John L Willis

US Patent:

6768443, Jul 27, 2004

Filed:

Nov 30, 2000

Appl. No.:

09/728027

Inventors:

John Willis - Austin TX 78749

International Classification:

H03M 112

US Classification:

341172, 341161

Abstract:

An improved switch capacitor circuit includes a capacitor, a 1st voltage reference module, a 2 voltage reference module, and a plurality of switching elements. The capacitor is operably coupled via the plurality of switching elements to sample an input signal during a 1 interval of a sampling period and during a 2 interval of the sampling period to provide a representation of the input signal. The 2 reference module produces a 2 reference voltage that is representative of the common mode of the supply (e. g. V and V ). The 1 voltage reference module produces a 1 reference voltage that is representative of the common mode of the analog input signal. As such, the capacitor is charged during the 1 interval based on the 1 reference voltage and discharged during the 2 interval based on the 2 reference voltage.

US Patent:

6859156, Feb 22, 2005

Filed:

Jun 25, 2003

Appl. No.:

10/603545

Inventors:

Marcus W. May - Austin TX, US
John Willis - Austin TX, US

Assignee:

Sigmatel, Inc. - Austin TX

International Classification:

H03M001/66
G05F001/10
G05F003/22

US Classification:

341144, 323314, 327540

Abstract:

A variable bandgap reference includes a fixed bandgap reference source and a supply voltage dependent voltage divider module. The fixed bandgap produces a fixed reference voltage. The supply voltage dependent voltage adjust module adjusts the fixed reference voltage to produce the reference voltage.

US Patent:

6965334, Nov 15, 2005

Filed:

Sep 17, 2004

Appl. No.:

10/944510

Inventors:

Marcus W. May - Austin TX, US
John Willis - Austin TX, US

Assignee:

Sigmatel, Inc. - Austin TX

International Classification:

H03M001/66
G05F001/10

US Classification:

341144, 327536, 323315

Abstract:

A variable bandgap reference includes a fixed bandgap reference source and a supply voltage dependent voltage divider module. The fixed bandgap produces a fixed reference voltage. The supply voltage dependent voltage adjust module adjusts the fixed reference voltage to produce the reference voltage.

US Patent:

7135909, Nov 14, 2006

Filed:

May 17, 2005

Appl. No.:

11/130946

Inventors:

John Willis - Austin TX, US

Assignee:

Sigmatel, Inc. - Austin TX

International Classification:

H03K 17/78

US Classification:

327512, 374178

Abstract:

A method and system for sensing the temperature of an integrated circuit are presented. The method compares a first current that is proportional to a temperature reading of the integrated circuit to a reference current. While the first current is greater than the reference current, a counter is incremented, and the reference current is increased in response to incrementing the counter. A system for sensing the temperature of an integrated circuit includes a first current source providing a source current to a node. The first current source is based on an input from a proportional to absolute temperature device. The system also includes a second current source providing a sink current to the node, with the amount of sink current being based on an input from a digital control module. The system also includes a comparator coupled to the node to provide a comparator signal that indicates a relationship between the source current and the sink current.

US Patent:

7372967, May 13, 2008

Filed:

Nov 26, 2003

Appl. No.:

10/723170

Inventors:

Matthew Brady Henson - Austin TX, US
Marcus W. May - Austin TX, US
John Willis - Austin TX, US

Assignee:

Sigmatel, Inc. - Austin TX

International Classification:

H04R 3/00

US Classification:

381111, 381113, 381112, 381122, 381 92

Abstract:

A microphone bias circuit includes a first integrated circuit (IC) pin, a second IC pin, a first resistor, and a variable supply voltage buffer. The first resistor is operably coupled to the first IC pin and a return voltage. The second IC pin is operably coupled to receive analog signals from a microphone. The variable supply voltage buffer is operably coupled to produce a buffered supply voltage based on a variable impedance setting, wherein at least one off-chip component couples the second IC pin to the first IC pin and wherein the variable supply voltage buffer provides the buffered supply voltage to second IC pin as a microphone bias voltage.

US Patent:

7388808, Jun 17, 2008

Filed:

Sep 23, 2004

Appl. No.:

10/947745

Inventors:

Shu-Schung Lee - Houston TX, US
John Willis - Houston TX, US
Yeashung Lin - Sugar Land TX, US

Assignee:

PGS Americas, Inc. - Houston TX

International Classification:

G01V 1/36

US Classification:

367 50, 367 51, 367 52, 367 53, 367 73

Abstract:

A method is disclosed for depth migrating seismic data. The method includes pre-stack time migrating the seismic data to form a stacked, time migrated image. The stacked, time migrated image is demigrated, and post-stack depth migration is then performed on the demigrated image. In some embodiments, the pre-stack time migration and the demigration account for ray bending in vertically transversely isotropic media.

US Patent:

7459955, Dec 2, 2008

Filed:

Sep 27, 2006

Appl. No.:

11/527914

Inventors:

John Willis - Austin TX, US

Assignee:

Sigmatel, Inc. - Austin TX

International Classification:

H01L 35/00

US Classification:

327512, 374178

Abstract:

A method and system for sensing the temperature of an integrated circuit are presented. The method compares a first current that is proportional to a temperature reading of the integrated circuit to a reference current. While the first current is greater than the reference current, a counter is incremented, and the reference current is increased in response to incrementing the counter. A system for sensing the temperature of an integrated circuit includes a first current source providing a source current to a node. The first current source is based on an input from a proportional to absolute temperature device. The system also includes a second current source providing a sink current to the node, with the amount of sink current being based on an input from a digital control module. The system also includes a comparator coupled to the node to provide a comparator signal that indicates a relationship between the source current and the sink current.

US Patent:

7609585, Oct 27, 2009

Filed:

Jul 28, 2006

Appl. No.:

11/495445

Inventors:

Junru Jiao - Katy TX, US
David Richard Lowrey - Houston TX, US
John Frier Willis - Houston TX, US
Daniel Solano - Spring TX, US

Assignee:

PGS Geophysical AS - Lysaker

International Classification:

G01V 1/00

US Classification:

367 50, 367 73

Abstract:

A method for interpreting seismic data below a salt layer includes depth migrating the seismic data to a bottom of the salt layer. The migrating including generating an initial model of velocities below the salt layer. The initial model is scaled by a plurality of scale factors at at least one image position. At least one of the plurality of scale factors for which a depth migrated image below the salt layer is optimum is selected as the scale factor.

Address:

5413 Meg Brauer Way, Austin, TX 78749

VIN:

1HGCM56897A106366

Make:

HONDA

Model:

ACCORD

Year:

2007

Address:

23311 Kobi Park Ct, Spring, TX 77373

Phone:

2819076142

VIN:

3GCEC14X37G178369

Make:

CHEVROLET

Model:

SILVERADO 1500 CLASSIC

Year:

2007