Patents by Inventor Ammisetti Prasad
Ammisetti Prasad 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: 9705458Abstract: An energy-efficient consumer device audio power output stage with gain control provides improved battery life and reduced power dissipation without clipping the audio output signal. A control circuit controls a power supply that supplies the power supply rails to the power amplified output stage. The voltage of the power supply rails is controlled in conformity with an input audio signal level, which may be determined from a volume control setting of the device and/or from a signal level detector that determines the amplitude of the signal being amplified. The gain applied to the audio input signal is reduced for a predetermined time period when a higher output voltage of the power supply is selected, to avoid clipping the audio output signal.Type: GrantFiled: July 29, 2015Date of Patent: July 11, 2017Assignee: CIRRUS LOGIC, INC.Inventors: John Christopher Tucker, Daniel John Allen, John L. Melanson, Ammisetti Prasad
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Patent number: 9112467Abstract: An energy-efficient consumer device audio power output stage with gain control provides improved battery life and reduced power dissipation without clipping the audio output signal. A power supply having a selectable operating mode supplies the power supply rails to the power amplified output stage. The operating mode is controlled in conformity with an input audio signal level, which may be determined from a volume control setting of the device and/or from a signal level detector that determines the amplitude of the signal being amplified. The gain applied to the audio input signal is reduced for a predetermined time period when a higher output voltage of the power supply is selected, to avoid clipping the audio output signal.Type: GrantFiled: October 16, 2012Date of Patent: August 18, 2015Assignee: Cirrus Logic, Inc.Inventors: John Christopher Tucker, Daniel John Allen, John L. Melanson, Ammisetti Prasad
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Patent number: 8311243Abstract: An energy-efficient consumer device audio power output stage provides improved battery life and reduced power dissipation. A power supply having a selectable operating mode supplies the power supply rails to the power amplified output stage. The operating mode is controlled in conformity with the audio signal level, which may be determined from a volume control setting of the device and/or from a signal level detector that determines the amplitude of the signal being amplified. The power supply may be a charge pump in which the operating mode uses a capacitive divider to provide for selection of a power supply output voltage that is a rational fraction of the power supply output voltage in a full-voltage operating mode.Type: GrantFiled: December 13, 2006Date of Patent: November 13, 2012Assignee: Cirrus Logic, Inc.Inventors: John Christopher Tucker, Daniel John Allen, John L. Melanson, Ammisetti Prasad
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Patent number: 7915995Abstract: A resistive circuit includes a first terminal and a second terminal and polycrystalline first and second resistive segments coupled between the first and second terminals. A third terminal A is coupled to the first resistive segment, and a third terminal B is coupled to the second resistive segment. The third terminal A has a first voltage with respect to the first terminal, and the third terminal B has a second voltage with respect to the second terminal. With this arrangement, the non-linearity of resistance of the first resistive segment at least partially compensates for non-linearity of resistance of the second resistive segment.Type: GrantFiled: September 29, 2009Date of Patent: March 29, 2011Assignee: Cirrus Logic, Inc.Inventors: Hua Yang, Ammisetti Prasad, John L. Melanson
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Publication number: 20100013050Abstract: A resistive circuit includes a first terminal and a second terminal and polycrystalline first and second resistive segments coupled between the first and second terminals. A third terminal A is coupled to the first resistive segment, and a third terminal B is coupled to the second resistive segment. The third terminal A has a first voltage with respect to the first terminal, and the third terminal B has a second voltage with respect to the second terminal. With this arrangement, the non-linearity of resistance of the first resistive segment at least partially compensates for non-linearity of resistance of the second resistive segment.Type: ApplicationFiled: September 29, 2009Publication date: January 21, 2010Applicant: CIRRUS LOGIC, INC.Inventors: Hua Yang, Ammisetti Prasad, John L. Melanson
