Patents by Inventor Chao-Cheng Lee

Chao-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).

  • Patent number: 7404094
    Abstract: A relay set in a network device. The relay includes a first switch, a switch control unit, and a first AC coupling unit. The first switch is coupled between a first receiving end of the network device and a first transmitting end of the network device. The switch control unit is configured to turn off the first switch when the network device is in a first state. The first AC coupling unit is configured to turn on the first switch according to a first signal received from the first receiving end when the network device is in a second state.
    Type: Grant
    Filed: March 7, 2006
    Date of Patent: July 22, 2008
    Assignee: Realtek Semiconductor Corp.
    Inventors: Chao-Cheng Lee, Shian-Ru Lin
  • Patent number: 7383528
    Abstract: A method of the invention is used for checking a wire layout causing high wire resistance. The method includes the steps of: selecting a first metal layer, a second metal layer and a third metal layer, wherein each of the first and third metal layer includes a power wire for transmitting power, and the second metal layer is adjacent to the first and third metal layers; selecting one region in the second metal layer, wherein the first and the third metal layers have the power wires at positions corresponding to the region and the second metal layer has no wire at the region; and disposing a conductive metal layer coupled to the first and third metal layer in the region for lowering the equivalent wire resistance.
    Type: Grant
    Filed: August 24, 2004
    Date of Patent: June 3, 2008
    Assignee: Realtek Semiconductor Corp.
    Inventors: Jai-Ming Lin, Chao-Cheng Lee
  • Patent number: 7378875
    Abstract: A circuit apparatus having compensation circuits for unequal input/output common mode voltages is presented. The apparatus includes a circuit unit, a feedback path and a current source. The circuit unit has at least an input terminal for receiving an input signal and at least an output terminal for generating an output signal. The input terminal configured to provide an input common mode voltage and the output terminal configured to provide an output common mode voltage. The feedback path couples the output terminal and the input terminal. The current source is coupled to the input terminal to supply a current. The voltage drop generated at the feedback path compensates the difference between the input common mode voltage and the output common mode voltage.
    Type: Grant
    Filed: November 14, 2005
    Date of Patent: May 27, 2008
    Assignee: Realtek Semiconductor Corp.
    Inventors: Chao-Cheng Lee, Tzung-Ming Chen
  • Publication number: 20080101521
    Abstract: A clock and data recovery circuit includes a voltage controlled oscillator for generating an output clock according to a control voltage signal, a loop filter for outputting the control voltage signal according to a current output, a charge pump unit for outputting the current output according to an error signal, and a controller for determining a run length corresponding to input data based on the output clock from the voltage controlled oscillator. The controller further controls at least one of the voltage controlled oscillator, the loop filter and the charge pump unit according to the run length to dynamically adjust loop bandwidth. A method of adjusting loop bandwidth is also disclosed.
    Type: Application
    Filed: October 26, 2007
    Publication date: May 1, 2008
    Applicant: Realtek Semiconductor Corp.
    Inventors: Chao-Cheng Lee, Tzu-Chien Tzeng
  • Publication number: 20080068071
    Abstract: A voltage converting circuit is able to convert an input voltage generated by a system to a voltage capable of being utilized by a chip, avoids the defects of conventional switching regulators and linear regulators, and achieves voltage regulation with extremely high power efficiency and without off-chip components. The voltage converting circuit is adapted in systems with a plurality of similar or identical circuits.
    Type: Application
    Filed: November 29, 2007
    Publication date: March 20, 2008
    Inventor: Chao-Cheng Lee
  • Publication number: 20080058030
    Abstract: A transmitter for transmitting a transmission signal is disclosed. The transmitter includes: a gain stage, for receiving an input signal and amplifying the input signal according to a gain to generate an amplified signal; and an output stage, coupled to the gain stage, for receiving a first reference voltage signal and the amplified signal and utilizing the first reference voltage signal to perform a predetermined operation on the amplified signal to generate the output signal.
    Type: Application
    Filed: March 23, 2007
    Publication date: March 6, 2008
    Inventor: Chao-Cheng Lee
  • Publication number: 20080048748
    Abstract: A delay adjustor for adjusting the delay time of a signal, the adjustor comprising: a first capacitance unit and a variable capacitance unit serially coupled to the first capacitor wherein the capacitance of the variable capacitance unit is adjusted according to a first control signal and the variable capacitance unit comprises a plurality of second capacitors and at least a first switch coupled to the at least one capacitor of the second capacitors.
    Type: Application
    Filed: July 24, 2007
    Publication date: February 28, 2008
    Inventor: Chao-Cheng Lee
  • Publication number: 20080048778
    Abstract: A common-mode feedback circuit is provided. An amplifier with a common-mode feedback circuit is compensated by adding a compensating unit so that the amplifier totally has two poles and one zero in its frequency response. Accordingly, the gain of the amplifier is not sacrificed, and both the stability and the phase margin of the circuit are improved.
