Patents by Inventor Yu-Kai Chou

Yu-Kai Chou 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: 8922409
    Abstract: A switch-driving circuit and a Digital-to-Analog Converter (DAC) using the switch-driving circuit are provided. The switch-driving circuit includes a main cell and a reference cell. The main cell includes a current source and a resistance-control component electronically connected to the current source. The reference cell is coupled to the current source and the resistance-control component, and includes a first loop, the first loop is configured to track a target reference voltage so as to provide at least one first control voltage to control a resistance change of the resistance-control component. The reference cell and the main cell are implemented by MOS transistors in place of capacitors which occupy an increased circuit area, rendering reduced circuit area for the switch-driving circuit, and decreasing manufacturing costs. Further, the switch-driving circuit outputs a voltage signal with reduced noise, increasing the performance of the Digital-to-Analog Converter.
    Type: Grant
    Filed: March 15, 2013
    Date of Patent: December 30, 2014
    Assignee: MediaTek Singapore Pte. Ltd.
    Inventors: Cheng Tao, Yue Feng, Kun Lan, Yu-Kai Chou
  • Patent number: 8836556
    Abstract: An Analog to Digital Converter (ADC), an analog-to-digital conversion method, and an integrated circuit including the ADC. The ADC includes an input adjustment buffer stage, a sub-ADC, and a sample switch. The sample switch is coupled between the output node of the input adjustment buffer stage and the input node of the sub-ADC. When the sample switch is opened, the input adjustment buffer stage is configured to switch between a first work state and a second work state according to a predetermined rule, and to adjust an input voltage signal of the input adjustment buffer stage based on transitions between the first and second work states. When the sample switch is closed, the input adjustment buffer stage is configured to provide an adjusted voltage signal to the input node of the sub-ADC, and the sub-ADC is configured to perform an analog-to-digital conversion onto the adjusted voltage signal.
    Type: Grant
    Filed: March 13, 2013
    Date of Patent: September 16, 2014
    Assignee: MediaTek Singapore Pte. Ltd.
    Inventors: Yingyi Liu, Yu-Kai Chou, Kun Lan
  • Patent number: 8810218
    Abstract: A voltage regulator includes a pass transistor, an operational amplifier and a voltage divider circuit. The pass transistor receives a supply voltage to generate a regulated output voltage according to a control signal. The operational amplifier generates the control signal according to a feedback voltage. The voltage divider circuit generates the feedback voltage at a feedback node according to the regulated output voltage, and includes a string of resistors and a stabilization element. The string of resistors is coupled to the pass transistor and includes multiple resistors. The stabilization element is coupled to the resistors and receives the regulated output voltage.
    Type: Grant
    Filed: September 12, 2012
    Date of Patent: August 19, 2014
    Assignee: Mediatek Singapore Pte. Ltd.
    Inventors: Yingyi Liu, Kun Lan, Chih-Chien Huang, Yu-Kai Chou
  • Patent number: 8730080
    Abstract: An analog-to-digital converter is provided. The analog-to-digital converter includes a sampling-voltage providing circuit, a first comparison circuit, a second comparison circuit, and an encoder circuit. The sampling-voltage providing circuit provides a group of first comparison voltages and a group of second comparison voltages. The first comparison circuit performs a first comparison operation to an analog-signal input quantity according to the group of first comparison voltages to generate a first comparison digital quantity. The second comparison circuit selects second comparison voltages among the group of second comparison voltages according to the first comparison digital quantity and performs a second comparison operation to the analog-signal input quantity according to the selected second comparison voltages to generate a second comparison digital quantity.
    Type: Grant
    Filed: August 13, 2012
    Date of Patent: May 20, 2014
    Assignee: Mediatek Singapore Pte. Ltd.
    Inventors: Cong Liu, Yu-Kai Chou
  • Patent number: 8723714
    Abstract: A multiplying digital-to-analog converter (MDAC) is provided. The MDAC includes a sub DAC decoding circuit, a capacitor-switch circuit, and an operation amplifier circuit. The capacitor-switch circuit includes at least two sampling capacitor sets which are coupled in parallel. The number of sampling capacitors in one of the sampling capacitor sets is larger than or equal to two. Each sampling capacitor set is coupled to an analog-signal input quantity through a sampling switch and to a corresponding output terminal of the sub DAC decoding circuit through a decoding switch. The sub DAC decoding circuit decodes a digital quantity and outputs a corresponding analog signal at each output terminal, such that the corresponding analog signals are applied to the respective sampling capacitor sets through the decoding switches and summed by the respective sampling capacitor sets to obtain an analog-signal quantity corresponding to the digital quantity.
