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).
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Patent number: 10958276Abstract: 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: GrantFiled: January 3, 2020Date of Patent: March 23, 2021Assignee: INTERNATIONAL BUSINESS MACHINES CORPORATIONInventors: Jingdong Deng, Rupert Shiu Chung Ho, David Flye, Zhenrong Jin, Ramana M. Malladi
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Patent number: 10693471Abstract: 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: GrantFiled: July 10, 2018Date of Patent: June 23, 2020Assignee: INTERNATIONAL BUSINESS MACHINES CORPORATIONInventors: Jingdong Deng, Rupert Shiu Chung Ho, David Flye, Zhenrong Jin, Ramana M. Malladi
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Patent number: 10686452Abstract: 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: GrantFiled: June 20, 2018Date of Patent: June 16, 2020Assignee: INTERNATIONAL BUSINESS MACHINES CORPORATIONInventors: Jingdong Deng, Rupert Shiu Chung Ho, David Flye, Zhenrong Jin, Ramana M. Malladi
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Publication number: 20200145012Abstract: 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: ApplicationFiled: January 3, 2020Publication date: May 7, 2020Inventors: Jingdong DENG, Rupert Shiu Chung HO, David FLYE, Zhenrong JIN, Ramana M. MALLADI
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Patent number: 10615806Abstract: 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: GrantFiled: May 31, 2018Date of Patent: April 7, 2020Assignee: INTERNATIONAL BUSINESS MACHINES CORPORATIONInventors: Jingdong Deng, Rupert Shiu Chung Ho, David Flye, Zhenrong Jin, Ramana M. Malladi
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Patent number: 10566981Abstract: 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: GrantFiled: October 5, 2018Date of Patent: February 18, 2020Assignee: INTERNATIONAL BUSINESS MACHINES CORPORATIONInventors: Jingdong Deng, Rupert Shiu Chung Ho, David Flye, Zhenrong Jin, Ramana M. Malladi
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Publication number: 20190036534Abstract: 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: ApplicationFiled: October 5, 2018Publication date: January 31, 2019Inventors: Jingdong DENG, Rupert Shiu Chung HO, David FLYE, Zhenrong JIN, Ramana M. MALLADI
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Patent number: 10164647Abstract: 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: GrantFiled: October 20, 2017Date of Patent: December 25, 2018Assignee: INTERNATIONAL BUSINESS MACHINES CORPORATIONInventors: Jingdong Deng, Rupert Shiu Chung Ho, David Flye, Zhenrong Jin, Ramana M. Malladi
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Patent number: 9673805Abstract: 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: GrantFiled: August 21, 2014Date of Patent: June 6, 2017Assignee: International Business Machines CorporationInventors: Sarveswara Bade, Shiu Chung Ho, Marcel A. Kossel, Pradeep Thiagarajan
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Publication number: 20160056809Abstract: 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: ApplicationFiled: August 21, 2014Publication date: February 25, 2016Inventors: SARVESWARA BADE, SHIU CHUNG HO, MARCEL A. KOSSEL, PRADEEP THIAGARAJAN
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Patent number: 8791728Abstract: 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: GrantFiled: October 18, 2011Date of Patent: July 29, 2014Assignee: International Business Machines CorporationInventors: John S. Austin, Kai D. Feng, Shiu Chung Ho, Zhenrong Jin
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Patent number: 8525561Abstract: 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: GrantFiled: October 18, 2011Date of Patent: September 3, 2013Assignee: International Business Machines CorporationInventors: John S. Austin, Kai D. Feng, Shiu Chung Ho, Zhenrong Jin
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Patent number: 8471595Abstract: 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: GrantFiled: January 19, 2012Date of Patent: June 25, 2013Assignee: International Business Machines CorporationInventors: John S. Austin, Kai D. Feng, Shiu Chung Ho, Zhenrong Jin, Michael R. Ouellette
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Publication number: 20130093481Abstract: 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: ApplicationFiled: October 18, 2011Publication date: April 18, 2013Applicant: INTERNATIONAL BUSINESS MACHINES CORPORATIONInventors: John S. Austin, Kai D. Feng, Shiu Chung Ho, Zhenrong Jin
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Publication number: 20130093463Abstract: 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: ApplicationFiled: October 18, 2011Publication date: April 18, 2013Applicant: INTERNATIONAL BUSINESS MACHINES CORPORATIONInventors: John S. Austin, Kai D. Feng, Shiu Chung Ho, Zhenrong Jin
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Patent number: 8289058Abstract: 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: GrantFiled: March 7, 2012Date of Patent: October 16, 2012Assignee: International Business Machines CorporationInventors: James Eckhardt, Shiu Chung Ho, Paul D. Muench, Scot H. Rider
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Publication number: 20120161838Abstract: 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: ApplicationFiled: March 7, 2012Publication date: June 28, 2012Applicant: International Business Machines CorporationInventors: James Eckhardt, Shiu Chung Ho, Paul D. Muench, Scot H. Rider
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Patent number: 8149035Abstract: 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: GrantFiled: February 2, 2010Date of Patent: April 3, 2012Assignee: International Business Machines CorporationInventors: James Eckhardt, Shiu Chung Ho, Paul D. Muench, Scot H. Rider
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Publication number: 20110187423Abstract: 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: ApplicationFiled: February 2, 2010Publication date: August 4, 2011Applicant: INTERNATIONAL BUSINESS MACHINES CORPORATIONInventors: James Eckhardt, Shiu Chung Ho, Paul D. Muench, Scot H. Rider
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Patent number: 7782114Abstract: 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: GrantFiled: January 8, 2009Date of Patent: August 24, 2010Assignee: International Business Machines CorporationInventors: Anirban Banerjee, Stephen F. Geissler, Shiu Chung Ho