Patents by Inventor Kevin T. Chan

Kevin T. Chan 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: 7835292
    Abstract: Aspects of the invention include determining or choosing any usable media pair from all existing media pairs of a first device. Any channel may be selected from all existing channels and the selected channel is chosen so that it is different from a general channel assignment corresponding to the determined usable media pair. The selected channel may be assigned to the media pair. A second device may be notified of the assigned channel which corresponds to the media pair chosen from all the media pairs. The second device may cross-connect a corresponding equivalent channel and media pair. The first and second device may be adapted to negotiate the assignment of the selected channel to any one of the media pairs. Alternatively, a particular channel and media pair assignment may be selected from a plurality of predetermined channel and media pair assignments and utilized by the first and second device.
    Type: Grant
    Filed: July 2, 2003
    Date of Patent: November 16, 2010
    Inventor: Kevin T. Chan
  • Publication number: 20100226387
    Abstract: The present invention describes a communications system having a first link partner and a second link partner that are connected by a communications link having at least four pairs of conductors. According to IEEE Standard 802.3 (e.g. Ethernet) for 1000Base-T, a data link is maintained (in a period absent data transmission) by sending idle signals over four pairs of conductors of the cable to maintain a logical connection. This idle signal scheme is replaced with an alternate idle signaling scheme that uses only two pairs of conductors to maintain a logical connection and therefore can operate with using lower power. The other two pairs of conductors of the four pairs of conductors are unused to maintain a logical connection absent data transfer, and therefore can be used to implement a Suspend Mode of operation. During Suspend Mode, the physical layer of each link partner powers down unnecessary circuitry so as to operate in a low power environment.
    Type: Application
    Filed: May 18, 2010
    Publication date: September 9, 2010
    Applicant: Broadcom Corporation
    Inventors: Richard G. THOUSAND, Kevin T. Chan, Kevin Brown
  • Patent number: 7778333
    Abstract: A power efficient and reduced electromagnetic interference (EMI) emissions multi-transmitter system for unshielded twisted pair (UTP) data communication applications. For each transmitter, digital transmit data is converted to a current-mode differential signal analog waveform by a digital-to-analog converter (DAC). The output current from each DAC is used to generate the required transmit voltage on the respective UTP line. Timing circuitry staggers the time base of each transmitter to reduce the aggregate EMI emissions of the multi-transmitter system.
    Type: Grant
    Filed: February 20, 2007
    Date of Patent: August 17, 2010
    Inventor: Kevin T. Chan
  • Patent number: 7769102
    Abstract: A power efficient and reduced electromagnetic interference (EMI) emissions transmitter for unshielded twisted pair (UTP) data communication applications. Transmit data is processed by a digital filter. The digital filter output data is converted to a current-mode analog waveform by a digital-to-analog converter (DAC). The digital filter is integrated with the DAC binary decoder in a memory device such as a ROM with time multiplexed output. DAC line driver cells are adaptively configurable to operate in either a class-A or a class-B mode depending on the desired operational modality. A discrete-time analog filter is integrated with the DAC line driver to provide additional EMI emissions suppression. An adaptive electronic transmission signal cancellation circuit separates transmit data from receive data in a bidirectional communication system operating in full duplex mode.
    Type: Grant
    Filed: December 4, 2007
    Date of Patent: August 3, 2010
    Inventor: Kevin T. Chan
  • Publication number: 20100177809
    Abstract: A physical layer device (PLD) includes a first serializer-deserializer (SERDES) device and a second SERDES device. Each SERDES device includes an analog portion with a serial port that is configured to communicate serial data with various network devices, and a digital portion that is configured to communicate parallel data with other various network devices. The PLD includes a first signal path that is configured to route serial data signals between the analog portions of the SERDES devices, bypassing the digital portions of the SERDES devices. Therefore, the SERDES devices can directly communicate serial data without performing parallel data conversion. A second signal path is configured to route recovered clock and data signals between the analog portions of the SERDES devices, but still bypassing the digital portions of the SERDES devices. The recovered clock and data signals are then regenerated before being transmitted over a network device.
