A parallelable constant-voltage digital audio power amplifier and broadcasting system

Abstract

The application discloses a kind of parallel constant voltage digital audio power amplifier and broadcast system, including line input module, line output module, first analog-digital conversion circuit, second analog-digital conversion circuit, third analog-digital conversion circuit, digital signal processor, single-chip microcomputer, digital-analog conversion circuit, error comparator, modulator, integration circuit, pulse width modulation input half-bridge output stage, first carrier frequency selection and gain adjustment module, second carrier frequency selection and gain adjustment module, first LC filter and high-frequency compensation network, communication bus and power switch.The existing multi-channel parallel digital constant voltage power amplifier is limited to the power amplifier channel inside the same power amplifier, and the parallel mode can only use the first channel as the master power amplifier and other channels as slave power amplifiers, which has certain limitations.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of power amplifier, in particular to a parallelable constant-voltage digital audio power amplifier and a broadcasting system. BACKGROUND

[0002] In a public broadcasting system, power amplifiers (PA) and loudspeakers are the terminal as the system terminal, which are indispensable core equipment and are used in large quantities. The broadcasting power amplifiers on the market are divided into traditional analog constant-voltage power amplifiers and digital constant-voltage power amplifiers, which generally have 70V and 100V output functions. Since the traditional analog constant-voltage power amplifier is large in size, heavy in weight, low in efficiency and poor in power grid adaptability, it has been on the verge of elimination. In the future, the digital constant-voltage power amplifier has a broader development prospect.

[0003] The current multi-channel parallelable digital constant-voltage power amplifier is limited to the power amplifier channels within the same power amplifier, and the parallel mode can only use the first channel as the master power amplifier and the other channels as the slave power amplifiers, which has certain limitations. If the master power amplifier fails, the power amplifier cannot be used normally. SUMMARY

[0004] The present application provides a parallelable constant-voltage digital audio power amplifier and a broadcasting system, which are used to solve the technical problem that the current multi-channel parallelable digital constant-voltage power amplifier is limited to the power amplifier channels within the same power amplifier, and the parallel mode can only use the first channel as the master power amplifier and the other channels as the slave power amplifiers, which has certain limitations.

[0005] Therefore, the present application provides a parallelable constant-voltage digital audio power amplifier, which comprises a line input module, a line output module, a first analog-to-digital conversion circuit, a second analog-to-digital conversion circuit, a third analog-to-digital conversion circuit, a digital signal processor, a single-chip microcomputer, a digital-to-analog conversion circuit, an error comparator, a modulator, an integration circuit, a pulse width modulation input half-bridge output stage, a first carrier frequency selection and gain adjustment module, a second carrier frequency selection and gain adjustment module, a first LC filter and high-frequency compensation network, a communication bus and a power switch.

[0006] The line input module is connected to the first analog-to-digital converter (ADC) and the line output module, respectively. The line output module is connected to the digital-to-analog converter (DAC). The first ADC is connected to the digital signal processor (DSP). The DSP is connected to the second ADC, the third ADC, the DAC, and the microcontroller, respectively. The DAC is connected to the error comparator. The error comparator is connected to the integrator, the modulator, the first LC filter and the high-frequency compensation network, and the first carrier frequency selection and gain adjustment module, respectively. The modulator is connected to the microcontroller and the pulse width modulation (PWM) input half-bridge output stage, respectively. The PWM input half-bridge output stage is connected to the integrator and the first LC filter and the high-frequency compensation network, respectively. The first LC filter and the high-frequency compensation network are connected to the first carrier frequency selection and gain adjustment module, the second carrier frequency selection and gain adjustment module, and the power switch, respectively. The microcontroller is connected to the communication bus, the power switch, and the second carrier frequency selection and gain adjustment module, respectively. The first carrier frequency selection and gain adjustment module is connected to the second carrier frequency selection and gain adjustment module, the second ADC, and the third ADC, respectively.

[0007] Optionally, it also includes an inverting pulse width modulation input half-bridge output stage, a second LC filter and a high-frequency compensation network, a first differential receiver amplifier, a second differential receiver amplifier, a third differential receiver amplifier, a fourth differential receiver amplifier, a fifth differential receiver amplifier and a sixth differential receiver amplifier;

[0008] The inverting pulse width modulation input half-bridge output stage is connected to the modulator and the second LC filter and the high-frequency compensation network, respectively. The second LC filter and the high-frequency compensation network are connected to the power switch.

