911results about "Audio amplifier" patented technology

An example apparatus includes: class D amplifier circuitry having a first input, a second input, a third input, and an output, the first input of the class D amplifier circuitry coupled to the output of the class D amplifier circuitry; and class AB amplifier circuitry having a first input, a second input, a third input, and an output, the first input of the class AB amplifier circuitry coupled to the first input of the class D amplifier circuitry and the output of the class D amplifier circuitry, the second and third inputs of the class AB amplifier circuitry coupled to the second and third inputs of the class D amplifier circuitry, and the output of the class AB amplifier circuitry.

A logarithmic amplifier includes programmable gain amplifiers each having a different gain, wherein an input of each of the programmable gain amplifiers is coupled to an input of the logarithmic amplifier; and a summing circuit having inputs coupled to a corresponding output of each of the programmable gain amplifiers and an output coupled to an output of the logarithmic amplifier, wherein the summing circuit generates a logarithmic transfer function having piecewise linear segments.

Signal processing is applied to a digital input audio signal. An analog audio output signal is provided based on the digital input audio signal via a switching converter circuit driven by a PWM signal. The analog audio output signal is sensed to generate an analog feedback signal. The applied signal processing includes: producing a digital error signal indicative of a difference between the digital input audio signal and a digital word signal; applying digital-to-analog conversion to the digital error signal to produce an analog replica of the digital error signal; producing an analog difference signal indicative of a difference between the analog replica of the digital error signal and the analog feedback signal; applying analog-to-digital conversion to the analog difference signal to produce the digital word signal; applying digital filtering to the digital word signal to produce a filtered digital word signal that generates the PWM signal.

The embodiment of the invention provides a closed-loop control method for power driving and protection, and the method comprises the steps: constructing a voltage feedback type circuit through a high-speed operational amplifier, and forming a closed-loop gain structure through a feedback network of the voltage feedback type circuit; the load current of the output end of the voltage feedback type circuit is monitored in real time, and when the load current exceeds a first set threshold value, a protection mechanism is triggered to turn off the output stage; the power-on surge current is limited through the soft start control circuit; phase information of a load reflection coefficient is obtained, an inductance / capacitance combination of the variable dynamic impedance matching network is selected according to phase information table look-up, inductance / capacitance parameters are switched through a relay, and the transmission standing-wave ratio between the power amplifier and a load is optimized; monitoring the temperature of the radiating fin of the power tube, and dynamically adjusting the resistance value of the feedback network; and performing cooperative control of short-circuit protection, over-temperature protection and surge suppression according to the priority. According to the embodiment of the invention, the performance bottleneck in a load fluctuation scene is broken through.

This application relates to methods and apparatus for driving a transducer. A transducer driver has a switch network 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.

A signal amplifier includes a driver and a network of switches forming a power converter coupled to a H-bridge circuit. The power converter has a flying capacitor and an inductor. The H-bridge circuit receives a converted voltage from the power converter and applies an output modulated voltage to a load, for instance a loudspeaker. The driver drives the network of switches in a neutral state, a first state and a second state. In the neutral state no voltage is applied to the load. In the first state, an input voltage supply and the inductor are serially coupled, and the flying capacitor is coupled in parallel with the serially coupled input voltage supply and inductor. In the second state, the flying capacitor is coupled in series with at least one of the input voltage supply and the inductor. The signal amplifier may be a multi-level class D or class H amplifier.

In various embodiments, a sound modification application selectively modifies one or more sounds included in one or more audio signals. In operation, the sound modification application determines classifications associated with multiple sounds included in one or more audio signals. The sound modification application selects a first frequency sub-band of a first sound included in the multiple sounds based on a first classification associated with the first sound. The sound modification application then modifies the first frequency sub-band of the first sound, without modifying at least a second frequency sub-band of the first sound, to generate a modified audio signal.