    Type: Grant
    Filed: August 6, 2012
    Date of Patent: May 13, 2014
    Assignee: Mediatek Singapore Pte. Ltd.
    Inventors: Cong Liu, Yu-Kai Chou
  • Patent number: 8711025
    Abstract: A method for configuring a plurality of analog-to-digital converter (ADC) keys includes: utilizing a processor for determining a plurality of divided-voltages respectively corresponding to the Keys according to a plurality of voltage variation ranges respectively corresponding to the Keys; and calculating a plurality of resistive values of a voltage dividing model according to at least the divided-voltages, wherein the voltage dividing model has a plurality of voltage dividing configurations respectively corresponding to the keys.
    Type: Grant
    Filed: September 12, 2012
    Date of Patent: April 29, 2014
    Assignee: MediaTek Singapore Pte. Ltd.
    Inventors: Kun Lan, Yingyi Liu, Yu-Kai Chou
  • Publication number: 20130314262
    Abstract: A switch-driving circuit and a Digital-to-Analog Converter (DAC) using the switch-driving circuit are provided. The switch-driving circuit includes a main cell and a reference cell. The main cell includes a current source and a resistance-control component electronically connected to the current source. The reference cell is coupled to the current source and the resistance-control component, and includes a first loop, the first loop is configured to track a target reference voltage so as to provide at least one first control voltage to control a resistance change of the resistance-control component. The reference cell and the main cell are implemented by MOS transistors in place of capacitors which occupy an increased circuit area, rendering reduced circuit area for the switch-driving circuit, and decreasing manufacturing costs. Further, the switch-driving circuit outputs a voltage signal with reduced noise, increasing the performance of the Digital-to-Analog Converter.
    Type: Application
    Filed: March 15, 2013
    Publication date: November 28, 2013
    Applicant: MEDIATEK SINGAPORE PTE. LTD.
    Inventors: Cheng TAO, Yue FENG, Kun LAN, Yu-Kai CHOU
  • Publication number: 20130293403
    Abstract: An Analog to Digital Converter (ADC), an analog-to-digital conversion method, and an integrated circuit including the ADC. The ADC includes an input adjustment buffer stage, a sub-ADC, and a sample switch. The sample switch is coupled between the output node of the input adjustment buffer stage and the input node of the sub-ADC. When the sample switch is opened, the input adjustment buffer stage is configured to switch between a first work state and a second work state according to a predetermined rule, and to adjust an input voltage signal of the input adjustment buffer stage based on transitions between the first and second work states. When the sample switch is closed, the input adjustment buffer stage is configured to provide an adjusted voltage signal to the input node of the sub-ADC, and the sub-ADC is configured to perform an analog-to-digital conversion onto the adjusted voltage signal.
    Type: Application
    Filed: March 13, 2013
    Publication date: November 7, 2013
    Applicant: MediaTek Singapore Pte. Ltd.
    Inventors: Yingyi LIU, Yu-Kai CHOU, Kun LAN
  • Publication number: 20130201042
    Abstract: A method for configuring a plurality of analog-to-digital converter (ADC) keys includes: utilizing a processor for determining a plurality of divided-voltages respectively corresponding to the Keys according to a plurality of voltage variation ranges respectively corresponding to the Keys; and calculating a plurality of resistive values of a voltage dividing model according to at least the divided-voltages, wherein the voltage dividing model has a plurality of voltage dividing configurations respectively corresponding to the keys.
    Type: Application
    Filed: September 12, 2012
    Publication date: August 8, 2013
    Inventors: Kun Lan, Yingyi Liu, Yu-Kai Chou
  • Publication number: 20130076325
    Abstract: A voltage regulator includes a pass transistor, an operational amplifier and a voltage divider circuit. The pass transistor receives a supply voltage to generate a regulated output voltage according to a control signal. The operational amplifier generates the control signal according to a feedback voltage. The voltage divider circuit generates the feedback voltage at a feedback node according to the regulated output voltage, and includes a string of resistors and a stabilization element. The string of resistors is coupled to the pass transistor and includes multiple resistors. The stabilization element is coupled to the resistors and receives the regulated output voltage.
