Patents by Inventor Tai-Cheng Lee

Tai-Cheng Lee 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: 20240213999
    Abstract: A continuous-time delta-sigma modulator (CT-DSM) includes a loop filter, a pipelined successive-approximation register analog-to-digital converter (SAR ADC), a feedback circuit, an excess loop delay (ELD) compensation circuit, and a logic circuit. The loop filter generates a first intermediate signal according to an input signal, a feedback signal, and a compensation signal. The pipelined SAR ADC generates a first digital code, a second digital code, a first quantization error signal, and a second quantization error signal according to the first intermediate signal. The feedback circuit generates the feedback signal according to the first digital code, the first quantization error signal, and the second quantization error signal. The ELD compensation circuit generates the compensation signal according to at least one output signal of the feedback circuit. The logic circuit generates an output digital code according to the first digital code and the second digital code.
    Type: Application
    Filed: November 27, 2023
    Publication date: June 27, 2024
    Inventors: YAN-HUI WU, Yao-Ming Lu, Tai-Cheng Lee, Chih-Lung Chen, Sheng-Yen Shih
  • Patent number: 11201722
    Abstract: A clock and data recovery circuit includes a first sampling phase detector and filter circuitry, a frequency detector circuit, a current source circuit, a band controller circuit, and a voltage controlled oscillator. The first sampling phase detector and filter circuitry generates a first voltage according to a pair of data and a first set of clock signals. The frequency detector circuit generates an up control signal and a down control signal according to the pair of data and the first set of clock signals. The current source circuit generates the first voltage according to the up control signal and the down control signal. The band controller circuit generates a band control signal according to the first voltage. The voltage controlled oscillator adjusts the first set of clock signals according to the band control signal and the first voltage.
    Type: Grant
    Filed: December 9, 2020
    Date of Patent: December 14, 2021
    Assignee: DigWise Technology Corporation, LTD
    Inventors: Shih-Hao Chen, Chiou-Bang Chen, Wen-Pin Hsieh, Tai-Cheng Lee, Heng-Jui Liu
  • Patent number: 11133813
    Abstract: An analog-to-digital converter (ADC) device includes an ADC circuitry and a digital slope ADC circuitry. The ADC circuitry is configured to generate first bits and a first voltage according to an input signal. The digital slope ADC circuitry is configured to generate a second voltage at a node according to the first voltage and to gradually adjust the second voltage to generate second bits. After the second bits are generated, the digital slope ADC circuitry is further configured to perform a noise shaping function according to a first residual signal of the node.
    Type: Grant
    Filed: April 14, 2020
    Date of Patent: September 28, 2021
    Assignee: REALTEK SEMICONDUCTOR CORPORATION
    Inventors: Jie-Fan Lai, Shih-Hsiung Huang, Yu-Chang Chen, Chih-Lung Chen, Tzu-Hao Hung, Tai-Cheng Lee
  • Publication number: 20210099183
    Abstract: An analog-to-digital converter (ADC) device includes an ADC circuitry and a digital slope ADC circuitry. The ADC circuitry is configured to generate first bits and a first voltage according to an input signal. The digital slope ADC circuitry is configured to generate a second voltage at a node according to the first voltage and to gradually adjust the second voltage to generate second bits. After the second bits are generated, the digital slope ADC circuitry is further configured to perform a noise shaping function according to a first residual signal of the node.
    Type: Application
    Filed: April 14, 2020
    Publication date: April 1, 2021
    Inventors: JIE-FAN LAI, SHIH-HSIUNG HUANG, YU-CHANG CHEN, CHIH-LUNG CHEN, TZU-HAO HUNG, TAI-CHENG LEE
  • Patent number: 9685970
    Abstract: An analog-to-digital converting system includes at least one first main analog-to-digital converting unit, at least one second main analog-to-digital converting unit, at least one auxiliary analog-to-digital converting unit, and a calibration unit. Each first main analog-to-digital converting unit is located on a first channel. The first channel includes sample period. Each first main analog-to-digital converting unit receives a first sampling value. Each first sampling value includes a first sample clock. An analog-to-digital converting method calibrates timing-skew of the analog-to-digital converters by delaying a time difference on the sampling value.
