Patents by Inventor Shiu Chung Ho

Shiu Chung Ho 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: 10958276
    Abstract: A phase locked loop circuit is disclosed. The phase locked loop circuit includes a ring oscillator. The phase locked loop circuit also includes a digital path including a digital phase detector. The phase locked loop circuit further includes an analog path including a linear phase detector. Additionally, the phase locked loop circuit includes a feedback path connecting an output of the ring oscillator to an input of the digital path and an input of the analog path. The digital path and the analog path are parallel paths. The digital path provides a digital tuning signal the ring oscillator that digitally controls a frequency of the ring oscillator. The analog path provides an analog tuning signal the ring oscillator that continuously controls the frequency of the ring oscillator.
    Type: Grant
    Filed: January 3, 2020
    Date of Patent: March 23, 2021
    Assignee: INTERNATIONAL BUSINESS MACHINES CORPORATION
    Inventors: Jingdong Deng, Rupert Shiu Chung Ho, David Flye, Zhenrong Jin, Ramana M. Malladi
  • Patent number: 10693471
    Abstract: A phase locked loop circuit is disclosed. The phase locked loop circuit includes a ring oscillator. The phase locked loop circuit also includes a digital path including a digital phase detector. The phase locked loop circuit further includes an analog path including a linear phase detector. Additionally, the phase locked loop circuit includes a feedback path connecting an output of the ring oscillator to an input of the digital path and an input of the analog path. The digital path and the analog path are parallel paths. The digital path provides a digital tuning signal the ring oscillator that digitally controls a frequency of the ring oscillator. The analog path provides an analog tuning signal the ring oscillator that continuously controls the frequency of the ring oscillator.
    Type: Grant
    Filed: July 10, 2018
    Date of Patent: June 23, 2020
    Assignee: INTERNATIONAL BUSINESS MACHINES CORPORATION
    Inventors: Jingdong Deng, Rupert Shiu Chung Ho, David Flye, Zhenrong Jin, Ramana M. Malladi
  • Patent number: 10686452
    Abstract: A phase locked loop circuit is disclosed. The phase locked loop circuit includes a ring oscillator. The phase locked loop circuit also includes a digital path including a digital phase detector. The phase locked loop circuit further includes an analog path including a linear phase detector. Additionally, the phase locked loop circuit includes a feedback path connecting an output of the ring oscillator to an input of the digital path and an input of the analog path. The digital path and the analog path are parallel paths. The digital path provides a digital tuning signal the ring oscillator that digitally controls a frequency of the ring oscillator. The analog path provides an analog tuning signal the ring oscillator that continuously controls the frequency of the ring oscillator.
    Type: Grant
    Filed: June 20, 2018
    Date of Patent: June 16, 2020
    Assignee: INTERNATIONAL BUSINESS MACHINES CORPORATION
    Inventors: Jingdong Deng, Rupert Shiu Chung Ho, David Flye, Zhenrong Jin, Ramana M. Malladi
  • Publication number: 20200145012
    Abstract: A phase locked loop circuit is disclosed. The phase locked loop circuit includes a ring oscillator. The phase locked loop circuit also includes a digital path including a digital phase detector. The phase locked loop circuit further includes an analog path including a linear phase detector. Additionally, the phase locked loop circuit includes a feedback path connecting an output of the ring oscillator to an input of the digital path and an input of the analog path. The digital path and the analog path are parallel paths. The digital path provides a digital tuning signal the ring oscillator that digitally controls a frequency of the ring oscillator. The analog path provides an analog tuning signal the ring oscillator that continuously controls the frequency of the ring oscillator.
    Type: Application
    Filed: January 3, 2020
    Publication date: May 7, 2020
    Inventors: Jingdong DENG, Rupert Shiu Chung HO, David FLYE, Zhenrong JIN, Ramana M. MALLADI
  • Patent number: 10615806
    Abstract: A phase locked loop circuit is disclosed. The phase locked loop circuit includes a ring oscillator. The phase locked loop circuit also includes a digital path including a digital phase detector. The phase locked loop circuit further includes an analog path including a linear phase detector. Additionally, the phase locked loop circuit includes a feedback path connecting an output of the ring oscillator to an input of the digital path and an input of the analog path. The digital path and the analog path are parallel paths. The digital path provides a digital tuning signal the ring oscillator that digitally controls a frequency of the ring oscillator. The analog path provides an analog tuning signal the ring oscillator that continuously controls the frequency of the ring oscillator.
