Cirrus Logic Inc.

Koninklijke Philips Corporation N.v.

Philips Lighting Holding B.v.

Audio Logic, Inc.

Other

Gn Resound A/s

Magnum Semiconductor, Inc.

Signify Holding B.v.

Cirrus Logic International Semiconductor Limited

Peak Audio, Inc.

Audiologic Hearing Systems LP

Dell Products Inc.

Tektronix, Inc.

Phillips International, B.v.

John L Melanson

Eric Jerome King

Tejasvi Das

Johann Guy Gaboriau

Xiaofan Fei

Ramin Zanbaghi

Siddharth Maru

Rahul Singh

Axel Thomsen

John Christopher Tucker

Zhaohui He

Xin Zhao

Lingli Zhang

Anthony Stephen Doy

Eric Lindemann

Lei Zhu

Thomas H Hoff

Michael Allan Kost

Ku He

Prashanth Drakshapalli

Daniel John Allen

Aniruddha Satoskar

Emmanuel A Marchais

Ammisetti Prasad

Amar Vellanki

Mauro L Gaetano

John Paul Lesso

Bruce Eliot Duewer

Aaron J Brennan

Eric J Swanson

Jason Powell Rhode

Stephen Timothy Hodapp

Robert Thomas Grisamore

Anindya Bhattacharya

Wai-Shun Shum

Murari L Kejariwal

William Draper

John James Paulos

Kartik Nanda

Brian David Trotter

Ahsan Habib Chowdhury

Jeffrey Donald Alderson

Jason William Lawrence

Firas Azrai

Karl Ernesto Thompson

Zhong You

Edmund Mark Schneider

Carl Lennart Ståhl

Yousof Mortazavi

Yongjie Cheng

Jon David Hendrix

Christian Larsen

Jack B Andersen

James Mitchell Kates

Vamsikrishna Parupalli

Nitin Kwatra

Mohit Sood

Marc John Kobayashi

Kyehyung Lee

Alan Mark Morton

Dayong Zhou

Gautham Devendra Kamath

Paul M Astrachan

Daniel J Baker

Chandra Prakash

Ali Abdollahzadeh Milani

Mark P Rygh

Sherry Xiaohong Wu

Bhoodev Kumar

Jaimin A Mehta

Aleksey Sergeyevich Khenkin

Eric Kimball

Cory Jay Peterson

Wilson E Taylor, Jr

Dylan Alexander Hester

Pablo Peso Parada

Ravi Kishore Kummaraguntla

Timothy Thomas Rueger

Ning Li

Paul Wilson

Chung-Kai Chow

Larry L Harris

Bryant Sorensen

Jing Bai

Ruoxin Jiang

Scott Allan Woodford

Jie Su

Marc Laurent Tarabbia

Dana John Taipale

Matthew Beardsworth

Shyam S Somayajula

Graeme G Mackay

Alfredo R Linz

Jonathan David Williams

Anand Ilango

Saurabh Singh

Justin Richardson

Gong Tom Lei

Ross Crawford Morgan

Chin Huang Yong

500 patents: CU Engineering alumnus now among top 100 most prolific inventors

A cascaded switched power converter provides a wide voltage conversion ratio and improved efficiency ins systems such as power supplies and amplifiers. A switched-capacitor charge pump circuit is operated by one or more first clock signals and is coupled in cascade with an inductor-based power supply circuit according to one or more second clock signals. A control circuit that generates clock signals so that the one or more second clock signals have a phase offset with respect to the one or more first clock signals that is set to adjust a conversion ratio of the cascaded combination of the switched-capacitor charge pump circuit and the inductor-based power supply circuit. The inductor of the inductor-based power supply circuit may be an inductive load, such as a speaker, and the phase offset may be modulated according to an audio signal to provide audio amplification.

