33 results about "Class-D amplifier" patented technology

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.

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.

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 input signal may be converted to a first PWM signal and a second PWM signal at a PWM controller circuit. The first PWM signal and the second signal output may drive a driver circuit. The driver circuit may receive a high voltage power supply from a boost converter or other power supply circuit. The driver circuit may include a high side device and a low side device. The output of the driver circuit may drive a filter circuit that includes a filter capacitor, an inductor, and a haptic actuator. The haptic actuator may generate a desired haptic response at the haptic actuator.

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.

The embodiment of the invention discloses a modulator, a modulation method and a class-D amplifier. According to the embodiment of the invention, the delay parameter is dynamically controlled according to the envelope of the input signal, and dynamic duty ratio reduction is carried out on the pulse width modulation signal obtained through preliminary modulation, so that the duty ratio of the pulse width modulation signal obtained through audio signal modulation can be effectively reduced when the signal is small, the conduction loss and the switching loss of a class-D amplifier are reduced, and the power consumption of the class-D amplifier is reduced. And the power consumption is optimized.

This application discloses a DC detection circuit and electronic device suitable for Class D amplifiers. A charge / discharge circuit controls the supply of charging current to a capacitor to establish a pre-charge voltage or controls the supply of discharge current required for capacitor discharge. A PWM signal processing circuit controls the charge / discharge circuit based on the duty cycle difference between a first pulse width modulation signal and a second pulse width modulation signal. A reset circuit is connected between the charge / discharge node and the common terminal. A comparator compares the voltage of the charge / discharge node with a reference voltage. The reset circuit is used to reset the voltage of the charge / discharge node when the input signal is a normal audio signal at a zero-crossing point; or, when the input signal is a DC signal, not to perform a reset operation; or, when the input signal switches from a normal audio signal to a DC signal, to end the reset operation. This application incorporates a reset circuit to avoid misjudgment during normal audio signal and DC signal switching, improving the accuracy and reliability of the DC detection circuit.

The application provides a class D amplifier and a method of operating the same, the class D amplifier including an output driver stage configured to output an output signal at an output node. The class D amplifier also includes a current sense circuit coupled to the output node of the output driver stage, and the current sense circuit may include: a peak detector coupled to the output node of the output driver stage, the peak detector configured to retrieve a peak of the output signal; and a current sensor coupled to the peak detector and configured to receive the peak of the output signal and generate a sensing current based on the peak of the output signal.

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

The present invention discloses a class D amplifier, comprising: a loop filter, a control signal generator, a first power driver and a first feedback circuit, configured to establish a first loop for signal amplification; a stabilization circuit, configured to combine with the loop filter and the control signal generator to establish a second loop, so as to stabilize the loop filter and the control signal generator before enabling the first loop; and a pre-charging circuit, configured to pre-charge the positive output terminal and the negative output terminal of the first power driver, respectively, the positive output terminal and the negative output terminal being the first positive feedback terminal and the first negative feedback terminal, respectively. The implementation of the present invention can eliminate popping and clicking noises.

The invention provides a class D amplifier with load current sensing and an operation method thereof. The class D amplifier includes an output driver stage and a current sensing circuit. The current sensing circuit includes: an operational amplifier having a positive input terminal and a negative input terminal; the source electrode of the positive input composite transistor is connected to the positive input terminal, and the drain electrode and the grid electrode of the positive input composite transistor are respectively connected to the drain electrode and the grid electrode of a first n-type output transistor; the source electrode of the negative input composite transistor is connected to the negative input terminal, and the drain electrode and the grid electrode of the negative input composite transistor are respectively connected to the drain electrode and the grid electrode of the second n-type output transistor.

The invention relates to a self-biased low-harmonic high-efficiency inverse class-D RF power amplifier circuitry. Power amplifier circuitry is disclosed having an inverse class D amplifier acting as a power amplifier and self-biasing circuitry that generates a gate bias voltage for a switched-mode power transistor within the power amplifier. The self-biasing circuitry includes a low dropout regulator that generates and applies a gate bias voltage in response to a feedback current scaled according to an operating current of the power amplifier. The current-based digital-to-analog converter is configured to generate a reference current based on the received digital value. In addition, a digital processor is configured to generate the digital value in response to the gate bias voltage. The power amplifier circuitry enhances performance and efficiency while ensuring precise control of power transistor operation, providing advantages for various applications requiring radio frequency signal amplification.