    Type: Application
    Filed: June 13, 2007
    Publication date: February 28, 2008
    Applicant: Realtek Semiconductor Corp.
    Inventors: Chao-Cheng Lee, Chieh-Min Feng
  • Publication number: 20080024228
    Abstract: The present invention discloses an apparatus for generating an output signal according to an input signal, including a signal generating circuit for generating a first and a second control signal according to the input signal; a first output stage has a first amplifying configuration for receiving the first control signal; and a second output stage has a second amplifying configuration for receiving the second control signal, wherein the first amplifying configuration is different from the second amplifying configuration.
    Type: Application
    Filed: July 26, 2007
    Publication date: January 31, 2008
    Inventor: Chao-Cheng Lee
  • Patent number: 7298214
    Abstract: An amplifying circuit with a variable supply voltage and a method thereof are disclosed. The amplifying circuit employs a voltage converter to adjust the supply voltage, thereby upgrading the energy efficiency of the circuit. The circuit also includes a control device, which can generate a control signal for controlling the voltage converter according to an output signal or input signal of the circuit.
    Type: Grant
    Filed: June 15, 2005
    Date of Patent: November 20, 2007
    Assignee: Realtek Semiconductor Corp.
    Inventors: Chao-Cheng Lee, Tzung-Ming Chen, Chieh-Min Feng
  • Publication number: 20070262810
    Abstract: The present invention relates to a power managing apparatus utilized for controlling a first supply voltage, a second supply voltage, and a substrate voltage of a digital circuit. The power managing apparatus includes a voltage generating device, for generating a first reference voltage and a second reference voltage; and a voltage switching device, coupled to the voltage generating device, for adjusting the first supply voltage, the second supply voltage, and the substrate voltage. When the digital circuit operates in a first operating mode, the voltage switching device outputs the second reference voltage to the first supply voltage and the substrate voltage; and when the digital circuit operates in a second operating mode, the voltage switching device outputs the first reference voltage to the first supply voltage, and outputs the second reference voltage to the second supply voltage.
    Type: Application
    Filed: May 8, 2007
    Publication date: November 15, 2007
    Inventors: Chao-Cheng Lee, Tzu-Chien Tzeng
  • Patent number: 7288976
    Abstract: A charge pump circuit capable of canceling current mismatch and suppressing clock feedthrough. The charge pump circuit comprises a current source enabled by a first logical signal, a current sink enabled by a second logical signal, an integrating capacitor coupled to both the current source and the current sink, and a switching device coupled between the integrating circuit and an output node. The switching device has two states. The switching device is set to a first state whenever a third logical signal is asserted and one of the first logical signal, the second logical signal, and a modulating signal is enabled. The switching device is set to a second state whenever the third logical signal is de-asserted, or none of the first logical signal, the second logical signal, and the modulating signal are asserted.
    Type: Grant
    Filed: March 31, 2006
    Date of Patent: October 30, 2007
    Assignee: Realtek Semiconductor Corp.
    Inventors: Chao-Cheng Lee, Ren-Chieh Liu
  • Publication number: 20070241823
    Abstract: The present invention discloses a voltage-controlled oscillating apparatus to generate an oscillating signal. The voltage-controlled oscillating device includes: a regulating circuit, a biasing circuit, and an oscillator. In which the regulating circuit includes an amplifier, with a first input terminal coupled to a control voltage; and a voltage adjusting circuit, coupled between a second input terminal and an output terminal to feed a feedback voltage back to the second input terminal of the amplifier, and adjust the feedback voltage according to the output signal in the output terminal of the amplifier. The biasing circuit is coupled to the output terminal of the amplifier to generate a biasing signal according to the output signal in the output terminal of the amplifier; and the oscillator is coupled to the biasing circuit to generate the oscillating signal according to the biasing signal.
    Type: Application
    Filed: March 22, 2007
    Publication date: October 18, 2007
    Inventors: Chao-Cheng Lee, Tzu-Chien Tzeng
  • Patent number: 7279931
    Abstract: An output stage structure includes first and second PMOS transistors and first and second NMOS transistors, wherein the MOS transistors are manufactured with a twin well process. The first PMOS transistor has a source coupled to a supply voltage (VDD), and a gate coupled to the first voltage. The second PMOS transistor has a source coupled to a drain of the first PMOS transistor, a gate coupled to the second voltage, and a drain coupled to an output pad. The first NMOS transistor has a drain coupled to the output pad, and a gate coupled to the third voltage. The second NMOS transistor has a drain coupled to source of the first NMOS transistor, a gate coupled to the fourth voltage, and a source coupled to ground.