[0009] The non-inverting input of the first differential receiver amplifier is connected to the output of the pulse width modulation input half-bridge output stage, the inverting input of the first differential receiver amplifier is connected to the output of the inverting pulse width modulation input half-bridge output stage, and the output of the first differential receiver amplifier is connected to the integrating circuit.

[0010] The non-inverting input of the second differential receiver amplifier is connected to the output of the first LC filter and the high-frequency compensation network, the inverting input of the second differential receiver amplifier is connected to the output of the second LC filter and the high-frequency compensation network, and the output of the second differential receiver amplifier is connected to the error comparator.

[0011] The non-inverting input of the third differential receiver amplifier is connected to the output of the first LC filter and high-frequency compensation network, the inverting input of the third differential receiver amplifier is connected to the output of the second LC filter and high-frequency compensation network, and the output of the third differential receiver amplifier is connected to the input of the first carrier frequency selection and gain adjustment module.

[0012] The non-inverting input of the fourth differential receiver amplifier is connected to the output of the first LC filter and high-frequency compensation network, the inverting input of the fourth differential receiver amplifier is connected to the output of the second LC filter and high-frequency compensation network, and the output of the fourth differential receiver amplifier is connected to the input of the first carrier frequency selection and gain adjustment module.

[0013] The non-inverting input of the fifth differential receiver amplifier is connected to the first output of the power switch, the inverting input of the fifth differential receiver amplifier is connected to the second output of the power switch, and the output of the fifth differential receiver amplifier is connected to the input of the first carrier frequency selection and gain adjustment module.

[0014] The non-inverting input of the sixth differential receiver amplifier is connected to the first output of the power switch, the inverting input of the sixth differential receiver amplifier is connected to the second output of the power switch, and the output of the sixth differential receiver amplifier is connected to the input of the second carrier frequency selection and gain adjustment module.

[0015] Optionally, the communication bus can be a proprietary protocol bus, a network bus, a CAN bus, or an RS485 bus.

[0016] Optionally, the line input module is used to send balanced or single-ended inputs directly to the line output module without any processing and to output balanced or single-ended inputs to the first analog-to-digital converter circuit after isolation by a small-signal transformer and buffer circuit.

[0017] Optionally, the line output module is used to connect the signal from the line input module to the normally closed terminal, connect the output signal of the digital-to-analog converter circuit to the normally open terminal, and output the two signals to the external power amplifier after switching between the two.

[0018] Optionally, the modulator is used to convert the modulated clock signal from the digital signal processor into a triangular wave and modulate the output signal of the error comparator into a pulse width modulated signal for output to the pulse width modulated input half-bridge output stage.

[0019] A second aspect of the present invention provides a broadcasting system comprising a parallel-connectable constant-voltage digital audio power amplifier as described in any of the first aspects, wherein the parallel-connectable constant-voltage digital audio power amplifier comprises at least two single-channel constant-voltage digital audio power amplifiers.

[0020] The line output module of the preamplifier that can be connected in parallel to the constant voltage digital audio power amplifier is connected to the line input module of the subsequent amplifier that can be connected in parallel to the constant voltage digital audio power amplifier. The amplifiers that can be connected in parallel to each other communicate with each other through a communication bus.

[0021] A third aspect of the present invention provides a broadcasting system comprising a parallel-connectable constant-voltage digital audio power amplifier as described in any of the first aspects, wherein the parallel-connectable constant-voltage digital audio power amplifier comprises at least one single-channel constant-voltage digital audio power amplifier and at least one multi-channel parallel-connectable constant-voltage digital audio power amplifier.

[0022] The line output module of the single-channel constant voltage digital audio power amplifier is connected to the line input module of one channel of the multi-channel constant voltage digital audio power amplifier that can be connected in parallel. Among the line output modules of the remaining channels of the multi-channel constant voltage digital audio power amplifier that can be connected in parallel, the line output module of the preamp channel is connected to the line input module of the amp channel. The constant voltage digital audio power amplifiers that can be connected in parallel communicate with each other through a communication bus.

[0023] A fourth aspect of the present invention provides a broadcasting system comprising a parallel-connectable constant-voltage digital audio power amplifier as described in any of the first aspects, wherein the parallel-connectable constant-voltage digital audio power amplifier comprises a multi-channel parallel-connectable constant-voltage digital audio power amplifier in at least two different host units.

[0024] The line output module of one channel of the preamplifier multi-channel parallel constant voltage digital audio power amplifier is connected to the line input module of one channel of the postamplifier multi-channel parallel constant voltage digital audio power amplifier. Among the line output modules of the remaining channels of the multi-channel parallel constant voltage digital audio power amplifier, the line output module of the preamplifier channel is connected to the line input module of the postamplifier channel. The channels communicate with each other through a communication bus.

