Patents by Inventor Zhi Zhu

Zhi Zhu 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: 8839020
    Abstract: A clock/data recovery circuit includes an edge detector circuit operable to receive a serial data burst and to generate a reset signal in response to a first edge of the serial data burst. The clock/data recovery circuit may also include an oscillator coupled to the edge detector circuit. The oscillator locks onto a target data rate prior to receipt of the serial data burst and locks onto a phase of the serial data burst in response to the reset signal. The clock/data recovery circuit may also include a phase detector circuit that receives the serial data burst. The phase detector circuit is coupled to the oscillator. The phase detector circuit adjusts the oscillator to maintain the lock onto the phase of the serial data burst during the serial data burst.
    Type: Grant
    Filed: March 15, 2012
    Date of Patent: September 16, 2014
    Assignee: QUALCOMM Incorporated
    Inventors: Jingcheng Zhuang, Nam V. Dang, Xiaohua Kong, Zhi Zhu, Tirdad Sowlati, Behnam Amelifard
  • Patent number: 8811458
    Abstract: A digitally controlled jitter injection apparatus for built in self-testing includes a transceiver circuit having a transmitter circuit and a receiver circuit. The digitally controlled jitter injection apparatus also includes a generator that generates a composite jitter including multi-tone jitter components. The digitally controlled jitter injection apparatus also includes a processor operable to digitally inject the composite jitter into a receiver circuit and/or a transmitter circuit of the transceiver circuit.
    Type: Grant
    Filed: October 4, 2012
    Date of Patent: August 19, 2014
    Assignee: QUALCOMM Incorporated
    Inventors: Xiaohua Kong, Zhi Zhu, Vannam Dang
  • Patent number: 8798217
    Abstract: In a particular embodiment, a digital circuit includes a frequency detection circuit operative to compare information related to transitions between sequential samples of a received signal. The frequency detection circuit is further operative to generate a control signal to reduce a sampling rate of the received signal in response to a predetermined number of the sequential samples having a same value. The digital circuit also includes a digital phase detector operative to provide the information related to the transitions between sequential samples to the frequency detection circuit.
    Type: Grant
    Filed: November 3, 2010
    Date of Patent: August 5, 2014
    Assignee: QUALCOMM Incorporated
    Inventors: Xiaohua Kong, Zhi Zhu, Nam V. Dang, Tirdad Sowlati
  • Patent number: 8767841
    Abstract: Techniques for de-modulating a high-supply-domain differential signal and a common-mode clock in a front-end receiver are described herein. In one embodiment, a method for receiving a signal comprises receiving the signal via a receiver input, the received signal comprising a differential signal and a common-mode clock signal. The method also comprises shifting the received signal from a first voltage range to a second voltage range that is lower than the first voltage range, and providing the shifted received signal on a first level-shifted signal line and a second level-shifted signal line. The method further comprises sensing voltage differences between the first and second level-shifted lines to recover the differential signal, and sensing common-mode voltages on the first and second level-shifted signal lines to recover the common-mode clock signal.
    Type: Grant
    Filed: March 4, 2013
    Date of Patent: July 1, 2014
    Assignee: QUALCOMM Incorporated
    Inventors: Miao Li, Xiaohua Kong, Yan Hu, Zhi Zhu
  • Patent number: 8742864
    Abstract: In a particular embodiment, a method includes adjusting an input to a divider on a feedback path of a phase locked loop circuit based on a stored digital value representing a portion of a time-based waveform that is applied to a modulator circuit. The stored digital value is retrieved based on an output of the feedback path.
    Type: Grant
    Filed: November 4, 2010
    Date of Patent: June 3, 2014
    Assignee: QUALCOMM Incorporated
    Inventors: Zhi Zhu, Xiaohua Kong, Nam V. Dang
  • Publication number: 20140098843
    Abstract: A digitally controlled jitter injection apparatus for built in self-testing includes a transceiver circuit having a transmitter circuit and a receiver circuit. The digitally controlled jitter injection apparatus also includes a generator that generates a composite jitter including multi-tone jitter components. The digitally controlled jitter injection apparatus also includes a processor operable to digitally inject the composite jitter into a receiver circuit and/or a transmitter circuit of the transceiver circuit.
    Type: Application
    Filed: October 4, 2012
    Publication date: April 10, 2014
    Applicant: QUALCOMM Incorporated
    Inventors: Xiaohua Kong, Zhi Zhu, Vannam Dang
  • Patent number: 8692368
    Abstract: A stacked integrated circuit (IC) device includes a semiconductor IC having an active face, and an interconnect structure. The active face receives a regulated voltage from a voltage regulator (MEG). An active portion of the VREG, which supplies the regulated voltage to the semiconductor IC is coupled to the interconnect structure. A packaging substrate includes one or more inductors including a first set of through vias. The first set of through vias are coupled to the interconnect structure and cooperate with the active portion to provide the regulated voltage for the semiconductor IC. The IC also includes a printed circuit board (PCB) coupled to the packaging substrate. The PCB includes a second set of through vias coupled to the first set of through vias. The IC also includes one or more conducting paths on the PCB. The conducting path(s) couple together at least two through vias of the second set of through vias.