    Type: Grant
    Filed: May 31, 2018
    Date of Patent: April 7, 2020
    Assignee: INTERNATIONAL BUSINESS MACHINES CORPORATION
    Inventors: Jingdong Deng, Rupert Shiu Chung Ho, David Flye, Zhenrong Jin, Ramana M. Malladi
  • Patent number: 10566981
    Abstract: A phase locked loop circuit is disclosed. The phase locked loop circuit includes a ring oscillator. The phase locked loop circuit also includes a digital path including a digital phase detector. The phase locked loop circuit further includes an analog path including a linear phase detector. Additionally, the phase locked loop circuit includes a feedback path connecting an output of the ring oscillator to an input of the digital path and an input of the analog path. The digital path and the analog path are parallel paths. The digital path provides a digital tuning signal the ring oscillator that digitally controls a frequency of the ring oscillator. The analog path provides an analog tuning signal the ring oscillator that continuously controls the frequency of the ring oscillator.
    Type: Grant
    Filed: October 5, 2018
    Date of Patent: February 18, 2020
    Assignee: INTERNATIONAL BUSINESS MACHINES CORPORATION
    Inventors: Jingdong Deng, Rupert Shiu Chung Ho, David Flye, Zhenrong Jin, Ramana M. Malladi
  • Publication number: 20190036534
    Abstract: A phase locked loop circuit is disclosed. The phase locked loop circuit includes a ring oscillator. The phase locked loop circuit also includes a digital path including a digital phase detector. The phase locked loop circuit further includes an analog path including a linear phase detector. Additionally, the phase locked loop circuit includes a feedback path connecting an output of the ring oscillator to an input of the digital path and an input of the analog path. The digital path and the analog path are parallel paths. The digital path provides a digital tuning signal the ring oscillator that digitally controls a frequency of the ring oscillator. The analog path provides an analog tuning signal the ring oscillator that continuously controls the frequency of the ring oscillator.
    Type: Application
    Filed: October 5, 2018
    Publication date: January 31, 2019
    Inventors: Jingdong DENG, Rupert Shiu Chung HO, David FLYE, Zhenrong JIN, Ramana M. MALLADI
  • Patent number: 10164647
    Abstract: A phase locked loop circuit is disclosed. The phase locked loop circuit includes a ring oscillator. The phase locked loop circuit also includes a digital path including a digital phase detector. The phase locked loop circuit further includes an analog path including a linear phase detector. Additionally, the phase locked loop circuit includes a feedback path connecting an output of the ring oscillator to an input of the digital path and an input of the analog path. The digital path and the analog path are parallel paths. The digital path provides a digital tuning signal the ring oscillator that digitally controls a frequency of the ring oscillator. The analog path provides an analog tuning signal the ring oscillator that continuously controls the frequency of the ring oscillator.
    Type: Grant
    Filed: October 20, 2017
    Date of Patent: December 25, 2018
    Assignee: INTERNATIONAL BUSINESS MACHINES CORPORATION
    Inventors: Jingdong Deng, Rupert Shiu Chung Ho, David Flye, Zhenrong Jin, Ramana M. Malladi
  • Patent number: 9673805
    Abstract: A method and system for reducing leakage current in a testing circuit are provided. Embodiments include a testing circuit that includes a digital buffer that includes a first transistor operatively coupled to a second transistor, where a drain of the first transistor is operatively coupled to a source of the second transistor. The second transistor is switched into cutoff mode. The digital buffer also includes a reference voltage generation circuit. The reference voltage generation circuit is operatively connected to the drain of the first transistor and the source of the second transistor. The reference voltage generation circuit is configured to reduce the leakage current in the digital buffer.
    Type: Grant
    Filed: August 21, 2014
    Date of Patent: June 6, 2017
    Assignee: International Business Machines Corporation
    Inventors: Sarveswara Bade, Shiu Chung Ho, Marcel A. Kossel, Pradeep Thiagarajan
  • Publication number: 20160056809
    Abstract: A method and system for reducing leakage current in a testing circuit are provided. Embodiments include a testing circuit that includes a digital buffer that includes a first transistor operatively coupled to a second transistor, where a drain of the first transistor is operatively coupled to a source of the second transistor. The second transistor is switched into cutoff mode. The digital buffer also includes a reference voltage generation circuit. The reference voltage generation circuit is operatively connected to the drain of the first transistor and the source of the second transistor. The reference voltage generation circuit is configured to reduce the leakage current in the digital buffer.