    Type: Application
    Filed: September 12, 2012
    Publication date: March 28, 2013
    Applicant: MEDIATEK SINGAPORE PTE. LTD.
    Inventors: Yingyi LIU, Kun LAN, Chih-Chien HUANG, Yu-Kai CHOU
  • Publication number: 20130038483
    Abstract: An analog-to-digital converter is provided. The analog-to-digital converter includes a sampling-voltage providing circuit, a first comparison circuit, a second comparison circuit, and an encoder circuit. The sampling-voltage providing circuit provides a group of first comparison voltages and a group of second comparison voltages. The first comparison circuit performs a first comparison operation to an analog-signal input quantity according to the group of first comparison voltages to generate a first comparison digital quantity. The second comparison circuit selects second comparison voltages among the group of second comparison voltages according to the first comparison digital quantity and performs a second comparison operation to the analog-signal input quantity according to the selected second comparison voltages to generate a second comparison digital quantity.
    Type: Application
    Filed: August 13, 2012
    Publication date: February 14, 2013
    Applicant: MEDIATEK SINGAPORE PTE. LTD.
    Inventors: Cong LIU, Yu-Kai CHOU
  • Publication number: 20130033391
    Abstract: A multiplying digital-to-analog converter (MDAC) is provided. The MDAC includes a sub DAC decoding circuit, a capacitor-switch circuit, and an operation amplifier circuit. The capacitor-switch circuit includes at least two sampling capacitor sets which are coupled in parallel. The number of sampling capacitors in one of the sampling capacitor sets is larger than or equal to two. Each sampling capacitor set is coupled to an analog-signal input quantity through a sampling switch and to a corresponding output terminal of the sub DAC decoding circuit through a decoding switch. The sub DAC decoding circuit decodes a digital quantity and outputs a corresponding analog signal at each output terminal, such that the corresponding analog signals are applied to the respective sampling capacitor sets through the decoding switches and summed by the respective sampling capacitor sets to obtain an analog-signal quantity corresponding to the digital quantity.
    Type: Application
    Filed: August 6, 2012
    Publication date: February 7, 2013
    Applicant: MEDIATEK SINGAPORE PTE. LTD.
    Inventors: Cong LIU, Yu-Kai CHOU
  • Publication number: 20130027232
    Abstract: An analog-to-digital converter is provided and comprises a most significant bit (MSB) conversion module, a successive approximation register analog-to-digital converter (SAR ADC) module, and an operation module. The MSB conversion module receives an analog signal to be converted, and converts the analog signal to an MSB with M bits, and obtains a redundancy signal. The SAR ADC module is coupled to the MSB conversion module. The SAR ADC receives the redundancy signal and processes the redundancy signal to be a least significant bit (LSB) with N bits. The operation module is coupled to the MSB conversion module and the SAR ADC module. The operation module receives the MSB with the M bits and the LSB with the N bits and generates a first digital signal with (M+N) bits. Each of M and N is positive, and (M+N) is a positive integer.
    Type: Application
    Filed: July 27, 2012
    Publication date: January 31, 2013
    Applicant: MEDIATEK SINGAPORE PTE. LTD.
    Inventors: Yingyi LIU, Yu-Kai CHOU, Kun LAN
  • Publication number: 20120273044
    Abstract: The disclosure provides an electrolyte composition and dye-sensitized solar cell using the same. The electrolyte composition includes a diionic liquid of Formula: Z?(X-Y-X)Z??, wherein X includes ammonium, imidazolium, pyridinium or phosphonium, Y is (CH2)n, n is an integer of 1-16, Z is I, and Z? is I, PF6, BF4, N(SO2CF3), NCS or N(CN)2.
