Patents by Inventor Kok Lim Chan

Kok Lim 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: 10243576
    Abstract: An asynchronous successive approximation register analog-to-digital converter (SAR ADC), which utilizes one or more overlapping redundant bits in each digital-to-analog converter (DAC) code word, is operable to generate an indication signal that indicates completion of each comparison step and indicates that an output decision for each comparison step is valid. A timer may be initiated based on the generated indication signal. A timeout signal may be generated that preempts the indication signal and forces a preemptive decision, where the preemptive decision sets one or more remaining bits up to, but not including, the one or more overlapping redundant bits in a corresponding digital-to-analog converter code word for a current comparison step to a particular value. For example, the one or more remaining bits may be set to a value that is derived from a value of a bit that was determined in an immediately preceding decision.
    Type: Grant
    Filed: May 9, 2018
    Date of Patent: March 26, 2019
    Assignee: Maxlinear, Inc.
    Inventors: Eric Fogleman, Sheng Ye, Xuefeng Chen, Kok Lim Chan
  • Publication number: 20180262201
    Abstract: An asynchronous successive approximation register analog-to-digital converter (SAR ADC), which utilizes one or more overlapping redundant bits in each digital-to-analog converter (DAC) code word, is operable to generate an indication signal that indicates completion of each comparison step and indicates that an output decision for each comparison step is valid. A timer may be initiated based on the generated indication signal. A timeout signal may be generated that preempts the indication signal and forces a preemptive decision, where the preemptive decision sets one or more remaining bits up to, but not including, the one or more overlapping redundant bits in a corresponding digital-to-analog converter code word for a current comparison step to a particular value. For example, the one or more remaining bits may be set to a value that is derived from a value of a bit that was determined in an immediately preceding decision.
    Type: Application
    Filed: May 9, 2018
    Publication date: September 13, 2018
    Inventors: Eric Fogleman, Sheng Ye, Xuefeng Chen, Kok Lim Chan
  • Patent number: 10033412
    Abstract: A driver circuit includes a plurality of output circuits coupled in parallel between a differential input and a differential output and having a first common node and a second common node. Each of the plurality of output circuits includes a series combination of a pair of inverters and a pair of resistors, coupled between the differential input and the differential output; first source terminals of the pair of inverters coupled to the first common node; and second source terminals of the pair of inverters coupled to the second common node. The driver circuit further includes a first voltage regulator having an output coupled to the first common node of the plurality of output circuits; a second voltage regulator having an output coupled to the second common node of the plurality of circuits; and a current compensation circuit coupled between the outputs of the first voltage regulator and the second voltage regulator.
    Type: Grant
    Filed: December 11, 2017
    Date of Patent: July 24, 2018
    Assignee: XILINX, INC.
    Inventors: Siok Wei Lim, Kok Lim Chan, Kee Hian Tan, Hongyuan Zhao, Chin Yang Koay, Yohan Frans, Kun-Yung Chang
  • Patent number: 10003347
    Abstract: An asynchronous successive approximation register analog-to-digital converter (SAR ADC), which utilizes one or more overlapping redundant bits in each digital-to-analog converter (DAC) code word, is operable to generate an indication signal that indicates completion of each comparison step and indicates that an output decision for each comparison step is valid. A timer may be initiated based on the generated indication signal. A timeout signal may be generated that preempts the indication signal and forces a preemptive decision, where the preemptive decision sets one or more remaining bits up to, but not including, the one or more overlapping redundant bits in a corresponding digital-to-analog converter code word for a current comparison step to a particular value. For example, the one or more remaining bits may be set to a value that is derived from a value of a bit that was determined in an immediately preceding decision.
    Type: Grant
    Filed: September 21, 2017
    Date of Patent: June 19, 2018
    Assignee: Maxlinear, Inc.
    Inventors: Eric Fogleman, Sheng Ye, Xuefeng Chen, Kok Lim Chan
  • Publication number: 20180102797
    Abstract: A driver circuit includes a plurality of output circuits coupled in parallel between a differential input and a differential output and having a first common node and a second common node. Each of the plurality of output circuits includes a series combination of a pair of inverters and a pair of resistors, coupled between the differential input and the differential output; first source terminals of the pair of inverters coupled to the first common node; and second source terminals of the pair of inverters coupled to the second common node. The driver circuit further includes a first voltage regulator having an output coupled to the first common node of the plurality of output circuits; a second voltage regulator having an output coupled to the second common node of the plurality of circuits; and a current compensation circuit coupled between the outputs of the first voltage regulator and the second voltage regulator.
    Type: Application
    Filed: December 11, 2017
    Publication date: April 12, 2018
    Applicant: Xilinx, Inc.