    Type: Application
    Filed: August 21, 2014
    Publication date: February 25, 2016
    Inventors: SARVESWARA BADE, SHIU CHUNG HO, MARCEL A. KOSSEL, PRADEEP THIAGARAJAN
  • Patent number: 8791728
    Abstract: A dynamic latch has a pair of parallel pass gates (a first parallel pass gate that receives a seed signal, and a second parallel pass gate that receives a data signal). A first latch logic circuit performs logic operations using signals output by the parallel pass gates to produce an updated data signal. An additional pass gate is operatively connected to the first latch logic circuit. An additional pass gate controls passage of the updated data signal. An inverter receives the updated data signal from the pass gate, and inverts and outputs the updated data signal as an output data signal. Thus, the dynamic latch comprises two inputs into the pair of parallel pass gates and performs only one of four logical operations on a received data signal. The four logical operations are performed using the signals applied to the two inputs.
    Type: Grant
    Filed: October 18, 2011
    Date of Patent: July 29, 2014
    Assignee: International Business Machines Corporation
    Inventors: John S. Austin, Kai D. Feng, Shiu Chung Ho, Zhenrong Jin
  • Patent number: 8525561
    Abstract: A phase lock loop (PLL) includes a PLL feedback circuit having a feedback divider. The feedback divider has a first dynamic latch, a first logic circuit, and a plurality of serially connected dynamic latches. Each of the serially connected dynamic latches receives and forwards additional data signals to subsequent ones of the serially connected dynamic latches in series. The second-to-last dynamic latch in the series outputs a fourth data signal to a last dynamic latch in the series. The last dynamic latch receives the fourth data signal and outputs a fifth data signal. A first feedback loop receives the fourth data signal from the second-to-last dynamic latch and the fifth data signal from the last dynamic latch. The first feedback loop comprises a NAND circuit that combines the fourth and fifth data signals and the first feedback loop outputs the first feedback signal.
    Type: Grant
    Filed: October 18, 2011
    Date of Patent: September 3, 2013
    Assignee: International Business Machines Corporation
    Inventors: John S. Austin, Kai D. Feng, Shiu Chung Ho, Zhenrong Jin
  • Patent number: 8471595
    Abstract: A selectable latch has a pair of parallel pass gates (a first parallel pass gate that receives a seed signal, and a second parallel pass gate that receives a data signal). A first latch logic circuit performs logic operations using signals output by the parallel pass gates to produce an updated data signal. An additional pass gate is operatively connected to the first latch logic circuit. An additional pass gate controls passage of the updated data signal. The output of the parallel pass gates and the additional pass gate is connected to a feedback loop. The feedback loop operates as a dynamic latch for high frequency applications or as a static latch for low frequency applications. Thus, the selectable latch comprises two inputs into the pair of parallel pass gates and performs only one of four logical operations on a received data signal.
    Type: Grant
    Filed: January 19, 2012
    Date of Patent: June 25, 2013
    Assignee: International Business Machines Corporation
    Inventors: John S. Austin, Kai D. Feng, Shiu Chung Ho, Zhenrong Jin, Michael R. Ouellette
  • Publication number: 20130093463
    Abstract: A dynamic latch has a pair of parallel pass gates (a first parallel pass gate that receives a seed signal, and a second parallel pass gate that receives a data signal). A first latch logic circuit performs logic operations using signals output by the parallel pass gates to produce an updated data signal. An additional pass gate is operatively connected to the first latch logic circuit. An additional pass gate controls passage of the updated data signal. An inverter receives the updated data signal from the pass gate, and inverts and outputs the updated data signal as an output data signal. Thus, the dynamic latch comprises two inputs into the pair of parallel pass gates and performs only one of four logical operations on a received data signal. The four logical operations are performed using the signals applied to the two inputs.
    Type: Application
    Filed: October 18, 2011
    Publication date: April 18, 2013
    Applicant: INTERNATIONAL BUSINESS MACHINES CORPORATION
    Inventors: John S. Austin, Kai D. Feng, Shiu Chung Ho, Zhenrong Jin
  • Publication number: 20130093481
    Abstract: A phase lock loop (PLL) includes a PLL feedback circuit having a feedback divider. The feedback divider has a first dynamic latch, a first logic circuit, and a plurality of serially connected dynamic latches. Each of the serially connected dynamic latches receives and forwards additional data signals to subsequent ones of the serially connected dynamic latches in series. The second-to-last dynamic latch in the series outputs a fourth data signal to a last dynamic latch in the series. The last dynamic latch receives the fourth data signal and outputs a fifth data signal. A first feedback loop receives the fourth data signal from the second-to-last dynamic latch and the fifth data signal from the last dynamic latch. The first feedback loop comprises a NAND circuit that combines the fourth and fifth data signals and the first feedback loop outputs the first feedback signal.
