Abstract: Methods and apparatus for a DC-DC converter having input voltage feedforward for reducing the effects of input voltage signal transients. In embodiments, a feedback circuit receives an output voltage and generates a feedback signal and a modulation circuit receives the feedback signal and generates a control signal for a switching element configured to generate the output voltage, which is boosted from an input voltage. A feedforward module combines the input voltage and current information for an inductive energy storage element, which forms a boost circuit for generating the output voltage, and provides a feedforward signal to the modulation circuit. The modulation circuit can generate the control signal from a ramp signal and the feedforward signal.
Abstract: The present disclosure is directed to an electronic circuit having a Hall effect element and a resistor bridge, all disposed over a common semiconductor substrate. The resistor bridge includes a first set of resistive elements having a first vertical epitaxial resistor and a first lateral epitaxial resistor coupled in series, and a second set of resistive elements having a second vertical epitaxial resistor and a second lateral epitaxial resistor coupled in series. The first set of resistive elements and the second set of resistive elements can be coupled in parallel. The resistor bridge can be configured to sense a stress value of the Hall effect element.
Abstract: In one aspect, an integrated circuit (IC) includes a sensor that includes a first magnetoresistive (MR) element and a second MR element less active to a presence of a magnetic field than the first MR element. The second MR element includes a metal layer diffused into other layers of the second MR element.
Abstract: A control circuit for a voltage regulator includes a digital compensator having adaptive compensation to permit operation over different operating conditions. The digital compensator includes a gain parameter that is inversely proportional to the input voltage and is independent of the switching frequency. In embodiments, the voltage regulator has a crossover frequency established by at least one pole and at least one zero and the corner frequency of the converter output filter has a first fixed, predetermined relationship with respect to the switching frequency, a second fixed, predetermined relationship with respect to the crossover frequency, and a third fixed, predetermined relationship with respect to the at least one pole and at least one zero.
Abstract: A control circuit for generating a feedforward control signal based on an input voltage includes a divider coupled to the input voltage to generate a divided voltage and a first buffer responsive to the divided voltage to generate a buffered voltage at an output of the first buffer. The control circuit also includes a first capacitor coupled to the first buffer output and configured to generate a feedforward current when there is a variation in the input voltage and a current mirror circuit including a current mirror output node at which a current mirror output voltage indicative of the input voltage variation is generated. A digitizing circuit is responsive to the current mirror output voltage to generate the feedforward control signal. A DC-DC converter and a method for generating a feedforward control signal based on an input voltage are also provided.
Abstract: Methods and apparatus for a sensor having non-ratiometric fault trip level setting. In embodiments, a sensor has a sensing element with a fixed gain. A signal processing module receives the fault trip level setting and maintains the fault trip level setting constant during changes in the supply voltage.
Type:
Grant
Filed:
October 21, 2015
Date of Patent:
October 16, 2018
Assignee:
ALLEGRO MICROSYSTEMS, LLC
Inventors:
Alexander Latham, Stephen Marshall, Aaron Cook
Abstract: Method and apparatus for providing error compensation for a magnetic field sensing element in a three-phase motor. In embodiments, a driving angle is determined from zero-crossings of the magnet pole-pairs and error compensation levels for the pole-pairs is determined to reduce distortions in the motor current waveform.
Type:
Application
Filed:
March 23, 2017
Publication date:
September 27, 2018
Applicant:
Allegro MicroSystems, LLC
Inventors:
Yisong Lu, Christopher Alger, Lyndon Ambruson
Abstract: In one aspect, a magnetic field sensor includes a chopper stabilized amplifier and a plurality of Hall-type elements in parallel and connected to the chopper stabilized amplifier. In another aspect, a magnetic field sensor includes a chopper stabilized amplifier and a plurality of Hall quad elements in parallel and connected to the chopper stabilized amplifier. In a further aspect, a current sensor has a bandwidth of 1 MHz and includes a chopper stabilized amplifier and a plurality of Hall quad elements, fabricated in silicon, in parallel and connected to the chopper stabilized amplifier.
