538results about "Audio amplifier" patented technology

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.

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.

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.

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.

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.

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.

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.

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.

A Class-D audio amplifier includes a triangular wave generator, a wave reshaping device and a pulse-width modulator. The triangular wave generator generates a first triangular wave. The wave reshaping device generates a second triangular wave by reshaping the first triangular wave. The pulse-width modulator modulates a pair of differential audio input waves with the second triangular wave instead of the first triangular wave to reduce a switching loss of the Class-D audio amplifier.

The invention provides a multi-phase pulse width modulation method and related equipment for reducing harmonic waves for a class-D power amplifier, and relates to the field of radio and television, and the method comprises the steps: sampling an original audio signal at a preset sampling rate, and obtaining a sine wave audio signal; generating a plurality of triangular wave signals corresponding to the sine wave audio signal according to a preset frequency multiple; performing amplitude comparison on the sampling signal and each triangular wave signal to obtain a pulse width modulation signal corresponding to each triangular wave signal; superposing the plurality of pulse width modulation signals to obtain a superposed signal; and inputting the superposed signal into a D-type power amplifier to obtain a power amplifier output signal after harmonic wave reduction. By implementing the method, the performance requirement on a post-stage low-pass filter can be reduced, so that the harmonic distortion of the output signal is suppressed on the premise of not increasing the cost and complexity of the filter.

A lavalier microphone has improved dynamic range. The lavalier microphone incorporates a pair of microphone transducer elements into the same housing or attached housings, with one of the microphone transducer elements being more sensitive to acoustic input than the other. The voltage signals from the respective transducer elements are processed and combined, resulting in a digital output audio signal with improved signal to noise both at lower and higher input acoustic levels.

The present invention relates to a high-performance audio amplifier (102) intended to control at least one loudspeaker (R44), the amplifier comprising a preamplifier stage (301) receiving an input signal (S1), a power amplifier stage (302) connected to the preamplifier stage (301), and a negative feedback loop delivering an image of an output signal (3) to the preamplifier stage (301), the power amplifier stage (302) comprising two power supply circuits (155a, 155b), the two power supply circuits comprising MOSFET transistors (M1, M2). The present invention is characterized in that it comprises: a subcircuit for assisting charging, a subcircuit for assisting discharging of the MOSFET transistors (M1, M2), and a voltage shifting subcircuit.

An audio amplifier that implements current mode control without the use of an explicit or separate current mode sensor is disclosed. The audio amplifier may include a pair of feedback loops that provide current from a node located before an inductor of an output filter and current from a node located after the inductor of the output filter to an integrator circuit. The integrator circuit may be formed from existing circuitry of the audio amplifier controller. Thus, current mode control can be implemented without a separate current mode sensor. Further, the audio amplifier can be implemented as a half bridge or as a full bridge design without increasing the number of operational amplifiers compared to the half bridge.

Apparatus and techniques for adaptively adjusting an input current limit of a boost converter that supplies power to a load, such as an amplifier. An exemplary circuit for supplying power generally includes a boost converter having an output coupled to the load, and logic configured to adaptively adjust the input current limit of the boost converter and apply the input current limit to the boost converter based on an estimated output power of the boost converter. One exemplary method for supplying power generally includes converting an input voltage to an output voltage by a boost converter to power a load for the boost converter, adaptively adjusting the input current limit of the boost converter based on the estimated output power of the boost converter, and applying the input current limit to the boost converter during conversion.

An example apparatus includes class D amplifier circuitry (130) having a first input, a second input, a third input, and an output, the first input of the class D amplifier circuitry (130) being coupled to the output of the class D amplifier circuitry (130); and class AB amplifier circuitry (140) having a first input, a second input, a third input, and an output, the first input of the class AB amplifier circuitry (140) being coupled to the first input of the class D amplifier circuitry (130) and the output of the class D amplifier circuitry (130), the second and third inputs of the class AB amplifier circuitry (140) are coupled to the second and third inputs of the class D amplifier circuitry (130) and the output of the class AB amplifier circuitry (140).

The present invention is in the field of underlying electronic circuits, in particular audio amplifiers, more particularly class D amplifiers, such as for digital audio converters and digital amplifier controllers, chips comprising said audio amplifiers, and devices comprising said audio amplifiers or said chips.

An acoustic apparatus includes a class-D amplifier including a current feedback circuit, and a speaker system including a voice coil driven by the class-D amplifier. The speaker system is configured such that, in a case where the speaker system is driven by an ordinary amplifier having a first output resistance lower than a second output impedance of the class-D amplifier, a Q factor of the speaker system falls below a predetermined lower limit of an ordinary Q factor range of an ordinary speaker system. The current feedback circuit is configured to increase the second output impedance of the class-D amplifier by feeding a current flowing to the voice coil back to an input of the class-D amplifier so as to increase a Q factor as the acoustic apparatus higher than the predetermined lower limit of the ordinary Q factor range and within the ordinary Q factor range.