A logarithmic amplifier system is disclosed. The system includes first and second amplifiers respectively having first and second gains; a first multiplier having an input connected to an output of the first amplifier, and being configured to output a first multiplied signal based on an output signal of the first amplifier and based on a received first multiplication factor equal to a value K; a second multiplier having an input connected to an output of the second amplifier, and being configured to output a second multiplied signal based on an output signal of the second amplifier and based on a received second multiplication factor equal to 1 minus the value K; a transition shaping circuit configured to change the value K from 0 to 1 with a filtered transfer function; and a summing circuit having inputs coupled to outputs of the first multiplier and the second multiplier.

A class D amplifier circuit receives an analog audio signal with a first reference voltage as its center level, and outputs an output pulse signal having a duty cycle that corresponds to the analog audio signal. A bias circuit generates a second reference voltage having a voltage level obtained as a division of the first reference voltage and the power supply voltage. A periodic voltage generating circuit of the class D amplifier circuit generates a periodic voltage having a triangle waveform or otherwise a sawtooth waveform having an amplitude that corresponds to the second reference voltage.

In an audio amplifier circuit, a power supply terminal receives a power supply voltage. A voltage source generates an internal power supply voltage obtained by multiplying the power supply voltage by a first gain and a bias voltage obtained by multiplying the power supply voltage by a second gain. An input gain circuit amplifies an analog audio signal with reference to the bias voltage. The input gain circuit has an input stage and a gain stage. A phase compensation capacitor is connected to the gain stage. A withstand voltage protection circuit clamps an output voltage of the gain stage to a predetermined clamp voltage.

This application relates to methods and apparatus for switched mode drivers. A BTL driver has a switch network operable in different switch states, wherein, in each switch state, each of first and second output nodes is connected to a respective one of a first switching voltage, a second switching voltage or an intermediate switching voltage between the first and second switching voltages which is provided by a driver capacitance. A controller is configured to control the switch network to operate in a sequence of switch states to generate a differential drive signal based on an input signal. The controller is configured such that operation of driver switch network in said sequence of switch states to generate said differential drive signal provides voltage regulation of the intermediate voltage provided by said driver capacitance.

An integrated circuit (IC), comprising: a first gain stage configured to apply a first gain to a first signal to generate a first amplified signal; a first converter configured to convert the first signal to a first output signal; a first output pin for outputting the first output signal; gain update circuitry configured to: output a first internal gain control signal to the first gain stage to update the first gain of the first gain stage, subsequently output a first external gain control signal to a second output pin of the IC, wherein output of the first external gain control signal is delayed relative to output of the first internal gain control signal by a first predetermined delay, the first predetermined delay to compensate for signal chain delay between the first gain stage and the first output pin.

An audio amplifier includes a loop filter, at least one high pass filter (HPF) circuit, a pulse width modulation (PWM) generator, and a power stage. The loop filter is arranged to receive an audio signal and a feedback signal, and includes a first amplifier and a second amplifier, wherein the first amplifier has a first output node, and is arranged to process the audio signal and the feedback signal; the second amplifier has a first input node, and is arranged to receive a first amplifier input and a second amplifier input; and the first amplifier input is obtained from a signal path coupled between the first output node and the first input node. The at least one HPF circuit is coupled between the first amplifier and the second amplifier, and is arranged generate and output the second amplifier input according to an amplifier output of the first amplifier.

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.

A voltage generation circuit includes a voltage input terminal, a voltage output terminal, a first resistor having a first terminal electrically connected to the voltage input terminal, a second resistor having a third terminal electrically connected to the second terminal and a fourth terminal electrically connected to a ground potential, a first capacitor having a first capacitive terminal electrically connected to the voltage input terminal, a third resistor having a fifth terminal electrically connected to a second capacitive terminal, a fourth resistor having a seventh terminal electrically connected to a sixth terminal, and a first operational amplifier having a first inverting input terminal electrically connected to the sixth terminal, a first non-inverting input terminal electrically connected to the second terminal, and a first output terminal electrically connected to the voltage output terminal and an eighth terminal.