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Patent number: 7616089Abstract: A resistive circuit includes a first terminal and a second terminal and polycrystalline first and second resistive segments coupled between the first and second terminals. A third terminal A is coupled to the first resistive segment, and a third terminal B is coupled to the second resistive segment. The third terminal A has a first voltage with respect to the first terminal, and the third terminal B has a second voltage with respect to the second terminal. With this arrangement, the non-linearity of resistance of the first resistive segment at least partially compensates for non-linearity of resistance of the second resistive segment.Type: GrantFiled: September 28, 2007Date of Patent: November 10, 2009Assignee: Cirrus Logic, Inc.Inventors: Hua Yang, Ammisetti Prasad, John L. Melanson
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Publication number: 20090085657Abstract: A resistive circuit includes a first terminal and a second terminal and polycrystalline first and second resistive segments coupled between the first and second terminals. A third terminal A is coupled to the first resistive segment, and a third terminal B is coupled to the second resistive segment. The third terminal A has a first voltage with respect to the first terminal, and the third terminal B has a second voltage with respect to the second terminal. With this arrangement, the non-linearity of resistance of the first resistive segment at least partially compensates for non-linearity of resistance of the second resistive segment.Type: ApplicationFiled: September 28, 2007Publication date: April 2, 2009Inventors: HUA YANG, Ammisetti Prasad, John L. Melanson
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Publication number: 20080044041Abstract: An energy-efficient consumer device audio power output stage provides improved battery life and reduced power dissipation. A power supply having a selectable operating mode supplies the power supply rails to the power amplified output stage. The operating mode is controlled in conformity with the audio signal level, which may be determined from a volume control setting of the device and/or from a signal level detector that determines the amplitude of the signal being amplified. The power supply may be a charge pump in which the operating mode uses a capacitive divider to provide for selection of a power supply output voltage that is a rational fraction of the power supply output voltage in a full-voltage operating mode.Type: ApplicationFiled: December 13, 2006Publication date: February 21, 2008Inventors: John Christopher Tucker, Daniel John Allen, John L. Melanson, Ammisetti Prasad
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Publication number: 20060232331Abstract: A chopping amplifier and method for chopping an input signal are disclosed. The chopping amplifier and method utilize at least two chopping amplifier stages. A chopping operation of an input signal is segmented across two or more chopping amplifier stages, and the two or more chopping amplifier stages are responsive to a master controller. Chop clock signals of the chopping amplifier stages are staggered so that they have non-overlapping periods and at least one of the chopping amplifier stages is not operating in an open loop at any given time. The non-overlapping periods are periodic so that a master chop clock of the master controller can be operated at a lower chop clock frequency. For every doubling of N number of chopping amplifier stages, magnitudes of chopping artifacts and aliased components are each respectively reduced by 3 dB.Type: ApplicationFiled: June 19, 2006Publication date: October 19, 2006Inventors: Karl Thompson, John Melanson, Chung-Kai Chow, Ammisetti Prasad
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Patent number: 7106132Abstract: A feed-forward operational amplifier including a dedicated summer circuit for summing a signal generated by a first amplifier stage of a feed-forward amplifier and a signal received from an external source to generate a sum signal and a second amplifier stage coupled to the summer circuit and receiving the sum signal. The second amplifier stage realizes a pole-zero doublet to decrease a unity gain frequency of the feed-forward operational amplifier.Type: GrantFiled: October 27, 2004Date of Patent: September 12, 2006Assignee: Cirrus Logic, Inc.Inventors: Muari Kewariwal, Ammisetti Prasad
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Patent number: 6885211Abstract: A method of testing an integrated circuit includes setting a guardbanded limit for a parameter associated with an embedded node, a deviation from the guardbanded limit under a set of test conditions correlated with a failure of the integrated circuit across a range of operating conditions. A test is performed under the test conditions to detect deviations of the parameter from the guardbanded limit to detect failures of the integrated circuit over the range of operating conditions.Type: GrantFiled: April 5, 2002Date of Patent: April 26, 2005Assignee: Cirrus Logic, Inc.Inventors: Axel Thomsen, Sherry Wu, Murari Kejariwal, Ammisetti Prasad, John Laurence Melanson