    Type: Application
    Filed: March 19, 2010
    Publication date: July 15, 2010
    Applicant: Broadcom Corporation
    Inventors: Kevin T. Chan, Michael Q. Le
  • Patent number: 7738482
    Abstract: The present invention describes a communications system having a first link partner and a second link partner that are connected by a communications link having at least four pairs of conductors. According to IEEE Standard 802.3 (e.g. Ethernet) for 1000Base-T, a data link is maintained (in a period absent data transmission) by sending idle signals over four pairs of conductors of the cable to maintain a logical connection. This idle signal scheme is replaced with an alternate idle signaling scheme that uses only two pairs of conductors to maintain a logical connection and therefore can operate with using lower power. The other two pairs of conductors of the four pairs of conductors are unused to maintain a logical connection absent data transfer, and therefore can be used to implement a Suspend Mode of operation. During Suspend Mode, the physical layer of each link partner powers down unnecessary circuitry so as to operate in a low power environment.
    Type: Grant
    Filed: November 12, 2004
    Date of Patent: June 15, 2010
    Assignee: Broadcom Corporation
    Inventors: Richard G. Thousand, Kevin T. Chan, Kevin Brown
  • Patent number: 7733994
    Abstract: An adaptive electronic transmission signal cancellation circuit for separating transmit data from receive data in a bidirectional communication system operating in full duplex mode is disclosed. The output of a main transmitter responsive to a first bias current is connected to the output of a receiver through an internal resistor. A first replica transmitter responsive to a second bias current and matched to the main transmitter current gain and rise/fall time characteristics is connected to the input terminal of the receiver, and produces a cancellation voltage between the output terminal of the main transmitter and the input terminal of the receiver as a function of the second bias current and the internal resistor.
    Type: Grant
    Filed: May 16, 2006
    Date of Patent: June 8, 2010
    Inventor: Kevin T. Chan
  • Patent number: 7706433
    Abstract: A physical layer device (PLD) includes a first serializer-deserializer (SERDES) device and a second SERDES device. Each SERDES device includes an analog portion with a serial port that is configured to communicate serial data with various network devices, and a digital portion that is configured to communicate parallel data with other various network devices. The PLD includes a first signal path that is configured to route serial data signals between the analog portions of the SERDES devices, bypassing the digital portions of the SERDES devices. Therefore, the SERDES devices can directly communicate serial data without performing parallel data conversion. A second signal path is configured to route recovered clock and data signals between the analog portions of the SERDES devices, but still bypassing the digital portions of the SERDES devices. The recovered clock and data signals are then regenerated before being transmitted over a network device.
    Type: Grant
    Filed: January 15, 2009
    Date of Patent: April 27, 2010
    Assignee: Broadcom Corporation
    Inventors: Kevin T. Chan, Michael Q. Le
  • Publication number: 20100080271
    Abstract: Provided is a method and system for controlling current characteristics in a transceiver having a transmitter. The transmitter includes a plurality of current cells. Each cell is configurable for operating in different modes. The method includes determining a first probability associated with transmitting data at a particular symbolic level and determining a second probability associated with each cell being used during a transmission at the particular symbolic level. Next, one of the modes for each cell is selected in accordance with anticipated performance requirements. An average current of the transmitter is then calculated based upon the determined first and second probabilities and the selected modes.
    Type: Application
    Filed: August 5, 2009
    Publication date: April 1, 2010
    Applicant: Broadcom Corporation
    Inventors: Yee Ling CHEUNG, Kevin T. Chan, Jan Mulder
  • Publication number: 20100062734
    Abstract: A transmitter includes a detection element to determine when a current power requirement of a communication link is less than the standard transmit power. The current power requirement may be determined by a current operation condition of the communication link, for instance. The transmit power of the transmitter may be set to be less than the standard power in any of a variety of ways. For example, a center tap voltage of the transmitter may be reduced. In another example, a class of operation of the transmitter may be changed. In yet another example, the transmitter may include a current mirror having a plurality of diode-connected transistors coupled in parallel, thereby reducing the current at output terminals of the transmitter. Reducing the current at the output terminals decreases the output power of the transmitter, which may reduce the power consumed by the transmitter.
