Aaron A Cook

US Patent:

20230056740, Feb 23, 2023

Filed:

Aug 22, 2022

Appl. No.:

17/821257

Inventors:

- Kyoto, JP
John R. HOVERSTEN - Arlington MA, US
Yevgeniy A. TKACHENKO - Belmont MA, US
Aaron COOK - Deerfield NH, US
Kapil KESARWANI - Bedford NH, US

Assignee:

Murata Manufacturing Co., Ltd. - Kyoto

International Classification:

H02M 3/158
H02M 1/00

Abstract:

A circuit comprising a first capacitor configured to be charged to a voltage representing state information of a compensator, a second capacitor, a buffer circuit configured to charge the second capacitor to a voltage substantially equal to that of the first capacitor and a switching network configured to transition between a first state and a second state. When the switching network is in the first state, the second capacitor is charged to the voltage across the first capacitor. When the switching network is in the second state, the buffer circuit is disconnected from the second capacitor and the first capacitor and the second capacitor are connected in parallel.

US Patent:

20190302196, Oct 3, 2019

Filed:

Mar 27, 2018

Appl. No.:

15/936888

Inventors:

- Worcester MA, US
Aaron Cook - Deerfield NH, US

Assignee:

Allegro MicroSystems, LLC - Worcester MA

International Classification:

G01R 33/07
H01L 43/06
G01D 5/14
H01L 43/04

Abstract:

A magnetic field sensor includes a first magnetic field sensing element configured to generate a first magnetic field signal indicative of a magnetic field associated with a target, a second magnetic field sensing element spaced from the first magnetic field sensing element and configured to generate a second magnetic field signal indicative of the magnetic field associated with the target. A switching module coupled to receive the first and second magnetic field signals is configured to generate a combined signal having alternating portions associated with the first and second magnetic field signals. A polarity module coupled to receive the combined signal is configured to invert a polarity of portions of the combined signal associated with one of the first magnetic field signal or the second magnetic field signal to generate an inverted polarity signal and a filter coupled to receive the inverted polarity signal is configured to generate an averaged signal corresponding to an average of the first and second magnetic field signals.

US Patent:

20190018079, Jan 17, 2019

Filed:

Sep 11, 2018

Appl. No.:

16/127295

Inventors:

- Manchester NH, US
Stephen Marshall - Manchester NH, US
Aaron Cook - Deerfield NH, US

Assignee:

Allegro MicroSystems, LLC - Manchester NH

International Classification:

G01R 33/07
G01R 33/00

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.

US Patent:

20180011140, Jan 11, 2018

Filed:

Sep 20, 2017

Appl. No.:

15/710136

Inventors:

- Worcester MA, US
Aaron Cook - Deerfield NH, US
Craig S. Petrie - Merrimack NH, US

Assignee:

Allegro MicroSystems, LLC - Worcester MA

International Classification:

G01R 31/28
G01R 33/00
G01R 33/07
G01R 33/09

Abstract:

A magnetic field sensor comprises at least one magnetic field sensing element configured to generate a measured magnetic field signal responsive to an external magnetic field; a diagnostic circuit configured to generate a diagnostic signal, wherein the diagnostic signal is not dependent on a measured magnetic field; a signal path comprising an amplifier and an analog-to-digital converter for processing the measured magnetic field signal to generate a sensor output signal indicative of the external magnetic field during a measured time period and for processing the diagnostic signal during a diagnostic time period; and a switch coupled to receive the measured magnetic field signal and the diagnostic signal and direct the measured magnetic field signal to the signal path during the measured time period and direct the diagnostic signal to the signal path during the diagnostic time period.

US Patent:

20170269627, Sep 21, 2017

Filed:

Mar 16, 2016

Appl. No.:

15/071298

Inventors:

- Worcester MA, US
Aaron Cook - Deerfield NH, US

Assignee:

Allegro Microsystems, LLC - Worcester MA

International Classification:

G05F 3/26

Abstract:

A bandgap reference circuit includes a voltage reference circuit configured to generate a reference voltage at a first output and a proportional to absolute temperature (PTAT) current source configured to generate a PTAT current reference at a second output. A divider circuit is coupled to the reference voltage and configured to generate a divided reference voltage at a third output of the bandgap reference circuit. The bandgap reference circuit further includes a tunable current source coupled to the divider circuit and configured to generate a tunable current reference at a fourth output of the bandgap reference circuit based, at least in part, on the divider circuit. A method of generating a tunable current with a bandgap circuit is also provided.

US Patent:

20170115362, Apr 27, 2017

Filed:

Oct 21, 2015

Appl. No.:

14/918716

Inventors:

- Worcester MA, US
Stephen Marshall - Manchester NH, US
Aaron Cook - Deerfield NH, US

Assignee:

ALLEGRO MICROSYSTEMS, LLC - Worcester MA

International Classification:

G01R 33/07
G01R 33/00

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.

US Patent:

20160299199, Oct 13, 2016

Filed:

Apr 8, 2015

Appl. No.:

14/681575

Inventors:

- Worcester MA, US
Aaron Cook - Deerfield NH, US

Assignee:

ALLEGRO MICROSYSTEMS, LLC - Worcester MA

International Classification:

G01R 33/00
G01R 33/07

Abstract:

An electronic circuit can be disposed upon a semiconductor substrate. An epitaxial layer can be disposed over the semiconductor substrate. The electronic circuit can include a Hall effect element, at least a portion of the Hall effect element disposed in the epitaxial layer. The electronic circuit can further include a current generator configured to generate a drive current that passes through the Hall effect element. The current generator can include a resistor disposed in the epitaxial layer and having characteristics such that a resistance of the resistor can vary with a stress of the semiconductor substrate, resulting in changes of the drive current, to compensate for variations in the sensitivity of the Hall effect element with the stress of the substrate.