Abstract: A motor control system is presented. The motor control system includes a motor controller and a motor driver. The motor controller and motor driver are coupled by an interface which includes a conductor configured to carry both a motor speed control signal from the motor controller to the motor driver and a motor feedback signal from the motor driver to the motor controller. The motor controller provides a motor speed control signal to the motor driver and the motor driver provides a motor feedback signal to the motor controller.
Type:
Grant
Filed:
June 17, 2014
Date of Patent:
February 28, 2017
Assignee:
Allegro Microsystems, LLC
Inventors:
Timothy Reynolds, Dennis Hwang, Walter Kim, Thomas Rowan
Abstract: A magnet includes a magnetic body having a length and width. The body has a first notch in one side and extending along at least a portion of the length of the body, and a second notch in an opposite side of the body extending along at least a portion of the length of the body. A magnetic field produced by the body has a substantially uniform magnetic flux along at least a portion of the length of the body. A system for detecting a target includes one or more magnetic field sensing elements positioned within the portion of the magnetic field having substantially uniform flux.
Abstract: A system for regulating voltage includes a power supply input node configured to receive a power supply voltage. The system also includes a voltage reduction circuit having an input node coupled to the power supply input node and an output node. The voltage reduction circuit is configured to generate a voltage at the output node that is lower than a voltage at the input node. The system also includes a voltage multiplier circuit having an input node and an output node and configured to generate a voltage its output node that is higher than a voltage at the input node of the voltage multiplier circuit. In embodiments, the voltage multiplier circuit may be a charge pump and the voltage reduction circuit may be a buck converter.
Abstract: A magnetic field sensor has an error correction signal generator circuit to inject an error correction signal into a primary signal channel to cancel an error signal component in the primary signal channel.
Abstract: An integrated circuit includes an output circuit having a first terminal adapted to couple to an external power supply, a second terminal adapted to couple to a reference potential, and a third, control terminal. The first and second terminals of the output circuit provide output terminals of the integrated circuit. The integrated circuit further includes an impedance measurement circuit responsive to the external power supply to generate a control signal for coupling to the control terminal of the output circuit. The control signal controls a current level associated with the output circuit. A corresponding method is also described.
Abstract: Method and apparatus for a current sensing device including a magnetoresistive magnetic field sensing element positioned with respect to a shaped conductor such that an applied field generated by current through the shaped conductor forms an offset angle theta defined by the applied field and a field of a pinning layer of the magnetoresistive element. The offset angle increases a linearity of the device output for current in the shaped conductor flowing in a first direction.
Abstract: A structure having collocated magnetic field sensing elements can be used to simultaneously determine magnetic field and mechanical stress. A primary magnetic field sensing element generates a primary signal responsive to a magnetic field and a secondary magnetic field sensing element generates a secondary signal responsive to mechanical stress. A system includes a stress compensation module to receive the primary and signals, and to compensate for mechanical stress in the primary signal.
Abstract: A magnetic field sensor and a method include a modulator coupled in a feedback arrangement and operable to modulate a calibration feedback signal with a modulator clock signal having a selected frequency and a selected relative phase operable to remove a gain error in the magnetic field sensor and in the method.
Abstract: A magnetic field sensor and a method include a modulator coupled in a feedback arrangement and operable to modulate a calibration feedback signal with a modulator clock signal having a selected frequency and a selected relative phase operable to remove a gain error in the magnetic field sensor and in the method.
Abstract: In one aspect, a system includes electrical components arranged in a daisy chain that include a first electrical component disposed at a first end of the daisy chain and a second electrical component disposed at an opposite end of the daisy chain than the first end. Each of the first and second electrical components includes an input port, an output port and a common port. The input port of the first electrical component is coupled to one of a supply voltage port or ground and the common ports of the first and second electrical components are coupled to the other one of the supply voltage or the ground. An address of the second electrical component is determined before addresses of the other of the electrical components are determined, and the addresses determine a position of an electrical component with respect to the other of the electrical components.
Abstract: A driver circuit for driving a switching transistor includes a dead time calibration circuit and/or a quick start circuit. The dead time calibration circuit includes a delay comparator to compare a present delay between the low side switch turning off or the high side switch turning off and a voltage at a switch node between the high side switch and the low side switch to a past delay and a controller responsive to the comparison is configured to adjust the delay of an adjustable delay element coupled to a control terminal of a switching transistor. The quick start circuit includes a quick start signal generator having an adjustable delay element to generate a quick start signal having a pulse to turn on the switching transistor for a quick start interval, a quick start comparator configured to monitor the quick start signal, and a control circuit responsive to the comparison by the quick start comparator to adjust the delay of the delay element.
Abstract: Method and apparatus for trimming a magnetic field sensor having a first magnetic field sensing element. In embodiments, trimming includes the use of a curve for normalized sensitivity of the first magnetic field sensing element derived from a first curve corresponding to current through a coil in a first direction at a first time to produce a field affecting the first magnetic field sensing element versus an external field and a second curve corresponding to current through the coil in a second direction opposite to the first direction at a second time to produce a field affecting the first magnetic field sensing element versus an external field.
