Alexander Fairgrieve from Sonora, CA, age 69

Us Patents

High Speed, Low-Power Cmos Circuit With Constant Output Swing And Variable Time Delay For A Voltage Controlled Oscillator
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US Patent:

6501317, Dec 31, 2002
Filed:

Apr 6, 2001
Appl. No.:

09/828398
Inventors:

Xijian Lin - Fremont CA
Barry Harvey - Los Altos CA
Alexander Fairgrieve - Menlo Park CA
Assignee:

Elantec Semiconductor, Inc. - Milpitas CA
International Classification:

H03K 522
US Classification:

327287, 327 65, 327266, 327280, 327274, 327309, 327318, 327327
Abstract:

A delay circuit is provided for use in a ring oscillator of a phase locked loop (PLL). The delay circuit includes a differential pair of NMOS transistors and with an NMOS transistor providing the tail current for the differential pair. Complementary NMOS and PMOS load transistors and provide loads for the differential transistor and. Transistors and together with an amplifier provide biasing for the delay device. The amplifier has a non-inverting input set to V -V. As configured, a constant output voltage swing from V to V -V is provided at the outputs V + and V - of the delay device, independent of a control voltage V used to set the tail current. The NMOS load transistor , as opposed to the PMOS transistor in FIG. , does not contribute to the gate parasitic capacitance enabling a high operation speed without consumption of more supply current. A wide frequency tuning range of a ring oscillator using the delay circuit of FIG.

Systems And Methods For Automatic Power Control Of Laser Diodes
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US Patent:

7061951, Jun 13, 2006
Filed:

Jul 2, 2003
Appl. No.:

10/612579
Inventors:

Alexander Fairgrieve - Menlo Park CA, US
D. Stuart Smith - San Jose CA, US
Theodore D. Rees - Mountain View CA, US
Bill R. Tang - San Jose CA, US
Assignee:

Elantec Semiconductor, Inc. - Milpitas CA
International Classification:

H01S 3/00
US Classification:

372 3802, 372 3801, 372 3807
Abstract:

Methods and system are provided for automatic power control of a laser diode, e. g. , in a laser driver. In accordance with an embodiment of the present invention, a power controller includes a detector circuit adapted to detect the output of the laser diode and to produce a measured output therefrom. A comparator compares a desired output to the measured output, and produces an error signal therefrom. The error signal is provided to an integrator circuit that produces an integrated error signal. At least one digital-to-analog converter (DAC) uses the integrated error signal to produce a current drive signal that drives the laser diode.

Adjustable Power Control For Laser Drivers And Laser Diodes
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US Patent:

7106769, Sep 12, 2006
Filed:

Feb 4, 2004
Appl. No.:

10/772051
Inventors:

Alexander Fairgrieve - Menlo Park CA, US
Assignee:

Elantec Semiconductor, Inc. - Milpitas CA
International Classification:

H01S 3/00
US Classification:

372 3804, 372 3807
Abstract:

Methods and systems and apparatuses for reducing power consumption, in an environment including a laser driver that drives a laser diode, are provided. The voltage drop across a laser diode, driven by a laser driver, is monitored. This enables a supply voltage, used to power the laser driver, to be appropriately adjusted, based at least in part on the monitored voltage drop. For example, the supply voltage is increased when the monitored voltage drop across the laser diode increases, and decreased when the monitored voltage drop across the laser diode decreases.

Optical Pick-Up Units And Laser Drivers With Increased Functionality
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US Patent:

7317674, Jan 8, 2008
Filed:

Mar 10, 2004
Appl. No.:

10/797261
Inventors:

Theodore D. Rees - Mountain View CA, US
Alexander Fairgrieve - Menlo Park CA, US
Bill R. Tang - San Jose CA, US
Barry Harvey - Los Altos CA, US
Yang Zhao - Fremont CA, US
Assignee:

Intersil Americas Inc. - Milpitas CA
International Classification:

G11B 7/12
US Classification:

369 5327, 369121, 369 475, 369116, 369 4752, 369 4755, 369 4753, 369 5912, 369 5911
Abstract:

Optical pick-up units and laser drivers are disclosed, which can be used in various types of information recording/reproducing apparatuses, such as, but not limited to, DVD and CD drives, DVD camcorders, and DVD video recorders. A laser driver integrated circuit (LDIC) includes an automatic power controller, a running optical power controller, and a write strategy generator. The LDIC can be part of a chip-set, to be located on an optical pick-up unit (OPU). The chip-set can also include a power monitor integrated circuit (PMIC) to monitor the laser diode, and a photo-detector integrated circuit (PDIC) to detect light produced by the laser diode. The PMIC and the PDIC each include their own offset, gain and sample-and-hold circuitry.