Power conversion by a phase-controlled cascade of an inductor-based power supply and a charge pump

Pre-conditioning circuitry for pre-conditioning a node of a circuit to support a change in operation of the circuit, wherein the circuit is operative to change a state of the node to effect the change in operation of the circuit, and wherein the pre-conditioning circuitry is configured to apply a voltage, current or charge directly to the node to reduce the magnitude of the change to the state of the node required by the circuit to achieve the change in operation of the circuit.

Pre-conditioning a node of a circuit

This application relates to methods and apparatus for driving a transducer. A transducer driver has a switch network that is operable to selectively connect a driver output to any of a first set of at least three different switching voltages which are, in use, maintained throughout a switching cycle of the driver apparatus. The switch network is also operable to selectively connect the driver output to flying capacitor driver. A controller is configured to control the switch network and flying capacitor driver to generate a drive signal at the driver output based on an input signal, wherein in one mode of operation the driver output is switched between two of the first set of switching voltages with a controlled duty cycle and in another mode of operation the driver output is connected to the flying capacitor driver which is switched between first and second states with a controlled duty cycle.

Driver circuitry and operation

A switched mode amplifier system may include a switched mode amplifier having an amplifier input coupled to an output of an analog integrator and an amplifier output, include a feedback network coupled between the amplifier output and an input of the analog integrator, include a loop filter configured to generate a digital loop filter output, include a quantizer configured to generate a pulse-width modulated representation of the digital loop filter output; and include a calibration system. The calibration system may be configured to force the input of the analog integrator to a fixed known input value, low-pass filter the pulse-width modulated representation of the digital loop filter output generated by the quantizer to generate a filtered quantizer output signal, determine an offset of the switched mode amplifier system based on the filtered quantizer output signal, and correct for the offset.

Calibration of pulse width modulation amplifier system

A system may include a plurality of sensors configured to sense a physical quantity and a calibration subsystem configured to perform a calibration comprising: comparing a measured characteristic from each of at least two sensors of the plurality of sensors to determine a sensitivity drift of at least one sensor of the plurality of sensors; based on the measured characteristics of the at least two sensors and stored reference characteristics for the at least two sensors, calculating a normalization factor; and applying the normalization factor to the measured characteristic of the at least one sensor to ensure sensitivity of the plurality of sensors relative to each other remains approximately constant.

Sensitivity equalization in multi-sensor inductive sensing applications

Methods and systems for determining clock signals for audio processing using different operating modes are provided. In one aspect, a transition control word is determined to transition from a first control word for a first operating mode to a second control word for the second operating mode. The transition control word may be used to process the received audio signal while transitioning between the operating modes. After the transition, the second control word may be used to process the received audio signal using the second operating mode. The transition control word may be used to transition between various aspects of the operating modes, including different frequencies or resolutions, control systems, power levels, and more.

Clock signal transitioning for multi-mode audio processing systems

This application relates to methods and apparatus for driving a transducer with switching drivers. A driver circuit has first and second switching drivers for driving the transducer in a bridge-tied-load configuration, each of the switching drivers having a respective output stage for controllably switching the respective driver output node between high and low switching voltages with a controlled duty cycle. Each of switching drivers is operable in a plurality of different driver modes, wherein the switching voltages are different in said different driver modes. A controller controls the driver mode of operation and the duty cycle of the switching drivers based on the input signal. The controller is configured to control the duty cycles of the first and second switching drivers within defined minimum and maximum limits of duty cycles; and to transition between driver modes of operation when the duty cycle of one of the switching drivers reaches a duty cycle limit.

A battery management system, may include an input configured to couple to a power supply, an output configured to couple to a battery, and battery management circuitry coupled between the power supply and the battery and configured to deliver electrical energy to the output at a significantly higher peak-to-average power ratio than receipt of electrical energy to the input.

Pulsed current battery management system

A system for estimating parameters of an electromagnetic load may include an input for receiving an input excitation signal to the electromagnetic load, a broadband content estimator that identifies at least one portion of the input excitation signal having broadband content, and a parameter estimator that uses the at least one portion of the input excitation signal to estimate and output one or more parameters of the electromagnetic load.

