Patents by Inventor Xuening Li
Xuening Li 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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Publication number: 20080042634Abstract: A method and apparatus for use in a multi-phase power system. The power system is of the type having a plurality of Pulse Width Modulation (PWM) controllers including a first PWM controller and at least one second PWM controller. The first PWM controller generates at least one first PWM output signal based on a cyclic signal having a cyclically recurring parameter, and provides the cyclic signal including the cyclically recurring parameter to the second PWM controller. The second PWM controller generates at least one second PWM output signal based on the cyclic signal, and synchronizes the generation of the first and second output signals using the cyclically recurring parameter within the cyclic signal, thereby maintaining a predetermined phase relationship between the first and second output signals.Type: ApplicationFiled: April 2, 2007Publication date: February 21, 2008Applicant: TEXAS INSTRUMENTS, INCORPORATEDInventors: William Todd Harrison, Xuening Li, Stefan W. Wiktor, Larry Joe Wofford
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Patent number: 7332898Abstract: A method and apparatus for use in a multi-phase power system. The power system is of the type having a plurality of Pulse Width Modulation (PWM) controllers including a first PWM controller and at least one second PWM controller. The first PWM controller generates at least one first PWM output signal based on a cyclic signal having a cyclically recurring parameter, and provides the cyclic signal including the cyclically recurring parameter to the second PWM controller. The second PWM controller generates at least one second PWM output signal based on the cyclic signal, and synchronizes the generation of the first and second output signals using the cyclically recurring parameter within the cyclic signal, thereby maintaining a predetermined phase relationship between the first and second output signals.Type: GrantFiled: April 2, 2007Date of Patent: February 19, 2008Assignee: Texas Instruments IncorporatedInventors: William Todd Harrison, Xuening Li, Stefan W Wiktor, Larry Joe Wofford
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Patent number: 7259687Abstract: A multi-module DC-DC converter provides synchronization between modules based on identification of a module within a chain. A resistor network can be used for the chain so that each module obtains a particular voltage based on its position within the chain. A master module provides a source current to drive the chain so that each module can determine its relative position in the chain based on voltage readings. With this configuration, a master module can determine how many modules are in the chain, and each slave module can determine its relative position in the chain. The module information contributes to synchronization between the modules for use in current ripple cancellation, for example, in the multi-module DC-DC converter.Type: GrantFiled: October 21, 2005Date of Patent: August 21, 2007Assignee: Texas Instruments IncorporatedInventors: Stefan W. Wiktor, Xuening Li
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Publication number: 20070091658Abstract: A multi-module DC-DC converter provides synchronization between modules based on identification of a module within a chain. A resistor network can be used for the chain so that each module obtains a particular voltage based on its position within the chain. A master module provides a source current to drive the chain so that each module can determine its relative position in the chain based on voltage readings. With this configuration, a master module can determine how many modules are in the chain, and each slave module can determine its relative position in the chain. The module information contributes to synchronization between the modules for use in current ripple cancellation, for example, in the multi-module DC-DC converter.Type: ApplicationFiled: October 21, 2005Publication date: April 26, 2007Inventors: Stefan Wiktor, Xuening Li
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Publication number: 20070002944Abstract: An apparatus for driving a pulse width modulation reference signal includes: (a) A converting unit receiving an input signal at an input locus and presenting an output current at an output locus. The input signal varies at a first frequency. The output current is substantially related with the first frequency. (b) A capacitive element coupled with the output locus for charging by the output current. The pulse width modulation reference signal is related with voltage across the capacitive element.Type: ApplicationFiled: June 29, 2005Publication date: January 4, 2007Inventors: Stefan Wiktor, Vladimir Muratov, Xuening Li