    Type: Application
    Filed: October 18, 2011
    Publication date: April 18, 2013
    Applicant: INTERNATIONAL BUSINESS MACHINES CORPORATION
    Inventors: John S. Austin, Kai D. Feng, Shiu Chung Ho, Zhenrong Jin
  • Patent number: 8289058
    Abstract: Controlling a PLL includes providing a voltage controlled oscillator (VCO) and coupling an output of the VCO to a shifter circuit. The shifter circuit has a shifter circuit output, the shifter circuit also including an activation input for receiving an activation signal, the shifter circuit causing at least one pulse of the output signal to be suppressed at the shifter output upon receipt of the activation signal. Controlling also includes coupling the shifter circuit output to a first frequency divider.
    Type: Grant
    Filed: March 7, 2012
    Date of Patent: October 16, 2012
    Assignee: International Business Machines Corporation
    Inventors: James Eckhardt, Shiu Chung Ho, Paul D. Muench, Scot H. Rider
  • Publication number: 20120161838
    Abstract: Controlling a PLL includes providing a voltage controlled oscillator (VCO) and coupling an output of the VCO to a shifter circuit. The shifter circuit has a shifter circuit output, the shifter circuit also including an activation input for receiving an activation signal, the shifter circuit causing at least one pulse of the output signal to be suppressed at the shifter output upon receipt of the activation signal. Controlling also includes coupling the shifter circuit output to a first frequency divider.
    Type: Application
    Filed: March 7, 2012
    Publication date: June 28, 2012
    Applicant: International Business Machines Corporation
    Inventors: James Eckhardt, Shiu Chung Ho, Paul D. Muench, Scot H. Rider
  • Patent number: 8149035
    Abstract: Controlling a PLL includes providing a voltage controlled oscillator (VCO) and coupling an output of the VCO to a shifter circuit. The shifter circuit has a shifter circuit output, the shifter circuit also including an activation input for receiving an activation signal, the shifter circuit causing at least one pulse of the output signal to be suppressed at the shifter output upon receipt of the activation signal. Controlling also includes coupling the shifter circuit output to a first frequency divider.
    Type: Grant
    Filed: February 2, 2010
    Date of Patent: April 3, 2012
    Assignee: International Business Machines Corporation
    Inventors: James Eckhardt, Shiu Chung Ho, Paul D. Muench, Scot H. Rider
  • Publication number: 20110187423
    Abstract: Controlling a PLL includes providing a voltage controlled oscillator (VCO) and coupling an output of the VCO to a shifter circuit. The shifter circuit has a shifter circuit output, the shifter circuit also including an activation input for receiving an activation signal, the shifter circuit causing at least one pulse of the output signal to be suppressed at the shifter output upon receipt of the activation signal. Controlling also includes coupling the shifter circuit output to a first frequency divider.
    Type: Application
    Filed: February 2, 2010
    Publication date: August 4, 2011
    Applicant: INTERNATIONAL BUSINESS MACHINES CORPORATION
    Inventors: James Eckhardt, Shiu Chung Ho, Paul D. Muench, Scot H. Rider
  • Patent number: 7782114
    Abstract: Disclosed are embodiments of a design structure for a voltage level shifter circuit that operates without forward biasing junction diodes, regardless of the sequence in which different power supplies are powered up. The circuit embodiments incorporate a pair of series connected switches (e.g., transistors) between an input terminal and a voltage adjusting circuit. Each switch is controlled by a different supply voltage from a different power supply. Only when both power supplies are powered-up and the different supply voltages are received at both switches will a first signal generated using one of the supply voltages be passed to a voltage adjusting circuit and thereafter converted into a second signal representative of the first signal, but generated using the second supply voltage. Incorporation of the pair of series connected switches into the voltage level shifter circuit prevents forward biasing of junction diodes in the circuit and thereby prevents current leakage from the power supplies.
    Type: Grant
    Filed: January 8, 2009
    Date of Patent: August 24, 2010
    Assignee: International Business Machines Corporation
    Inventors: Anirban Banerjee, Stephen F. Geissler, Shiu Chung Ho