Patents by Inventor Kai Yiu Tam

Kai Yiu Tam 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: 10958213
    Abstract: A clock oscillator includes with a pullable BAW oscillator to generate an output signal with a target frequency. The BAW oscillator is based on a BAW resonator and voltage-controlled variable load capacitance, responsive to a capacitance control signal to provide a selectable load capacitance. An oscillator driver (such as a differential negative gm transconductance amplifier), is coupled to the BAW oscillator to provide an oscillation drive signal. The BAW oscillator is responsive to the oscillation drive signal to generate the output signal with a frequency based on the selectable load capacitance. The oscillator driver can include a bandpass filter network with a resonance frequency substantially at the target frequency.
    Type: Grant
    Filed: May 8, 2020
    Date of Patent: March 23, 2021
    Assignee: TEXAS INSTRUMENTS INCORPORATED
    Inventors: Ben-yong Zhang, Seong-Ryong Ryu, Ali Kiaei, Ting-Ta Yen, Kai Yiu Tam
  • Publication number: 20210044300
    Abstract: A high linearity phase interpolator (PI) is disclosed. A phase value parameter indicative of a desired phase difference between an output signal and an input clock signal edge may be provided by control logic. A first capacitor may be charged for a first period of time with a first current that is proportional to the phase value parameter to produce a first voltage on the capacitor that is proportional to the phase value parameter. The first capacitor may be further charged for a second period of time with a second current that has a constant value to form a voltage ramp offset by the first voltage. A reference voltage may be compared to the voltage ramp during the second period of time. The output signal may be asserted at a time when the voltage ramp equals the reference voltage.
    Type: Application
    Filed: October 27, 2020
    Publication date: February 11, 2021
    Inventors: Baher Haroun, Wenting Zhou, Kai Yiu Tam, Reza Hoshyar, Ali Kiaei
  • Patent number: 10855294
    Abstract: A high linearity phase interpolator (PI) is disclosed. A phase value parameter indicative of a desired phase difference between an output signal and an input clock signal edge may be provided by control logic. A first capacitor may be charged for a first period of time with a first current that is proportional to the phase value parameter to produce a first voltage on the capacitor that is proportional to the phase value parameter. The first capacitor may be further charged for a second period of time with a second current that has a constant value to form a voltage ramp offset by the first voltage. A reference voltage may be compared to the voltage ramp during the second period of time. The output signal may be asserted at a time when the voltage ramp equals the reference voltage.
    Type: Grant
    Filed: November 8, 2016
    Date of Patent: December 1, 2020
    Assignee: TEXAS INSTRUMENTS INCORPORATED
    Inventors: Baher Haroun, Wenting Zhou, Kai Yiu Tam, Reza Hoshyar, Ali Kiaei
  • Publication number: 20200274485
    Abstract: A clock oscillator includes with a pullable BAW oscillator to generate an output signal with a target frequency. The BAW oscillator is based on a BAW resonator and voltage-controlled variable load capacitance, responsive to a capacitance control signal to provide a selectable load capacitance. An oscillator driver (such as a differential negative gm transconductance amplifier), is coupled to the BAW oscillator to provide an oscillation drive signal. The BAW oscillator is responsive to the oscillation drive signal to generate the output signal with a frequency based on the selectable load capacitance. The oscillator driver can include a bandpass filter network with a resonance frequency substantially at the target frequency.
    Type: Application
    Filed: May 8, 2020
    Publication date: August 27, 2020
    Inventors: Ben-yong Zhang, Seong-Ryong Ryu, Ali Kiaei, Ting-Ta Yen, Kai Yiu Tam
  • Patent number: 10651789
    Abstract: A clock oscillator includes with a pullable BAW oscillator to generate an output signal with a target frequency. The BAW oscillator is based on a BAW resonator and voltage-controlled variable load capacitance, responsive to a capacitance control signal to provide a selectable load capacitance. An oscillator driver (such as a differential negative gm transconductance amplifier), is coupled to the BAW oscillator to provide an oscillation drive signal. The BAW oscillator is responsive to the oscillation drive signal to generate the output signal with a frequency based on the selectable load capacitance. The oscillator driver can include a bandpass filter network with a resonance frequency substantially at the target frequency.
    Type: Grant
    Filed: September 28, 2017
    Date of Patent: May 12, 2020
    Assignee: TEXAS INSTRUMENTS INCORPORATED
    Inventors: Ben-yong Zhang, Seong-Ryong Ryu, Ali Kiaei, Ting-Ta Yen, Kai Yiu Tam
  • Publication number: 20180131378
    Abstract: A high linearity phase interpolator (PI) is disclosed. A phase value parameter indicative of a desired phase difference between an output signal and an input clock signal edge may be provided by control logic. A first capacitor may be charged for a first period of time with a first current that is proportional to the phase value parameter to produce a first voltage on the capacitor that is proportional to the phase value parameter. The first capacitor may be further charged for a second period of time with a second current that has a constant value to form a voltage ramp offset by the first voltage. A reference voltage may be compared to the voltage ramp during the second period of time. The output signal may be asserted at a time when the voltage ramp equals the reference voltage.