    Inventors: Siok Wei Lim, Kok Lim Chan, Kee Hian Tan, Hongyuan Zhao, Chin Yang Koay, Yohan Frans, Kun-Yung Chang
  • Publication number: 20180041232
    Abstract: A driver circuit includes a plurality of output circuits coupled in parallel between a differential input and a differential output and having a first common node and a second common node. Each of the plurality of output circuits includes a series combination of a pair of inverters and a pair of resistors, coupled between the differential input and the differential output; first source terminals of the pair of inverters coupled to the first common node; and second source terminals of the pair of inverters coupled to the second common node. The driver circuit further includes a first voltage regulator having an output coupled to the first common node of the plurality of output circuits; a second voltage regulator having an output coupled to the second common node of the plurality of circuits; and a current compensation circuit coupled between the outputs of the first voltage regulator and the second voltage regulator.
    Type: Application
    Filed: August 3, 2016
    Publication date: February 8, 2018
    Applicant: Xilinx, Inc.
    Inventors: Siok Wei Lim, Kok Lim Chan, Kee Hian Tan, Hongyuan Zhao, Chin Yang Koay, Yohan Frans, Kun-Yung Chang
  • Patent number: 9887710
    Abstract: A driver circuit includes a plurality of output circuits coupled in parallel between a differential input and a differential output and having a first common node and a second common node. Each of the plurality of output circuits includes a series combination of a pair of inverters and a pair of resistors, coupled between the differential input and the differential output; first source terminals of the pair of inverters coupled to the first common node; and second source terminals of the pair of inverters coupled to the second common node. The driver circuit further includes a first voltage regulator having an output coupled to the first common node of the plurality of output circuits; a second voltage regulator having an output coupled to the second common node of the plurality of circuits; and a current compensation circuit coupled between the outputs of the first voltage regulator and the second voltage regulator.
    Type: Grant
    Filed: August 3, 2016
    Date of Patent: February 6, 2018
    Assignee: XILINX, INC.
    Inventors: Siok Wei Lim, Kok Lim Chan, Kee Hian Tan, Hongyuan Zhao, Chin Yang Koay, Yohan Frans, Kun-Yung Chang
  • Publication number: 20180013442
    Abstract: An asynchronous successive approximation register analog-to-digital converter (SAR ADC), which utilizes one or more overlapping redundant bits in each digital-to-analog converter (DAC) code word, is operable to generate an indication signal that indicates completion of each comparison step and indicates that an output decision for each comparison step is valid. A timer may be initiated based on the generated indication signal. A timeout signal may be generated that preempts the indication signal and forces a preemptive decision, where the preemptive decision sets one or more remaining bits up to, but not including, the one or more overlapping redundant bits in a corresponding digital-to-analog converter code word for a current comparison step to a particular value. For example, the one or more remaining bits may be set to a value that is derived from a value of a bit that was determined in an immediately preceding decision.
    Type: Application
    Filed: September 21, 2017
    Publication date: January 11, 2018
    Inventors: Eric Fogleman, Sheng Ye, Xuefeng Chen, Kok Lim Chan
  • Patent number: 9853642
    Abstract: An example output driver includes a plurality of output circuits coupled in parallel between a first voltage supply node and a second voltage supply node. Each of the plurality of output circuits includes a differential input that is coupled to receive a logic signal of a plurality of logic signals and a differential output that is coupled to a common output node. The output driver further includes voltage regulator(s), coupled to the voltage supply node(s), and a current compensation circuit. The current compensation circuit includes a switch coupled in series with a current source, where the switch and the current source are coupled between the first voltage supply node and the second voltage supply node. An event detector is coupled to the switch to supply an enable signal and to control state of the enable signal based on presence of a pattern in the plurality of logic signals.
    Type: Grant
    Filed: August 11, 2016
    Date of Patent: December 26, 2017
    Assignee: XILINX, INC.
    Inventors: Kee Hian Tan, Kok Lim Chan, Siok Wei Lim
  • Publication number: 20170346500
    Abstract: A system for processing signals may be configured to detect occurrence of particular errors, comprising meta-stability events, during digital conversion to analog signals, and to handle any detected meta-stability event, such as by adjusting at least a portion of a corresponding digital output based on detection of the meta-stability event. The adjusting of the digital output may comprise setting at least the portion of the digital output, such as to one of a plurality of predefined digital values or patterns. The system may comprise a code generator for generating and/or outputting the predefined digital values or patterns. The system may comprise a selector for adaptively selecting, for portions of the digital output, between output of normal processing path and between predefined values or patterns.
