Patents by Inventor Alexander Fairgrieve

Alexander Fairgrieve has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Patent number: 8384832
    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., red, green and blue laser diodes or LEDs) are driven with output currents of the DACs.
    Type: Grant
    Filed: July 27, 2010
    Date of Patent: February 26, 2013
    Assignee: Intersil Americas Inc.
    Inventors: Alexander Fairgrieve, D. Stuart Smith
  • Publication number: 20110157485
    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., red, green and blue laser diodes or LEDs) are driven with output currents of the DACs.
    Type: Application
    Filed: July 27, 2010
    Publication date: June 30, 2011
    Applicant: INTERSIL AMERICAS INC.
    Inventors: Alexander Fairgrieve, D. Stuart Smith
  • Patent number: 7511931
    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.
    Type: Grant
    Filed: June 11, 2007
    Date of Patent: March 31, 2009
    Assignee: Intersil Americas Inc.
    Inventor: Alexander Fairgrieve
  • Patent number: 7492686
    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.
    Type: Grant
    Filed: September 22, 2005
    Date of Patent: February 17, 2009
    Assignee: Intersil Americas Inc.
    Inventors: Miguel Gabino Perez, Alexander Fairgrieve, Akihiro Asada
  • Patent number: 7382807
    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.
    Type: Grant
    Filed: April 7, 2006
    Date of Patent: June 3, 2008
    Assignee: Elantec Semiconductor, Inc.
    Inventors: Alexander Fairgrieve, D. Stuart Smith, Theodore D. Rees, Bill R. Tang
  • Publication number: 20080030910
    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.
    Type: Application
    Filed: June 11, 2007
    Publication date: February 7, 2008
    Applicant: INTERSIL AMERICAS INC.
    Inventor: Alexander Fairgrieve
  • Patent number: 7317674
    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.
    Type: Grant
    Filed: March 10, 2004
    Date of Patent: January 8, 2008
    Assignee: Intersil Americas Inc.
    Inventors: Theodore D. Rees, Alexander Fairgrieve, Bill R. Tang, Barry Harvey, Yang Zhao
  • Publication number: 20060280089
    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.
    Type: Application
    Filed: September 22, 2005
    Publication date: December 14, 2006
    Applicant: Intersil Americas Inc.
    Inventors: Miguel Perez, Alexander Fairgrieve, Akihiro Asada
  • Patent number: 7106769
    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.
    Type: Grant
    Filed: February 4, 2004
    Date of Patent: September 12, 2006
    Assignee: Elantec Semiconductor, Inc.
    Inventor: Alexander Fairgrieve
  • Publication number: 20060182159
    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.
    Type: Application
    Filed: April 7, 2006
    Publication date: August 17, 2006
    Applicant: Elantec Semiconductor, Inc.
    Inventors: Alexander Fairgrieve, D. Smith, Theodore Rees, Bill Tang
  • Patent number: 7061951
    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.
    Type: Grant
    Filed: July 2, 2003
    Date of Patent: June 13, 2006
    Assignee: Elantec Semiconductor, Inc.
    Inventors: Alexander Fairgrieve, D. Stuart Smith, Theodore D. Rees, Bill R. Tang
  • Publication number: 20040202215
    Abstract: A laser driver includes a programmable damping resistor that provides an adjustable damping resistance to improve a laser light output response. The laser driver can also includes a controller that is adapted to adjust the programmable damping resistor based on an input signal. Such an input signal can, for example, specify characteristics of a driven load, components that make up the load, or the like. The controller can then determine and select a desirable damping resistance based on the provided input.
    Type: Application
    Filed: February 3, 2004
    Publication date: October 14, 2004
    Applicant: Elantec Semiconductor, Inc.
    Inventor: Alexander Fairgrieve
  • Publication number: 20040202216
    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.
    Type: Application
    Filed: February 4, 2004
    Publication date: October 14, 2004
    Applicant: Elantec Semiconductor, Inc.
    Inventor: Alexander Fairgrieve
  • Publication number: 20040202072
    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.
    Type: Application
    Filed: March 10, 2004
    Publication date: October 14, 2004
    Applicant: Elantec Semiconductor, Inc.
    Inventors: Theodore D. Rees, Alexander Fairgrieve, Bill R. Tang, Barry Harvey, Yang Zhao
  • Publication number: 20040120369
    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.
    Type: Application
    Filed: July 2, 2003
    Publication date: June 24, 2004
    Applicant: Elantec Semiconductor, Inc.