    Type: Application
    Filed: November 8, 2016
    Publication date: May 10, 2018
    Inventors: Baher Haroun, Wenting Zhou, Kai Yiu Tam, Reza Hoshyar, Ali Kiaei
  • Publication number: 20180091095
    Abstract: A clock oscillator includes with a pullable BAW oscillator to generate an output signal with a target frequency. The BAW oscillator is based on a BAW resonator and voltage-controlled variable load capacitance, responsive to a capacitance control signal to provide a selectable load capacitance. An oscillator driver (such as a differential negative gm transconductance amplifier), is coupled to the BAW oscillator to provide an oscillation drive signal. The BAW oscillator is responsive to the oscillation drive signal to generate the output signal with a frequency based on the selectable load capacitance. The oscillator driver can include a bandpass filter network with a resonance frequency substantially at the target frequency.
    Type: Application
    Filed: September 28, 2017
    Publication date: March 29, 2018
    Inventors: Ben-yong Zhang, Seong-Ryong Ryu, Ali Kiaei, Ting-Ta Yen, Kai Yiu Tam
  • Patent number: 9692356
    Abstract: The systems and methods of oscillator frequency tuning using a bulk acoustic wave resonator include a relaxation oscillator, a BAW oscillator, a frequency counter, and an adjustment module. The BAW oscillator provides an accurate time reference even over temperature changes. The BAW oscillator is turned on periodically and the relaxation oscillator is calibrated with the BAW oscillator. A temporary and periodic enablement of the BAW oscillator maintains a low current consumption. The frequency counter counts a number of full periods of the BAW oscillator that occur in one period of the relaxation oscillator. Since each frequency is known, the number of pulses of the BAW oscillator that should occur during one period of the relaxation oscillator is known. If the count is different from what should be counted, a correction may be made by adjusting an input parameter of the relaxation oscillator.
    Type: Grant
    Filed: November 20, 2015
    Date of Patent: June 27, 2017
    Assignee: TEXAS INSTRUMENTS INCORPORATED
    Inventors: Baher S. Haroun, Ali Kiaei, Kai Yiu Tam
  • Publication number: 20170149386
    Abstract: The systems and methods of oscillator frequency tuning using a bulk acoustic wave resonator include a relaxation oscillator, a BAW oscillator, a frequency counter, and an adjustment module. The BAW oscillator provides an accurate time reference even over temperature changes. The BAW oscillator is turned on periodically and the relaxation oscillator is calibrated with the BAW oscillator. A temporary and periodic enablement of the BAW oscillator maintains a low current consumption. The frequency counter counts a number of full periods of the BAW oscillator that occur in one period of the relaxation oscillator. Since each frequency is known, the number of pulses of the BAW oscillator that should occur during one period of the relaxation oscillator is known. If the count is different from what should be counted, a correction may be made by adjusting an input parameter of the relaxation oscillator.
    Type: Application
    Filed: November 20, 2015
    Publication date: May 25, 2017
    Applicant: Texas Instruments Incorporated
    Inventors: Baher S. Haroun, Ali Kiaei, Kai Yiu Tam
  • Patent number: 9356554
    Abstract: A relaxation oscillator reduces temperature sensitivity and phase noise at low offset frequency by periodically swapping a first current and a second current so that after the first current has been input to a first pair of circuits and the second current has been input to a second pair of circuits, the second current is input to the first pair of circuits and the first current is input to the second pair of circuits.
    Type: Grant
    Filed: July 12, 2014
    Date of Patent: May 31, 2016
    Assignee: TEXAS INSTRUMENTS INCORPORATED
    Inventors: Kai Yiu Tam, Ali Kiaei, Baher S. Haroun
  • Publication number: 20160013753
    Abstract: A relaxation oscillator reduces temperature sensitivity and phase noise at low offset frequency by periodically swapping a first current and a second current so that after the first current has been input to a first pair of circuits and the second current has been input to a second pair of circuits, the second current is input to the first pair of circuits and the first current is input to the second pair of circuits.
    Type: Application
    Filed: July 12, 2014
    Publication date: January 14, 2016
    Applicant: TEXAS INSTRUMENTS INCORPORATED
    Inventors: Kai Yiu Tam, Ali Kiaei, Baher S. Haroun