Matthew R Grant

US Patent:

7265504, Sep 4, 2007

Filed:

Jun 8, 2006

Appl. No.:

11/450232

Inventors:

Matthew Alan Grant - Palo Alto CA, US

Assignee:

Semtech Corporation - Camarilla CA

International Classification:

G05F 1/00

US Classification:

315308, 315224

Abstract:

A power supply for plural loads coupled in parallel comprises a voltage regulator, a plurality of current regulators, and an error control circuit. The voltage regulator provides a common output voltage to the plural loads. The voltage regulator comprises a sensor circuit providing a voltage sense signal corresponding to the output voltage, which provides feedback to regulate the output voltage at a selected level. The plurality of current regulators are coupled to respective ones of the plural loads. Each of the plurality of current regulators regulates current drawn by respective ones of the plural loads to within a desired regulation range. The plurality of current regulators each further provide a respective error signal corresponding to an ability to remain within the desired regulation range. The error control circuit is operatively coupled to the voltage regulator and to the plurality of current regulators. The error control circuit receives the error signals from the plurality of current regulators and provides a common error signal to the voltage regulator.

US Patent:

7522431, Apr 21, 2009

Filed:

Jul 31, 2007

Appl. No.:

11/888599

Inventors:

Steven Huynh - Sunnyvale CA, US
Matthew Grant - Palo Alto CA, US
David Kunst - Cupertino CA, US
Zhibo Tao - San Jose CA, US

Assignee:

Active-Semi International, Inc.

International Classification:

H02M 3/335

US Classification:

363 2112, 363 2105, 363 2113, 363 2115, 363 2116

Abstract:

A comparing circuit and a control loop are used to maintain the peak level of current flowing through an inductor of a flyback converter. An inductor switch control signal controls an inductor switch through which the inductor current flows. The inductor current increases at a ramp-up rate during a ramp time and stops increasing at the end of the ramp time. The comparing circuit generates a timing signal that indicates a target time at which the inductor current would reach a predetermined current limit if the inductor current continued to increase at the ramp-up rate. The control loop then receives the timing signal and compares the target time to the end of the ramp time. The pulse width of the inductor switch control signal is increased when the target time occurs after the end of the ramp time. Adjusting the pulse width controls the peak of the inductor current.

US Patent:

7667987, Feb 23, 2010

Filed:

Jul 26, 2007

Appl. No.:

11/881666

Inventors:

Steven Huynh - Sunnyvale CA, US
Matthew Grant - Palo Alto CA, US
David Kunst - Cupertino CA, US

Assignee:

Active-Semi, Inc.

International Classification:

H02M 3/335

US Classification:

363 2112, 363 2101, 363 2113, 363 2118

Abstract:

A comparing circuit and a control loop are used to maintain the peak level of current flowing through an inductor of a flyback converter. An inductor switch control signal controls a switch through which the inductor current flows. The inductor current increases at a ramp-up rate during a ramp time and stops increasing at the end of the ramp time. The comparing circuit generates a timing signal that indicates a target time at which the inductor current would reach a predetermined current limit if the inductor current continued to increase at the ramp-up rate. The control loop then receives the timing signal and compares the target time to the end of the ramp time. The pulse width of the inductor switch control signal is increased when the target time occurs after the end of the ramp time. Adjusting the frequency and pulse width controls the peak of the inductor current.

US Patent:

7679936, Mar 16, 2010

Filed:

Aug 14, 2007

Appl. No.:

11/893231

Inventors:

Steven Huynh - Sunnyvale CA, US
Matthew Grant - Palo Alto CA, US
David Kunst - Cupertino CA, US
Zhibo Tao - San Jose CA, US

Assignee:

Active-Semi, Inc.

International Classification:

H02M 3/335

US Classification:

363 16, 363 2102, 363 2112, 363 24

Abstract:

A comparing circuit and a control loop are used to maintain the peak level of current flowing through an inductor of a flyback converter. An inductor switch control signal controls a switch through which the inductor current flows. The inductor current increases at a ramp-up rate during a ramp time and stops increasing at the end of the ramp time. The comparing circuit generates a timing signal that indicates a target time at which the inductor current would reach a predetermined current limit if the inductor current continued to increase at the ramp-up rate. The control loop then receives the timing signal and compares the target time to the end of the ramp time. The pulse width of the inductor switch control signal is increased when the target time occurs after the end of the ramp time. Adjusting the frequency and pulse width controls the peak of the inductor current.

