Patents by Inventor Ramin Zanbaghi
Ramin Zanbaghi 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: 20240106448Abstract: A system may include a sampling capacitor and a switch network. The switch network may include one or more first sampling switches electrically coupled to the sampling capacitor and configured to be activated during a first phase of a sampling cycle of the system and one or more second sampling switches electrically coupled to the sampling capacitor and configured to be activated during a second phase of the sampling cycle, wherein the switch network is configured to reset the sampling capacitor to a data-independent and/or signal-independent charge during a reset phase of the sampling cycle.Type: ApplicationFiled: September 26, 2022Publication date: March 28, 2024Applicant: Cirrus Logic International Semiconductor Ltd.Inventors: Arashk NOROUZPOURSHIRAZI, Ramin ZANBAGHI, Stephen T. HODAPP, Christophe J. AMADI, Ravi K. KUMMARAGUNTLA, Dhrubajyoti DUTTA
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Patent number: 11854738Abstract: A system may include an electromagnetic load, a driver configured to drive the electromagnetic load with a driving signal, and a processing system communicatively coupled to the electromagnetic load and configured to, during a haptic mode of the system couple a first terminal of the electromagnetic load to a ground voltage and cause the driving signal to have a first slew rate, and during a load sensing mode of the system for sensing a current associated with the electromagnetic load, couple the first terminal to a current-sensing circuit having a sense resistor coupled between the first terminal and an electrical node driven to a common-mode voltage and cause the driving signal to have a second slew rate lower than the first slew rate.Type: GrantFiled: December 2, 2021Date of Patent: December 26, 2023Assignee: Cirrus Logic Inc.Inventors: Chandra B. Prakash, Ramin Zanbaghi
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Patent number: 11811370Abstract: A system for sensing an electrical quantity may include a sensing stage configured to sense the electrical quantity and generate a sense signal indicative of the electrical quantity, wherein the electrical quantity is indicative of an electrical signal generated by a Class-DG amplifier configured to drive a load wherein the Class-DG amplifier has multiple signal-level common modes and a common-mode compensator configured to compensate for changes to a common-mode voltage of a differential supply voltage of the driver occurring when switching between signal-level common modes of the Class-DG amplifier.Type: GrantFiled: October 15, 2021Date of Patent: November 7, 2023Assignee: Cirrus Logic Inc.Inventors: Ramin Zanbaghi, Lingli Zhang, Wei Xu, Justin Richardson, John L. Melanson
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Patent number: 11791779Abstract: A method for use in an analog circuit having a plurality of differential pairs of elements, wherein for each pair of the plurality of differential pairs of elements, the elements of the pair are designed to match but may have mismatch that induces error. The method includes, for each pair of at least two pairs of the plurality of differential pairs of elements: spectrally separating the mismatch-induced error of the pair from mismatch-induced error of a remainder of the plurality of differential pairs of elements, monitoring, by an analog-to-digital converter (ADC), an output of the analog circuit, and analyzing the monitored output to measure the mismatch-induced error of the pair.Type: GrantFiled: December 11, 2020Date of Patent: October 17, 2023Assignee: Cirrus Logic, Inc.Inventors: Ramin Zanbaghi, John L. Melanson, Edmund M. Schneider
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Publication number: 20230308060Abstract: Amplifier circuits provide operation with low-distortion zero crossings outside of a unipolar power supply voltage range. The amplifiers include multiple driver circuits and a control circuit. The control circuit selects between actively operating selected ones of the multiple driver circuits or all of the multiple driver circuits, according to an input signal to be reproduced by one or more of the multiple amplifier driver circuits. The control circuit determines a splice point at which the control circuit selects between actively operating selected ones of the multiple driver circuits or all of the multiple driver circuits.Type: ApplicationFiled: May 31, 2023Publication date: September 28, 2023Inventors: John L. Melanson, Cory J. Peterson, Chandra Prakash, Ramin Zanbaghi, Eric Kimball
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Patent number: 11750157Abstract: A system may include a Class-D stage comprising a first high-side switch coupled between a supply voltage and a first output terminal of the Class-D stage, a second high-side switch coupled between the supply voltage and a second output terminal of the Class-D stage, a first low-side switch coupled between a ground voltage and the first output terminal, and a second low-side switch coupled between the ground voltage and the second output terminal. The system may also include current sensing circuitry comprising a sense resistor, such that an output current through a load coupled between the first output terminal and the second output terminal causes a first sense voltage proportional to the output current across the sense resistor.Type: GrantFiled: February 8, 2022Date of Patent: September 5, 2023Assignee: Cirrus Logic Inc.Inventors: Ramin Zanbaghi, Cory J. Peterson, Eric Kimball
