Patents by Inventor James M. Nohrden

James M. Nohrden 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).

  • Publication number: 20220224127
    Abstract: A two-cell battery management system may include a switching network comprising a plurality of switches configured to electrically couple two battery cells to one another and a first load configured to receive electrical energy from the two battery cells and control circuitry configured to dynamically control the switching network among a plurality of switching configurations comprising a first switching configuration in which the first load is in parallel with both of the two battery cells, a second switching configuration in which the first load is in parallel with a first battery cell of the two battery cells and is electrically isolated from a second battery cell of the two battery cells, and a third switching configuration in which the first load is in parallel with the second battery cell and is electrically isolated from the first battery cell.
    Type: Application
    Filed: September 3, 2021
    Publication date: July 14, 2022
    Applicant: Cirrus Logic International Semiconductor Ltd.
    Inventors: Emmanuel A. MARCHAIS, James M. NOHRDEN, John L. MELANSON
  • Patent number: 7995981
    Abstract: In one embodiment, a method is provided. An in-band calibration tone is generated at a frequency of an undesired interfering signal. A receiver is calibrated using the calibration tone to reject image interference caused by the undesired interfering signal.
    Type: Grant
    Filed: October 31, 2005
    Date of Patent: August 9, 2011
    Assignee: Silicon Laboratories Inc.
    Inventors: Li Gao, Richard A Johnson, James M. Nohrden
  • Patent number: 7962113
    Abstract: In one embodiment, a method provides multiple-tone wideband I/Q mismatch calibration. A plurality of calibration frequencies is selected within a channel. A calibration tone is applied to the channel at each of the plurality of calibration frequencies. An I/Q mismatch is estimated at each of the plurality of calibration frequencies. An n-th order filter is constructed to compensate received signals relative to the estimated I/Q mismatch related to each calibration frequency.
    Type: Grant
    Filed: October 31, 2005
    Date of Patent: June 14, 2011
    Assignee: Silicon Laboratories Inc.
    Inventors: Li Gao, Richard A Johnson, James M. Nohrden
  • Patent number: 7675996
    Abstract: A receiver (1100) includes a direct digital frequency synthesizer (130), a mixer (105), and a clock source (1110, 1130). The direct digital frequency synthesizer has an input terminal for receiving a first clock signal at a first frequency, and an output terminal for providing a digital local oscillator signal synchronously with the first clock signal. The mixer (105) has a first input terminal for receiving a radio frequency (RF) signal, a second input terminal coupled to the output terminal of the direct digital frequency synthesizer (130), and an output terminal for providing an IF signal having a spectrum centered about a selectable one of a plurality of center frequencies. The clock source (1110, 1130) has an output terminal for providing the first clock signal without using a harmonic frequency that overlaps the spectrum for the plurality of center frequencies.
    Type: Grant
    Filed: July 29, 2005
    Date of Patent: March 9, 2010
    Inventors: Richard A. Johnson, James M. Nohrden, Scott T. Dupuie, Andrew W. Dornbusch
  • Patent number: 7558546
    Abstract: A method in which one of a high-side mix mode and a low-side mix mode is selected in response to an interference characteristic of a desired channel of a radio frequency (RF) input signal is disclosed. In the high-side mix mode, a direct digital frequency synthesizer (130) is initialized to output a digital local oscillator signal at a first frequency suitable for performing a high-side mix of the desired channel to an intermediate frequency (IF). In the low-side mix mode, the direct digital frequency synthesizer (130) is initialized to output the digital local oscillator signal at a second frequency suitable for performing a low-side mix of the desired channel to said IF. The RF input signal is mixed with the digital local oscillator signal to provide an IF output signal at the IF.
    Type: Grant
    Filed: September 30, 2005
    Date of Patent: July 7, 2009
    Assignee: Silicon Laboratories, Inc.
    Inventors: Richard A. Johnson, James M. Nohrden, Li Gao
  • Patent number: 7443911
    Abstract: According to one embodiment of the present invention, a device may receive one of multiple frequencies at a clock input of the device; determine which of the multiple frequencies is received; and generate at least one internal clock frequency for operation of the device using the received frequency. For example, such a device may be embedded within a system having a receiver to receive a satellite signal spectrum and to tune a signal channel and baseband circuitry coupled to the receiver to process digital data corresponding to the signal channel, where the baseband circuitry operates at the frequency provided to the device.
    Type: Grant
    Filed: June 24, 2004
    Date of Patent: October 28, 2008
    Assignee: Silicon Laboratories Inc.
    Inventors: Shahram Tadayyon, James M. Nohrden, James Ting-Yu Kao
  • Patent number: 7142255
    Abstract: A transport stream and channel selection system for digital video transmissions and associated method are disclosed that use predictive analyses to tune additional digital transport streams that contain desirable or optimal groupings of multiplexed channels. An analysis is made of which channels are multiplexed together at any given time to determine which transport streams provide a desirable and/or optimal combination of multiplexed channels, and a wide variety of information and algorithms can be used in determining the transport streams and channels to select. Thus, in addition to having available the channels multiplexed with the currently selected channel, a plurality of other channels multiplexed together in additional digital transport streams are made available for pre-processing. As such, the available channels for use in providing predictive pre-selection and for use in reducing delay experienced by a user in changing channels are greatly enhanced.
    Type: Grant
    Filed: October 8, 2003
    Date of Patent: November 28, 2006
    Assignee: Silicon Laboratories Inc.
    Inventor: James M. Nohrden
  • Patent number: 6944301
    Abstract: Distortion discrimination circuitry for digital radio receivers and corresponding methods are disclosed that accurately and efficiently discriminate distortion events, including impulse noise and multipath distortion events, to improve the quality of audio output signals. The distortion discrimination circuitry monitors and analyzes the demodulator output to determine when a distortion event has occurred and provides an appropriate indication signal for use by other circuitry within the radio receiver. More particularly, the distortion discrimination circuitry includes impulse noise circuitry that looks for high frequency noise in both the magnitude and multiplexed outputs of the demodulator to determine the occurrence of impulse noise distortion events.
    Type: Grant
    Filed: March 10, 1999
    Date of Patent: September 13, 2005
    Assignee: Cirrus Logic, Inc.
    Inventors: James M. Nohrden, Brian D. Green, Brian P. Lum Shue Chan
  • Patent number: 6389270
    Abstract: Station scan circuitry for a radio-frequency receiver and corresponding methods are disclosed that efficiently determine the presence of a station on available channels. The station scan circuitry includes circuitry that determines if the signal power on a given channel exceeds a threshold value. Additional circuitry compares the channel signal strength and the adjacent channel signal to determine if a ratio of the two exceeds a threshold level. If both the signal power and the signal strength ratio are sufficient, the station scan circuitry indicates that a station has been found. To make the signal strength comparison, the station scan circuitry includes circuitry for determining a post-filter signal strength and a pre-filter signal strength for the received signal.
    Type: Grant
    Filed: March 10, 1999
    Date of Patent: May 14, 2002
    Assignee: Cirrus Logic, Inc.
    Inventors: James M. Nohrden, Brian P. Lum Shue Chan