    Type: Grant
    Filed: February 7, 2012
    Date of Patent: April 8, 2014
    Assignee: QUALCOMM Incorporated
    Inventors: Yuancheng Christopher Pan, Lew G. Chua-Eoan, Zhi Zhu, Junmou Zhang
  • Publication number: 20140062559
    Abstract: A method includes receiving an input clock signal at a programmable buffer. The method further includes filtering an output signal from the programmable buffer to generate a filtered signal having a voltage level, where the voltage level indicates a duty cycle of the output signal. The method further includes comparing the voltage level to a reference voltage. The method further includes modifying at least one operating parameter of the programmable buffer to adjust the duty cycle of the output signal.
    Type: Application
    Filed: August 29, 2012
    Publication date: March 6, 2014
    Applicant: QUALCOMM Incorporated
    Inventors: Jason Gonzalez, Vannam Dang, Zhi Zhu
  • Patent number: 8593227
    Abstract: A circuit includes a controllable oscillator and a controller coupled to the controllable oscillator. The controller is configured to provide a current control and a gain control to the controllable oscillator. The gain control is configured to change a gain of the controllable oscillator during a calibration process.
    Type: Grant
    Filed: August 5, 2011
    Date of Patent: November 26, 2013
    Assignee: QUALCOMM Incorporated
    Inventors: Zhi Zhu, Xiaohua Kong, Nam Van Dang, Cheng Zhong
  • Patent number: 8542039
    Abstract: In an example, a high-speed pre-driver and voltage level converter with built-in de-emphasis for HDMI transmit applications is provided. An exemplary integrated circuit includes a serializer, a pre-driver coupled to receive a differential input from the serializer, and a driver. The pre-driver includes all-p-type metal-oxide-silicon (PMOS) cross-coupled level converter comprising four PMOS transistors and two de-emphasis PMOS transistors forming a de-emphasis tap coupled to the output of the cross-coupled level converter. The driver is coupled to the pre-driver output and is configured to receive a differential input from the pre-driver.
    Type: Grant
    Filed: November 11, 2011
    Date of Patent: September 24, 2013
    Assignee: QUALCOMM Incorporated
    Inventors: Miao Li, Zhi Zhu, Xiaohua Kong, Nam V. Dang
  • Patent number: 8527797
    Abstract: Systems and methods of leakage control in an asynchronous pipeline are disclosed. In an embodiment, a signal is received from a preceding stage at an operative stage of an asynchronous circuit device, and a switch associated with the operative stage is activated in response to the control signal being sent to the operative stage to enable power to the operative stage.
    Type: Grant
    Filed: December 26, 2007
    Date of Patent: September 3, 2013
    Assignee: QUALCOMM Incorporated
    Inventors: Xiaohua Kong, Lew G. Chua-Eoan, Sei Seung Yoon, Zhi Zhu
  • Publication number: 20130216014
    Abstract: Systems and methods for automatic detection and compensation of frequency offset in point-to-point communication. A burst mode clock and data recovery (CDR) system comprises input data received at a first frequency and a reference clock operating at a second frequency. A master phase-locked loop (PLL) comprising a first gated voltage controlled oscillator (GVCO) is configured to align the phases of reference clock and the input data, and provide phase error information and a recovered clock. A second GVCO is controlled by the recovered clock to sample the input data. A frequency alignment loop comprising a feedback path from the second GVCO to the master PLL is configured to use the phase error information to correct a frequency offset between the first frequency and the second frequency.
    Type: Application
    Filed: February 21, 2012
    Publication date: August 22, 2013
    Applicant: QUALCOMM Incorporated
    Inventors: Xiaohua Kong, Zhi Zhu, Nam V. Dang
  • Publication number: 20130191679
    Abstract: A clock/data recovery circuit includes an edge detector circuit operable to receive a serial data burst and to generate a reset signal in response to a first edge of the serial data burst. The clock/data recovery circuit may also include an oscillator coupled to the edge detector circuit. The oscillator locks onto a target data rate prior to receipt of the serial data burst and locks onto a phase of the serial data burst in response to the reset signal. The clock/data recovery circuit may also include a phase detector circuit that receives the serial data burst. The phase detector circuit is coupled to the oscillator. The phase detector circuit adjusts the oscillator to maintain the lock onto the phase of the serial data burst during the serial data burst.
    Type: Application
    Filed: March 15, 2012
    Publication date: July 25, 2013
    Applicant: QUALCOMM Incorporated
    Inventors: Jingcheng Zhuang, Nam V. Dang, Xiaohua Kong, Zhi Zhu, Tirdad Sowlati, Behnam Amelifard
  • Publication number: 20130120029
    Abstract: In an example, a high-speed pre-driver and voltage level converter with built-in de-emphasis for HDMI transmit applications is provided. An exemplary integrated circuit includes a serializer, a pre-driver coupled to receive a differential input from the serializer, and a driver. The pre-driver includes all-p-type metal-oxide-silicon (PMOS) cross-coupled level converter comprising four PMOS transistors and two de-emphasis PMOS transistors forming a de-emphasis tap coupled to the output of the cross-coupled level converter. The driver is coupled to the pre-driver output and is configured to receive a differential input from the pre-driver.