Systems And Methods For Automatic Power Control Of Laser Diodes
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US Patent:

7382807, Jun 3, 2008
Filed:

Apr 7, 2006
Appl. No.:

11/399976
Inventors:

Alexander Fairgrieve - Menlo Park CA, US
D. Stuart Smith - San Jose CA, US
Theodore D. Rees - Mountain View CA, US
Bill R. Tang - San Jose CA, US
Assignee:

Elantec Semiconductor, Inc. - Milpitas CA
International Classification:

H01S 3/30
H01S 3/13
H01S 3/00
US Classification:

372 8, 372 2901, 372 3802
Abstract:

Methods and system are provided for automatic power control of a laser diode, e. g. , in a laser driver. In accordance with an embodiment of the present invention, a power controller includes a detector circuit adapted to detect the output of the laser diode and to produce a measured output therefrom. A comparator compares a desired output to the measured output, and produces an error signal therefrom. The error signal is provided to an integrator circuit that produces an integrated error signal. At least one digital-to-analog converter (DAC) uses the integrated error signal to produce a current drive signal that drives the laser diode.

Flexible Multipulse Generator
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US Patent:

7492686, Feb 17, 2009
Filed:

Sep 22, 2005
Appl. No.:

11/233193
Inventors:

Miguel Gabino Perez - Mountain View CA, US
Alexander Fairgrieve - Menlo Park CA, US
Akihiro Asada - Chigasaki, JP
Assignee:

Intersil Americas Inc. - Milpitas CA
International Classification:

G11B 5/09
US Classification:

369 5911
Abstract:

Embodiments of the present invention relate to systems and methods for providing flexible multipulse strategies. In specific embodiments, a plurality of multipulse location registers are dedicated to storing multipulse location information. Each of a plurality of different mark-lengths that can result in at least one multipulse is mapped to one or more bit location within the multipulse location registers, such that a unique multipulse execution strategy can be defined for each of the plurality of different mark-lengths. Each bit location within the multipulse location registers can contain a first type of bit or a second type of bit. The first type of bit is used to indicate where to execute a multipulse, and the second type of bit is used to indicate where to not execute a multipulse. This abstract is not intended to be a complete description of the various embodiments of the present invention.

Self Protecting Output Stage
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US Patent:

7511931, Mar 31, 2009
Filed:

Jun 11, 2007
Appl. No.:

11/761285
Inventors:

Alexander Fairgrieve - Menlo Park CA, US
Assignee:

Intersil Americas Inc. - Milpitas CA
International Classification:

H02H 9/06
H02H 3/22
US Classification:

361 56, 361111
Abstract:

A transistor for use in an output stage is selectively part of one of two different circuits, one circuit being an electrostatic discharge (ESD) clamp circuit, the other circuit being an output stage circuit. For example, the transistor can be selectively connected such that it is part of the ESD clamp circuit, e. g. , when a load (e. g. , laser diode) connected to a current path terminal (e. g. , drain or collector) of the transistor is not to be driven by a drive circuit. However, when the load connected to the current path terminal of the transistor is to be driven by the drive circuit, the transistor can be connected such that it receives a drive signal at its control terminal, from the drive circuit. This abstract is not intended to describe all embodiments of the present invention.

Systems And Methods For Partitioned Color, Double Rate Video Transfer
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US Patent:

8384832, Feb 26, 2013
Filed:

Jul 27, 2010
Appl. No.:

12/844691
Inventors:

Alexander Fairgrieve - Sunnyvale CA, US
D. Stuart Smith - Milpitas CA, US
Assignee:

Intersil Americas Inc. - Milpitas CA
International Classification:

H04N 9/28
US Classification:

348744
Abstract:

Systems, methods and devices provide for fast and power efficient transfer of three color data words (e. g. , a M-bit red color word, a M bit green color word and a M-bit blue color word) per pixel from a controller to a laser diode driver (LDD). First and second transfer words are produced based on the three color data words. The first transfer word is transferred from the controller to the LDD and stored at LDD in response to a low-to-high portion of a cycle of a data transfer clock, and the second transfer word is transferred and stored in response to a high-to-low portion of a cycle of the data transfer clock. The first, second and third color data words are reproduced by the LDD in dependence on the first and second received transfer words. First, second and third DACs of the LDD are driven with the first color data word, the second color data word, and the third color data word. Three light sources (e. g.