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).
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Patent number: 10958213Abstract: 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: GrantFiled: May 8, 2020Date of Patent: March 23, 2021Assignee: TEXAS INSTRUMENTS INCORPORATEDInventors: Ben-yong Zhang, Seong-Ryong Ryu, Ali Kiaei, Ting-Ta Yen, Kai Yiu Tam
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Publication number: 20210044300Abstract: 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: ApplicationFiled: October 27, 2020Publication date: February 11, 2021Inventors: Baher Haroun, Wenting Zhou, Kai Yiu Tam, Reza Hoshyar, Ali Kiaei
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Patent number: 10855294Abstract: 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: GrantFiled: November 8, 2016Date of Patent: December 1, 2020Assignee: TEXAS INSTRUMENTS INCORPORATEDInventors: Baher Haroun, Wenting Zhou, Kai Yiu Tam, Reza Hoshyar, Ali Kiaei
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Publication number: 20200274485Abstract: 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: ApplicationFiled: May 8, 2020Publication date: August 27, 2020Inventors: Ben-yong Zhang, Seong-Ryong Ryu, Ali Kiaei, Ting-Ta Yen, Kai Yiu Tam
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Patent number: 10651789Abstract: 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: GrantFiled: September 28, 2017Date of Patent: May 12, 2020Assignee: TEXAS INSTRUMENTS INCORPORATEDInventors: Ben-yong Zhang, Seong-Ryong Ryu, Ali Kiaei, Ting-Ta Yen, Kai Yiu Tam
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Publication number: 20180131378Abstract: 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: ApplicationFiled: November 8, 2016Publication date: May 10, 2018Inventors: Baher Haroun, Wenting Zhou, Kai Yiu Tam, Reza Hoshyar, Ali Kiaei
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Publication number: 20180091095Abstract: 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: ApplicationFiled: September 28, 2017Publication date: March 29, 2018Inventors: Ben-yong Zhang, Seong-Ryong Ryu, Ali Kiaei, Ting-Ta Yen, Kai Yiu Tam
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Patent number: 9692356Abstract: 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: GrantFiled: November 20, 2015Date of Patent: June 27, 2017Assignee: TEXAS INSTRUMENTS INCORPORATEDInventors: Baher S. Haroun, Ali Kiaei, Kai Yiu Tam
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Publication number: 20170149386Abstract: 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: ApplicationFiled: November 20, 2015Publication date: May 25, 2017Applicant: Texas Instruments IncorporatedInventors: Baher S. Haroun, Ali Kiaei, Kai Yiu Tam
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Patent number: 9356554Abstract: 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: GrantFiled: July 12, 2014Date of Patent: May 31, 2016Assignee: TEXAS INSTRUMENTS INCORPORATEDInventors: Kai Yiu Tam, Ali Kiaei, Baher S. Haroun
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Publication number: 20160013753Abstract: 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: ApplicationFiled: July 12, 2014Publication date: January 14, 2016Applicant: TEXAS INSTRUMENTS INCORPORATEDInventors: Kai Yiu Tam, Ali Kiaei, Baher S. Haroun