US Patent:

7697308, Apr 13, 2010

Filed:

Dec 3, 2008

Appl. No.:

12/315418

Inventors:

Steven Huynh - Sunnyvale CA, US
Matthew Grant - Palo Alto CA, US
David Kunst - Cupertino CA, US
Zhibo Tao - San Jose CA, US

Assignee:

Active-Semi, Inc.

International Classification:

H02M 3/335

US Classification:

363 2116, 363 2104, 363 2105, 363 2113, 323300

Abstract:

A comparing circuit and a control loop are used to maintain the peak level of current flowing through an inductor of a flyback converter. An inductor switch control signal controls an inductor switch through which the inductor current flows. The inductor current increases at a ramp-up rate during a ramp time and stops increasing at the end of the ramp time. The comparing circuit generates a timing signal that indicates a target time at which the inductor current would reach a predetermined current limit if the inductor current continued to increase at the ramp-up rate. The control loop then receives the timing signal and compares the target time to the end of the ramp time. The pulse width of the inductor switch control signal is increased when the target time occurs after the end of the ramp time. Adjusting the pulse width controls the peak of the inductor current.

US Patent:

7746673, Jun 29, 2010

Filed:

May 10, 2008

Appl. No.:

12/152035

Inventors:

Matthew A. Grant - Palo Alto CA, US
Zhibo Tao - San Jose CA, US

Assignee:

Active-Semi, Inc.

International Classification:

H02M 3/335

US Classification:

363 2118, 363 2112

Abstract:

A flyback AC/DC switching converter has a constant voltage (CV) mode. The CV mode has sub-modes. In one sub-mode (“mid output power sub-mode”), the output voltage (VOUT) of the converter is regulated using both pulse width modulation and pulse frequency modulation. Both types of modulation are used simultaneously. In a second sub-mode (“low output power sub-mode”), VOUT is regulated using pulse width modulation, but the converter switching frequency is fixed at a first frequency. By setting the first frequency at a frequency above the frequency limit of human hearing, an undesirable audible transformer humming that might otherwise occur is avoided. In some embodiments, the converter has a third sub-mode (“high output power sub-mode”), in which pulse width modulation is used but the switching frequency is fixed at a second frequency. By proper setting of the second frequency, undesirable EMI radiation and other problems that might otherwise occur are avoided.

US Patent:

7795761, Sep 14, 2010

Filed:

Dec 19, 2008

Appl. No.:

12/317223

Inventors:

Steven Huynh - Fremont CA, US
Matthew A. Grant - Palo Alto CA, US
Lin Chen - Mountain View CA, US

Assignee:

Active-Semi, Inc.

International Classification:

H01H 9/54

US Classification:

307140

Abstract:

A power converter having a switched capacitor buck/boost operation has first and second switches coupled to a first switching node, third and fourth switches coupled to a second switching node, a capacitor coupled between the first and second switching nodes, and an inductor coupled to the first switching node. A switch controller controls the switches to operate in voltage step-down mode and voltage step-up mode depending on a difference between converter output voltage VOUT and converter input voltage VIN. In a buck-optimized topology operating in a step-down mode, an output current flowing through the first switching node flows through only one switch at a given time. In a boost-optimized topology operating in a step-up mode, an output current flowing through the first switching node flows through only one switch at a given time. As a result, a more compact and efficient power converter may be realized at lower cost.

US Patent:

7869229, Jan 11, 2011

Filed:

Aug 28, 2007

Appl. No.:

11/897131

Inventors:

Steven Huynh - Sunnyvale CA, US
Matthew Grant - Palo Alto CA, US
David Kunst - Cupertino CA, US
Zhibo Tao - San Jose CA, US

Assignee:

Active-Semi, Inc.

International Classification:

H02M 3/335

US Classification:

363 2101, 363 2104, 363 2112, 34063612

Abstract:

A cord correction circuit in a primary-side-controlled flyback converter compensates for the loss of output voltage caused by the resistance of the charger cord. In one embodiment, a correction voltage is subtracted from a feedback voltage received from a primary-side auxiliary inductor. A pre-amplifier then compares a reference voltage to the corrected feedback voltage. In another embodiment, the correction voltage is summed with the reference voltage, and the pre-amplifier compares the feedback voltage to the corrected reference voltage. The difference between the voltages on the input leads of the pre-amplifier is used to increase the output voltage to compensate for the voltage lost through the charger cord. The flyback converter also has a comparing circuit and a control loop that maintain the peak level of current flowing through the primary inductor of the converter. Adjusting the frequency and pulse width of an inductor switch signal controls the converter output current.

Address:

1625 Mason Knl Rd, Saint Louis, MO 63131

VIN:

1GKFK63887J289310

Make:

GMC

Model:

YUKON

Year:

2007