Patents by Inventor Zhengzheng Wu

Zhengzheng Wu 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: 11626883
    Abstract: A digital-to-time converter (DTC) converts a digital code into a time delay using a capacitor digital-to-analog converter (CDAC) that functions as a charging capacitor. The DTC includes a switched capacitor voltage-to-current converter for the formation of a charging current (or a discharging current) for charging (or for discharging) the charging capacitor responsive to a triggering clock edge that begins the time delay. A comparator compares a voltage on the charging capacitor to a threshold voltage to determine an end of the time delay.
    Type: Grant
    Filed: September 28, 2021
    Date of Patent: April 11, 2023
    Assignee: QUALCOMM INCORPORATED
    Inventors: Zhengzheng Wu, Chao Song, Karthik Nagarajan
  • Patent number: 11533058
    Abstract: A digital phase-frequency detector characterizes a delay between two input clock signals using a ring oscillator. A cycle count of a ring oscillator signal circulating through a loop in the ring oscillator during the delay provides a coarse measurement of the delay. A phase of the ring oscillator signal in the loop at the end of the delay provides a fine measurement of the delay. A digital phase-locked loop may control an oscillation frequency of a digitally-controlled oscillator responsive to the fine measurement of the delay and control a division within a clock divider responsive to the coarse measurement of the delay.
    Type: Grant
    Filed: December 17, 2020
    Date of Patent: December 20, 2022
    Assignee: QUALCOMM INCORPORATED
    Inventors: Zhengzheng Wu, Chao Song, Karthik Nagarajan
  • Publication number: 20220200608
    Abstract: A digital phase-frequency detector characterizes a delay between two input clock signals using a ring oscillator. A cycle count of a ring oscillator signal circulating through a loop in the ring oscillator during the delay provides a coarse measurement of the delay. A phase of the ring oscillator signal in the loop at the end of the delay provides a fine measurement of the delay. A digital phase-locked loop may control an oscillation frequency of a digitally-controlled oscillator responsive to the fine measurement of the delay and control a division within a clock divider responsive to the coarse measurement of the delay.
    Type: Application
    Filed: December 17, 2020
    Publication date: June 23, 2022
    Inventors: Zhengzheng WU, Chao SONG, Karthik NAGARAJAN
  • Publication number: 20220182065
    Abstract: A digital-to-time converter (DTC) converts a digital code into a time delay using a capacitor digital-to-analog converter (CDAC) that functions as a charging capacitor. The DTC includes a switched capacitor voltage-to-current converter for the formation of a charging current (or a discharging current) for charging (or for discharging) the charging capacitor responsive to a triggering clock edge that begins the time delay. A comparator compares a voltage on the charging capacitor to a threshold voltage to determine an end of the time delay.
    Type: Application
    Filed: September 28, 2021
    Publication date: June 9, 2022
    Inventors: Zhengzheng WU, Chao SONG, Karthik NAGARAJAN
  • Patent number: 11196410
    Abstract: A method of generating precise and PVT-stable time delay or frequency using CMOS circuits is disclosed. In some implementations, the method includes providing a reference voltage using a resistive module at a positive input terminal of an operational amplifier, coupling gates of a pair of p-type metal oxide semiconductor (pMOS) transistors and a compensation capacitor to an output terminal of the operational amplifier to generate a first bias signal, and coupling a pair of n-type metal oxide semiconductor (nMOS) transistors to a negative terminal of the operational amplifier to generate a second bias signal at the negative terminal, wherein the pair of nMOS transistors is substantially the same as a pair of nMOS transistors in the CMOS delay circuit.
    Type: Grant
    Filed: September 16, 2020
    Date of Patent: December 7, 2021
    Assignee: QUALCOMM INCORPORATED
    Inventors: Zhengzheng Wu, Xu Zhang, Xuhao Huang
  • Patent number: 11177819
    Abstract: A digital-to-time converter (DTC) converts a digital code into a time delay using a capacitor digital-to-analog converter (CDAC) that functions as a charging capacitor. The DTC includes a switched capacitor voltage-to-current converter for the formation of a charging current (or a discharging current) for charging (or for discharging) the charging capacitor responsive to a triggering clock edge that begins the time delay. A comparator compares a voltage on the charging capacitor to a threshold voltage to determine an end of the time delay.
    Type: Grant
    Filed: December 3, 2020
    Date of Patent: November 16, 2021
    Assignee: QUALCOMM INCORPORATED
    Inventors: Zhengzheng Wu, Chao Song, Karthik Nagarajan
  • Publication number: 20210194474
    Abstract: A method of generating precise and PVT-stable time delay or frequency using CMOS circuits is disclosed. In some implementations, the method includes providing a reference voltage using a resistive module at a positive input terminal of an operational amplifier, coupling gates of a pair of p-type metal oxide semiconductor (pMOS) transistors and a compensation capacitor to an output terminal of the operational amplifier to generate a first bias signal, and coupling a pair of n-type metal oxide semiconductor (nMOS) transistors to a negative terminal of the operational amplifier to generate a second bias signal at the negative terminal, wherein the pair of nMOS transistors is substantially the same as a pair of nMOS transistors in the CMOS delay circuit.
