Allegro Microsystems, LLC

Christian Feucht

Shaun D Milano

Alexander Latham

Wade Bussing

Andreas P Friedrich

Andrea Foletto

Thomas J Kovalcik

Systems and methods described herein are directed towards differential current sensing a current sensor having two or more magnetic field sensing elements that are oriented to sense a magnetic field generated by a current through an external conductor in the same direction. The current sensor can be positioned such that at least one first magnetic field sensing element is vertically aligned with the external conductor and at least one second magnetic field sensing element is not vertically aligned with the external conductor. The magnetic field sensing elements may be spaced from each to measure a gradient field and can generate a magnetic field signal indicative of a distance between the respective magnetic field sensing element and the current carrying external conductor. A difference between the magnetic field signals can be determined that is indicative of the current through the external conductor.

Systems and methods for current sensing

Systems and methods are described herein for reducing the effects of magnetic field cross-coupling in a multi-conductor current sensor system. A current sensor system includes one or more current sensors, each positioned proximate to at least one conductor and spaced from at least one other conductor. Each conductor carries a current intended to be measured by a respective current sensor. The current sensors include one or more magnetic field sensing elements to generate a magnetic field signal indicative of a detected magnetic field. A characterization measurement is performed to determine the coupling between each current sensor and the respective current conductor and to determine the coupling between the current sensor and the other ones of the current conductors, by providing a reference current to each of the conductors and measuring the outputs at each of the current sensors. The characterization measurement can be used to generate a coupling matrix.

Current sensor system

Apparatuses, systems, and methods that provide a delayed output signal with reduced sampling error are described. Embodiments include a clock circuit that generates a sample clock signal having a predetermined sample clock period. A sampling circuit may generate samples of a received signal during each sample clock period. An interpolation circuit may estimate a value of the received signal at times between the samples of the received signal based on at least a first sample and a second sample of the received signal. The interpolation circuit may estimate a time that the received signal crosses a threshold, and determine a time delta between the first sample and the estimated time that the received signal crosses the threshold. A delay circuit to generate a time delay substantially equal to the time delta is also included. An output signal changes state after the generated time delay.

Magnetic field sensor with delayed output

A magnetic field sensor for detecting motion of an object includes magnetic field sensing elements to generate at least two phase-separated magnetic field signals and a processor including a vector angle generator to generate vector angle values as a function of the magnetic field signals and a vector angle comparator to generate a comparator output signal indicative of a difference between a plurality of vector angle values. An output signal generator responsive to the comparator output signal is configured to generate a sensor output signal indicative of a one or more conditions of motion of the object including: an absence of normal rotation, a direction change, and a vibration. In some embodiments, the vector angle comparator may generate a comparator output signal indicative of a comparison of a vector angle value and one or more threshold values. In this case, the output signal generator may be configured to generate a sensor output signal indicative of a speed of motion and/or a position of the object.

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Annecy, France

Christian Feucht