    Type: Application
    Filed: July 4, 2012
    Publication date: November 1, 2012
    Applicant: INDUSTRIAL TECHNOLOGY RESEARCH INSTITUTE
    Inventors: Yung-Liang Tung, Jia-Yin Wu, Jen-An Chen, Wen-Yueh Ho, Yu-Kai Chou
  • Patent number: 7911370
    Abstract: A pipeline analog-to-digital converter (ADC) comprises a plurality of pipeline stages is disclosed. The first pipeline stage has programmable gain function. The first pipeline stage includes a sub-analog-to-digital converter (sub-ADC) and a multiplying digital-to-analog converter (MDAC) implemented by switched capacitor (SC) circuits. Different capacitances in the sub-ADC and MDAC are provided so as to provide different gains by controlling switches in the SC circuits.
    Type: Grant
    Filed: June 25, 2009
    Date of Patent: March 22, 2011
    Assignee: Mediatek Inc.
    Inventor: Yu-kai Chou
  • Publication number: 20100328129
    Abstract: A pipeline analog-to-digital converter (ADC) comprises a plurality of pipeline stages is disclosed. The first pipeline stage has programmable gain function. The first pipeline stage includes a sub-analog-to-digital converter (sub-ADC) and a multiplying digital-to-analog converter (MDAC) implemented by switched capacitor (SC) circuits. Different capacitances in the sub-ADC and MDAC are provided so as to provide different gains by controlling switches in the SC circuits.
    Type: Application
    Filed: June 25, 2009
    Publication date: December 30, 2010
    Applicant: MEDIATEK INC.
    Inventor: Yu-kai Chou
  • Patent number: 7847720
    Abstract: A pipelined analog-to-digital converter includes at least one multiplying digital-to-analog converter and at least one sub-ADC. The multiplying digital-to-analog converter includes at least one first capacitor, at least one second capacitor, an amplifier, and a plurality of switches. The amplifier is coupled to the first and the second capacitors. The switches control a connection between the first and the second capacitors according to a first control signal, a second control signal and a digital signal. In a first period, the first capacitor is connected to the second capacitor in parallel. In a second period, the first capacitor is connected to the second capacitor in series. At least one switch among the switches is composed of a transistor. The sub-ADC provides a digital signal according to the first and second control signals.
    Type: Grant
    Filed: January 16, 2009
    Date of Patent: December 7, 2010
    Assignee: Mediatek Inc.
    Inventor: Yu-Kai Chou
  • Patent number: 7847601
    Abstract: A comparator includes a plurality of switches, a capacitor, an amplifier, and a latch. The switches provide an input signal during a first period and provide a reference signal during a second period. A first switch among the switches is composed of a first transistor. The capacitor receives the input signal during the first period and receives the reference signal during the second period. The amplifier is coupled to the capacitor for receiving a difference voltage between the input signal and the reference signal and amplifies the difference voltage during the second period to generate an amplified result. The determining circuit provides a digital signal according to the amplified result.
    Type: Grant
    Filed: November 21, 2008
    Date of Patent: December 7, 2010
    Assignee: Mediatek Inc.
    Inventor: Yu-Kai Chou
  • Patent number: 7847629
    Abstract: A sample-and-hold amplifier is provided. The sample-and-hold amplifier comprises a sample-and-hold circuit and a buffer circuit. The sample-and-hold circuit receives an input signal and transmits the input signal to a first node according to a control signal. The buffer circuit is coupled between a supply voltage source and a ground and controlled by the first node to provide an output signal at an output node. The buffer circuit comprises a native MOS transistor coupled to the output node.
    Type: Grant
    Filed: January 22, 2009
    Date of Patent: December 7, 2010
    Assignee: Mediatek Inc.
    Inventor: Yu-Kai Chou
  • Publication number: 20100182179
    Abstract: A pipelined analog-to-digital converter includes at least one multiplying digital-to-analog converter and at least one sub-ADC. The multiplying digital-to-analog converter includes at least one first capacitor, at least one second capacitor, an amplifier, and a plurality of switches. The amplifier is coupled to the first and the second capacitors. The switches control a connection between the first and the second capacitors according to a first control signal, a second control signal and a digital signal. In a first period, the first capacitor is connected to the second capacitor in parallel. In a second period, the first capacitor is connected to the second capacitor in series. At least one switch among the switches is composed of a transistor. The sub-ADC provides a digital signal according to the first and second control signals.
    Type: Application
    Filed: January 16, 2009
    Publication date: July 22, 2010
    Applicant: MEDIATEK INC.
    Inventor: Yu-Kai Chou