    Type: Application
    Filed: September 16, 2020
    Publication date: June 24, 2021
    Inventors: Zhengzheng WU, Xu ZHANG, Xuhao HUANG
  • Patent number: 10812056
    Abstract: A method of generating precise and PVT-stable time delay or frequency using CMOS circuits is disclosed. In some implementations, the method includes providing a reference voltage using a resistive module at a positive input terminal of an operational amplifier, coupling gates of a pair of p-type metal oxide semiconductor (pMOS) transistors and a compensation capacitor to an output terminal of the operational amplifier to generate a first bias signal, and coupling a pair of n-type metal oxide semiconductor (nMOS) transistors to a negative terminal of the operational amplifier to generate a second bias signal at the negative terminal, wherein the pair of nMOS transistors is substantially the same as a pair of nMOS transistors in the CMOS delay circuit.
    Type: Grant
    Filed: December 20, 2019
    Date of Patent: October 20, 2020
    Assignee: QUALCOMM Incorporated
    Inventors: Zhengzheng Wu, Xu Zhang, Xuhao Huang
  • Patent number: 10707854
    Abstract: A sub-ranging time-to-digital converter (TDC) is disclosed that includes two ring oscillators for determining a time difference between two clock edges.
    Type: Grant
    Filed: November 14, 2019
    Date of Patent: July 7, 2020
    Assignee: QUALCOMM Incorporated
    Inventors: Zhengzheng Wu, Deping Huang, Jeffrey Mark Hinrichs, Marzio Pedrali-Noy
  • Publication number: 20200083873
    Abstract: A sub-ranging time-to-digital converter (TDC) is disclosed that includes two ring oscillators for determining a time difference between two clock edges.
    Type: Application
    Filed: November 14, 2019
    Publication date: March 12, 2020
    Inventors: Zhengzheng WU, Deping HUANG, Jeffrey Mark HINRICHS, Marzio PEDRALI-NOY
  • Patent number: 10545523
    Abstract: A load circuit of a low-dropout (LDO) regulator is disclosed herein according to certain aspects. The load circuit includes a field effect transistor having a source coupled to a supply rail, a gate, and a drain coupled to a gate of a pass transistor of the LDO regulator. The load circuit also includes an adjustable voltage source coupled between the drain and the gate of the field effect transistor, and a voltage control circuit configured to detect a change in a current load through the pass transistor, and to adjust a voltage of the adjustable voltage source based on the detected change in the current load.
    Type: Grant
    Filed: October 25, 2018
    Date of Patent: January 28, 2020
    Assignee: QUALCOMM Incorporated
    Inventors: Zhengzheng Wu, Chao Song
  • Patent number: 10520901
    Abstract: A subranging time-to-digital converter (TDC) is disclosed that includes two ring oscillators for determining a time difference between two clock edges.
    Type: Grant
    Filed: February 23, 2018
    Date of Patent: December 31, 2019
    Assignee: QUALCOMM Incorporated
    Inventors: Zhengzheng Wu, Deping Huang, Jeffrey Mark Hinrichs, Marzio Pedrali-Noy
  • Publication number: 20190268010
    Abstract: A subranging time-to-digital converter (TDC) is disclosed that includes two ring oscillators for determining a time difference between two clock edges.
    Type: Application
    Filed: February 23, 2018
    Publication date: August 29, 2019
    Inventors: Zhengzheng Wu, Deping Huang, Jeffrey Mark Hinrichs, Marzio Pedrali-Noy
  • Patent number: 10312891
    Abstract: In certain aspects, an integrated circuit comprises a signal path having a path delay from an input to an output, wherein the signal path comprises a path capacitor having a path capacitance. The integrated circuit also comprises a variation tracking circuit coupled to the signal path, wherein the variation tracking circuit comprises a tracking resistor have a tracking resistance, and wherein a product of the tracking resistance and the path capacitance is substantially constant over process variation.
    Type: Grant
    Filed: September 26, 2018
    Date of Patent: June 4, 2019
    Assignee: QUALCOMM Incorporated
    Inventors: Chao Song, Zhengzheng Wu, Haitao Cheng, Ye Lu
  • Patent number: 9742373
    Abstract: A method of making a temperature-compensated resonator is presented. The method comprises the steps of: (a) providing a substrate including a device layer; (b) replacing material from the device layer with material having an opposite temperature coefficient of elasticity (TCE) along a pre-determined region of high strain energy density for the resonator; (c) depositing a capping layer over the replacement material; and (d) etch-releasing the resonator from the substrate. The resonator may be a part of a micro electromechanical system (MEMS).
    Type: Grant
    Filed: October 31, 2012
    Date of Patent: August 22, 2017
    Assignee: The Regents of the University of Michigan
    Inventors: Mina Raieszadeh, Zhengzheng Wu, Vikram Atul Thakar, Adam Peczalski