    Type: Application
    Filed: November 17, 2009
    Publication date: March 11, 2010
    Applicant: Broadcom Corporation
    Inventor: Kevin T. CHAN
  • Patent number: 7643804
    Abstract: A transmitter includes a detection element to determine when a current power requirement of a communication link is less than the standard transmit power. The current power requirement may be determined by a current operation condition of the communication link, for instance. The transmit power of the transmitter may be set to be less than the standard power in any of a variety of ways. For example, a center tap voltage of the transmitter may be reduced. In another example, a class of operation of the transmitter may be changed. In yet another example, the transmitter may include a current mirror having a plurality of diode-connected transistors coupled in parallel, thereby reducing the current at output terminals of the transmitter. Reducing the current at the output terminals decreases the output power of the transmitter, which may reduce the power consumed by the transmitter.
    Type: Grant
    Filed: September 8, 2005
    Date of Patent: January 5, 2010
    Assignee: Broadcom Corporation
    Inventor: Kevin T. Chan
  • Publication number: 20090302926
    Abstract: An apparatus and system are provided to adjust an output voltage of an integrated circuit (IC) die. For instance, the apparatus can include an on-chip source termination and a bias generator. The bias generator can be configured to provide a source current to the on-chip source termination to adjust the output voltage. In particular, when adjusting the output voltage of the IC die, the bias generator can adjust the source current using a first current with a first adjustable current gain and a second current source with a second adjustable current gain.
    Type: Application
    Filed: July 10, 2009
    Publication date: December 10, 2009
    Applicant: Broadcom Corporation
    Inventor: Kevin T. CHAN
  • Patent number: 7599447
    Abstract: In a transmitter that includes a plurality of partitioned DAC processing cells coupled to a corresponding plurality of partitioned encoder processing cells, a method for processing signals may include aggregating outputs of each of the plurality of partitioned DAC processing cells to generate an analog output signal. The transmitter may be a direct drive transmitter. The generated analog output signal may be a reduced emissions analog signal. The plurality of encoder processing cells may be partitioned into at least a group of odd encoder processing cells and a group of even encoder processing cells. The plurality of DAC processing cells may be partitioned into at least a group of odd DAC processing cells for processing outputs of the group of odd encoder processing cells and a group of even DAC processing cells for processing outputs of the group of even encoder processing cells.
    Type: Grant
    Filed: November 30, 2007
    Date of Patent: October 6, 2009
    Assignee: Broadcom Corporation
    Inventor: Kevin T. Chan
  • Patent number: 7589655
    Abstract: Provided is a method and system for controlling current characteristics in a transceiver having a transmitter. The method includes identifying a phase control signal from an adjacent current cell preceding the particular current cell in time and logically ORing the phase control signal from the preceding cell with a phase control signal from the particular current cell.
    Type: Grant
    Filed: September 4, 2008
    Date of Patent: September 15, 2009
    Assignee: Broadcom Corporation
    Inventors: Yee Ling Cheung, Kevin T. Chan, Jan Mulder
  • Patent number: 7587181
    Abstract: Provided is a method and system for controlling current characteristics in a transceiver having a transmitter. The transmitter includes a plurality of current cells. Each cell is configurable for operating in different modes. The method includes determining a first probability associated with transmitting data at a particular symbolic level and determining a second probability associated with each cell being used during a transmission at the particular symbolic level. Next, one of the modes for each cell is selected in accordance with anticipated performance requirements. An average current of the transmitter is then calculated based upon the determined first and second probabilities and the selected modes.