According to an aspect of an embodiment, thermal management system for an audio amplifier system may include a heatsink and an active thermal management system. The heatsink may be coupled to an enclosure housing the audio amplifier system and an amplifier of the audio amplifier system. The heatsink may be configured to passively dissipate heat generated in the amplifier to the enclosure and provide structural support for the enclosure. The active thermal management system may include a temperature sensor configured to generate temperature data, a fan configured to provide air to the audio amplifier system to lower temperature measured using the temperature sensor and an embedded computing device configured to obtain the temperature data from the temperature sensor and control the fan based on the temperature data.

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 plurality of sensors, each sensor configured to sense a current associated with a respective one of the first high-side switch, second high-side switch, first low-side switch, and second low-side switch. The system may also include short-circuit detection circuitry configured to determine a presence and a location of a short circuit in the Class-D stage based on the sensed currents.

A circuit comprises a first half-bridge power stage including a first set of switches and a second half-bridge power stage including a second set of switches. The circuit further comprises a first power source and a second power source that are coupled to the first and second half-bridge power stages for supplying a first direct current (DC) voltage and a second DC voltage, respectively. The circuit further comprises an output interface coupled to the first and second half-bridge power stages and configured to couple to a speaker load. The first and second half-bridge power stages are configured to generate a five-level differential signal for driving the speaker load. Each set of switches includes a respective first subset of switches configured to operate at a first voltage level and a respective second subset of switches configured to operate at a second voltage level.

Provided in the present application are an audio system and a terminal device, which can be applied to the technical field of audio. In the audio system of the present application, a second audio power amplifier is added to a first audio power amplifier, wherein the first audio power amplifier is a common audio power amplifier, the second audio power amplifier is a high-power audio power amplifier, such that the sound effect of a terminal device can be improved by means of the second audio power amplifier. In addition, an audio processor in the audio system can dynamically adjust, on the basis of a volume level, a battery charge level or a battery temperature, audio streams input into the first audio power amplifier and the second audio power amplifier, and can dynamically adjust an input voltage of the second audio power amplifier on the basis of the volume level, the battery charge level or the battery temperature, such that the power consumption of the terminal device can be reduced while the sound effect of the terminal device is improved.

A handheld wireless microphone body may be connected to an assortment of microphone heads, providing compatibility between models from differing manufactures including accommodating differing attachment threads and electrical / audio output contact configurations without the need for hardware or software substitution.

Provided is a differential amplifier comprising: a first differential amplification circuit that has a first input terminal, a second input terminal, a first output terminal and a second output terminal which respectively output a first output signal and a second output signal; an RC filter that filters the first output signal and the second output signal and outputs them; a second differential amplification circuit that has a third input terminal and a fourth input terminal to which the first output signal and the second output signal filtered by the RC filter are respectively input and a third output terminal which outputs a third output signal; and a third amplification circuit that has a fifth input terminal to which the third output signal is input and a fourth output terminal which outputs a fourth output signal according to the third output signal.

In some embodiments, a calibration circuit for an audio amplification system can include a tone generator configured to provide a tone having a frequency to an input path of an audio amplifier, such that an input signal provided to the audio amplifier includes the tone, a a first sampling circuit configured to sample an output signal at an output node of the audio amplifier, and a second sampling circuit configured to sample the input signal at an input node of the audio amplifier. The calibration circuit can further include a gain adjustment circuit configured to generate a correction signal based on the sampled output signal and the sampled input signal to correct for a gain variation of the audio amplifier.

A method includes determining whether an audio signal processed in a class-D amplifier is clipping. Responsive to clipping of the audio signal, a speaker voltage is estimated as a ratio of a power supply voltage of the class-D amplifier to a resistance of a speaker driven by the class-D amplifier. An amplitude of the audio signal is controlled based on the speaker voltage.