To provide a self-oscillating Class-D amplifier device which implements the improvement of acoustic performance, the reduction of distortion and the improvement of stability.SOLUTION: An amplifier device 300 for amplifying an input signal Sx at a device input X to an output signal Sy at a device output Y, for driving reactive load such as a loudspeaker, comprises a self-oscillating Class-D power amplifier stage K with transfer function KA(s). The amplifier stage includes a comparator, a power stage, a second-order low-pass output filter and a time delay unit. The time delay unit provides a delay determined by the comparator, the power stage, and a first feedback filter Hosc. The output signal Sy is fed back to the comparator via a first feedback path. A correction stage comprises a second feedback path that feeds the output signal Sy to a virtual ground input of a transimpedance amplifier. A third feedback path for further enhancing correction includes a passive network which applies a first transfer function H2 to the output signal Sy and applies a second transfer function H3 to the input signal Sx.SELECTED DRAWING: Figure 2

The present application relates to a class-D amplifier. The class-D amplifier includes a loop filter configured to receive first and second feedback signals, and receive first and second input signals through first and second resistors, respectively, and filter the first and second input signals and the first and second feedback signals to generate first and second filtered signals; a triangle wave generator configured to generate a triangle wave based on first and second reference voltages; first and second comparators configured to compare the first and second filtered signals to the triangle wave to generate first and second pulse width modulation signals, respectively; first and second driver circuits configured to generate first and second output signals based on the first and second pulse width modulation signals, respectively; and a reference voltage generator circuit configured to generate the first and second reference voltages based on a control signal.

High-efficiency dual-frequency homologous frequency-modulated radio broadcast modulation and transmission system, which relates to the field of radio and television technology and solves the problem of low power efficiency of existing multi-program homologous transmitters. The system includes a frequency modulator and a power amplifier circuit. The power amplifier circuit includes an amplitude modulator and a carrier amplifier. The frequency modulator includes a processor, a V oscillator, a U oscillator, a pulse generator, a pulse modulator, an inverter, a phase detector, and a data selector. The power amplification circuit of the present invention not only has the function of signal amplification, but also participates in the frequency synthesis of frequency-modulated programs in the form of high-power amplitude modulation, which is a new technical route. Therefore, the power amplifier circuit can use class C or higher class D amplifiers with higher power efficiency, and the output high-power program signal can be directly transmitted.

The present invention provides a method, device, and medium for detecting audio output of a Class D amplifier in the field of Class D amplifier technology. The method includes: step S10, inputting a sine wave signal of a preset frequency into the Class D amplifier; step S20, connecting a filter circuit to the load end of the Class D amplifier and setting the cutoff frequency of the filter circuit; step S30, the Class D amplifier superimposes the sine wave signal on a carrier signal and outputs the signal through the filter circuit; step S40, sampling the output signal of the filter circuit through an ADC and performing a fast Fourier transform to obtain a complex sequence corresponding to the sampling points, thereby calculating the effective value of the input signal; step S50, multiplying the sine wave signal by the amplification factor of the Class D amplifier, comparing the value obtained with the corresponding effective value, and analyzing the complex sequence to determine whether the output of the Class D amplifier is normal. The advantage of the present invention is that it greatly improves the accuracy of audio output detection of the Class D amplifier.

