Abstract: A magnetic field sensor can use a variety of different current spinning phase sequences, and/or can provide an angle error value to correct and/or minimize errors of the magnetic field sensor, A circuit using this magnetic field sensor can process output signals from an angle sensing element to provide an output signal that has a high degree of angle accuracy and a relatively high speed.
Abstract: A driver circuit for driving a switch includes a high output impedance driver circuit portion having a high impedance output node coupled to the control terminal of the transistor and a low output impedance driver circuit portion having a low impedance output node also coupled to the control terminal of the transistor. The slew rate of the control signal is established by at least one of the high impedance driver circuit portion and the low impedance driver circuit portion.
Abstract: Systems and methods for detecting a magnetic target include a plurality of magnetic field sensing elements arranged about a central point. Each one of the plurality of magnetic field sensing elements is configured to measure a magnetic field produced by a magnetic target and provide a respective output signal that represents a respective measurement of a strength of the magnetic field. A processor circuit is coupled to receive the output signal from each one of the plurality of magnetic field sensing elements and determine a barycenter of the measurements of the magnetic field based on a position of the magnetic field sensing elements.
Type:
Application
Filed:
December 23, 2014
Publication date:
June 23, 2016
Applicant:
ALLEGRO MICROSYSTEMS, LLC
Inventors:
Yannick Vuillermet, Andreas P. Friedrich, Andrea Foletto
Abstract: Methods and apparatus to provide a magnetic field sensor device including a magnetic sensor element, a die having wafer bumps, wherein the magnetic sensor element is positioned in relation to the die, and conductive leadfingers having respective portions electrically connected to the wafer bumps. In embodiments, the device includes a region about the magnetic sensor element that does not contain electrically conductive material for preventing eddy current flow.
Type:
Application
Filed:
February 22, 2016
Publication date:
June 16, 2016
Applicant:
ALLEGRO MICROSYSTEMS, LLC
Inventors:
Shaun D. Milano, Michael C. Doogue, William P. Taylor
Abstract: In one aspect, a direct connected silicon control rectifier (DCSCR) includes a substrate having a semiconductor surface, a parasitic PNP bipolar transistor and a parasitic NPN bipolar transistor formed in the semiconductor surface. The parasitic PNP bipolar transistor includes a p+ emitter, an nbase and a pcollector and the parasitic NPN bipolar includes an n+ emitter, a pbase and an ncollector. The DCSCR also includes an electrically conductive line connecting an n+ contact to the nbase to a p+ contact to the pbase so that the nbase and the pbase are shorted.
Type:
Grant
Filed:
February 13, 2015
Date of Patent:
June 14, 2016
Assignee:
Allegro Microsystems, LLC
Inventors:
Zhixin Wang, Juin Jei Liou, Ruei-Cheng Sun
Abstract: A magnetic field sensor for sensing an external magnetic field includes at least one magnetic field sensing element for measuring a magnetic field produced by a first magnetic field generating source and a current generator configured to receive one or more drive current signals at an input thereof and to generate a drive current signal having a periodic waveform and an amplitude offset at an output thereof. Also included is a second magnetic field generating source configured to receive the drive current signal at an input thereof and in response thereto, provide a magnetic field to the at least one magnetic field sensing element. Additionally included is a comparator configured to receive a reference voltage as a first input and an output signal from the at least one magnetic field sensing element as a second input, and in response thereto to generate a comparator output signal having a duty cycle.
Abstract: In an embodiment, a circuit is configured to produce a magnetic field signal having a frequency spectrum. The circuit may also produce a temperature signal. A modulation circuit may modulate the temperature signal with a frequency outside the frequency spectrum of the magnetic field signal. The modulated signal and the magnetic field signal may be combined to produce a combined signal. A separation circuit may be configured to separate component signals from the combined signal. The separation circuit may include a first filter, which, when applied to the combined signal, produces a filtered signal; a modulation circuit configured to shift the data representing the temperature signal to a baseband frequency; and a second filter configured to separate the data representing the temperature signal from the combined signal.
Type:
Grant
Filed:
December 26, 2012
Date of Patent:
May 31, 2016
Assignee:
Allegro Microsystems, LLC
Inventors:
Mathew Drouin, Devon Fernandez, William P. Taylor
Abstract: A magnetic field sensor includes a plurality of magnetic field sensing elements, wherein the plurality of magnetic field sensing elements is configured to generate a plurality of magnetic field signals, each magnetic field sisal responsive to a magnetic field. The magnetic field sensor additionally includes a sequence switches circuit coupled to the plurality of magnetic field sensing elements. The sequence switches circuit is configured to sequentially select from among the plurality of magnetic field signals to generate a sequenced output signal representative of sequentially selected ones of the plurality of magnetic field signals. The magnetic field sensor also includes a variable potentiometer coupled to the sequence switches circuit. The magnetic field sensor additionally includes a gain circuit coupled to receive a signal representative of the offset attenuated sequenced output signal. A corresponding method is also provided.
Abstract: An apparatus and method for measuring battery voltage includes a first capacitor configured to receive a charge from a battery. A first switch may be configured to selectively couple the first capacitor to the battery. A second capacitor may be coupled to a reference potential. A second switch may be configured to selectively couple the second capacitor to the first capacitor to transfer at least a portion of the charge on the first capacitor to the second capacitor.
Abstract: A magnetic field sensor includes at least one magnetic field sensing element configured to generate a measured magnetic field signal responsive to an external magnetic field and to generate a reference magnetic field signal responsive to a reference magnetic field and a calibration circuit configured to divide the measured magnetic field signal by the reference magnetic field signal to generate a calibrated magnetic field signal. The calibrated signal has reduced susceptibility to stress influences.