Type:
Application
Filed:
July 17, 2015
Publication date:
January 19, 2017
Applicant:
ALLEGRO MICROSYSTEMS, LLC
Inventors:
Virag V. Chaware, Jesse Lapomardo, David J. Haas
Abstract: A vertical Hall Effect element includes a low voltage P-well region disposed at a position between pickups of a vertical Hall Effect element to result in an improved sensitivity of the vertical Hall Effect element. A method results in the vertical Hall Effect element having the improved sensitivity.
Abstract: Described embodiments provide a magnetic field sensor has a circular vertical Hall (CVH) sensing element with a plurality of vertical Hall elements disposed over a common implant region in a substrate. The magnetic field sensor generates output signals responsive to a magnetic field generated by a multi-pole magnet having a plurality of north poles and also a plurality of south poles. An angle sensor generates an angle signal representative of an angle of a direction component of the magnetic field. A pole pair counter generates a count signal representative of a count of a number of the pole pairs of the multi-pole magnet that move past the CVH sensing element. An angle interpolation module generates a reconstructed angle signal representative of an angular position of the multi-pole magnet relative to the CVH sensing element based upon the count signal and the angle signal. Corresponding methods are also described.
Abstract: A driver circuit for driving a switching transistor includes a dead time calibration circuit and/or a quick start circuit. The dead time calibration circuit includes a delay comparator to compare a present delay between the low side switch turning off or the high side switch turning off and a voltage at a switch node between the high side switch and the low side switch to a past delay and a controller responsive to the comparison is configured to adjust the delay of an adjustable delay element coupled to a control terminal of a switching transistor. The quick start circuit includes a quick start signal generator having an adjustable delay element to generate a quick start signal having a pulse to turn on the switching transistor for a quick start interval, a quick start comparator configured to monitor the quick start signal, and a control circuit responsive to the comparison by the quick start comparator to adjust the delay of the delay element.
Abstract: A driver circuit for driving one or more loads in a controlled manner includes multiple operational modes. In one mode, bypass switching may be used to adjust a drive signal applied to the one or more loads. In another mode, a DC-DC converter may be used to adjust the drive signal applied to the one or more loads. In at least one embodiment, the driver circuit is a light emitting diode driver circuit.
Abstract: A monitor circuit for monitoring a level of a first and second regulated source may monitor a voltage level of regulated voltages or a current level of regulated currents. In an embodiment, the monitor circuit includes circuitry responsive to a first regulated voltage and to a second regulated voltage. A first circuit responsive to the first regulated voltage and to the second regulated voltage generates a first error signal indicative of at least one of an overvoltage condition of the first regulated voltage and an undervoltage condition of the second regulated voltage. A second circuit responsive to the first regulated voltage and to the second regulated voltage generates a second error signal indicative of at least one of an undervoltage condition of the first regulated voltage and an overvoltage condition of the second regulated voltage. A method for monitoring the levels of first and second regulated sources is also provided.
Type:
Application
Filed:
June 24, 2015
Publication date:
December 29, 2016
Applicant:
ALLEGRO MICROSYSTEMS, LLC
Inventors:
Jay M. Towne, Sam Tran, P. Karl Scheller
Abstract: A magnetoresistance element has a double pinned arrangement with two antiferromagnetic pinning layers, two pinned layers, and a free layer. A spacer layer between one of the two antiferromagnetic pinning layers and the free layer has a material selected to allow a controllable partial pinning by the one of the two antiferromagnetic pinning layers.
Type:
Grant
Filed:
August 6, 2014
Date of Patent:
December 27, 2016
Assignee:
Allegro MicroSystems, LLC
Inventors:
Claude Fermon, Myriam Pannetier-Lecoeur, Marie-Claire Cyrille, Cyril Dressler, Paolo Campiglio
Abstract: A circuit includes a current source having at least first terminal and a second, control terminal. The current source is configured to receive a current control signal at the control terminal and in response thereto generates a first current signal at the first terminal. The current control signal controls a current level of the first current signal. The circuit also includes at least one sensing element responsive to one or more sense parameters and having an input adapted to couple to the first terminal of said current source. The sensing element is configured to receive one or more current signals comprising at least the first current signal and in response thereto generates a sensed output signal at an output thereof. A corresponding method for operating the circuit is also provided.
Type:
Grant
Filed:
April 27, 2015
Date of Patent:
December 20, 2016
Assignee:
Allegro MicroSystems, LLC
Inventors:
Jay M. Towne, P. Karl Scheller, Eric G. Shoemaker
Abstract: In one aspect, an integrated circuit (IC) is configured to receive an input signal. The IC includes a boost switch driver configured to provide a switching operation to a boost converter to drive a string of light emitting diodes (LEDs), a current sink driver connected to a current source and configured to provide a current signal to the string of LEDs, and a delay module configured to delay the current signal to the string of LEDs with respect to the input signal.