    Type: Application
    Filed: November 11, 2011
    Publication date: May 16, 2013
    Applicant: QUALCOMM INCORPORATED
    Inventors: Miao Li, Zhi Zhu, Xiaohua Kong, Nam V. Dang
  • Publication number: 20130120036
    Abstract: A gated voltage controlled oscillator has four identically structured delay cells, each of the delay cells having the same output load by connecting to the same number of inputs of other ones of the delay cells. Optionally a four phase sampling clock selects from the delay cell output and samples, at a four phase sampler, an input signal. Optionally an edge detector synchronizes the phase of the gated voltage controlled oscillator to coincide with NRZ bits. Optionally a variable sampling rate selects different phases from the delay cells to selectively sample NRZ bits at a lower rate. Optionally, a pulse width modulation (PWM) mode synchronizes a phase of the sampling clock to sample PWM symbols and recover encoded bits.
    Type: Application
    Filed: February 1, 2012
    Publication date: May 16, 2013
    Applicant: QUALCOMM Incorporated
    Inventors: Zhi Zhu, Xiaohua Kong, Nam V. Dang
  • Publication number: 20130033329
    Abstract: A circuit includes a controllable oscillator and a controller coupled to the controllable oscillator. The controller is configured to provide a current control and a gain control to the controllable oscillator. The gain control is configured to change a gain of the controllable oscillator during a calibration process.
    Type: Application
    Filed: August 5, 2011
    Publication date: February 7, 2013
    Applicant: QUALCOMM INCORPORATED
    Inventors: Zhi Zhu, Xiaohua Kong, Vannam Dang, Cheng Zhong
  • Publication number: 20120293972
    Abstract: A stacked integrated circuit (IC) device includes a semiconductor IC having an active face, and an interconnect structure. The active face receives a regulated voltage from a voltage regulator (MEG). An active portion of the VREG, which supplies the regulated voltage to the semiconductor IC is coupled to the interconnect structure. A packaging substrate includes one or more inductors including a first set of through vias. The first set of through vias are coupled to the interconnect structure and cooperate with the active portion to provide the regulated voltage for the semiconductor IC. The IC also includes a printed circuit board (PCB) coupled to the packaging substrate. The PCB includes a second set of through vias coupled to the first set of through vias. The IC also includes one or more conducting paths on the PCB. The conducting path(s) couple together at least two through vias of the second set of through vias.
    Type: Application
    Filed: February 7, 2012
    Publication date: November 22, 2012
    Applicant: QUALCOMM INCORPORATED
    Inventors: Yuancheng Christopher Pan, Lew G. Chua-Eoan, Zhi Zhu, Junmou Zhang
  • Patent number: 8295082
    Abstract: A re-programmable gate logic includes a plurality of non-volatile re-configurable resistance state-based memory circuits in parallel, wherein the circuits are re-configurable to implement or change a selected gate logic, and the plurality of non-volatile re-configurable resistance state-based memory circuits are each adapted to receive a logical input signal. An evaluation switch in series with the plurality of parallel non-volatile re-configurable resistance state-based memory circuits is configured to provide an output signal based on the programmed states of the memory circuits. A sensor is configured to receive the output signal and provide a logical output signal on the basis of the output signal and a reference signal provided to the sensor. The reconfigurable logic may be implemented based on using spin torque transfer (STT) magnetic tunnel junction (MTJ) magnetoresistance random access memory (MRAM) as the re-programmable memory elements. The logic configuration is retained without power.
    Type: Grant
    Filed: August 15, 2008
    Date of Patent: October 23, 2012
    Assignee: QUALCOMM Incorporated
    Inventors: Lew G. Chua-Eoan, Xiaochun Zhu, Zhi Zhu
  • Publication number: 20120112809
    Abstract: In a particular embodiment, a method includes adjusting an input to a divider on a feedback path of a phase locked loop circuit based on a stored digital value representing a portion of a time-based waveform that is applied to a modulator circuit. The stored digital value is retrieved based on an output of the feedback path.
    Type: Application
    Filed: November 4, 2010
    Publication date: May 10, 2012
    Applicant: QUALCOMM Incorporated
    Inventors: Zhi Zhu, Xiaohua Kong, Nam V. Dang
  • Publication number: 20120109356
    Abstract: In a particular embodiment, a digital circuit includes a frequency detection circuit operative to compare information related to transitions between sequential samples of a received signal. The frequency detection circuit is further operative to generate a control signal to reduce a sampling rate of the received signal in response to a predetermined number of the sequential samples having a same value. The digital circuit also includes a digital phase detector operative to provide the information related to the transitions between sequential samples to the frequency detection circuit.
    Type: Application
    Filed: November 3, 2010
    Publication date: May 3, 2012
    Applicant: QUALCOMM INCORPORATED
    Inventors: Xiaohua Kong, Zhi Zhu, Nam V. Dang, Tirdad Sowlati