Abstract: A motion sensor has an output protocol processor configured to provide a validated output signal after a determined time period, wherein the determined time period is extended if a vibration is detected.
Type:
Grant
Filed:
June 3, 2010
Date of Patent:
May 21, 2013
Assignee:
Allegro Microsystems, Inc.
Inventors:
Andrea Foletto, Devon Fernandez, Eric Burdette
Abstract: A magnetic field sensor includes built in self-test circuits that allow a self-test of most of, or all of, the circuitry of the magnetic field sensor, including self-test of a magnetic field sensing element used within the magnetic field sensor, while the magnetic field sensor is functioning in normal operation.
Type:
Grant
Filed:
February 16, 2010
Date of Patent:
May 21, 2013
Assignee:
Allegro Microsystems, Inc.
Inventors:
Andreas P. Friedrich, Andrea Foletto, Michael C. Doogue, William P. Taylor, Ravi Vig, P. Karl Scheller
Abstract: An integrated circuit sensor includes circuitry and methods for generating a high speed delay fault test clock signal. A trimmable oscillator generates a master clock signal for use by an output protocol processor to provide the sensor output signal. A fault test clock signal generator is responsive to the master clock signal and to a test trigger signal for generating the test clock signal having a launch pulse and a capture pulse, each having edges substantially coincident with like edges of pulses of the master clock signal and a spacing between launch and capture pulses established by the trimmable master clock signal.
Type:
Application
Filed:
November 7, 2011
Publication date:
May 9, 2013
Applicant:
Allegro Microsystems, Inc.
Inventors:
Glenn A. Forrest, Aaron Cook, Dana Briere, Devon Fernandez, Naota Nakayama
Abstract: Motor control circuits and associated methods to control an electric motor provide an ability to synchronize a rotational speed of the electric motor with an external clock signal, resulting in reduced jitter in the rotational speed of the electric motor.
Abstract: Motor control circuits and associated methods to control an electric motor provide a plurality of drive signal channels at the same phase, resulting in reduced jitter in the rotational speed of the electric motor.
Abstract: A switched capacitor notch filter for sampling an input signal using multiple sampling capacitors during multiple non-overlapping time periods. The charge from one set of sampling capacitors is averaged and transferred to the filter output during one non-overlapping time and the charge from another set of sampling capacitors is averaged and transferred to the filter output during a second non-overlapping time period.
Abstract: An integrated circuit and a method of making the integrated circuit provide a Hall effect element having a germanium Hall plate. The germanium Hall plate provides an increased electron mobility compared with silicon, and therefore, a more sensitive Hall effect element.
Type:
Grant
Filed:
February 19, 2010
Date of Patent:
February 26, 2013
Assignee:
Allegro Microsystems, Inc.
Inventors:
Harianto Wong, William P. Taylor, Ravi Vig
Abstract: A current sensor packaged in an integrated circuit package to include a magnetic field sensing circuit, a current conductor and an insulator that meets the safety isolation requirements for reinforced insulation under the UL 60950-1 Standard is presented. The insulator is provided as an insulation structure having at least two layers of thin sheet material. The insulation structure is dimensioned so that plastic material forming a molded plastic body of the package provides a reinforced insulation. According to one embodiment, the insulation structure has two layers of insulating tape. Each insulating tape layer includes a polyimide film and adhesive. The insulation structure and the molded plastic body can be constructed to achieve at least a 500 VRMS working voltage rating.
Abstract: A Hall effect element includes a Hall plate having geometric features selected to result in a highest ratio of a sensitivity divided by a plate resistance. The resulting shape is a so-called “wide-cross” shape.
Abstract: An electronic circuit and an associated method used to drive an electric motor provide a user selectable relationship between rotational speed of the electric motor and phase advances of signals used to drive the electric motor. By selecting the relationship, efficiency of the electric motor drive can be improved.
Abstract: A magnetic field sensor and a method associated with the magnetic field sensor provide gain correction coefficients and/or offset correction coefficients stored in the magnetic field sensor in digital form. The gain correction coefficients and/or offset correction coefficients can be used to generate analog control signals to control a sensitivity and/or an offset of an analog signal path through the magnetic field sensor.
Abstract: A magnetic field sensor includes a compensation loop coupled in series with normal circuit couplings in order to reduce a transient signal that would otherwise be generated when the magnetic field sensor experiences a high rate of change of magnetic field. In some embodiments, the magnetic field sensor is a current sensor responsive to a magnetic field generated by a current-carrying conductor.
