Patents by Inventor David Welland

David Welland 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: 9597495
    Abstract: The invention is a method of identifying a preferred location for an electrode array to the neural characteristics of an individual subject. The response to electrical neural stimulation varies from subject to subject and array location to array location. Measure of impedance may be used to predict the electrode height from the neural tissue and, thereby, predict the preferred location. Alternatively, electrode height may be measured directly to predict the preferred location.
    Type: Grant
    Filed: April 20, 2012
    Date of Patent: March 21, 2017
    Assignee: Second Sight Medical Products, Inc.
    Inventors: Robert J. Greenberg, Jone Fine, Arup Roy, Matthew J. McMahon, Mark S. Humayun, James David Welland, Alan M. Horsager, Dao Min Zhou, Amy Hines, Sumit Yadav, Rongqing Dai
  • Patent number: 9013232
    Abstract: A method and apparatus is provided for reducing interference in circuits. A management strategy is provided to reduce reference spurs and interference in circuits. The management strategy uses a combination of one or more techniques which reduce the digital current, minimize mutual inductance, utilize field cancellation, prevent leakage current, and/or manage impedance. These techniques may be used alone, or preferably, used on combination with one another.
    Type: Grant
    Filed: December 31, 2012
    Date of Patent: April 21, 2015
    Assignee: Silicon Laboratories Inc.
    Inventors: David Welland, Donald Kerth, Caiyi Wang
  • Patent number: 9000838
    Abstract: A method and apparatus is provided for reducing interference in circuits. A management strategy is provided to reduce reference spurs and interference in circuits. The management strategy uses a combination of one or more techniques which reduce the digital current, minimize mutual inductance, utilize field cancellation, prevent leakage current, and/or manage impedance. These techniques may be used alone, or preferably, used on combination with one another.
    Type: Grant
    Filed: December 30, 2012
    Date of Patent: April 7, 2015
    Assignee: Silicon Laboratories Inc.
    Inventors: David Welland, Donald Kerth, Caiyi Wang
  • Publication number: 20120203293
    Abstract: The invention is a method of identifying a preferred location for an electrode array to the neural characteristics of an individual subject. The response to electrical neural stimulation varies from subject to subject and array location to array location. Measure of impedance may be used to predict the electrode height from the neural tissue and, thereby, predict the preferred location. Alternatively, electrode height may be measured directly to predict the preferred location.
    Type: Application
    Filed: April 20, 2012
    Publication date: August 9, 2012
    Inventors: Robert J. Greenberg, Jone Fine, Arup Roy, Matthew J. McMahon, Mark S. Humayun, James David Welland, Alan M. Horsager, Dao Min Zhou, Amy Hines, Sumit Yadav, Rongqing Dai
  • Patent number: 8193822
    Abstract: A circuit for determining a value of a variable capacitor includes first circuitry for generating a first indication when a variable voltage across the variable capacitor exceeds a threshold voltage. Second circuitry generates a second indication when a reference voltage across a reference capacitor exceeds the threshold voltage. Control logic responsive to the first and second indications generate a control signal indicating whether the first indication or the second indication occurs first. A successive approximation engine generates an N-bit control value responsive to the control signal. A variable current source is responsive to the N-bit control value for generating a variable current to the first circuitry. A reference current source generates a reference current to the second circuitry.
    Type: Grant
    Filed: June 30, 2009
    Date of Patent: June 5, 2012
    Assignee: Silicon Laboratories Inc.
    Inventor: David Welland
  • Publication number: 20120054379
    Abstract: An integrated control circuit is disclosed including a central processing unit operating in a normal full system power mode and in a reduced system low power mode, and a memory. A plurality of peripheral units are provided, at least one of which includes an input/output for interfacing with at least an external system for receiving information therefrom and a process block. The process block processes the received information from the external system and during the processing of the received information, data is stored in the at least one peripheral unit, and data is transferred at least to or at least from the memory. The input/output and process blocks are fully operable in the full system power mode and the reduced system power mode. A direct memory access (DMA) transfers data directly between the at least one peripheral and the memory when such data transfer is required by the peripheral.
    Type: Application
    Filed: August 30, 2010
    Publication date: March 1, 2012
    Inventors: Kafai Leung, Brent Wilson, Yonghong Tao, Shan Wang, Shantonu Bhadury, Suby Pellissery, Raghavendra Pai Kateel, David Welland, David Andreas, Gabriel Vogel
  • Publication number: 20120050206
    Abstract: A method for interfacing with a capacitive touch screen is disclosed. The method includes charging an internal capacitor in the touch screen, which internal capacitor is disposed proximate a fixed location on the touch screen and is capable of changing in response to a touch at the specific location. After charging, the charge on the internal capacitor is transferred from the touch screen and the value of the charge on the internal capacitor then determined.