    Type: Grant
    Filed: November 12, 2004
    Date of Patent: September 8, 2009
    Assignee: Broadcom Corporation
    Inventors: Yee Ling Cheung, Kevin T. Chan, Jan Mulder
  • Publication number: 20090154381
    Abstract: An adaptive electronic transmission signal cancellation circuit for separating transmit data from receive data in bidirectional communication system operating in full duplex mod is disclosed. The output of a main transmitter responsive to a first bias current is connected to the output of a receiver through an internal resistor. A first replica transmitter responsive to a second bias current and matched to the main transmitter current gain and rise/fall time characteristics is connected to the input terminal of the receiver, and produces a cancellation voltage between the output terminal of the main transmitter and the input terminal of the receiver as a function of the second bias current and the internal resistor.
    Type: Application
    Filed: February 17, 2009
    Publication date: June 18, 2009
    Inventor: Kevin T. Chan
  • Publication number: 20090135890
    Abstract: A physical layer device (PLD) includes a first serializer-deserializer (SERDES) device and a second SERDES device. Each SERDES device includes an analog portion with a serial port that is configured to communicate serial data with various network devices, and a digital portion that is configured to communicate parallel data with other various network devices. The PLD includes a first signal path that is configured to route serial data signals between the analog portions of the SERDES devices, bypassing the digital portions of the SERDES devices. Therefore, the SERDES devices can directly communicate serial data without performing parallel data conversion. A second signal path is configured to route recovered clock and data signals between the analog portions of the SERDES devices, but still bypassing the digital portions of the SERDES devices. The recovered clock and data signals are then regenerated before being transmitted over a network device.
    Type: Application
    Filed: January 15, 2009
    Publication date: May 28, 2009
    Applicant: Broadcom Corporation
    Inventors: Kevin T. Chan, Michael Q. Le
  • Publication number: 20090121910
    Abstract: Provided is a method and system for controlling current characteristics in a transceiver having a transmitter. The method includes identifying a phase control signal from an adjacent current cell preceding the particular current cell in time and logically ORing the phase control signal from the preceding cell with a phase control signal from the particular current cell.
    Type: Application
    Filed: September 4, 2008
    Publication date: May 14, 2009
    Applicant: Broadcom Corporation
    Inventors: Yee Ling Cheung, Kevin T. Chan, Jan Mulder
  • Patent number: 7492840
    Abstract: An adaptive electronic transmission signal cancellation circuit for separating transmit data from receive data in a bidirectional communication system operating in full duplex mode is disclosed. The output of a main transmitter responsive to a first bias current is connected to the output of a receiver through an internal resistor. A first replica transmitter responsive to a second bias current and matched to the main transmitter current gain and rise/fall time characteristics is connected to the input terminal of the receiver, and produces a cancellation voltage between the output terminal of the main transmitter and the input terminal of the receiver as a function of the second bias current and the internal resistor.
    Type: Grant
    Filed: May 18, 2004
    Date of Patent: February 17, 2009
    Assignee: Broadcom Corporation
    Inventor: Kevin T. Chan
  • Patent number: 7486721
    Abstract: A physical layer device (PLD) includes a first serializer-deserializer (SERDES) device and a second SERDES device. Each SERDES device includes an analog portion with a serial port that is configured to communicate serial data with various network devices, and a digital portion that is configured to communicate parallel data with other various network devices. The PLD includes a first signal path that is configured to route serial data signals between the analog portions of the SERDES devices, bypassing the digital portions of the SERDES devices. Therefore, the SERDES devices can directly communicate serial data without performing parallel data conversion. A second signal path is configured to route recovered clock and data signals between the analog portions of the SERDES devices, but still bypassing the digital portions of the SERDES devices. The recovered clock and data signals are then regenerated before being transmitted over a network device.
    Type: Grant
    Filed: August 21, 2007
    Date of Patent: February 3, 2009
    Assignee: Broadcom Corporation
    Inventors: Kevin T. Chan, Michael Q. Le