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Patent number: 11722107Abstract: Class-D amplifier circuits provide operation with low-distortion zero crossings outside of a unipolar power supply voltage range. The amplifiers include a first H-bridge driver circuit and a second H-bridge driver circuit. The class-D amplifier circuits also include a control circuit having an input for receiving an input signal to be reproduced by the class-D amplifier circuit. The control circuit has outputs coupled to inputs of the first and second H-bridge drivers, and includes one or more modulators. The control circuit selects between actively operating a selected one of the driver circuits or both, according to the signal to be reproduced, while setting an unselected driver circuit to turn either a high-side switch or a low-side switch of the unselected one of the first driver circuit or the second driver circuit fully on for at least some cycles of the one or more modulators.Type: GrantFiled: January 31, 2022Date of Patent: August 8, 2023Assignee: CIRRUS LOGIC, INC.Inventors: John L. Melanson, Cory J. Peterson, Chandra Prakash, Ramin Zanbaghi, Eric Kimball
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Publication number: 20230178279Abstract: A system may include an electromagnetic load, a driver configured to drive the electromagnetic load with a driving signal, and a processing system communicatively coupled to the electromagnetic load and configured to, during a haptic mode of the system couple a first terminal of the electromagnetic load to a ground voltage and cause the driving signal to have a first slew rate, and during a load sensing mode of the system for sensing a current associated with the electromagnetic load, couple the first terminal to a current-sensing circuit having a sense resistor coupled between the first terminal and an electrical node driven to a common-mode voltage and cause the driving signal to have a second slew rate lower than the first slew rate.Type: ApplicationFiled: December 2, 2021Publication date: June 8, 2023Applicant: Cirrus Logic International Semiconductor Ltd.Inventors: Chandra B. PRAKASH, Ramin ZANBAGHI
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Publication number: 20230122394Abstract: A system for sensing an electrical quantity may include a sensing stage configured to sense the electrical quantity and generate a sense signal indicative of the electrical quantity, wherein the electrical quantity is indicative of an electrical signal generated by a Class-DG amplifier configured to drive a load wherein the Class-DG amplifier has multiple signal-level common modes and a common-mode compensator configured to compensate for changes to a common-mode voltage of a differential supply voltage of the driver occurring when switching between signal-level common modes of the Class-DG amplifier.Type: ApplicationFiled: October 15, 2021Publication date: April 20, 2023Applicant: Cirrus Logic International Semiconductor Ltd.Inventors: Ramin ZANBAGHI, Lingli ZHANG, Wei XU, Justin RICHARDSON, John L. MELANSON
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Patent number: 11552649Abstract: A delta-sigma modulator may include a loop filter, a quantizer, an input gain element having a programmable input gain and coupled between an input of the delta-sigma modulator and an input of the loop filter, a feedforward gain element having a programmable feedforward gain and coupled between the input of the delta-sigma modulator and an output of the loop filter, and a quantizer gain element having a quantizer gain and coupled between the output of the loop filter and an input of the quantizer. The programmable input gain is controlled in order to control a variable gain of the delta-sigma modulator. The programmable feedforward gain is controlled to be equal to the ratio of the programmable input gain and the quantizer gain such that the delta-sigma modulator has a fixed phase response.Type: GrantFiled: December 3, 2021Date of Patent: January 10, 2023Assignee: Cirrus Logic, Inc.Inventor: Ramin Zanbaghi
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Patent number: 11500406Abstract: Current monitoring techniques are included in an electronic system that provides power to a load from a power output stage that supplies power to a load. Multiple current control devices form the power output stage in series with multiple sense resistors that provide corresponding sense voltages indicative of current provided through the multiple current control devices to the load in the same or different time intervals. A calibration control circuit controls injection of current through the multiple sense resistors individually and measures the corresponding sense voltages generated by the current to determine resistance values of the multiple sense resistors. A correction subsystem computes a first ratio of a first resistance to a second resistance and a second ratio of a third resistance to a fourth resistance of the multiple sense resistors, and controls compensation for a difference between the first ratio and the second ratio to remove the measurement error.Type: GrantFiled: March 25, 2021Date of Patent: November 15, 2022Assignee: CIRRUS LOGIC, INC.Inventors: Ramin Zanbaghi, Eric Kimball