To reduce distortion contained in an output signal while reducing application cost by incorporating an externally arranged current limiting resistor.SOLUTION: A class-D amplifier circuit includes: a first input terminal and a second input terminal to which a 3-value PWM signal can be inputted; and a first output terminal and a second output terminal to which a capacitive load is connected. The class-D amplifier circuit further includes: a first class-D driver circuit having a first driver output terminal capable of changeover based on a signal level at the first input terminal; and a second class-D driver circuit having a second driver output terminal capable of changeover based on a signal level at the second input terminal. A first current limiting resistor is connected between the first driver output terminal and the first output terminal, and a second current limiting resistor is connected between the second driver output terminal and the second output terminal. Changeover state of a first switch connected to the first current limiting resistor in parallel and the second switch connected to the second current limiting resistor in parallel are controlled so that an applied voltage to the capacitive load becomes the power supply voltage or less, based on the first signal level and the second signal level.SELECTED DRAWING: Figure 1

This invention provides a CMOS ultra-wideband high-gain high-power amplifier, relating to the field of power amplifier technology. It includes a multi-drive improved Class D amplifier and a multi-stage compact coupled peaking distributed amplifier. The multi-stage compact coupled peaking distributed amplifiers are connected sequentially. The input RF signal is connected to the first-stage compact coupled peaking distributed amplifier via an input line. The output of the Nth-stage compact coupled peaking distributed amplifier is connected to the input of the multi-drive improved Class D amplifier via an output line. The output of the multi-drive improved Class D amplifier outputs the RF signal. The advantage of this invention is that it solves the problems of large area, low gain, and low output power in traditional distributed amplifiers.

This application discloses a sine wave generation circuit and an electronic device. The sine wave generation circuit includes a first signal conversion module, a Class D amplifier, a second signal conversion module, and a voltage control module. The first signal conversion module converts a square wave signal into a first sine wave signal with adjustable amplitude. The Class D amplifier amplifies and modulates the power of the first sine wave signal, and then outputs a high-frequency carrier pulse-width modulated signal. The second signal conversion module demodulates and boosts the high-frequency carrier pulse-width modulated signal to output a second sine wave signal. The voltage control module outputs an adjustment signal to the first signal conversion module to adjust the amplitude of the first sine wave signal based on the control signal and the second sine wave signal until the voltages of the control signal and the second sine wave signal satisfy a preset relationship. This method allows for the output of a corresponding sine wave signal according to user needs, and is highly reliable due to its high conversion efficiency.

A method includes determining whether an audio signal processed in a class D amplifier is clipping (404). In response to clipping of the audio signal, a speaker voltage is estimated as a ratio of a supply voltage of the class D amplifier to a resistance of a speaker driven by the class D amplifier (408). An amplitude of the audio signal is controlled based on the speaker voltage.

The present disclosure relates to a full-bridge class D amplifier comprising a first and second half-bridge circuit, wherein each half-bridge comprises a half-bridge output terminal between a high-side switch and a low-side switch. Wherein the first and second half-bridge circuits are controlled by a respective control signal to operate in differential mode with a predetermined switching frequency and wherein each half-bridge circuit further comprises an output terminal inductor connected between the half-bridge output terminal and ground. The amplifier further comprises a first and second coil coupled to form a common mode choke, wherein the first half-bridge output terminal is connected to an input terminal of the first coil, and wherein the second half-bridge output terminal is connected to an input terminal of the second coil.

The present disclosure relates to an amplifier device for amplifying an input signal Sx at a device input X into an output signal Sy at a device output Y for driving a loudspeaker or comparable reactive load, comprising a self-oscillating class D power amplifier stage with a transfer function KA (s). The amplifier stage includes a comparator, a power stage, and a second order low-pass output filter including an inductor and a capacitor. A time delay unit provides a delay determined by one or more of the comparator, the power stage, and the first feedback filter. The output signal Sy is fed back to the comparator via a first feedback path to establish an oscillation and provide a basic low frequency feedback. A correction stage is provided that includes a second feedback path that feeds an output signal Sy to a virtual ground input of a transimpedance amplifier via a scaling resistor. This enables pre-distortion of the amplifier input SKin by subtracting the filtered distortion component derived from the tracking filter. To further enhance the correction, a third feedback path is included. It comprises a passive network applying a first transfer function H2 to the output signal Sy and a second transfer function H3 different from the first transfer function H2 to the input signal Sx. The resulting signal is summed as a current into a transimpedance amplifier, which outputs a correction reference signal defining the signal Sr as a correction stage.