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Patent number: 7019502Abstract: A multiphase synthetic ripple voltage generator for a multiphase DC-DC regulator including a master clock circuit that generates a master clock signal, sequence logic and a ripple regulator for each phase. The DC-DC regulator includes multiple switching circuits, each responsive to a corresponding PWM signal to switch input voltages via a phase node through an output inductor to develop an output voltage. The sequence logic sets each PWM signal in sequential order based on the master clock signal. Each ripple generator includes a transconductance amplifier, a ripple capacitor and a comparator. The transconductance amplifier has an input coupled to a corresponding output inductor and an output coupled to a corresponding ripple capacitor. The comparator has a first input coupled to the ripple capacitor, a second input receiving an error voltage, and an output coupled to the sequence logic for resetting a corresponding PWM signal.Type: GrantFiled: May 25, 2004Date of Patent: March 28, 2006Assignee: Intersil America's Inc.Inventors: Michael M. Walters, Xuening Li, Thomas A. Jochum
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Patent number: 7015757Abstract: A transconductance amplifier with multi-emitter structure for balancing current of a multi-phase regulator including multiple transistors, a bias current device, multiple current mirrors, and multiple current sources. Each transistor has first and second current terminals and a current control terminal receiving a corresponding one of multiple sense voltages. Each sense voltage is indicative of output inductor current of a corresponding phase of the multi-phase regulator. The bias current device is coupled to the first current terminal of each transistor. Each current mirror has an input coupled to a second current terminal of a corresponding transistor and an output coupled to a corresponding one of multiple correction nodes. Each current source is coupled to a corresponding one of multiple correction nodes. In this manner, each correction node provides a correction current for a corresponding phase of the regulator.Type: GrantFiled: March 17, 2004Date of Patent: March 21, 2006Assignee: Intersil Americas Inc.Inventors: Xuening Li, Thomas A. Jochum
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Publication number: 20060043949Abstract: A regulator circuit to regulate a voltage for a load includes a sensing circuit to sense a change in voltage for the load, a variable frequency circuit to output a signal having a frequency component; and a control circuit responsive to the sensing circuit to control the variable frequency circuit by changing the frequency component and the voltage.Type: ApplicationFiled: September 22, 2004Publication date: March 2, 2006Inventors: Xuening Li, Stefan Wiktor
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Publication number: 20060043948Abstract: A regulator circuit to regulate a voltage for a load includes a sensing circuit to sense a charge in voltage for the load, a variable frequency circuit to output a signal having a frequency component; and a control circuit responsive to the sensing circuit to control the variable frequency circuit by changing the frequency component and the voltage.Type: ApplicationFiled: August 30, 2004Publication date: March 2, 2006Inventors: Xuening Li, Stefan Wiktor
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Patent number: 6922044Abstract: A multiphase ripple voltage regulator generator employs a hysteretic comparator referenced to upper and lower voltage thresholds. The hysteretic comparator monitors a master ripple voltage waveform developed across a capacitor supplied with a current proportional to the difference between the output voltage and either the input voltage or ground. The output of the hysteretic comparator generates a master clock signal that is sequentially coupled to PWM latches, the states of which define the durations of respective components of the synthesized ripple voltage. A respective PWM latch has a first state initiated by a selected master clock signal and terminated by an associated phase voltage comparator that monitors a respective phase node voltage.Type: GrantFiled: September 29, 2003Date of Patent: July 26, 2005Assignee: Intersil Americas Inc.Inventors: Michael M. Walters, Xuening Li, Thomas A. Jochum
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Publication number: 20050128005Abstract: A transconductance amplifier with multi-emitter structure for balancing current of a multi-phase regulator including multiple transistors, a bias current device, multiple current mirrors, and multiple current sources. Each transistor has first and second current terminals and a current control terminal receiving a corresponding one of multiple sense voltages. Each sense voltage is indicative of output inductor current of a corresponding phase of the multi-phase regulator. The bias current device is coupled to the first current terminal of each transistor. Each current mirror has an input coupled to a second current terminal of a corresponding transistor and an output coupled to a corresponding one of multiple correction nodes. Each current source is coupled to a corresponding one of multiple correction nodes. In this manner, each correction node provides a correction current for a corresponding phase of the regulator.Type: ApplicationFiled: March 17, 2004Publication date: June 16, 2005Applicant: Intersil Americas Inc.Inventors: Xuening Li, Thomas Jochum
