detection unit according to the seventh signal and the eighth signal. The first frequency indication signal, the second frequency indication signal and the period indication signal are generated by a frequency generation module according to the filtered analog signal or the digital signal.

A rotational angle sensor device and a corresponding method are provided. Two signals which have a phase offset with respect to one another are generated based on a modulated magnetic field using a sensor arrangement. Three signals which have a phase offset with respect to one another are generated from the signals.

A method including: calculating a value of an average phase offset between a first signal and a second signal, wherein: (i) the first signal is generated by one or more first magnetic field sensing elements in response to the magnetic field, (ii) the second signal is generated by one or more second magnetic field sensing elements in response to the magnetic field, and (iii) the magnetic field is associated with a rotating target; storing the value of the average phase offset between the first signal and the second signal at an address in a non-volatile memory of the sensor; when the sensor is restarted, copying the value of the average phase offset from the address in the non-volatile memory to a working memory of the sensor; and using the copy of the value of the average phase offset that is stored in the working memory of the sensor to generate an output signal, the output signal being generated further based on the first signal and the second signal.

A magnetic field sensor for detecting motion of an object includes one or more magnetic field sensing elements configured to generate a magnetic field signal in response to a magnetic field associated with the motion of the object and a detector responsive to the magnetic field signal and to a threshold signal and configured to generate a comparison signal having edges occurring in response to a comparison of the magnetic field signal to the threshold signal. A threshold generator is configured to generate the threshold signal at a first level when a peak-to-peak value of the magnetic field signal is greater than a first predetermined value and at a second level when the peak-to-peak value of the magnetic field signal is less than a second predetermined value different than the first predetermined value.

A process for determining the total pitch deviation of a position sensor fitted with a magnetic disk and a magnetic detector, the magnetic disk comprising pairs of magnetic poles, the process includes recording, over one mechanical turn, an angular signal of the magnetic intensity measured by the magnetic detector as a function of the angle of rotation of the magnetic disk, determining zero-crossing positions based on the angular signal recorded and the number of zero-crossing position determined, determining the pole pair lengths based on the zero-crossing positions, and determining the total pitch deviation based on the pole pair lengths.