Patents by Inventor Andrew J. HOWLETT
Andrew J. HOWLETT 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: 20240154592Abstract: An integrated circuit (IC), comprising: a first input pin for receiving a first input signal; a first converter configured to convert the first input signal to a first output signal; a first gain stage configured to apply a first gain to the first output signal; gain update circuitry configured to: output a first external gain control signal to a first output pin of the IC; and subsequently output a first internal gain control signal to the first gain stage to update the first gain of the first gain stage, wherein output of the first internal gain control signal is delayed relative to output of the first external gain control signal by a first predetermined delay, the first predetermined delay to compensate for signal chain delay between the first input pin and the first gain stage, wherein the gain update circuitry comprises level detection circuitry configured to determine a signal level of the first input signal or the first output signal.Type: ApplicationFiled: November 9, 2023Publication date: May 9, 2024Applicant: Cirrus Logic International Semiconductor Ltd.Inventors: Andrew J. HOWLETT, Michael CHANDLER-PAGE, David P. SINGLETON, Erich P. ZWYSSIG, Craig MCADAM
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Publication number: 20240154612Abstract: The application relates to voltage supply in switched-mode driver integrated circuit (IC). The IC has an output bridge with first and second circuit branches, where each of the circuit branches has an output node (102a, 102b) connected between first and second transistor switches (103a, 104a; 103b, 104b) for selectively connecting the output node to respective first and second voltages (VH, VL). There are discrete first and second IC die contacts (208a, 208b) for receiving the first voltage, and the first and second circuit branches are connected to the first and second IC die contacts respectively. Ancillary circuitry (105) is configured to receive a supply voltage from a voltage supply node voltage which is connected to the first and second IC die contacts via respective first and second respectively matched resistances.Type: ApplicationFiled: October 10, 2023Publication date: May 9, 2024Applicant: Cirrus Logic International Semiconductor Ltd.Inventors: Kapil SHARMA, Andrew J. HOWLETT, Matthew PETHERBRIDGE, John B. BOWLERWELL, Graeme S. ANGUS, Gordon RUSSELL
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Publication number: 20240097633Abstract: The present disclosure relates to circuitry comprising audio amplifier circuitry for receiving an audio signal to be amplified; and first and second output nodes for outputting first and second differential output signals. The circuitry further comprises common mode buffer circuitry configured to receive a common mode voltage and to selectively output the common mode voltage to the first and second output nodes.Type: ApplicationFiled: November 28, 2023Publication date: March 21, 2024Applicant: Cirrus Logic International Semiconductor Ltd.Inventors: David P. SINGLETON, Andrew J. HOWLETT, John B. BOWLERWELL
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Patent number: 11881826Abstract: The present disclosure relates to circuitry comprising audio amplifier circuitry for receiving an audio signal to be amplified; and first and second output nodes for outputting first and second differential output signals. The circuitry further comprises common mode buffer circuitry configured to receive a common mode voltage and to selectively output the common mode voltage to the first and second output nodes.Type: GrantFiled: January 6, 2021Date of Patent: January 23, 2024Assignee: Cirrus Logic Inc.Inventors: David P. Singleton, Andrew J. Howlett, John B. Bowlerwell
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Publication number: 20230353111Abstract: An integrated circuit (IC), comprising: a first input pin for receiving a first input signal; a first converter configured to convert the first input signal to a first output signal; a first gain stage configured to apply a first gain to the first output signal; gain update circuitry configured to: output a first external gain control signal to a first output pin of the IC; and subsequently output a first internal gain control signal to the first gain stage to update the first gain of the first gain stage, wherein output of the first internal gain control signal is delayed relative to output of the first external gain control signal by a first predetermined delay, the first predetermined delay to compensate for signal chain delay between the first input pin and the first gain stage.Type: ApplicationFiled: November 8, 2022Publication date: November 2, 2023Applicant: Cirrus Logic International Semiconductor Ltd.Inventors: Andrew J. HOWLETT, Michael CHANDLER-PAGE, David P. SINGLETON, Erich P. ZWYSSIG
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Publication number: 20230353937Abstract: Signal processing circuitry configured to receive an input signal and to output a processed output signal, wherein the signal processing circuitry is configured to: receive an indication of a temporal location of a transient in the input signal; and provide, in the processed output signal, a masking signal bridging the temporal location of the transient to mask the transient.Type: ApplicationFiled: November 8, 2022Publication date: November 2, 2023Applicant: Cirrus Logic International Semiconductor Ltd.Inventors: Andrew J. HOWLETT, Michael CHANDLER-PAGE, Lea S. GEORGIEVA
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Publication number: 20230344351Abstract: The present disclosure relates to power converter circuitry, and in particular to power converter circuitry for providing a supply voltage to a load such as amplifier circuitry. In one aspect the invention provides a system comprising: amplifier circuitry; and power converter circuitry for receiving a supply voltage and providing an output voltage to the amplifier circuitry, the power converter circuitry comprising: a control loop for regulating an output voltage of the power converter circuitry in accordance with a target output voltage value; and controller circuitry configured to adjust the target output voltage value if the supply voltage to the power converter circuitry is within a first predefined threshold of a requested output voltage of the power converter circuitry.Type: ApplicationFiled: April 13, 2023Publication date: October 26, 2023Applicant: Cirrus Logic International Semiconductor Ltd.Inventors: Alastair M. BOOMER, John B. BOWLERWELL, James MUNGER, Andrew J. HOWLETT