Abstract: Presented is a sensor that includes a magnetoresistive (MR) sensing device to sense a magnetic field and to produce an AC signal voltage proportional to the sensed magnetic field. The sensor also includes circuitry, coupled to the MR sensing device, to remove DC offset from the AC signal voltage. The DC offset may be related to the hysteresis characteristics of the MR sensing device. To remove DC offset, the circuitry may obtain an averaged DC offset and subtract the averaged DC offset from the AC signal voltage to produce a sensor output signal.
Type:
Application
Filed:
August 21, 2012
Publication date:
December 13, 2012
Applicant:
Allegro Microsystems, Inc.
Inventors:
John Cummings, William P. Taylor, David J. Haas
Abstract: A circuit for driving an LED load with a controllable converter includes a control circuit configured to turn off the converter in response to a PWM signal having a first level and to turn on the converter in response to the PWM signal having a second level. A load disconnect switch coupled in series with the LED load is also controlled by the PWM signal so that the load disconnect switch is opened when the PWM signal turns off the converter to thereby open the load current path.
Abstract: A circuit to detect a movement of an object has a calibration time period that ends when peak detectors in the circuit stop updating for a predetermined amount of time. A method associated with the circuit is also described.
Abstract: A differential magnetic field sensor that enables operation that is independent of sensor-to-target orientation is presented. The differential magnetic field sensor is provided with at least two differential channels. Each differential channel includes a pair of magnetic field sensing elements and has a respective sensing axis defined by those magnetic field sensing elements. The sensing axes are not aligned with respect to each other. One sensing axis is positioned relative to a reference axis of a target profile to define an orientation angle between the sensing axis and the reference axis. The differential magnetic field sensor includes circuitry to produce differential signals associated with the differential channels and use those differential signals to produce a single differential signal having an amplitude that is independent of the orientation angle.
Abstract: A circuit for detecting object movement includes one or more predetermined threshold detectors, one or more tracking threshold detectors, and an output selector to generate an output signal related to at least one of an output of a predetermined threshold detector or an output of a tracking threshold detector based on a predetermined condition. A method of detecting object movement includes generating: a magnetic field signal proportional to a magnetic field associated with the object, a tracking signal to track peaks of the magnetic field signal, a predetermined threshold output signal responsive to the magnetic field signal and to a predetermined threshold, and a tracking threshold output signal responsive to the magnetic field signal and to the tracking signal, and providing an output signal related to a selected one of the predetermined threshold output signal or the tracking threshold output signal based upon a predetermined condition.
Type:
Application
Filed:
March 31, 2011
Publication date:
October 4, 2012
Applicant:
Allegro Microsystems, Inc.
Inventors:
Andreas P. Friedrich, Andrea Foletto, Ravi Vig
Abstract: An electronic circuit includes circuit portions for identifying a largest voltage drop through one of a plurality of series connected diode strings and for controlling a boost switching regulator according to the largest voltage drop. The electronic circuit can sense an open circuit series connected diode string, which would otherwise have the largest voltage drop, and can disconnect that open circuit series connected diode string from control of the boost switching regulator. Another electronic circuit includes a current limiting circuit coupled to or within a boost switching regulator and configured to operate with a diode load. Another electronic circuit includes a pulse width modulation circuit configured to dim a series connected string of light emitting diodes.
Abstract: Presented is a sensor that includes a magnetoresistive (MR) sensing device to sense a magnetic field and to produce an AC signal voltage proportional to the sensed magnetic field. The sensor also includes circuitry, coupled to the MR sensing device, to remove DC offset from the AC signal voltage. The DC offset may be related to the hysteresis characteristics of the MR sensing device. To remove DC offset, the circuitry may obtain an averaged DC offset and subtract the averaged DC offset from the AC signal voltage to produce a sensor output signal.
Type:
Grant
Filed:
February 27, 2008
Date of Patent:
September 18, 2012
Assignee:
Allegro Microsystems, Inc.
Inventors:
John Cummings, William P. Taylor, David J. Haas
Abstract: An electronic circuit includes a plurality of sensing elements configured to generate a plurality of sensing element signals. The electronic circuit also includes a control signal generator configured to generate a plurality of control signals. The electronic circuit also includes a combining circuit. The combining circuit includes a plurality of switching circuits. Each switching circuit is configured to generate a respective switching circuit output signal being representative of either a non-inverted or an inverted respective one of the plurality of sensing element signals depending upon the first state or the second state of a respective one of the plurality of control signals. The combining circuit also includes a summing circuit coupled to receive the switching circuit output and configured to generate a summed output signal corresponding to a sum of the switching circuit output signals.