    Type: Application
    Filed: August 29, 2010
    Publication date: March 1, 2012
    Inventor: DAVID WELLAND
  • Publication number: 20100201382
    Abstract: A circuit for determining a value of a variable capacitor comprises first circuitry for generating a first indication when a variable voltage across the variable capacitor exceeds a threshold voltage. Second circuitry generates a second indication when a reference voltage across a reference capacitor exceeds the threshold voltage. Control logic responsive to the first and second indications generate a control signal indicating whether the first indication or the second indication occurs first. A successive approximation engine generates an N-bit control value responsive to the control signal. A variable current source is responsive to the N-bit control value for generating a variable current to the first circuitry. A reference current source generates a reference current to the second circuitry.
    Type: Application
    Filed: June 30, 2009
    Publication date: August 12, 2010
    Applicant: SILICON LABORATORIES INC.
    Inventor: DAVID WELLAND
  • Patent number: 7720176
    Abstract: In one embodiment, the present invention includes an apparatus having multiple transmission paths, including a first transmission path configured to receive and process baseband data in a first mode of operation to generate a radio frequency (RF) signal for output via a common output path, and a second transmission path configured to receive and process the baseband data in a second mode of operation to generate the RF signal for output via the common output path.
    Type: Grant
    Filed: August 25, 2006
    Date of Patent: May 18, 2010
    Assignee: ST-Ericsson SA
    Inventor: David Welland
  • Patent number: 7697901
    Abstract: A method includes controlling a mixer gain to provide a range of selected power output levels from the mixer using a first control scheme for a low portion of the range and using a second control scheme for a high portion of the range. Using the selected mixer gain, incoming baseband signals may be upconverted in the mixer to a transmission frequency and output from the mixer at the selected power output level.
    Type: Grant
    Filed: March 30, 2006
    Date of Patent: April 13, 2010
    Assignee: ST-Ericsson SA
    Inventors: Srinath Sridharan, Ahmed Emira, Aria Eshraghi, David Welland
  • Publication number: 20080008259
    Abstract: A ratiometric clock system for an integrated receiver and associated method are disclosed that provide an advantageous solution for combining digital signal processing (DSP) circuitry on the same integrated circuit as mixer and local oscillator (LO) generation circuitry. The generation circuitry generates an oscillation signal that is passed through a first divider to generate mixing signals for the mixer and that is passed through a second divider to generate a digital clock signal that is utilized by the DSP circuitry. This digital clock signal can be utilized by integrated analog-to-digital conversion circuitry, as well.
    Type: Application
    Filed: September 14, 2007
    Publication date: January 10, 2008
    Inventors: G. Tuttle, David Welland, Scott Willingham
  • Publication number: 20070072558
    Abstract: A method includes controlling a mixer gain to provide a range of selected power output levels from the mixer using a first control scheme for a low portion of the range and using a second control scheme for a high portion of the range. Using the selected mixer gain, incoming baseband signals may be upconverted in the mixer to a transmission frequency and output from the mixer at the selected power output level.
    Type: Application
    Filed: March 30, 2006
    Publication date: March 29, 2007
    Inventors: Srinath Sridharan, Ahmed Emira, Aria Eshraghi, David Welland
  • Publication number: 20070071129
    Abstract: In one embodiment, the present invention includes an apparatus having multiple transmission paths, including a first transmission path configured to receive and process baseband data in a first mode of operation to generate a radio frequency (RF) signal for output via a common output path, and a second transmission path configured to receive and process the baseband data in a second mode of operation to generate the RF signal for output via the common output path.
    Type: Application
    Filed: August 25, 2006
    Publication date: March 29, 2007
    Inventor: David Welland
  • Publication number: 20060284746
    Abstract: An exemplary PLL circuit includes a VCO responsive to a plurality of sub-varactor control signals. A digital loop filter for the PLL digitally generates a varactor control word, which is digitally expanded into a plurality of digital values, each of which is conveyed to a corresponding one of a plurality of DACs. A multiplexer is configured to respectively convey the DAC output signals to a group of sub-varactor control signals according to the varactor control word, and to drive remaining sub-varactor control signals to either the full-scale high value or the full-scale low value of the DAC outputs. Each of the DACs preferably includes a hybrid first order/second order sigma-delta modulator, and in certain embodiments, a NRZ-to-RZ coder circuit, and a linear filter circuit.