    Inventors: Alexander Fairgrieve, D. Stuart Smith, Theodore D. Rees, Bill R. Tang
  • Patent number: 6501317
    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 102 and 103 with an NMOS transistor 101 providing the tail current for the differential pair. Complementary NMOS and PMOS load transistors 104,106 and 105, 107 provide loads for the differential transistor 102 and 103. Transistors 111-114 and 121-122 together with an amplifier 130 provide biasing for the delay device. The amplifier 130 has a non-inverting input set to VDD−VCLAMP. As configured, a constant output voltage swing from VDD to VDD−VCLAMP is provided at the outputs VOUT+ and VOUT− of the delay device, independent of a control voltage VCTL used to set the tail current. The NMOS load transistor 104, as opposed to the PMOS transistor 4 in FIG. 1, does not contribute to the gate parasitic capacitance enabling a high operation speed without consumption of more supply current.
    Type: Grant
    Filed: April 6, 2001
    Date of Patent: December 31, 2002
    Assignee: Elantec Semiconductor, Inc.
    Inventors: Xijian Lin, Barry Harvey, Alexander Fairgrieve
  • Publication number: 20020145460
    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 102 and 103 with an NMOS transistor 101 providing the tail current for the differential pair. Complementary NMOS and PMOS load transistors 104,106 and 105,107 provide loads for the differential transistor 102 and 103. Transistors 111-114 and 121-122 together with an amplifier 130 provide biasing for the delay device. The amplifier 130 has a non-inverting input set to VDD−VCLAMP. As configured, a constant output voltage swing from VDD to VDD−VCLAMP is provided at the outputs VOUT+ and VOUT− of the delay device, independent of a control voltage VCTL used to set the tail current. The NMOS load transistor 104, as opposed to the PMOS transistor 4 in FIG. 1, does not contribute to the gate parasitic capacitance enabling a high operation speed without consumption of more supply current.
    Type: Application
    Filed: April 6, 2001
    Publication date: October 10, 2002
    Inventors: Xijian Lin, Barry Harvey, Alexander Fairgrieve
  • Patent number: 6031424
    Abstract: The present invention is a differential amplifier with circuitry to eliminate the effect of transistor impedance other than an actual load impedance on voltage gain. The circuitry includes a pair of transistors 400 and 402, each with a base connected to a respective input of the differential amplifier along with a similar base connection of a respective one of transistors 100 and 102, and an emitter connected to a current source 404. A collector of transistor 400 is connected through transistor 410 to the emitter of a current sink transistor 306, while the collector of transistor 402 is connected through transistor 412 to the emitter of a current sink transistor 308. Operational amplifiers (opamps) 420 and 422 serve as voltage followers to connect the collector of transistor 100 to the base of transistor 412, and the collector of transistor 102 to the base of transistor 410.
    Type: Grant
    Filed: September 10, 1998
    Date of Patent: February 29, 2000
    Assignee: Elantec Semiconductor, Inc.
    Inventor: Alexander Fairgrieve
  • Patent number: 5898334
    Abstract: A circuit for generating an output signal used for driving a grounded load is provided. The circuit provides an output signal without glitches or spikes. The circuit also outputs a drive signal with enhanced responsiveness in transitioning from one output value level to another output value level. The circuit includes a plurality of control devices for providing respective output signals responsive to respective control signals. The base of a PNP transistor is coupled to the output of the control devices and acts as a buffer. The emitter of the PNP transistor is coupled to a voltage source and the collector is coupled to a grounded load for providing the drive current. Alternatively, an NPN transistor and current source provides the drive current to the grounded load. The circuitry may be used in an optical disk drive with the load and ground being a laser diode used for providing a laser beam in reading/writing an optical disk.
    Type: Grant
    Filed: May 12, 1997
    Date of Patent: April 27, 1999
    Assignee: Elantec Semiconductor, Inc.
    Inventor: Alexander Fairgrieve
  • Patent number: 5874865
    Abstract: A variable frequency oscillator providing a constant amplitude with variations in frequency. The variable frequency oscillator includes: an oscillator having an input connected for receiving a current I.sub.1, and outputs for providing complementary signals having a frequency varying in proportion to the current I.sub.1 ; first and second transistors, each having a base connected to a respective one of the oscillator outputs; current supply circuitry having a first output connected to the input of the oscillator for providing the current I.sub.1, and a second output connected to the emitters of the first and second transistors for providing a current I.sub.3, the current I.sub.3 varying in proportion to the current I.sub.
    Type: Grant
    Filed: May 12, 1997
    Date of Patent: February 23, 1999
    Assignee: Elantec Semiconductor, Inc.
    Inventor: Alexander Fairgrieve