Methods and systems for estimating transducer parameters

This application relates to voltage regulators and, particular, to low-dropout regulators (LDOs). The regulator () has an output stage () which receives an input voltage (Vin) and outputs an output voltage (Vout) and which includes at least one transistor () as an output device configured to pass an output current to the output, based on a drive voltage (V). A differential amplifier () is configured to receive a feedback signal derived from the output voltage and also a reference voltage (REF) to generate an amplifier output to control the drive voltage (V) to minimise any difference between the feedback signal and the reference voltage. A controller () is operable to selectively reconfigure the output stage to provide a change in output current in response to a load activity signal (ACT), which is indicative of a change in load activity that results in a change in load current demand for a load connected, in use, to the output.

Voltage regulators

Accurate operation of a current monitor is provided by injecting a bias voltage to a maintain de-selected sense amplifier input in an active state. An electronic system includes an output stage to supply a load current and includes two push-pull output drivers having sense resistors supplying a first and a second sense voltage. An included mode control circuit selects between a first and a second operating mode and selects a polarity of the current. An included current monitor receives the sense voltages and has a control input coupled to the mode selection control circuit. The current monitor provides an output that is dependent on both sense voltages in the first operating mode and is indicative of one of the sense voltages selected according to the selected polarity in the second operating mode. The bias voltage is injected into an unselected sense inputs to maintain active operation of the sense amplifier.

Compensating current monitor for electronic systems having mode-sensitive selection of current-sensing inputs

A system may include amplifier circuitry configured to drive an electromagnetic load with a driving signal and a processing system communicatively coupled to the electromagnetic load and configured to compensate for current-sensing error of the processing system caused by feedback circuitry of the amplifier circuitry.

Compensating for current splitting errors in a measurement system

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.

Splice-point determined zero-crossing management in audio amplifiers

A driver apparatus for driving a load with a differential drive signal is described. For a level of input signal within a first range, a first switching driver modulates the voltage at a first output node with a first modulation index by switchably connecting at least one flying capacitor to the first output node, whilst a second switching driver modulates the voltage at a second output node with a second modulation index by controlling switching between DC voltages that are maintained throughout a switching cycle of the driver apparatus. The first and second switching drivers are controlled so, for at least a first part of the first input range, a change in input signal level results in a change of the first controlled modulation index that has a different magnitude to any change in the second controlled modulation index, a constant modulation frequency of the differential drive signal is maintained.

Circuitry for acoustic crosstalk cancellation between first and second acoustic signals, the circuitry comprising: crosstalk cancellation circuitry configured to: receive a first audio signal and, based on the received first audio signal, generate a first crosstalk cancellation signal; receive a second audio signal and, based on the received second audio signal, generate a second crosstalk cancellation signal; combine the first crosstalk cancellation signal with a signal indicative of the second audio signal to generate a first crosstalk cancellation circuitry output signal; and combine the second crosstalk cancellation signal with a signal indicative of the first audio signal to generate a second crosstalk cancellation circuitry output signal; and output stage circuitry configured to: receive the first crosstalk cancellation circuitry output signal and, based on the received first crosstalk cancellation circuitry, generate a first drive signal for driving a first speaker to generate the first acoustic signal; and receive the second crosstalk cancellation circuitry output signal and, based on the received second crosstalk cancellation circuitry, generate a second drive signal for driving a second speaker to generate the second acoustic signal, wherein a parameter of the crosstalk cancellation circuitry is variable based on one or more of: a position of a user of a host device incorporating the circuitry with respect to the host device; a volume setting of the host device; a level of the first and/or second crosstalk cancellation signal; and an operational parameter of the output stage circuitry.

Acoustic crosstalk cancellation

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Austin, TX, United States of America

John L Melanson