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Publication number: 20220308613Abstract: Current monitoring techniques are included in an electronic system that provides power to a load from a power output stage that supplies power to a load. Multiple current control devices form the power output stage in series with multiple sense resistors that provide corresponding sense voltages indicative of current provided through the multiple current control devices to the load in the same or different time intervals. A calibration control circuit controls injection of current through the multiple sense resistors individually and measures the corresponding sense voltages generated by the current to determine resistance values of the multiple sense resistors. A correction subsystem computes a first ratio of a first resistance to a second resistance and a second ratio of a third resistance to a fourth resistance of the multiple sense resistors, and controls compensation for a difference between the first ratio and the second ratio to remove the measurement error.Type: ApplicationFiled: March 25, 2021Publication date: September 29, 2022Inventors: Ramin Zanbaghi, Eric Kimball
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Publication number: 20220247367Abstract: Class-D amplifier circuits provide operation with low-distortion zero crossings outside of a unipolar power supply voltage range. The amplifiers include a first H-bridge driver circuit and a second H-bridge driver circuit. The class-D amplifier circuits also include a control circuit having an input for receiving an input signal to be reproduced by the class-D amplifier circuit. The control circuit has outputs coupled to inputs of the first and second H-bridge drivers, and includes one or more modulators. The control circuit selects between actively operating a selected one of the driver circuits or both, according to the signal to be reproduced, while setting an unselected driver circuit to turn either a high-side switch or a low-side switch of the unselected one of the first driver circuit or the second driver circuit fully on for at least some cycles of the one or more modulators.Type: ApplicationFiled: January 31, 2022Publication date: August 4, 2022Inventors: John L. Melanson, Cory J. Peterson, Chandra Prakash, Ramin Zanbaghi, Eric Kimball
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Publication number: 20220190794Abstract: A method for matching a pair of composite circuit elements (CEs) included in a circuit includes fabricating N CEs (e.g., resistors, transistors, current sources, capacitors) designed to match and switches configurable, according to M different combinations, to connect N/2 of the N CEs to form a first composite CE and to connect a remaining N/2 of the N CEs to form a second composite CE. Sequentially in time, for each combination of the M combinations, the switches are configured to form the first and second composite CEs according to the combination and a characteristic of the circuit is measured that includes the formed first and second composite CEs. The characteristic indicates how well the formed composite CEs match. A final combination of the M combinations is chosen whose measured characteristic indicates a best match and the final combination is used to configure the switches to form the composite CEs.Type: ApplicationFiled: May 26, 2021Publication date: June 16, 2022Inventors: Edmund M. Schneider, Ramin Zanbaghi, Terence C. Bowness, Eric Kimball
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Publication number: 20220190789Abstract: A method for use in an analog circuit having a plurality of differential pairs of elements, wherein for each pair of the plurality of differential pairs of elements, the elements of the pair are designed to match but may have mismatch that induces error. The method includes, for each pair of at least two pairs of the plurality of differential pairs of elements: spectrally separating the mismatch-induced error of the pair from mismatch-induced error of a remainder of the plurality of differential pairs of elements, monitoring, by an analog-to-digital converter (ADC), an output of the analog circuit, and analyzing the monitored output to measure the mismatch-induced error of the pair.Type: ApplicationFiled: December 11, 2020Publication date: June 16, 2022Inventors: Ramin Zanbaghi, John L. Melanson, Edmund M. Schneider