Type:
Application
Filed:
May 25, 2018
Publication date:
September 27, 2018
Applicant:
Allegro MicroSystems, LLC
Inventors:
David J. Haas, Michael Gaboury, Alexander Latham
Abstract: An isolation switch driver includes a control circuit to control conduction of an isolation switch and a voltage monitor circuit to monitor a control voltage coupled to the isolation switch and to generate a fault indication if the control voltage is less than a predetermined threshold. The isolator driver can drive an isolation switch coupled between a bridge network and a motor in a motor control system. The monitor circuit can monitor a voltage between a gate terminal and a source terminal of the isolation switch and include a resistive element coupled between the gate terminal and the source terminal to generate a current proportional to the VGS voltage, a current mirror to shift a level of the current to a reference potential, and a comparator to compare the level-shifted current to a threshold current.
Abstract: A magnetic field sensor and an associated method use one or more magnetoresistance elements driven with an AC mixing current and experiencing an AC mixing magnetic field to generate a DC voltage signal or a DC voltage signal component related to a slope of a transfer curve of the one or more magnetoresistance elements.
Type:
Grant
Filed:
September 30, 2015
Date of Patent:
September 18, 2018
Assignees:
Allegro MicroSystems, LLC, Commissariat à l'énergie atomique et aux énergies alternatives
Inventors:
Gerardo A. Monreal, Andreas P. Friedrich, Claude Fermon, Myriam Pannetier-Lecoeur
Abstract: A magnetic field sensor includes one or more magnetic field sensing elements configured to generate a magnetic field signal responsive to a magnetic field and a detector coupled to receive an interpolated threshold and a signal representative of the magnetic field signal, wherein the detector is configured to compare the interpolated threshold with the signal representative of the magnetic field signal to generate a detector output signal. A memory is configured to store a first threshold value indicative of a threshold value at a first temperature and a second threshold value indicative of a threshold value at a second temperature lower than the first temperature and a threshold module coupled to the memory and configured to generate the interpolated threshold based on the stored first and second threshold values.
Type:
Application
Filed:
May 10, 2018
Publication date:
September 13, 2018
Applicant:
Allegro MicroSystems, LLC
Inventors:
Devon Fernandez, Eric G. Shoemaker, Michael Morris, Dominik Weiland
Abstract: Methods and apparatus for a DC-DC converter having input voltage feedforward for reducing the effects of input voltage signal transients. In embodiments, a feedback circuit receives an output voltage and generates a feedback signal and a modulation circuit receives the feedback signal and generates a control signal for a switching element configured to generate the output voltage, which is boosted from an input voltage. A feedforward module combines the input voltage and current information for an inductive energy storage element, which forms a boost circuit for generating the output voltage, and provides a feedforward signal to the modulation circuit. The modulation circuit can generate the control signal from a ramp signal and the feedforward signal.
Abstract: Methods and apparatus embodiments to communicate data via a digital isolator by receiving an input data stream having first and second states, generating a first pulse train for the first state and a second pulse train for the second state. The first and second pulse types are transmitted across a voltage barrier of a digital signal isolator and received by a receive channel. The first and second pulse trains are processed to recover the input data stream in an output data stream. Data/System integrity functionality can identify fault conditions from an alteration of transmitted pulses.
Type:
Application
Filed:
March 1, 2018
Publication date:
September 13, 2018
Applicant:
Allegro MicroSystems, LLC
Inventors:
Alejandro Gabriel Milesi, Guillermo Stuarts, Juan Guido Salaya
Abstract: A signal isolator integrated circuit package includes a first die in a first voltage domain and a second die in a second voltage domain. The integrated circuit package also includes a first signal path from the first die to the second die via a first isolation barrier supported by the first die. The first isolation barrier includes a first conductive layer disposed over a surface of the first die and a first insulating layer disposed over the first conductive layer. The first isolation barrier also includes a second insulating layer disposed over the first insulating layer and a second conductive layer disposed over the second insulating layer. A first floating conductive plate is disposed between the first insulating layer and the second insulating layer.