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Publication number: 20230328438Abstract: An audio codec integrated circuit (IC), comprising: an audio input interface; an audio output interface, wherein a first one of the audio input interface and the audio output interface comprises a plurality of interface pins, each interface pin configured to receive a respective one of a plurality of audio input signals or output a respective one of a plurality of audio output signals; a plurality of data converters for converting the plurality of audio input signals into the plurality of audio output signals; and routing circuitry for routing the plurality of audio input signals to the data converters and the plurality of audio output signals from the data converters, the routing circuitry configurable by at least one select pin to adjust the order of routing of the plurality of audio input signals to the data converters or the order of routing of the plurality of audio output signals from the data converters.Type: ApplicationFiled: March 8, 2023Publication date: October 12, 2023Applicant: Cirrus Logic International Semiconductor Ltd.Inventor: Andrew J. HOWLETT
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Publication number: 20230299575Abstract: An integrated circuit (IC), comprising: a converter comprising: one or more core devices; and one or more output internal nodes, each internal node coupled to one of the one or more core devices; protection circuitry comprising: one or more isolation switches, each of the one or more isolation switches coupled between a respective one of the one or more internal output nodes and a respective output external pin of the IC, wherein the protection circuitry configured to: monitor a characteristic at each respective external output pin of the IC; and if the characteristic is outside an operating specification of the one or more core devices, open one or more of the one or more isolation switches to isolate one or more of the one or more core devices from the respective external pin of the IC.Type: ApplicationFiled: March 14, 2023Publication date: September 21, 2023Applicant: Cirrus Logic International Semiconductor Ltd.Inventors: David P. SINGLETON, Andrew J. HOWLETT, Sharjeel RIAZ, John B. BOWLERWELL
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Patent number: 11528031Abstract: This application relates to ADC circuitry. An ADC circuit (200) has first and second conversion paths (201a, 201b) for converting analogue signals to digital and is operable in first and second modes. In the first mode, the first and second conversion paths are connected to respective first and second input nodes (202a, 202b) to receive and convert full scale first and second analogue input signals (Ain1, Ain2) to separate digital outputs (Dout1, Dout2). In the second mode, the first and second conversion paths are both connected to the first input node (202a), to convert the first analogue input signal (Ain1) to respective first and second digital signals, and the first and second conversion paths are configured for processing different signal levels of the first analogue input signal. A selector (207) select the first digital signal or the second digital to be output as an output signal based on an indication of amplitude of the first analogue input signal.Type: GrantFiled: February 24, 2021Date of Patent: December 13, 2022Assignee: Cirrus Logic, Inc.Inventors: Andrew J. Howlett, David P. Singleton, Aniruddha Satoskar
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Patent number: 11500404Abstract: The present disclosure relates to circuitry for selecting a bias voltage to output at a bias voltage output node of the circuitry. The circuitry comprises a first circuit node configured to receive a first voltage from a first, unregulated, voltage source and a second circuit node configured to receive a second voltage from a second, regulated, voltage source. A switch arrangement configured to selectively couple the bias voltage output node to the first circuit node or the second circuit node is also provided.Type: GrantFiled: January 4, 2021Date of Patent: November 15, 2022Assignee: Cirrus Logic, Inc.Inventors: John B. Bowlerwell, Andrew J. Howlett, Graeme S. Angus, Andrei Dumitriu
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Patent number: 11483654Abstract: This application relates to driver circuitry (200) for receiving a digital input signal (D) and outputting, at first and second output nodes (203p, 203n), first and second analogue driving signals respectively for driving a transducer (101), e.g. loudspeaker, in a bridge-tied-load configuration. The driver circuitry may particularly be suitable for driving low-impedance transducers. The driver circuitry has first and second digital-to-analogue converters (201p, 201n) configured to receive the digital input signal and the outputs of the first and second digital-to-analogue converters are coupled to the first and second output nodes respectively. A differential-output amplifier circuit (202) has outputs connected to the first and second output nodes and is configured to regulate the outputs of the digital-to-analogue converters at output nodes to provide the analogue driving signals.Type: GrantFiled: January 26, 2021Date of Patent: October 25, 2022Assignee: Cirrus Logic, Inc.Inventors: Andrew J. Howlett, Sharjeel Riaz, John P. Lesso
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Patent number: 11418153Abstract: This application relates to amplifier circuitry and, in particular, to class-D amplifier circuits. The application describes amplifier circuitry (400) for receiving an input signal (Sin) and generating first and second driving signals (SoutP, SoutN) for driving a bridge-tied-load. The amplifier circuitry includes first and second class-D output stages (403p, 403n) for generating the first and second driving signals based on the input signal. A controller (406) controllably varies a common-mode component of the first and second driving signals based on an indication of amplitude of the first and second driving signals. The controller varies the common-mode component, at lower signal amplitudes, so the common-mode level of the first and second driving signals is moved away from an operating region that leads to distortion.Type: GrantFiled: June 10, 2020Date of Patent: August 16, 2022Assignee: Cirrus Logic, Inc.Inventors: John P. Lesso, Andrew J. Howlett
