Abstract: Techniques for providing access to scope-delimited sensitive data are disclosed. A user provides sensitive data to a first party associated with a payment service provider. The first party stores the sensitive data with the payment service provider, and the payment service provider provides the first party merchant with an encoding of the payment data. The first party provides a purchasing opportunity to the user for goods offered by a third party also associated with the payment service provider. The first party transmits a sensitive data grant request to the payment service provider. In response, the payment service provides a scope-delimited encoding of the sensitive data. The first party provides the scope-delimited encoding of the payment data to the third party. The third party merchant creates a transaction using the scope-delimited encoding of the sensitive data. At some time later, access to the scope-delimited encoding of the sensitive data is revoked.

Abstract: A smart speaker power controller may be configured to receive power conforming to one of a plurality of power modes from an input power source. The power controller may be further configured to communicate the power mode to at least one component of a processing system or at least one component of an audio system for operating the smart speaker according to the received power mode, including determining a current limit of a power converter; determining a shutdown voltage threshold and safely shutting down the smart speaker if the input voltage falls below the threshold, and/or modifying audio operation of the smart speaker in response to the power mode. The smart speaker can further include an audio power supply controller configured to monitor energy required to reproduce an audio signal and to servo a power supply voltage provided to an audio amplifier in response to this energy level.

Abstract: A smart speaker power controller may be configured to receive power conforming to one of a plurality of power modes from an input power source. The power controller may be further configured to communicate the power mode to at least one component of a processing system or at least one component of an audio system for operating the smart speaker according to the received power mode, including determining a current limit of a power converter; determining a shutdown voltage threshold and safely shutting down the smart speaker if the input voltage falls below the threshold, and/or modifying audio operation of the smart speaker in response to the power mode. The smart speaker can further include an audio power supply controller configured to monitor energy required to reproduce an audio signal and to servo a power supply voltage provided to an audio amplifier in response to this energy level.

Abstract: A smart speaker power controller may be configured to receive power conforming to one of a plurality of power modes from an input power source. The power controller may be further configured to communicate the power mode to at least one component of a processing system or at least one component of an audio system for operating the smart speaker according to the received power mode, including determining a current limit of a power converter; determining a shutdown voltage threshold and safely shutting down the smart speaker if the input voltage falls below the threshold, and/or modifying audio operation of the smart speaker in response to the power mode. The smart speaker can further include an audio power supply controller configured to monitor energy required to reproduce an audio signal and to servo a power supply voltage provided to an audio amplifier in response to this energy level.

Abstract: A smart speaker power controller may be configured to receive power conforming to one of a plurality of power modes from an input power source. The power controller may be further configured to communicate the power mode to at least one component of a processing system or at least one component of an audio system for operating the smart speaker according to the received power mode, including determining a current limit of a power converter; determining a shutdown voltage threshold and safely shutting down the smart speaker if the input voltage falls below the threshold, and/or modifying audio operation of the smart speaker in response to the power mode. The smart speaker can further include an audio power supply controller configured to monitor energy required to reproduce an audio signal and to servo a power supply voltage provided to an audio amplifier in response to this energy level.

Abstract: Techniques for providing access to scope-delimited sensitive data are disclosed. A user provides sensitive data to a first party associated with a payment service provider. The first party stores the sensitive data with the payment service provider, and the payment service provider provides the first party merchant with an encoding of the payment data. The first party provides a purchasing opportunity to the user for goods offered by a third party also associated with the payment service provider. The first party transmits a sensitive data grant request to the payment service provider. In response, the payment service provides a scope-delimited encoding of the sensitive data. The first party provides the scope-delimited encoding of the payment data to the third party. The third party merchant creates a transaction using the scope-delimited encoding of the sensitive data. At some time later, access to the scope-delimited encoding of the sensitive data is revoked.

Abstract: Techniques for providing access to scope-delimited sensitive data are disclosed. A user provides sensitive data to a first party associated with a payment service provider. The first party stores the sensitive data with the payment service provider, and the payment service provider provides the first party merchant with an encoding of the payment data. The first party provides a purchasing opportunity to the user for goods offered by a third party also associated with the payment service provider. The first party transmits a sensitive data grant request to the payment service provider. In response, the payment service provides a scope-delimited encoding of the sensitive data. The first party provides the scope-delimited encoding of the payment data to the third party. The third party merchant creates a transaction using the scope-delimited encoding of the sensitive data. At some time later, access to the scope-delimited encoding of the sensitive data is revoked.

Abstract: Input device power consumption can be reduced with a magnetic drive system. In some examples, the input device can include a transformer configured to generate a desired high output voltage from logic-level input pulses. In some examples, the distributed capacitance and associated resonance of the transformer can act as a low-pass filter, and can create a relatively clean output waveform from input logic signal waveforms. In some examples, the transformer can be an autotransformer. In some examples, to stabilize an amplitude of the output by sampling the output of the transformer and adjusting the input to the transformer based on the sampled output.

Abstract: Input device power consumption can be reduced with a magnetic drive system. In some examples, the input device can include a transformer configured to generate a desired high output voltage from logic-level input pulses. In some examples, the distributed capacitance and associated resonance of the transformer can act as a low-pass filter, and can create a relatively clean output waveform from input logic signal waveforms. In some examples, the transformer can be an autotransformer. In some examples, to stabilize an amplitude of the output by sampling the output of the transformer and adjusting the input to the transformer based on the sampled output.

Abstract: Techniques for providing access to scope-delimited sensitive data are disclosed. A user provides sensitive data to a first party associated with a payment service provider. The first party stores the sensitive data with the payment service provider, and the payment service provider provides the first party merchant with an encoding of the payment data. The first party provides a purchasing opportunity to the user for goods offered by a third party also associated with the payment service provider. The first party transmits a sensitive data grant request to the payment service provider. In response, the payment service provides a scope-delimited encoding of the sensitive data. The first party provides the scope-delimited encoding of the payment data to the third party. The third party merchant creates a transaction using the scope-delimited encoding of the sensitive data. At some time later, access to the scope-delimited encoding of the sensitive data is revoked.