    Type: Grant
    Filed: July 29, 2016
    Date of Patent: June 20, 2017
    Assignees: NATIONAL TAIWAN UNIVERSITY, MEDIA TEK INC.
    Inventors: Tai-Cheng Lee, Chin-Yu Lin, Yen-Hsin Wei
  • Patent number: 8787424
    Abstract: A spread spectrum transmission circuit includes a phase locked loop composed of a filter. The phase locked loop generates a series of incremental control signals and decreasing control signals based on the frequency difference and phase difference between a reference clock signal and a feedback signal. The circuit further has a frequency locked loop an amplitude locked loop, a digital-analog converter, an injection current source, an extraction current source, a multiplexer is connected to the locked phase loop and a rail-to-rail digital signal generator having an input connected to the multiplexer and an output connected to inputs of the locked frequency loop and the locked amplitude loop.
    Type: Grant
    Filed: June 26, 2013
    Date of Patent: July 22, 2014
    Assignee: National Taiwan University
    Inventors: Tai-Cheng Lee, Chien-Heng Wong
  • Publication number: 20140146933
    Abstract: A spread spectrum transmission circuit includes a phase locked loop composed of a filter. The phase locked loop generates a series of incremental control signals and decreasing control signals based on the frequency difference and phase difference between a reference clock signal and a feedback signal. The circuit further has a frequency locked loop an amplitude locked loop, a digital-analog converter, an injection current source, an extraction current source, a multiplexer is connected to the locked phase loop and a rail-to-rail digital signal generator having an input connected to the multiplexer and an output connected to inputs of the locked frequency loop and the locked amplitude loop.
    Type: Application
    Filed: June 26, 2013
    Publication date: May 29, 2014
    Inventors: Tai-Cheng Lee, Chien-Heng Wong
  • Patent number: 8471753
    Abstract: A pipelined analog-to-digital converter with less power consumption is provided. In one embodiment, the pipelined analog-to-digital converter comprises a first stage, a second stage, and a third stage. The first stage receives a first stage input signal to derive a first stage output signal and a first residue. The second stage receives a second stage input signal to derive a second stage output signal and a second residue, wherein the second stage input signal corresponds to the first residue. The third stage receives a third stage input signal to derive a third stage output signal and a third residue, wherein the third stage input signal corresponds to the second residue. The first, second and third stages share an operational amplifier by utilizing at least three phases to control the operational amplifier.
    Type: Grant
    Filed: February 25, 2011
    Date of Patent: June 25, 2013
    Assignees: Mediatek Inc., National Taiwan University
    Inventors: Yen-Chuan Huang, Tai-Cheng Lee
  • Patent number: 7982650
    Abstract: The digital-to-analog converter in accordance with the present invention comprises an R-2R transistor-only ladder converter and a digital controller. The controller connects to the R-2R transistor-only ladder converter and comprises at least one regulating transistor and at least one shifting transistor. The at least one regulating transistor has an aspect ratio of kR(W/L). The at least one shifting transistor has an aspect ratio of kS(W/L). Setting the aspect ratios kR(W/L) and kS(W/L) of the shifting and regulating transistors adjusts a linear output current waveform to a non-linear waveform. The method to output a non-linear current comprises acts of determining an optimum non-linear output current, dividing a linear output current into multiple sections, determining slopes of the waveform of the output current, adding a controller corresponding to an R-2R transistor-only ladder converter, setting aspect ratios kR(W/L) of regulating transistors and setting an aspect ratios kS(W/L) of shifting transistors.
    Type: Grant
    Filed: October 1, 2009
    Date of Patent: July 19, 2011
    Assignee: National Taiwan University
    Inventors: Tai-Cheng Lee, Cheng-Hsiao Lin
  • Patent number: 7932849
    Abstract: A method for achieving high-speed analog-to-digital conversion without degrading accuracy includes: receiving digital outputs of a plurality of pipelined analog-to-digital converters (ADCs) that perform analog-to-digital conversion on a same analog signal; and performing digital calculations on the digital outputs to generate a calibrated digital output. An apparatus for achieving high-speed analog-to-digital conversion without degrading accuracy is further provided. The apparatus includes: a digital module arranged to receive digital outputs of a plurality of pipelined ADCs that perform analog-to-digital conversion on a same analog signal. In addition, the digital module includes a plurality of digital calculation paths respectively corresponding to the pipelined ADCs, wherein each digital calculation path corresponding to an associate pipelined ADC of the pipelined ADCs is electrically connected to the associate pipelined ADC.
