Cirrus Logic Inc.

Amazon Technologies, Inc.

Integral Wave Technologies, Inc.

Other

Philips Lighting Holding B.v.

Philips International, B.v.

Cirrus Logic International Semiconductor Limited

Firas Azrai

Eric Jerome King

John L Melanson

Jeffrey Allen May

Jason William Lawrence

Robert Thomas Grisamore

Roger David Serwy

Ramin Zanbaghi

Jie Su

Siddharth Maru

Rahul Singh

Rong Hu

Roberto Napoli

Mohit Sood

Sachin Purushottam Joglekar

Temesghen Kahsai Azene

Jean-Charles Pina

Stefan Williams

Michael Yates

David Nelms

Kadirvel Chockalingam Vanniarajan

Michael Allan Kost

Stephen Timothy Hodapp

Prashanth Drakshapalli

Aaron J Brennan

Wesley Ladd Mokry

Charles D Ward

Arnab Dutta

Thirumalai Rengachari

Jieyeon Choi

David M Wheeler

Naveen Kumar Thangavel

Systems, devices, and methods are provided for establishing trust between devices using a proximity channel and a cloud channel. An enrollee device and manager may perform a mutual authentication process where grant codes are exchanged, wherein the enrollee grants the manager the ability to be a manager in the enrollment process and the manger grants the enrollee the ability to issue an identity certificate. A proximity channel may be used to establish proof-of-possession and a cloud-based authorization may be performed to verify that the enrollee is a legitimate participant.

Techniques for enrolling a device or service using a proximity channel and a cloud channel

Systems, devices, and methods are provided for cloud-based privacy controls. User content is encrypted using a content encryption key (CEK). The CEK may be double-encrypted by the data producer—the inner envelope is encrypted using keys associated with privacy domains that are authorized to access the user content. The outer envelope is encrypted using a cloud privacy control's public key. When a data consumer requests access the user content, the cloud privacy control evaluates privacy policies and determine whether access should be permitted. If permitted, the cloud privacy control decrypts the outer envelope and provides the inner envelope with CEK to the requestor. Upon receiving the inner envelope, the data consumer may then decrypt the inner envelope with its privacy domain private key to obtain the CEK. The CEK may then be used to perform a decryption and obtain the user content.

Techniques for cloud-based privacy controls

In accordance with embodiments of the present disclosure, a system may include a circuit having a power converter and an amplifier, wherein the power converter is configured to generate an intermediate voltage, provide the intermediate voltage as an amplifier supply voltage to the amplifier, and share the intermediate voltage with one or more additional circuits external to the circuit, wherein at least one of the one or more additional circuits is configured to generate the intermediate voltage.

Multi-phase power converter system using multiple amplifier integrated circuits

This application describes methods and apparatus for loudspeaker protection. A loudspeaker protection system () is described having a first frequency band-splitter () for splitting an input audio signal (Vin) into a plurality of audio signals (v, v. . . ,vn) in different respective frequency bands (&#x3c9;. . . &#x3c9;&#x3b7;). A first gain block () is configured to apply a respective frequency band gain (gt, gt. . . ,gt) to each of the audio signals in the different respective frequency bands and a gain controller () is provided for controlling the respective band gains. A thermal controller () determines, for each of a plurality of the different respective frequency bands, a power dissipation for the loudspeaker in that frequency band and also determines a respective thermal gain setting based on the determined power dissipation for that frequency band. The gain controller is configured to control the respective frequency band gains based on the thermal gain settings.

Loudspeaker protection

This application describes methods and apparatus for loudspeaker protection. A loudspeaker protection system () is described having a first frequency band-splitter () for splitting an input audio signal (Vin) into a plurality of audio signals (v, v. . . , vn) in different respective frequency bands (&#x3c9;. . . , &#x3c9;n). A first gain block () is configured to apply a respective frequency band gain (g, g. . . , g) to each of the audio signals in the different respective frequency bands and a gain controller () is provided for controlling the respective band gains. A displacement modeller () determines a plurality of displacement signals (x, x. . . , xn) based on the input audio signal (Vin) and a displacement model () where each displacement signal corresponds to a modelled cone displacement for the loudspeaker for one of said different respective frequency bands. The gain controller () is configured to control the respective frequency band gains based on the plurality of displacement signals.

In accordance with embodiments of the present disclosure, a system may include a series combination of a boost converter and a power converter coupled together in series, such that the series combination boosts an input voltage to the series combination to an output voltage greater than the input voltage such that a voltage boost provided by the series combination is greater than a voltage boost provided by the boost converter alone. The system may also include an amplifier, wherein an input of the amplifier is coupled to an output of the series combination of the boost converter and the power converter.