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Publication number: 20050001597Abstract: A multiphase synthetic ripple voltage generator for a multiphase DC-DC regulator including a master clock circuit that generates a master clock signal, sequence logic and a ripple regulator for each phase. The DC-DC regulator includes multiple switching circuits, each responsive to a corresponding PWM signal to switch input voltages via a phase node through an output inductor to develop an output voltage. The sequence logic sets each PWM signal in sequential order based on the master clock signal. Each ripple generator includes a transconductance amplifier, a ripple capacitor and a comparator. The transconductance amplifier has an input coupled to a corresponding output inductor and an output coupled to a corresponding ripple capacitor. The comparator has a first input coupled to the ripple capacitor, a second input receiving an error voltage, and an output coupled to the sequence logic for resetting a corresponding PWM signal.Type: ApplicationFiled: May 25, 2004Publication date: January 6, 2005Applicant: Intersil Americas Inc.Inventors: Michael Walters, Xuening Li, Thomas Jochum
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Patent number: 6836160Abstract: A modified Brokaw cell-based circuit produces a current which varies linearly with temperature. The collector-emitter current flow path of a diode-connected transistor is connected in series with the PTAT current produced by a control transistor. The base of the control transistor receives a control voltage whose value defines a limited range of variation of output current with temperature. The output transistor is coupled to an input port of a current mirror, which mirrors the linear collector current from the output transistor. The current through the output transistor is controlled by a composite of a CTAT base-emitter voltage of the diode-connected transistor and a PTAT voltage across a resistor, so that the output transistor produces an output current having a linear temperature coefficient.Type: GrantFiled: November 19, 2002Date of Patent: December 28, 2004Assignee: Intersil Americas Inc.Inventor: Xuening Li
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Patent number: 6815936Abstract: A diode emulator for a DC—DC buck converter employs a variable current ramp-based circuit that monitors the state of the phase voltage at the common node between two power switching devices. Incrementally with each pulse width modulation cycle, the diode emulator adjusts the time of turn-off of the lower power switching device, until the monitored phase voltage indicates that the emulator is effectively tracking the negative going, zero-crossing of the ripple current through an output inductor.Type: GrantFiled: August 21, 2002Date of Patent: November 9, 2004Assignee: Intersil Americas Inc.Inventors: Stefan Wlodzimierz Wiktor, Xuening Li
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Publication number: 20040095187Abstract: A modified Brokaw cell-based circuit produces a current which varies linearly with temperature. The collector-emitter current flow path of a diode-connected transistor is connected in series with the PTAT current produced by a control transistor. The base of the control transistor receives a control voltage whose value defines a limited range of variation of output current with temperature. The output transistor is coupled to an input port of a current mirror, which mirrors the linear collector current from the output transistor. The current through the output transistor is controlled by a composite of a CTAT base-emitter voltage of the diode-connected transistor and a PTAT voltage across a resistor, so that the output transistor produces an output current having a linear temperature coefficient.Type: ApplicationFiled: November 19, 2002Publication date: May 20, 2004Applicant: Intersil Americas Inc.Inventor: Xuening Li
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Publication number: 20040070382Abstract: A multiphase ripple voltage regulator generator employs a hysteretic comparator referenced to upper and lower voltage thresholds. The hysteretic comparator monitors a master ripple voltage waveform developed across a capacitor supplied with a current proportional to the difference between the output voltage and either the input voltage or ground. The output of the hysteretic comparator generates a master clock signal that is sequentially coupled to PWM latches, the states of which define the durations of respective components of the synthesized ripple voltage. A respective PWM latch has a first state initiated by a selected master clock signal and terminated by an associated phase voltage comparator that monitors a respective phase node voltage.Type: ApplicationFiled: September 29, 2003Publication date: April 15, 2004Applicant: Intersil Americas Inc.Inventors: Michael M. Walters, Xuening Li, Thomas A. Jochum
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Publication number: 20040036459Abstract: A diode emulator for a DC-DC buck converter employs a variable current ramp-based circuit that monitors the state of the phase voltage at the common node between two power switching devices. Incrementally with each pulse width modulation cycle, the diode emulator adjusts the time of turn-off of the lower power switching device, until the monitored phase voltage indicates that the emulator is effectively tracking the negative going, zero-crossing of the ripple current through an output inductor.Type: ApplicationFiled: August 21, 2002Publication date: February 26, 2004Applicant: Intersil Americas Inc.Inventors: Stefan Wlodzimierz Wiktor, Xuening Li