    Type: Grant
    Filed: December 24, 2008
    Date of Patent: April 26, 2011
    Assignees: Mediatek Inc., National Taiwan University
    Inventors: Li-Han Hung, Tai-Cheng Lee
  • Publication number: 20100156682
    Abstract: A method for achieving high-speed analog-to-digital conversion without degrading accuracy includes: receiving digital outputs of a plurality of pipelined analog-to-digital converters (ADCs) that perform analog-to-digital conversion on a same analog signal; and performing digital calculations on the digital outputs to generate a calibrated digital output. An apparatus for achieving high-speed analog-to-digital conversion without degrading accuracy is further provided. The apparatus includes: a digital module arranged to receive digital outputs of a plurality of pipelined ADCs that perform analog-to-digital conversion on a same analog signal. In addition, the digital module includes a plurality of digital calculation paths respectively corresponding to the pipelined ADCs, wherein each digital calculation path corresponding to an associate pipelined ADC of the pipelined ADCs is electrically connected to the associate pipelined ADC.
    Type: Application
    Filed: December 24, 2008
    Publication date: June 24, 2010
    Inventors: Li-Han Hung, Tai-Cheng Lee
  • Publication number: 20100141498
    Abstract: The digital-to-analog converter in accordance with the present invention comprises an R-2R transistor-only ladder converter and a digital controller. The controller connects to the R-2R transistor-only ladder converter and comprises at least one regulating transistor and at least one shifting transistor. The at least one regulating transistor has an aspect ratio of kR(W/L). The at least one shifting transistor has an aspect ratio of kS(W/L). Setting the aspect ratios kR(W/L) and kS(W/L) of the shifting and regulating transistors adjusts a linear output current waveform to a non-linear waveform. The method to output a non-linear current comprises acts of determining an optimum non-linear output current, dividing a linear output current into multiple sections, determining slopes of the waveform of the output current, adding a controller corresponding to an R-2R transistor-only ladder converter, setting aspect ratios kR(W/L) of regulating transistors and setting an aspect ratios kS(W/L) of shifting transistors.
    Type: Application
    Filed: October 1, 2009
    Publication date: June 10, 2010
    Applicant: National Taiwan University
    Inventors: Tai-Cheng LEE, Cheng-Hsiao Lin
  • Publication number: 20090125272
    Abstract: A method for analyzing circuit comprises the steps of selecting a plurality of elements; sampling the selected elements, resulting in a plurality of sampling-parameter sets; simulating the sampling-parameter sets to generate a plurality of simulation-results, and process the regression operation for the sampling-parameter sets and simulation-results in order to acquire the contribution rank of each sampling-parameter set and element. Accordingly, while analyzing similar circuits, the partial elements can be selected according to the contribution rank and further sampled; thereby, the amount of sampling-parameter sets can be advantageously reduced, and the analysis efficiency can be improved according to the circuit.
    Type: Application
    Filed: November 7, 2008
    Publication date: May 14, 2009
    Inventors: Hsin-Lan CHANG, Tai-Cheng Lee, Sheng-Yow Chen
  • Patent number: 6864753
    Abstract: A stabilization technique that relaxes the tradeoff between the settling speed and the magnitude of output sidebands in phase-locked frequency synthesizers. The method introduces a zero in the open-loop transfer function through the use of a discrete-time delay element, thereby obviating the need for resistors in the loop filter.
    Type: Grant
    Filed: January 29, 2003
    Date of Patent: March 8, 2005
    Assignee: The Regents of the University of California
    Inventors: Tai-Cheng Lee, Behzad Razavi
  • Publication number: 20030227332
    Abstract: A stabilization technique that relaxes the tradeoff between the settling speed and the magnitude of output sidebands in phase-locked frequency synthesizers. The method introduces a zero in the open-loop transfer function through the use of a discrete-time delay element, thereby obviating the need for resistors in the loop filter.
    Type: Application
    Filed: January 29, 2003
    Publication date: December 11, 2003
    Applicant: The Regents of the University of California
    Inventors: Tai-Cheng Lee, Behzad Razavi