Abstract: Methods and apparatus for a signal isolator having inductive and capacitive coupling. In embodiments, magnetic and electric fields are coupled by coils and capacitive plates. In embodiments, a floating plate can enable a top and bottom capacitive plate to be offset from each other.
Abstract: Methods and apparatus to provide an integrated circuit having a magnetic sensing element having differential first and second outputs and an input, the input to receive current and first and second switches coupled to a respective one of the differential first and second outputs. A first voltage source is coupled between the first and second switches, the first and second switches having a first state in which the first voltage source is coupled across the differential first and second outputs, and an IC output can output a voltage corresponding to the first voltage source when the first and second switches are in the first state for monitoring operation of a signal path from the magnetic sensing element to the IC output.
Type:
Grant
Filed:
December 22, 2014
Date of Patent:
September 11, 2018
Assignee:
ALLEGRO MICROSYSTEMS, LLC
Inventors:
Shaun D. Milano, Georges El Bacha, Michael C. Doogue, William P. Taylor
Abstract: A magnetic field sensor includes a semiconductor substrate, a circular vertical Hall (CVH) sensing element comprising a plurality of Hall elements arranged over an implant region in a semiconductor substrate, adjacent ones of the plurality of vertical Hall element at predetermined angles from each other. A CVH output stage may comprise one or more of drive circuits to drive the plurality of vertical Hall elements and produce an analog signal, and a filter coupled to the CVH output stage to receive the analog signal. The filter may be configured to remove a DC component from the analog signal to produce a filtered signal. An analog-to-digital converter may be coupled to receive the filtered signal and produce a digital signal. A processor stage may be coupled to receive the filtered signal and operable to compute an estimated angle of the external magnetic field.
Abstract: An integrated circuit can have a first substrate supporting a magnetic field sensing element and a second substrate supporting another magnetic field sensing element. The first and second substrates can be arranged in a variety of configurations. Another integrated circuit can have a first magnetic field sensing element and second different magnetic field sensing element disposed on surfaces thereof.
Type:
Grant
Filed:
December 30, 2016
Date of Patent:
September 4, 2018
Assignee:
Allegro MicroSystems, LLC
Inventors:
Michael C. Doogue, William P. Taylor, Vijay Mangtani
Abstract: A magnetic field sensor includes a magnetic field sensing element configured to generate a magnetic field signal; a measured threshold module configured to generate a measured threshold signal in accordance with positive peaks and negative peaks of the magnetic field signal; a memory device coupled to receive and configured to store, at each one of a plurality of storage times, a respective value of the measured threshold signal; a threshold module coupled to receive from the memory device, at a calculation time, a stored value of the measured threshold signal and configured to generate a calculated threshold value; and a comparison circuit coupled to receive the calculated threshold value and to receive the magnetic field signal. The comparison circuit is configured to compare the calculated threshold value with the magnetic field signal to generate an output signal. A corresponding method is associated with the magnetic field sensor.
Type:
Grant
Filed:
March 23, 2017
Date of Patent:
September 4, 2018
Assignee:
Allegro MicroSystems, LLC
Inventors:
Andrea Foletto, Peter Cisar, Eric Shoemaker
Abstract: A magnetic field sensor, a magnetic assembly, and a method provide circuits and techniques for or measuring one or more displacement angles of a magnet using magnetic field sensing elements. Applications include, but are not limited to, joysticks.
Type:
Grant
Filed:
January 30, 2017
Date of Patent:
September 4, 2018
Assignee:
Allegro Microsystems, LLC
Inventors:
Ali Husain Yusuf Sirohiwala, James Rice