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Publication number: 20220158597Abstract: A system may include a Class-D stage comprising a first high-side switch coupled between a supply voltage and a first output terminal of the Class-D stage, a second high-side switch coupled between the supply voltage and a second output terminal of the Class-D stage, a first low-side switch coupled between a ground voltage and the first output terminal, and a second low-side switch coupled between the ground voltage and the second output terminal. The system may also include current sensing circuitry comprising a sense resistor, such that an output current through a load coupled between the first output terminal and the second output terminal causes a first sense voltage proportional to the output current across the sense resistor.Type: ApplicationFiled: February 8, 2022Publication date: May 19, 2022Applicant: Cirrus Logic International Semiconductor Ltd.Inventors: Ramin ZANBAGHI, Cory J. PETERSON, Eric KIMBALL
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Patent number: 11329617Abstract: Class-D amplifiers and modulators therefor provide control of the DC operating point of the outputs of the amplifiers. The modulators generate a sum and difference signal using combiners and introduce the sum signal to a reference input of the quantizer, while the quantization input of the quantizer receives the difference signal. A difference mode loop filter circuit may filter the difference signal and a common mode loop filter may filter the sum signal. Outputs of the quantizer operate a pair of switching circuits to provide either a differential output with the sum signal set to a constant voltage and the difference signal provided by the signal to be reproduced, or a pair of single-ended outputs with the individual input signals used to generate the sum and difference signal, and selection of a differential or dual single-ended operating mode may be performed by a control circuit that reconfigures the combiners.Type: GrantFiled: January 19, 2021Date of Patent: May 10, 2022Assignee: CIRRUS LOGIC, INC.Inventors: Cory J. Peterson, Chandra Prakash, Ramin Zanbaghi, Eric Kimball
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Patent number: 11316508Abstract: A system may include an output driving stage comprising a first switch configured to selectively open and close an electrical path between a first supply voltage and an output terminal of the output driving stage and a second switch configured to selectively open and close an electrical path between a second supply voltage and the output terminal of the output driving stage, wherein the second supply voltage is lower than the first supply voltage. The system may also include detection and protection circuitry configured to monitor a physical quantity indicative of the second supply voltage and responsive to the physical quantity exceeding an overvoltage threshold, electrically isolate the output terminal from the second supply voltage.Type: GrantFiled: March 17, 2020Date of Patent: April 26, 2022Assignee: Cirrus Logic, Inc.Inventors: Ramin Zanbaghi, Cory J. Peterson
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Patent number: 11309853Abstract: A class-D amplifier includes a first differential modulator circuit, a first driver circuit including a first high-side switch and a first low-side switch. An input of the first driver circuit may be coupled to a first output of the first differential modulator circuit so that the first differential modulator circuit controls the first driver circuit. The class-D amplifier may also include a second driver circuit including a second high-side switch and a second low-side switch coupling the second and control logic that selects between a single-ended operating state and a differential operating state of the class-D amplifier circuit. The control logic may selectively determine the input of the second driver circuit in conformity with a current operating state of the class-D amplifier circuit so that the first differential modulator circuit controls the second driver circuit when the differential operating state is selected.Type: GrantFiled: January 29, 2021Date of Patent: April 19, 2022Assignee: CIRRUS LOGIC, INC.Inventors: Cory J. Peterson, Chandra Prakash, Ramin Zanbaghi, Eric Kimball
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Patent number: 11296663Abstract: A system may include a Class-D stage comprising a first high-side switch coupled between a supply voltage and a first output terminal of the Class-D stage, a second high-side switch coupled between the supply voltage and a second output terminal of the Class-D stage, a first low-side switch coupled between a ground voltage and the first output terminal, and a second low-side switch coupled between the ground voltage and the second output terminal. The system may also include current sensing circuitry comprising a first sense resistor coupled between the first low-side switch and the ground voltage, such that an output current through a load coupled between the first output terminal and the second output terminal causes a first sense voltage proportional to the output current across the first sense resistor when the first low-side switch is activated.Type: GrantFiled: May 1, 2020Date of Patent: April 5, 2022Assignee: Cirrus Logic, Inc.Inventors: Ramin Zanbaghi, Cory J. Peterson, Anand Ilango, Eric Kimball