The invention provides an audio system and terminal equipment, which can be applied to the technical field of audio. In the audio system, the second audio power amplifier is added on the basis of the first audio power amplifier, the first audio power amplifier is a common audio power amplifier, the second audio power amplifier is a high-power audio power amplifier, and the sound effect of the terminal equipment can be improved through the second audio power amplifier. Besides, an audio processor in the audio system can dynamically adjust audio streams input to the first audio power amplifier and the second audio power amplifier according to the volume level, the battery electric quantity or the battery temperature, and can dynamically adjust the input voltage of the second audio power amplifier according to the volume level, the battery electric quantity or the battery temperature. While the sound effect of the terminal equipment is improved, the power consumption of the terminal equipment can be reduced.

This application relates to methods and apparatus for current monitoring in switched mode drivers. A switching driver has an output stage with a network of switches for switching an output node between different switching voltages and a modulator for controlling a duty-cycle of the switching output stage based on the input signal, where the modulator generates a modulator signal based on the input signal. A current monitor is configured to receive a first current signal indicative of a sensed first driver current and to determine and / or limit a second driver current using the first current signal and the modulator signal. One of the first driver current and the second driver current is an output current to the load and the other of the first driver current and the second driver current is an input current from a power supply.

Provided are an audio playing module and an audio processing circuit thereof, and an electronic device, which belong to the technical field of electronics. In the audio processing circuit, by adding a feedback control circuit between a power circuit and an audio amplifier, the feedback control circuit can control, according to a change in the amplitude of an audio signal received by the audio amplifier, the power circuit to adjust a power supply voltage provided for the audio amplifier. Thus, when the amplitude of the audio signal changes, an appropriate power supply voltage can be matched for the audio amplifier by means of the feedback control circuit, thereby solving the problem of the audio playing module generating whistling when the amplitude of the audio signal changes, and thus optimizing the sound quality of played sounds.

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.

A hearing system in particular a binaural hearing system that is configured to produce monaural or binaural beats and, to that end, has at least one hearing device containing a primary signal path. The hearing device moreover has a secondary signal path, containing a signal generator for generating a first beat signal. The first beat signal being frequency-shifted in relation to a further signal by a beat frequency in such a way that the effect of the monaural or binaural beat is produced for the user during operation. The signal generator has an associated adjusting apparatus that has an adjustable amplifier element. The adjusting apparatus has an analysis unit for determining an instantaneous signal level of the input signal, and the respective adjusting apparatus is configured to set a signal level of the first beat signal on the basis of the instantaneous signal level.

This application relates to sensing of signals with a common-mode variation. Embodiments describe a switching driver circuit with a modulator configured to control modulation of an output node between different switching voltages and a current sensor configured to sense a voltage drop across a sense resistor connected in series with the output node. The current sensor performs sensing during a first time window that occurs at regular intervals and the modulator avoids any transition in switching voltage at the first output node during the first time window. Embodiments also describe a sensing circuit for sensing a differential voltage with a common-mode variation which has a first sensing portion implemented to provide a floating voltage domain and a second sensing portion implemented to provide a static voltage domain. At least one switched capacitor provides a boundary between the voltage domains and is switched to transfer charge between the voltage domains.

The invention relates to a low-power-consumption high-performance D-type power amplifier modulation method and circuit and a D-type audio power amplifier, and the method comprises the steps: separating a pair of BD mode modulated signals outputted by a PWM modulation module in the D-type audio power amplifier circuit into a common mode component and a differential mode component, and outputting the common mode component and the differential mode component; feeding back the common-mode component and the differential-mode component to a differential input end through a common-mode feedback link and a differential-mode feedback link respectively; wherein the common-mode component and the common-mode feedback link are completely arranged in the chip; the differential mode component and the differential mode feedback link are realized by a power MOSFET (Metal-Oxide-Semiconductor Field Effect Transistor) integrated inside the chip or an external power MOSFET; and outputting the differential mode component to a to-be-driven object through the power output stage. According to the method, after two feedback links are separated, in a zero-input mute state, no common-mode signal is sent to an output stage for amplification, and power consumption is not caused at the output stage, so that the overall efficiency is greatly improved; and meanwhile, static bottom noise is almost eliminated.