    Type: Application
    Filed: July 31, 2006
    Publication date: December 21, 2006
    Inventors: Yunteng Huang, Bruno Garlepp, David Welland
  • Publication number: 20060215771
    Abstract: An isolation system is provided that is suitable for use in telephony, medical instrumentation, industrial process control and other applications. Preferred embodiments of the invention comprise a capacitive isolation barrier across which a digital signal is communicated. The system provides a means of communication across the isolation barrier that is highly immune to amplitude and phase noise interference. Clock recovery circuitry may be employed on one side of the isolation barrier to extract timing information from the digital signal communicated across the barrier, and to filter the effects of phase noise introduced at the barrier. Delta-sigma converters may be disposed on both sides of the isolation barrier to convert signals between analog and digital domains. An isolated power supply may also be provided on the isolated side of the barrier, whereby direct current is generated in response to the digital data received across the isolation barrier.
    Type: Application
    Filed: April 5, 2006
    Publication date: September 28, 2006
    Inventors: Jeffrey Scott, Navdeep Sooch, David Welland
  • Publication number: 20060197847
    Abstract: An image processor system for a charge coupled device (CCD) or CMOS imaging system includes a correlated double sample and variable gain (CDSVGA) circuit for receiving data from a CCD system and an automatic gain control (AGC) circuit which first controls gain by adjusting said CCD system and then for yet a higher gain level makes gain adjustments in said CDSVGA circuit AND a digital gain circuit to produce a combined target gain level. A processing system for an imager device includes a camera system for producing an imager signal, a correlated double sample (CDS) circuit for receiving data from an imager, a variable gain amplifier (VGA), an analog-to-digital converter (ADC) coupled to said CDS circuit, a digital gain circuit (DGC) coupled to said ADC, and an automatic gain control (AGC) circuit coupled to said DGC for controlling the CDS circuit and the DGC.
    Type: Application
    Filed: May 1, 2006
    Publication date: September 7, 2006
    Inventors: Sandra Johnson, Shih-Chung Chao, Nadi Itani, Caiyi Wang, Brannon Harris, Ash Prabala, Douglas Holberg, Alan Hansford, Syed Azim, David Welland
  • Publication number: 20060073793
    Abstract: An RF transmitter (104) includes a shared local oscillator circuit (126), transmit path circuitry (120, 122, 124), a divider (134), and a lowpass filter (322). The shared local oscillator circuit (126) generates a shared LO signal (116). The transmit path circuitry (120, 122, 124) mixes a baseband signal (107) and an IF mixing signal (116) to provide an IF signal (112), and converts the IF signal (112) to an RF transmit signal (105) at a desired frequency using an RF mixing signal received at a mixing input thereof. The divider (134) divides the shared LO signal (116) to provide an unfiltered RF mixing signal. The lowpass filter (322) has an input for receiving the unfiltered RF mixing signal, and an output coupled to the mixing input of the transmit path circuitry (120, 122, 124) for providing the RF mixing signal.
    Type: Application
    Filed: September 12, 2005
    Publication date: April 6, 2006
    Applicant: SILICON LABORATORIES, INC.
    Inventors: David Welland, Ramkishore Ganti, CaiYi Wang
  • Publication number: 20060008075
    Abstract: An isolation system is provided that is suitable for use in telephony, medical instrumentation, industrial process control and other applications. Preferred embodiments of the invention comprise a capacitive isolation barrier across which a digital signal is communicated. The system provides a means of communication across the isolation barrier that is highly immune to amplitude and phase noise interference. Clock recovery circuitry may be employed on one side of the isolation barrier to extract timing information from the digital signal communicated across the barrier, and to filter the effects of phase noise introduced at the barrier. Delta-sigma converters may be disposed on both sides of the isolation barrier to convert signals between analog and digital domains. An isolated power supply may also be provided on the isolated side of the barrier, whereby direct current is generated in response to the digital data received across the isolation barrier.
    Type: Application
    Filed: July 7, 2004
    Publication date: January 12, 2006
    Inventors: Jeffrey Scott, Navdeep Sooch, David Welland
  • Publication number: 20060003706
    Abstract: A ratiometric transmit path architecture for communication systems and related methods are disclosed. This ratiometric transmit path architecture utilizes a single local oscillator signal and dividers to provide mixing signals for intermediate frequency (IF) mixing circuitry and feedback mixing circuitry, thereby eliminating the need for separate IF and radio frequency (RF) voltage controlled oscillators (VCOs) in prior solutions.
    Type: Application
    Filed: March 31, 2005
    Publication date: January 5, 2006
    Inventors: David Welland, Caiyi Wang
  • Publication number: 20060003707
    Abstract: Mixing circuitry for quadrature processing in communication systems and related methods are disclosed. The weighted mixing circuitry allows for arbitrary dividers to be utilized in generating the mixing signals for quadrature processing and thereby provides a significant advantage over prior architectures where 90 degree offset I and Q mixing signals were needed for quadrature mixing.
    Type: Application
    Filed: March 31, 2005
    Publication date: January 5, 2006
    Inventors: David Welland, Caiyi Wang