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Publication number: 20210391831Abstract: This application relates to amplifier circuitry and, in particular, to class-D amplifier circuits. The application describes amplifier circuitry (400) for receiving an input signal (Sin) and generating first and second driving signals (SoutP, SoutN) for driving a bridge-tied-load. The amplifier circuitry includes first and second class-D output stages (403p, 403n) for generating the first and second driving signals based on the input signal. A controller (406) controllably varies a common-mode component of the first and second driving signals based on an indication of amplitude of the first and second driving signals. The controller varies the common-mode component, at lower signal amplitudes, so the common-mode level of the first and second driving signals is moved away from an operating region that leads to distortion.Type: ApplicationFiled: June 10, 2020Publication date: December 16, 2021Applicant: Cirrus Logic International Semiconductor Ltd.Inventors: John P. LESSO, Andrew J. HOWLETT
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Publication number: 20210351753Abstract: The present disclosure relates to circuitry for providing an output voltage. The circuitry comprises: voltage generator circuitry configured to provide an output voltage to an output node of the circuitry; current limiter circuitry operable to perform current limiting so as to limit a current supplied at the output node of the circuitry; detection circuitry configured to output a detection signal when a load voltage across a load coupled to the output node of the circuitry reaches a target voltage; and delay circuitry configured to receive the detection signal and to output a control signal to deactivate current limiting by the current limiter circuitry after a predetermined delay period after receiving the detection signal.Type: ApplicationFiled: April 19, 2021Publication date: November 11, 2021Applicant: Cirrus Logic International Semiconductor Ltd.Inventors: John B. BOWLERWELL, Andrew J. HOWLETT, Saurabh SINGH, Andrew BUIST
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Publication number: 20210273646Abstract: This application relates to ADC circuitry. An ADC circuit (200) has first and second conversion paths (201a, 201b) for converting analogue signals to digital and is operable in first and second modes. In the first mode, the first and second conversion paths are connected to respective first and second input nodes (202a, 202b) to receive and convert full scale first and second analogue input signals (Ain1, Ain2) to separate digital outputs (Dout1, Dout2). In the second mode, the first and second conversion paths are both connected to the first input node (202a), to convert the first analogue input signal (Ain1) to respective first and second digital signals, and the first and second conversion paths are configured for processing different signal levels of the first analogue input signal. A selector (207) select the first digital signal or the second digital to be output as an output signal based on an indication of amplitude of the first analogue input signal.Type: ApplicationFiled: February 24, 2021Publication date: September 2, 2021Applicant: Cirrus Logic International Semiconductor Ltd.Inventors: Andrew J. HOWLETT, David P. SINGLETON, Aniruddha SATOSKAR
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Publication number: 20210250685Abstract: This application relates to driver circuitry (200) for receiving a digital input signal (D) and outputting, at first and second output nodes (203p, 203n), first and second analogue driving signals respectively for driving a transducer (101), e.g. loudspeaker, in a bridge-tied-load configuration. The driver circuitry may particularly be suitable for driving low-impedance transducers. The driver circuitry has first and second digital-to-analogue converters (201p, 201n) configured to receive the digital input signal and the outputs of the first and second digital-to-analogue converters are coupled to the first and second output nodes respectively. A differential-output amplifier circuit (202) has outputs connected to the first and second output nodes and is configured to regulate the outputs of the digital-to-analogue converters at output nodes to provide the analogue driving signals.Type: ApplicationFiled: January 26, 2021Publication date: August 12, 2021Applicant: Cirrus Logic International Semiconductor Ltd.Inventors: Andrew J. HOWLETT, Sharjeel RIAZ, John P. LESSO
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Publication number: 20210242847Abstract: The present disclosure relates to circuitry comprising audio amplifier circuitry for receiving an audio signal to be amplified; and first and second output nodes for outputting first and second differential output signals. The circuitry further comprises common mode buffer circuitry configured to receive a common mode voltage and to selectively output the common mode voltage to the first and second output nodes.Type: ApplicationFiled: January 6, 2021Publication date: August 5, 2021Applicant: Cirrus Logic International Semiconductor Ltd.Inventors: David P. SINGLETON, Andrew J. HOWLETT, John B. BOWLERWELL
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Publication number: 20210232165Abstract: The present disclosure relates to circuitry for selecting a bias voltage to output at a bias voltage output node of the circuitry. The circuitry comprises a first circuit node configured to receive a first voltage from a first, unregulated, voltage source and a second circuit node configured to receive a second voltage from a second, regulated, voltage source. A switch arrangement configured to selectively couple the bias voltage output node to the first circuit node or the second circuit node is also provided.Type: ApplicationFiled: January 4, 2021Publication date: July 29, 2021Applicant: Cirrus Logic International Semiconductor Ltd.Inventors: John B. BOWLERWELL, Andrew J. HOWLETT, Graeme S. ANGUS, Andrei DUMITRIU