    Type: Application
    Filed: August 11, 2017
    Publication date: November 30, 2017
    Inventors: Xuefeng Chen, Kok Lim Chan, Eric Fogleman, Sheng Ye
  • Patent number: 9800253
    Abstract: An asynchronous successive approximation register analog-to-digital converter (SAR ADC), which utilizes one or more overlapping redundant bits in each digital-to-analog converter (DAC) code word, is operable to generate an indication signal that indicates completion of each comparison step and indicates that an output decision for each comparison step is valid. A timer may be initiated based on the generated indication signal. A timeout signal may be generated that preempts the indication signal and forces a preemptive decision, where the preemptive decision sets one or more remaining bits up to, but not including, the one or more overlapping redundant bits in a corresponding digital-to-analog converter code word for a current comparison step to a particular value. For example, the one or more remaining bits may be set to a value that is derived from a value of a bit that was determined in an immediately preceding decision.
    Type: Grant
    Filed: August 8, 2016
    Date of Patent: October 24, 2017
    Assignee: Maxlinear, Inc.
    Inventors: Eric Fogleman, Sheng Ye, Xuefeng Chen, Kok Lim Chan
  • Publication number: 20170134032
    Abstract: An asynchronous successive approximation register analog-to-digital converter (SAR ADC), which utilizes one or more overlapping redundant bits in each digital-to-analog converter (DAC) code word, is operable to generate an indication signal that indicates completion of each comparison step and indicates that an output decision for each comparison step is valid. A timer may be initiated based on the generated indication signal. A timeout signal may be generated that preempts the indication signal and forces a preemptive decision, where the preemptive decision sets one or more remaining bits up to, but not including, the one or more overlapping redundant bits in a corresponding digital-to-analog converter code word for a current comparison step to a particular value. For example, the one or more remaining bits may be set to a value that is derived from a value of a bit that was determined in an immediately preceding decision.
    Type: Application
    Filed: August 8, 2016
    Publication date: May 11, 2017
    Inventors: Eric Fogleman, Sheng Ye, Xuefeng Chen, Kok Lim Chan
  • Patent number: 9537503
    Abstract: Systems and methods are provided for detecting meta-stability during processing of signals. A meta-stability detector may comprise a timing control circuit, a plurality of signal adjustment circuits, and a plurality of signal state circuits. The timing control circuit may measure comparison time for each conversion cycle during analog-to-digital conversions. Each signal adjustment circuit may apply a logical operation to one or more input signals to the signal adjustment circuit, and provide a corresponding output signal. Each signal state circuit may store state information relating to one or more input signals to the signal state circuit, for at least one processing cycle; and provide an output signal based on prior stored information. The plurality of signal state circuits, plurality of signal adjustment circuits, and the timing control circuit may be arranged to generate one or more control signals for controlling an analog-to-digital converter (ADC) during the analog-to-digital conversions.
    Type: Grant
    Filed: May 10, 2016
    Date of Patent: January 3, 2017
    Assignee: MAXLINEAR, INC.
    Inventors: Xuefeng Chen, Kok Lim Chan, Eric Fogleman, Sheng Ye
  • Publication number: 20160322985
    Abstract: Systems and methods are provided for detecting meta-stability during processing of signals. A meta-stability detector may comprise a timing control circuit, a plurality of signal adjustment circuits, and a plurality of signal state circuits. The timing control circuit may measure comparison time for each conversion cycle during analog-to-digital conversions. Each signal adjustment circuit may apply a logical operation to one or more input signals to the signal adjustment circuit, and provide a corresponding output signal. Each signal state circuit may store state information relating to one or more input signals to the signal state circuit, for at least one processing cycle; and provide an output signal based on prior stored information.
    Type: Application
    Filed: May 10, 2016
    Publication date: November 3, 2016
    Inventors: Xuefeng Chen, Kok Lim Chan, Eric Fogleman, Sheng Ye
  • Patent number: 9413378
    Abstract: Methods and systems are provided for asynchronous successive approximation register (SAR) analog-to-digital converters (ADCs) that utilize preemptive bit setting decisions. In particular, such SAR ADC may be operable to, when a failure to determine a valid output decision for each comparison step occurs, set one or more remaining bits, up to but not including one or more overlapping redundant bits in a code word corresponding to the comparison step, to a particular value. The value may be derived from a value of a bit determined in an immediately preceding decision. The failure may be determined based on dynamic and/or adaptive criteria. The criteria may be set, e.g., so as to guarantee that a magnitude of a difference between an analog input voltage to the SAR ADC and analog output voltage of a digital-to-analog converter (DAC) used therein is within overlapping ranges of voltages corresponding to the overlapping redundant bits.
    Type: Grant
    Filed: September 2, 2015
    Date of Patent: August 9, 2016
    Assignee: Maxlinear, Inc.