Abstract: Methods and apparatus for processing a signal comprise at least one circuit configured to generate a measured signal during a measured time period and a reference signal during a reference time period. Also included is at least one dual- or multi-path analog-to-digital converter comprising at least a first processing circuit configured to process the measured signal, at least a second processing circuit configured to process the reference signal, and a third processing circuit configured to process both the measured signal and the reference signal.
Abstract: Methods and apparatus for processing a signal comprise at least one circuit configured to generate a measured signal during a measured time period and a reference signal during a reference time period. Also included is at least one dual- or multi-path analog-to-digital converter comprising at least a first processing circuit configured to process the measured signal, at least a second processing circuit configured to process the reference signal, and a third processing circuit configured to process both the measured signal and the reference signal.
Abstract: In one aspect, a circuit includes a switching regulator configured to provide power to a load, a current regulator circuit coupled to the load and a response circuit configured to provide a control signal to the switching regulator in response to electrical changes of the current regulator circuit. The control signal changes non-linearly with respect to the electrical changes at the current regulator circuit. In another aspect, a circuit includes an adaptive regulation voltage circuit configured to provide a regulation voltage to a first input of an amplifier to maintain operability of a current regulator circuit. The adaptive regulation voltage circuit replicates electrical characteristics of the current regulator circuit.
Type:
Grant
Filed:
January 6, 2014
Date of Patent:
May 10, 2016
Assignee:
Allegro Microsystems, LLC
Inventors:
Gregory Szczeszynski, Matthew Szaniawski
Abstract: A magnetic field sensor has a plurality of magnetic field sensing elements and operates as a motion detector for sensing a rotation or other movement of a target object.
Abstract: A magnetic field sensor for detecting motion of an object includes error detection circuiting and processing. Magnetic field sensing elements are configured to generate at least two magnetic field signals in response to a magnetic field associated with the object which signals are used by detectors to generate right and left channel signals with edges indicative of motion of the object. A direction calculation processor responsive to right and left channel signals generates a direction signal having a state indicative of a direction of motion of the object and an output signal generator generates an output signal having a pulse indicative of the direction of motion of the object in response to the direction signal. An error detection processor responsive to the output signal and to the direction signal is configured to detect an error in at least one of the direction signal and the output signal.
Type:
Application
Filed:
October 31, 2014
Publication date:
May 5, 2016
Applicant:
Allegro Microsystems, LLC
Inventors:
Steven E. Snyder, Craig McConnell, Peter G. Wells
Abstract: A magnetic field sensor operates as a motion detector for sensing a movement of a ferromagnetic target object having features. The magnetic field sensor has a plurality of magnetoresistance elements to generate, in a first channel, a feature signal indicative of a proximity of a feature of a ferromagnetic target object and, in a second channel, an edge signal indicative of a proximity of an edge of a feature of a ferromagnetic target object.
Type:
Application
Filed:
October 31, 2014
Publication date:
May 5, 2016
Applicant:
ALLEGRO MICROSYSTEMS, LLC
Inventors:
Andrea Foletto, Jeffrey Eagen, Paul A. David
Abstract: A magnetic field sensor operates as a motion detector for sensing a movement of a ferromagnetic target object having features. The magnetic field sensor has a plurality of magnetoresistance elements to generate, in a first channel, a feature signal indicative of a proximity of a feature of a ferromagnetic target object and, in a second channel, an edge signal indicative of a proximity of an edge of a feature of a ferromagnetic target object.
Type:
Application
Filed:
October 31, 2014
Publication date:
May 5, 2016
Applicant:
ALLEGRO MICROSYSTEMS, LLC
Inventors:
Andrea Foletto, Yannick Vuillermet, Andreas P. Friedrich
Abstract: 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.
Type:
Application
Filed:
October 31, 2014
Publication date:
May 5, 2016
Applicant:
ALLEGRO MICROSYSTEMS, LLC
Inventors:
Christian Feucht, Andreas P. Friedrich, Andrea Foletto
Abstract: Electronic circuits used in magnetic field sensors use transistors for passing a current through the transistors and also through a magnetoresistance element.
Type:
Application
Filed:
October 31, 2014
Publication date:
May 5, 2016
Applicant:
Allegro MicroSystems, LLC
Inventors:
Mathew Drouin, Devon Fernandez, Jay M. Towne, Alejandro G. Milesi
Abstract: Presented herein is a magnetic field sensor architecture that uses outputs of a peak detector and threshold detector operating in parallel to detect magnetic anomalies that may be associated with the target being sensed, e.g., a rotational ferromagnetic object such as a toothed gear, and use such detection to prevent sensor malfunction. The sensor includes an edge detection circuit and an error detection circuit. In one embodiment, the edge detection circuit includes circuits to detect edges (or transitions) of the threshold and peak detector output signals and the error detection circuit includes circuits, responsive to the edge detection circuit, to indicate an error when a “missed transition” occurs or a peak-to-peak value of an input signal as detected by the peak detector for a current cycle differs from an expected peak-to-peak value by a predetermined amount.
Type:
Grant
Filed:
May 31, 2012
Date of Patent:
May 3, 2016
Assignee:
Allegro Microsystems, LLC
Inventors:
Andrea Foletto, Michael Morris, Mathew Drouin, Devon Fernandez, Andreas P. Friedrich, P. Karl Scheller