    Type: Grant
    Filed: August 25, 2005
    Date of Patent: October 9, 2007
    Assignee: Realtek Semiconductor Corp.
    Inventors: Chao-Cheng Lee, Yung-Hao Lin, Wen-Chi Wang, Jui-Yuan Tsai
  • Publication number: 20070229130
    Abstract: A charge pump circuit capable of canceling current mismatch and suppressing clock feedthrough. The charge pump circuit comprises a current source enabled by a first logical signal, a current sink enabled by a second logical signal, an integrating capacitor coupled to both the current source and the current sink, and a switching device coupled between the integrating circuit and an output node. The switching device has two states. The switching device is set to a first state whenever a third logical signal is asserted and one of the first logical signal, the second logical signal, and a modulating signal is enabled. The switching device is set to a second state whenever the third logical signal is de-asserted, or none of the first logical signal, the second logical signal, and the modulating signal are asserted.
    Type: Application
    Filed: March 31, 2006
    Publication date: October 4, 2007
    Inventors: Chao-Cheng Lee, Ren-Chieh Liu
  • Publication number: 20070229164
    Abstract: A low noise amplifier for operating in response to different gain modes is disclosed. The low noise amplifier includes a voltage adjusting circuit, which provides a first bias voltage at a first gain mode and provides a second bias voltage at a second gain mode, where the second bias voltage is different from the first bias voltage; and an amplifying circuit coupled to the voltage adjusting circuit, for providing a first transfer characteristic according to the first bias voltage during the first gain mode in order to amplify an input signal to generate an output signal, and for providing a second transfer characteristic according to the second bias voltage during the second gain mode in order to amplify the input signal to generate the output signal.
    Type: Application
    Filed: March 19, 2007
    Publication date: October 4, 2007
    Inventors: Ying-Yao Lin, Chao-Cheng Lee, Ying-Hsi Lin
  • Publication number: 20070194850
    Abstract: An operational amplifier is dynamically compensated depending on the internal state of the operational amplifier. Compensation is fully enabled only when the internal state indicates a risk of instability. When the internal state of the operational amplifier indicates there is no risk of instability, the compensation is totally or partially turned off.
    Type: Application
    Filed: February 13, 2007
    Publication date: August 23, 2007
    Inventors: Chia-Liang Lin, GERCHIH CHOU, Chao-Cheng Lee
  • Publication number: 20070188953
    Abstract: The present invention is to provide a latch-up resistant electrostatic discharge (ESD) protection circuit and method thereof, which comprises a clamping circuit being able to discharge when activated, a sustaining unit for directing electrostatic charge via said sustaining unit to said clamping circuit when activated and a sensing unit for activating said clamping circuit and said sustaining unit. When an ESD event, a signal noise or a power bounce is detected, said clamping circuit and said sensing unit is activated, said sustaining unit is activated to increase discharging ability of said clamping circuit, and then said sensing unit self resets after a period of time to deactivate said sustaining unit, thereby said clamping circuit is deactivated and a latch-up is prevented.
    Type: Application
    Filed: February 15, 2007
    Publication date: August 16, 2007
    Inventors: Chao-Cheng Lee, Yung-Ming Chiu
  • Patent number: 7257729
    Abstract: A processor with an adjustable operating frequency and method thereof. The pipeline processor includes a clock providing module for providing a reference clock, and a processing core coupled to the clock providing module for processing a first instruction according to the reference clock. The clock providing module contains a multi-phase clock generator for generating a plurality of original clocks with different phases, and a phase selector for selecting an original clock to generate the reference clock according to the first instruction.
    Type: Grant
    Filed: March 18, 2005
    Date of Patent: August 14, 2007
    Assignee: Realtek Semiconductor Corp.
    Inventors: Chao-Cheng Lee, Yi-Chih Huang, Chi-Kung Kuan
  • Patent number: 7257787
    Abstract: A method of the invention is used for checking the via density between two adjacent layers of an IC layout. The method includes selecting a first metal layer and a second metal layer, wherein the first metal layer is adjacent to the second one, each of the metal layers has at least a wire, and the metal layers are coupled to each other through at least a first via; calculating the cross-sectional area of the first via and the overlapping area of the overlapped part of the wires in the first and the second metal layers; and disposing at least a second via in the overlapped part to couple the first and the second metal layers if the ratio of the cross-sectional area to the overlapping area is smaller than a predetermined ratio value.
    Type: Grant
    Filed: August 24, 2004
    Date of Patent: August 14, 2007
    Assignee: Realtek Semiconductor Corp.
    Inventors: Jai-Ming Lin, Chao-Cheng Lee