This application relates to the field of electronic technology and discloses a power supply voltage control method, an audio power amplifier system, an electronic device, and a chip. The method, applied to an audio power amplifier system, includes: obtaining audio data input to the audio power amplifier system; determining the input amplitude of the audio data; determining a control voltage based on the input amplitude; and adjusting the power amplifier supply voltage based on the control voltage to power the power amplifier of the audio power amplifier system based on the power amplifier supply voltage. The power supply voltage of the power amplifier of the audio power amplifier system is determined based on the input amplitude of the audio data, and the audio data is amplified based on the supply voltage. This reduces the power consumption of the audio power amplifier system and improves conversion efficiency while ensuring that the audio signal does not produce truncation distortion.

A single integrated circuit (9) may include: a signal path configured to receive an input signal (V) IN Generate output signal (V) OUT ), wherein the signal path includes a signal configured to drive the output signal (V). OUT The amplifier (16); a DC-DC power converter (10) having a power inductor integrated in a single integrated circuit (9) and configured to generate a power supply voltage (V) from the source voltage to the amplifier. SUPPLY ); and a control circuit for controlling the operation of the converter switch of the DC-DC power converter (10) so that the power supply voltage (V SUPPLY Tracking input signal (V) IN ) and output signal (V OUT At least one of them.

The invention discloses a quick turn-off circuit, a power amplification circuit, an audio playing device and a vehicle, the quick turn-off circuit is suitable for turning off the power amplification circuit, the power amplification circuit comprises a current source and at least one stage of amplification unit, the quick turn-off circuit comprises a first turn-off unit, the first turn-off unit is suitable for being connected with the current source, and the first turn-off unit is suitable for being connected with the current source; the first turn-off unit is connected with the current source, is suitable for receiving a turn-off signal and is configured to turn off the current source under the condition that the turn-off signal is received; and the second turn-off unit is connected with the first turn-off unit, and the second turn-off unit is configured to synchronously turn off the at least one stage of amplification unit when the first turn-off unit turns off the current source. According to the circuit, when the first turn-off unit turns off the current source, at least one stage of amplification unit is turned off, so that the power amplification circuit is turned off quickly, and the service life of a power device is prolonged.

The embodiments of the present invention provide a microphone amplifier circuit, a microphone circuit, and an electronic device. The microphone amplifier circuit comprises a first transistor, a first constant-current source, and a source follower. A gate electrode of the first transistor serves as an input end of the microphone amplifier circuit, a source electrode of the first transistor serves as an output end of the microphone amplifier circuit, and a drain electrode of the first transistor is grounded. An input end of the first constant-current source is connected to a power supply, and an output end of the first constant-current source is connected to the source electrode of the first transistor. The source follower at least comprises a second transistor. A drain electrode of the second transistor is connected to the power supply, a gate electrode of the second transistor is connected to the source electrode of the first transistor, and a source electrode of the second transistor is connected to the drain electrode of the first transistor. The present invention at least facilitates an improvement to the THD performance of microphone amplifier circuits.

A class D amplifier including a pulse width modulation (PWM) control loop, an H-bridge driver, a PWM controller having a PWM pulse generator to generate PWM pulses supplied to the H-bridge driver in response to an ADC value output by an analog-to-digital converter of the PWM control loop, and a comparator. The comparator is configured to trigger a cutoff of a PWM pulse generated by the PWM pulse generator during a respective loop cycle of the PWM control loop and to trigger generation of at least one counter PWM pulse with an opposite polarity in the respective loop cycle such that a net pulse energy of the cutoff PWM pulse and of the at least one generated counter PWM pulse corresponds to a pulse energy representing the ADC value provided by the analog-to-digital converter of the PWM control loop during the respective loop cycle.

A class-D amplifier includes an output driver stage and a current sensing circuit connected. The current sensing circuit includes: an operational amplifier having a positive input terminal and a negative input terminal; a positive input replica transistor, where a source of the positive input replica transistor is connected to the positive input terminal, a drain and a gate of the positive input replica transistor is connected to the drain and the gate of a first n-type output transistor, respectively; and a negative input replica transistor, where a source of the negative input replica transistor is connected to the negative input terminal, a drain and a gate of the negative input replica transistor is connected to the drain and the gate of the second n-type output transistor, respectively.

This application relates to methods and apparatus for controlling a switching driver to drive a load with a drive signal based on an input signal. A controller is configured to control modulation of at least one driver output node between selected switching voltages of a set of at least four different switching voltages to generate the drive signal. The output node is modulated according to a switching pattern and the controller is configured such that, for a given level of drive signal, the controller can selectively operate with a plurality of different switching patterns and selects an appropriate switching pattern to control at least one parameter of the switching driver other than the drive voltage.

A differential delta-sigma-modulator has an integrator (49) including a pair of single-ended amplifiers (46, 47). The differential delta-sigma-modulator comprises a sample clock (50) driving a first switchable capacitor configuration (31) and a second switchable capacitor configuration (32) at a predetermined switching cycle. The second switchable capacitor configuration (32) is adapted for sampling respective outputs from the pair of single-ended amplifiers (46, 47) on a pair of output sampling capacitors (C3, C5) in the first part of the switching cycle (P1), and charging a common mode capacitor (C4) with the average voltage of the voltage sampled by the pair of output sampling capacitors (C3, C5) in the second part of the switching cycle (P2). The voltage across the common mode capacitor (C4) represents the common mode voltage for the integrator (49).