A class D amplifier includes a loop filter, a pulse width modulation generator, a first multiplexer, a second multiplexer, and a power stage. The loop filter generates positive and negative loop filtering signals according to an input signal. The pulse width modulation generator is coupled to the loop filter and generates first positive and negative pulse width modulation signals according to the positive and negative loop filtering signals. The first multiplexer is coupled to the pulse width modulation generator, and selects and outputs a first multiplexer signal from a signal group including a first positive and negative pulse width modulation signal. The second multiplexer is also coupled to the pulse width modulation generator, and selects and outputs a second multiplexer signal from the signal group. The power stage is coupled to the two multiplexers, generates a positive output signal to a positive output terminal according to the first multiplexer signal, and generates a negative output signal to a negative output terminal according to the second multiplexer signal.

There is provided a carrier generator including a clock generator that outputs a clock signal based on a first comparison signal and a second comparison signal; the spread spectrum module is used for outputting a shift code stream signal based on a spread spectrum graph and a clock signal; a carrier generation module which outputs a carrier signal based on the clock signal and the shift code stream signal; and the comparison module is used for respectively comparing the carrier signal with the first amplitude reference voltage and the second amplitude reference voltage and respectively outputting a first comparison signal and a second comparison signal. The circuit is simple, the spread spectrum of the clock signal is controlled through the first comparison signal and the second comparison signal, it is guaranteed that the amplitude of the carrier signal is fixed and controllable, and meanwhile the frequency change of the carrier signal and the spread spectrum frequency change are the same through the synchronization effect of the clock signal and the shift code stream signal.

This application relates to sensing of signals with a variable common-mode component, e.g. at the output of a class D amplifier. Embodiments describe a switching driver circuit with a modulator (601,

The present invention provides a dynamic modulation method for a class-D amplifier and its electronic circuit. In the dynamic modulation method of the class-D amplifier, by dynamically adjusting the average duty cycle of the audio amplification signal, the average duty cycle of the audio amplification signal is made to be a suitable duty cycle to reduce the circuit power consumption, that is, the average duty cycle of the audio amplification signal is maintained at a relatively low level when there is no audio input, thereby reducing the static power consumption, and when the power is medium or low, the loss caused by the inductor ripple current is also reduced.

One method involves determining whether clipping is present in an audio signal processed by a Class-D amplifier. In response to clipping, a speaker voltage is estimated as the ratio of the Class-D amplifier's power supply voltage to the resistance of a speaker driven by the Class-D amplifier. The amplitude of the audio signal is then controlled based on this speaker voltage.

A class D amplifier driving circuit is used to generate an output gate driving voltage according to an input voltage that dynamically varies with the amplitude of an audio signal, and the driving voltage is used to drive the high-voltage transistor of the class D amplifier. The class D amplifier driving circuit includes: a reference voltage generation circuit for generating a second reference voltage according to a first reference voltage; a clamping circuit for clamping the input voltage; a low dropout (LDO) linear regulator pre-stage for generating an intermediate voltage according to the second reference voltage; and an LDO linear regulator output stage for generating the driving voltage according to the input voltage and the intermediate voltage.

An integrated circuit die forming method, for forming a plurality of integrated circuit dies on a semiconductor wafer, comprising: forming a first device, a second device in a first die in a first area; forming a metal layer connected to the first device and the second device; forming a third device, a fourth device in a second die in a second area; forming the metal layer connected to the third device and the fourth device, wherein a scribe area exists between the first area and the second area is separated by; wherein the first device and the third device are used for synchronization and are components of a class D amplifier; wherein the second device is used for preventing leakage currents of the first die and the fourth device is used for preventing leakage currents of the second die.

An input signal can be converted into a first PWM signal and a second PWM signal by a PWM controller circuit. The first PWM signal and the second signal output can drive a control circuit. The control circuit can receive a high-voltage supply from a boost converter or other power circuit. The control circuit can include a high-side device and a low-side device. The output of the control circuit can drive a filter circuit, which includes a filter capacitor, an inductor, and a haptic actuator. The haptic actuator can generate a desired haptic response.