    Inventors: Eric Fogleman, Sheng Ye, Xuefeng Chen, Kok Lim Chan
  • Patent number: 9337859
    Abstract: Methods and systems are provided for controlling signal processing outputs. In signal processing circuitry, searching through a plurality of quantization levels for a quantization level that matches an analog input, and when the search fails within a particular amount of time, adjusting at least a portion of an output of the signal processing circuitry. The adjusting comprises setting the at least portion of the output to a predefined value. Setting the output, or portions thereof, may comprise selecting between output of a normal processing path and output of a code generation path configured for handling search failures. Timing information may be generated for use in controlling generating of the output of the signal processing circuitry. The timing information may be used in measuring per-cycle operation time during the search through the plurality of quantization levels.
    Type: Grant
    Filed: July 29, 2015
    Date of Patent: May 10, 2016
    Assignee: MAXLINEAR, INC.
    Inventors: Xuefeng Chen, Kok Lim Chan, Eric Fogleman, Sheng Ye
  • Publication number: 20160006450
    Abstract: Methods and systems are provided for controlling signal processing outputs. In signal processing circuitry, searching through a plurality of quantization levels for a quantization level that matches an analog input, and when the search fails within a particular amount of time, adjusting at least a portion of an output of the signal processing circuitry. The adjusting comprises setting the at least portion of the output to a predefined value. Setting the output, or portions thereof, may comprise selecting between output of a normal processing path and output of a code generation path configured for handling search failures. Timing information may be generated for use in controlling generating of the output of the signal processing circuitry. The timing information may be used in measuring per-cycle operation time during the search through the plurality of quantization levels.
    Type: Application
    Filed: July 29, 2015
    Publication date: January 7, 2016
    Inventors: Xuefeng Chen, Kok Lim Chan, Eric Fogleman, Sheng Ye
  • Publication number: 20150381196
    Abstract: Methods and systems are provided for asynchronous successive approximation register (SAR) analog-to-digital converters (ADCs) that utilize preemptive bit setting decisions. In particular, such SAR ADC may be operable to, when a failure to determine a valid output decision for each comparison step occurs, set one or more remaining bits, up to but not including one or more overlapping redundant bits in a code word corresponding to the comparison step, to a particular value. The value may be derived from a value of a bit determined in an immediately preceding decision. The failure may be determined based on dynamic and/or adaptive criteria. The criteria may be set, e.g., so as to guarantee that a magnitude of a difference between an analog input voltage to the SAR ADC and analog output voltage of a digital-to-analog converter (DAC) used therein is within overlapping ranges of voltages corresponding to the overlapping redundant bits.
    Type: Application
    Filed: September 2, 2015
    Publication date: December 31, 2015
    Inventors: Eric Fogleman, Sheng Ye, Xuefeng Chen, Kok Lim Chan
  • Patent number: 9136859
    Abstract: An asynchronous successive approximation register analog-to-digital converter (SAR ADC), which utilizes one or more overlapping redundant bits in each digital-to-analog converter (DAC) code word, is operable to generate an indication signal that indicates completion of each comparison step and indicates that an output decision for each comparison step is valid. A timer may be initiated based on the generated indication signal. A timeout signal may be generated that preempts the indication signal and forces a preemptive decision, where the preemptive decision sets one or more remaining bits up to, but not including, the one or more overlapping redundant bits in a corresponding digital-to-analog converter code word for a current comparison step to a particular value. For example, the one or more remaining bits may be set to a value that is derived from a value of a bit that was determined in an immediately preceding decision.
    Type: Grant
    Filed: December 30, 2014
    Date of Patent: September 15, 2015
    Assignee: MAXLINEAR, INC.
    Inventors: Eric Fogleman, Sheng Ye, Xuefeng Chen, Kok Lim Chan
  • Patent number: 9124291
    Abstract: A system for processing signals may be configured to detect occurrence of particular errors, comprising meta-stability events, during digital conversion to analog signals, and to handle any detected meta-stability event, such as by adjusting at least a portion of a corresponding digital output based on detection of the meta-stability event. The adjusting of the digital output may comprise setting at least the portion of the digital output, such as to one of a plurality of predefined digital values or patterns. The system may comprise a code generator for generating and/or outputting the predefined digital values or patterns. The system may comprise a selector for adaptively selecting, for portions of the digital output, between output of normal processing path and between predefined values or patterns.
    Type: Grant
    Filed: July 18, 2013
    Date of Patent: September 1, 2015
    Assignee: MAXLINEAR, INC.
    Inventors: Xuefeng Chen, Kok Lim Chan, Eric Fogleman, Sheng Ye