Combined boost converter and power converter

A predictive brownout prevention system may be configured to prevent brownout of an audio output signal. Particularly, the brownout prevention system may be configured to receive information indicative of an amplitude of the audio input signal, receive information indicative of a condition of the power supply, receive information indicative of one or more of the following: 1) adaptive estimates of power supply conditions; 2) anticipated effects of power supply capacitance; and 3) condition of a load impedance, determine from the received information whether a brownout condition exists, and responsive to determining the brownout condition exists, generate the selectable attenuation signal to reduce an amplitude of the audio output signal such that the signal path attenuates the audio input signal or a derivative thereof in order to prevent brownout prior to propagation to the audio output of a portion of the audio input signal having the brownout condition.

Method for limiting amplifier input current to avoid low voltage conditions

A predictive brownout prevention system may be configured to prevent brownout of an audio output signal. Particularly, the brownout prevention system may be configured to receive information indicative of adaptive estimates of power supply conditions, wherein the information indicative of adaptive estimates of the power supply conditions comprises information regarding a voltage component and a resistive component received from an adaptive battery model of a battery for providing electrical energy to a power supply for generating the power supply voltage and adapt the adaptive battery model based on a monitored battery voltage output by the battery and loading events of the signal path and excluding loading events of components other than the signal path which are powered from the battery.

A method may include receiving information indicative of an amplitude of an audio output signal, receiving information indicative of a predicted voltage of a power supply of a signal path having an audio input for receiving an audio input signal and an audio output for generating the audio output signal based on the audio input signal, predicting from the information indicative of the amplitude of the audio output signal and the information indicative of the predicted voltage of the power supply whether the audio output signal will exceed an available supply voltage generated by the power supply, and responsive to determining the audio output signal will exceed the available supply voltage generated by the power supply, attenuating the audio input signal or a derivative thereof to reduce the amplitude of the audio output signal such that the audio output signal does not exceed the available supply voltage of the power supply.

Prevention of signal clipping due to decrease in amplifier supply voltage

A bipolar junction transistor (BJT) may be used to generate a supply voltage for operating a controller, such as a lighting controller for a LED-based light bulb. A base of the BJT may receive current generated from the supply voltage to control operation of the BJT. Although the base of the BJT would be at a lower voltage than the emitter, a base drive circuit may be coupled between the emitter and the base of the BJT to increase the voltage. As one example, the base drive circuit may be a charge pump. In another example, the BJT may function as its own charge pump. In yet another example, a positive and a negative base current of the BJT may be independently controlled to regulate an output supply voltage Vfrom the BJT.

Charge pump-based drive circuitry for bipolar junction transistor (BJT)-based power supply

A system and method includes a controller that alternately enables at least two different current paths for a current flowing through a dimmer when the dimmer is in an OFF mode. In at least one embodiment, enabling and disabling the current paths allows a power supply of the dimmer to continue functioning and provides the controller sufficient voltage to continue functioning. One of the current paths is a low impedance path and another current path is a path to a voltage supply node of a switching power converter controller. In at least one embodiment, the controller generates an impedance control signal to enable a low impedance current path for a current in the dimmer and alternately provide a current path to the voltage supply node for the controller.

Dimmer compatibility with reactive loads

A turn-off transition time period, also referred to as a reverse recovery time period, may be compensated for by a controller of a power stage including a bipolar junction transistor (BJT). The reverse recovery time period may be measured in one switching cycle and a subsequent switching cycle may include compensations based on the measured reverse recovery time period. That is the switching on and off of the BJT may be compensated to obtain a desired average output current to a load. When the reverse recovery time period is known, an error in the peak current obtained due to the reverse recovery time period may be calculated. The calculated error may be used to offset the target peak current for controlling the switching of the BJT to begin a turn-off transition of the BJT earlier in a switching cycle and thus reduce error in peak current at the BJT.

Compensating for a reverse recovery time period of a bipolar junction transistor (BJT) in switch-mode operation of a light-emitting diode (LED)-based bulb

In accordance with systems and methods of the present disclosure, an apparatus for providing compatibility between a load having a reactive impedance and a secondary winding of an electronic transformer may include a power converter and a circuit. The power converter may be configured to transfer electrical energy from the secondary winding to the load. The circuit may be configured to charge an energy storage device coupled to the power converter following start-up of the electronic transformer in order to increase a voltage of the energy storage device to at least a voltage level sufficient for the electronic transformer to enter steady-state operation.

Systems and methods for low-power lamp compatibility with an electronic transformer

In at least one embodiment, a lighting system receives an input signal, such as a supply voltage, that can be affected by a dimmer. The supply voltage can be affected by a dimmer when, for example, a dimmer phase cut (i.e. chopped) the supply voltage. A dimmer detection system of the lighting system determines if a dimmer is affecting the supply voltage. In at least one embodiment, the dimmer detection system also determines a type of the dimmer, such as detecting if the dimmer is a leading edge or trailing edge dimmer. In at least one embodiment, the dimmer detection system provides dimmer type data to one or more other circuits such as a switching power converter controller. The one or more other circuits utilize the dimmer type data to affect their operation.

Growing community of inventors

Austin, TX, United States of America

Firas Azrai