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: 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: 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 a plurality of drive signal channels at the same phase, 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 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: 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: Circuits and methods provide an ability to track a direction of a magnetic field, and, more particular, to track a direction of a rapidly rotating magnetic field. The circuits and methods use a plurality of magnetic field sensing elements, for example, as may be embodied in a circular vertical Hall (CVH) sensing element. However, the circuits and methods can track the direction of the sensed magnetic field by processing at any time fewer than all of the plurality of magnetic field sensing elements, for example, one or two of the plurality of magnetic field sensing elements.
Abstract: A magnetic field sensor includes a circular vertical Hall (CVH) sensing element and at least one planar Hall element. The CVH sensing element has contacts arranged over a common implant region in a substrate. In some embodiments, the at least one planar Hall element is formed as a circular planar Hall (CPH) sensing element also having contacts disposed over the common implant region. A CPH sensing element and a method of fabricating the CPH sensing element are separately described.
Type:
Application
Filed:
September 7, 2011
Publication date:
March 7, 2013
Applicant:
ALLEGRO MICROSYSTEMS, INC.
Inventors:
Andreas P. Friedrich, Andrea Foletto, Gary T. Pepka
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 magnetic field sensor and a method used therein provide a measured signal representative of an angular speed of rotation of a target object. The magnetic field sensor, in accordance with the measured speed of rotation, can automatically change various characteristics of the magnetic field sensor.
Type:
Application
Filed:
August 19, 2011
Publication date:
February 21, 2013
Applicant:
ALLEGRO MICROSYSTEMS, INC.
Inventors:
Mark J. Donovan, Michael C. Doogue, Ryan Metivier
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: 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 integrated circuit (IC) current sensor that self-calibrates to adjust its signal gain when employed in a current divider configuration is presented. The current sensor includes an integrated current conductor, a magnetic field transducer, a controllable gain stage and a calibration controller. The integrated current conductor is adapted to receive a portion of a calibration current. The calibration current corresponds to a full scale current. The magnetic field transducer, responsive to the calibration current portion, provides a magnetic field signal having a magnitude proportional to a magnetic field generated by the calibration current portion. The controllable gain stage is configured to amplify the magnetic field signal with an adjustable gain to provide an amplified magnetic field signal.
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: 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: An electronic circuit, referred to as an on-time extension circuit herein, provides an ability to adjust a power delivered to a load by pulsing a predetermined current to the load. The on time of the a DC-DC converter used to provide the power iS extended to be longer than the on time of the current pulse when the on time of the current pulses becomes very short.
Abstract: Circuits and methods used therein provide an adjustable average current through a load in accordance with a pulse width modulated (PWM) signal. A condition detection circuit is configured to identify a condition of the electronic circuit and to generate a condition signal indicative of the condition. A current extension circuit is coupled receive the condition signal and coupled to receive the PWM signal. The current extension circuit is configured to generate, at the output node of the current extension circuit, an extended PWM signal having a first state and a second state. The first state of the extended PWM signal longer in time than a first state of the PWM signal by an amount related to a value or a state of the condition signal. Current pulses through the load are extended to be longer in accordance with the extended PWM signal.
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.