Patents by Inventor Song Stone Shi
Song Stone Shi 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).
-
Publication number: 20140111276Abstract: Techniques for controlling boost converter operation in an envelope tracking (ET) system. In an aspect, an enable generation block is provided to generate an enable signal for a boost converter, wherein the enable signal is turned on in response to detecting that a sum of a first headroom voltage and an enable peak of a tracking supply voltage is greater than an amplifier supply voltage of the ET system. The enable signal may be turned on for a predetermined enable on duration. In another aspect, a target generation block is provided to generate a target voltage for the boost converter, wherein the target voltage comprises the sum of a second headroom voltage and a target peak of the tracking supply voltage.Type: ApplicationFiled: October 24, 2012Publication date: April 24, 2014Applicant: QUALCOMM INCORPORATEDInventors: Lennart Karl-Axel Mathe, Song Stone Shi, Yunfei Shi
-
Publication number: 20140111170Abstract: Simple and efficient techniques for closed loop control of a boost converter. In an aspect, a current feed-forward (CFF) mode of operation includes providing current information to a control logic block controlling transistor switches of the boost converter to advantageously smooth the signals present in the closed loop control of the system. In another aspect, a modified peak current (MPC) mode of operation includes providing a simplified control mechanism based on a peak current mode of operation. Both CFF mode and MPC mode may share similar circuit elements, allowing a single implementation to selectively implement either of these modes of control. Further techniques are provided for determining average current information for the logic block.Type: ApplicationFiled: October 24, 2012Publication date: April 24, 2014Applicant: QUALCOMM INCORPORATEDInventors: Song Stone Shi, Lennart Karl-Axel Mathe, Yunfel Shi
-
Patent number: 8633763Abstract: Output circuits using pulse width modulation (PWM) and/or pulse density modulation (PDM) are described. In one aspect, a PWM output circuit includes a PWM modulator that operates based on a square wave signal instead of a sawtooth or triangular wave signal. In another aspect, a PDM output circuit includes a PDM modulator that uses variable reference voltages to reduce variations in switching frequency. In yet another aspect, a dual-mode output circuit supports both PWM and PDM and includes a pulse modulator and a class D amplifier. The pulse modulator performs PWM on an input signal if a PWM mode is selected and performs PDM on the input signal if a PDM mode is selected. The class D amplifier receives a driver signal from the pulse modulator and generates an output signal.Type: GrantFiled: August 4, 2011Date of Patent: January 21, 2014Assignee: QUALCOMM IncorporatedInventors: Brett C Walker, Song Stone Shi
-
Patent number: 8536938Abstract: Output circuits using pulse width modulation (PWM) and/or pulse density modulation (PDM) are described. In one aspect, a PWM output circuit includes a PWM modulator that operates based on a square wave signal instead of a sawtooth or triangular wave signal. In another aspect, a PDM output circuit includes a PDM modulator that uses variable reference voltages to reduce variations in switching frequency. In yet another aspect, a dual-mode output circuit supports both PWM and PDM and includes a pulse modulator and a class D amplifier. The pulse modulator performs PWM on an input signal if a PWM mode is selected and performs PDM on the input signal if a PDM mode is selected. The class D amplifier receives a driver signal from the pulse modulator and generates an output signal.Type: GrantFiled: August 4, 2011Date of Patent: September 17, 2013Assignee: QUALCOMM, IncorporatedInventors: Brett C Walker, Song Stone Shi
-
Publication number: 20110285463Abstract: Output circuits using pulse width modulation (PWM) and/or pulse density modulation (PDM) are described. In one aspect, a PWM output circuit includes a PWM modulator that operates based on a square wave signal instead of a sawtooth or triangular wave signal. In another aspect, a PDM output circuit includes a PDM modulator that uses variable reference voltages to reduce variations in switching frequency. In yet another aspect, a dual-mode output circuit supports both PWM and PDM and includes a pulse modulator and a class D amplifier. The pulse modulator performs PWM on an input signal if a PWM mode is selected and performs PDM on the input signal if a PDM mode is selected. The class D amplifier receives a driver signal from the pulse modulator and generates an output signal.Type: ApplicationFiled: August 4, 2011Publication date: November 24, 2011Applicant: QUALCOMM INCORPORATEDInventors: Brett C. Walker, Song Stone Shi
-
Publication number: 20110285472Abstract: Output circuits using pulse width modulation (PWM) and/or pulse density modulation (PDM) are described. In one aspect, a PWM output circuit includes a PWM modulator that operates based on a square wave signal instead of a sawtooth or triangular wave signal. In another aspect, a PDM output circuit includes a PDM modulator that uses variable reference voltages to reduce variations in switching frequency. In yet another aspect, a dual-mode output circuit supports both PWM and PDM and includes a pulse modulator and a class D amplifier. The pulse modulator performs PWM on an input signal if a PWM mode is selected and performs PDM on the input signal if a PDM mode is selected. The class D amplifier receives a driver signal from the pulse modulator and generates an output signal.Type: ApplicationFiled: August 4, 2011Publication date: November 24, 2011Applicant: QUALCOMM INCORPORATEDInventors: Brett C. Walker, Song Stone Shi
-
Patent number: 8022756Abstract: Output circuits using pulse width modulation (PWM) and/or pulse density modulation (PDM) are described. In one aspect, a PWM output circuit includes a PWM modulator that operates based on a square wave signal instead of a sawtooth or triangular wave signal. In another aspect, a PDM output circuit includes a PDM modulator that uses variable reference voltages to reduce variations in switching frequency. In yet another aspect, a dual-mode output circuit supports both PWM and PDM and includes a pulse modulator and a class D amplifier. The pulse modulator performs PWM on an input signal if a PWM mode is selected and performs PDM on the input signal if a PDM mode is selected. The class D amplifier receives a driver signal from the pulse modulator and generates an output signal.Type: GrantFiled: May 15, 2007Date of Patent: September 20, 2011Assignee: QUALCOMM, IncorporatedInventors: Brett C. Walker, Song Stone Shi
-
Publication number: 20080284508Abstract: Output circuits using pulse width modulation (PWM) and/or pulse density modulation (PDM) are described. In one aspect, a PWM output circuit includes a PWM modulator that operates based on a square wave signal instead of a sawtooth or triangular wave signal. In another aspect, a PDM output circuit includes a PDM modulator that uses variable reference voltages to reduce variations in switching frequency. In yet another aspect, a dual-mode output circuit supports both PWM and PDM and includes a pulse modulator and a class D amplifier. The pulse modulator performs PWM on an input signal if a PWM mode is selected and performs PDM on the input signal if a PDM mode is selected. The class D amplifier receives a driver signal from the pulse modulator and generates an output signal.Type: ApplicationFiled: May 15, 2007Publication date: November 20, 2008Inventors: Brett C. Walker, Song Stone Shi