Abstract: An apparatus includes: a power supply circuit including at least a first stage having a push-pull circuit topology, the first stage including at least one transformer that isolates a primary side of the first stage from a secondary side of the first stage; a clamp circuit coupled to a center tap of the transformer, the clamp circuit including a first element that stores energy, and a second element that controls a flow of current between the center tap of the transformer and the first element; and a control module receiving power from the clamp circuit. The control module is configured to provide control signals to one or more elements of the power supply circuit.

Abstract: A power supply injects a series of “tickle” pulses into a pulse width modulated (PWM) controller to induce the controller to generate PWM pulses at a minimum switching frequency, preferably one that is super-sonic (especially for audio applications). The switching frequency may also be selected or controlled such that it avoids resonances in the power supply. The “tickle” pulses may be clocked by the same clock that times the PWM controller, and they may be shaped to help ensure that the power supply maintains some regulation during low-load conditions.

Abstract: An audio power amplifier includes a first and a second amplification unit, each including a switching voltage amplifier, an output filter, a current compensator, an inner current feedback loop feeding a measurement of current measured at the output inductor back to a summing input of the current compensator, a voltage compensator coupled to the summing input of the current compensator, and an outer voltage feedback loop. A controlled signal path provides the output of the voltage compensator of the first amplification unit to the current compensator of the second amplification unit. The first and second amplification units are operable with separate loads, in parallel driving a common load, or across a bridge-tied-load. A second pair of amplification units may be added and operated together with the first pair to drive a single speaker with a parallel pair of amplifiers on each side of a bridge-tied-load.

Abstract: A power conversion device includes a magnetic core; and a plurality of windings surrounding portions of the magnetic core, including a first set of windings defining a first magnetic flux path, a second set of windings defining a second magnetic flux path magnetically orthogonal to the first magnetic flux path, and a third set of windings. Each winding of the third set of windings is configured to be excitable via both the first flux path and the second flux path.

Abstract: An apparatus for driving speakers includes user-configurable amplifier cells for driving selected speakers, a synchronous rectifier circuit, and a control system. Each cell connects between power rails. The rectifier circuit provides current on the rails for consumption by the cells. The current depends on the configuration. The control system implements a model of the rectifier circuit and cells and uses it to control an audio input signal in response to information concerning electrical outputs of the amplifier cells. This indirectly limits current drawn from the synchronous rectifier circuit.

Abstract: An audio power amplifier includes a first and a second amplification unit, each including a switching voltage amplifier, an output filter, a current compensator, an inner current feedback loop feeding a measurement of current measured at the output inductor back to a summing input of the current compensator, a voltage compensator coupled to the summing input of the current compensator, and an outer voltage feedback loop. A controlled signal path provides the output of the voltage compensator of the first amplification unit to the current compensator of the second amplification unit. The first and second amplification units are operable with separate loads, in parallel driving a common load, or across a bridge-tied-load. A second pair of amplification units may be added and operated together with the first pair to drive a single speaker with a parallel pair of amplifiers on each side of a bridge-tied-load.

Abstract: An audio power amplifier includes a first and a second amplification unit, each including a switching voltage amplifier, an output filter, a current compensator, an inner current feedback loop feeding a measurement of current measured at the output inductor back to a summing input of the current compensator, a voltage compensator coupled to the summing input of the current compensator, and an outer voltage feedback loop. A controlled signal path provides the output of the voltage compensator of the first amplification unit to the current compensator of the second amplification unit. The first and second amplification units are operable with separate loads, in parallel driving a common load, or across a bridge-tied-load. A second pair of amplification units may be added and operated together with the first pair to drive a single speaker with a parallel pair of amplifiers on each side of a bridge-tied-load.

Abstract: An audio power amplifier includes a first and a second amplification unit, each including a switching voltage amplifier, an output filter, a current compensator, an inner current feedback loop feeding a measurement of current measured at the output inductor back to a summing input of the current compensator, a voltage compensator coupled to the summing input of the current compensator, and an outer voltage feedback loop. A controlled signal path provides the output of the voltage compensator of the first amplification unit to the current compensator of the second amplification unit. The first and second amplification units are operable with separate loads, in parallel driving a common load, or across a bridge-tied-load. A second pair of amplification units may be added and operated together with the first pair to drive a single speaker with a parallel pair of amplifiers on each side of a bridge-tied-load.

Abstract: An apparatus includes: a power supply circuit including at least a first stage having a push-pull circuit topology, the first stage including at least one transformer that isolates a primary side of the first stage from a secondary side of the first stage; a clamp circuit coupled to a center tap of the transformer, the clamp circuit including a first element that stores energy, and a second element that controls a flow of current between the center tap of the transformer and the first element; and a control module receiving power from the clamp circuit. The control module is configured to provide control signals to one or more elements of the power supply circuit.

Abstract: An audio power amplifier includes a first and a second amplification unit, each including a switching voltage amplifier, an output filter, a current compensator, an inner current feedback loop feeding a measurement of current measured at the output inductor back to a summing input of the current compensator, a voltage compensator coupled to the summing input of the current compensator, and an outer voltage feedback loop. A controlled signal path provides the output of the voltage compensator of the first amplification unit to the current compensator of the second amplification unit. The first and second amplification units are operable with separate loads, in parallel driving a common load, or across a bridge-tied-load. A second pair of amplification units may be added and operated together with the first pair to drive a single speaker with a parallel pair of amplifiers on each side of a bridge-tied-load.