[0025] The fifth aspect of the present invention provides a broadcasting system, including any of the parallel-connectable constant-voltage digital audio power amplifiers described in the first aspect, wherein the parallel-connectable constant-voltage digital audio power amplifiers include at least two multi-channel parallel-connectable constant-voltage digital audio power amplifiers within the same host.

[0026] In the multi-channel constant voltage digital audio power amplifier, the line output module of the preamplifier channel is connected to the line input module of the power amplifier channel, and the channels communicate with each other through a communication bus.

[0027] As can be seen from the above technical solutions, the parallel-connectable constant-voltage digital audio power amplifier provided by the present invention has the following advantages:

[0028] The parallel-connectable constant-voltage digital audio power amplifier provided by this invention includes a line input module, a line output module, a first analog-to-digital converter (ADC), a second ADC, a third ADC, a digital signal processor, a microcontroller, a digital-to-analog converter (DAC), an error comparator, a modulator, an integrator, a pulse-width modulation (PWM) input half-bridge output stage, a first carrier frequency selection and gain adjustment module, a second carrier frequency selection and gain adjustment module, a first LC filter and a high-frequency compensation network, a communication bus, and a power switch. This parallel-connectable constant-voltage digital audio power amplifier enables parallel connection of single-channel constant-voltage digital audio power amplifiers and multi-channel... This invention enables parallel connection of constant-voltage digital audio power amplifiers within the same host unit, parallel connection of a single-channel constant-voltage digital audio power amplifier with another multi-channel constant-voltage digital audio power amplifier, and parallel connection of a multi-channel constant-voltage digital audio power amplifier with another multi-channel constant-voltage digital audio power amplifier. It is not limited to parallel connection between different channels within the same power amplifier, thus solving the technical limitations of existing multi-channel parallel-connectable constant-voltage digital power amplifiers, which are limited to power amplifier channels within the same power amplifier and where the parallel connection method can only use the first channel as the master power amplifier and the others as slave power amplifiers. Attached Figure Description

[0029] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0030] Figure 1 This is a schematic diagram of a parallel-connected constant-voltage digital audio power amplifier provided in an embodiment of the present invention;

[0031] Figure 2 This is a schematic diagram of the parallel structure of a single-channel constant-voltage digital audio power amplifier provided in an embodiment of the present invention;

[0032] Figure 3 This is a schematic diagram of the parallel structure of the multi-channel parallel constant voltage digital audio power amplifier provided in the embodiments of the present invention within the same host;

[0033] Figure 4 This is a schematic diagram of the parallel connection between a single-channel constant-voltage digital audio power amplifier and another multi-channel constant-voltage digital audio power amplifier provided in an embodiment of the present invention.

[0034] Figure 5 This is a schematic diagram of the parallel connection of a multi-channel parallel-connectable constant-voltage digital audio power amplifier and another multi-channel parallel-connectable constant-voltage digital audio power amplifier provided in an embodiment of the present invention.

[0035] Figure 6 This is a schematic diagram of another parallel structure of a constant voltage digital audio power amplifier provided in an embodiment of the present invention. Detailed Implementation

[0036] To enable those skilled in the art to better understand the present invention, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0037] For easier understanding, please refer to Figure 1 This invention provides an embodiment of a parallel constant-voltage digital audio power amplifier, including a line input module, a line output module, a first analog-to-digital converter (ADC), a second ADC, a third ADC, a digital signal processor, a microcontroller, a digital-to-analog converter (DAC), an error comparator, a modulator, an integrator, a pulse width modulation input half-bridge output stage, a first carrier frequency selection and gain adjustment module, a second carrier frequency selection and gain adjustment module, a first LC filter and a high-frequency compensation network, a communication bus, and a power switch;

[0038] The line input module is connected to the first analog-to-digital converter (ADC) and the line output module, respectively. The line output module is connected to the digital-to-analog converter (DAC). The first ADC is connected to the digital signal processor (DSP). The DSP is connected to the second ADC, the third ADC, the DAC, and the microcontroller, respectively. The DAC is connected to the error comparator. The error comparator is connected to the integrator, the modulator, the first LC filter and the high-frequency compensation network, and the first carrier frequency selection and gain adjustment module, respectively. The modulator is connected to the microcontroller and the pulse width modulation (PWM) input half-bridge output stage, respectively. The PWM input half-bridge output stage is connected to the integrator and the first LC filter and the high-frequency compensation network, respectively. The first LC filter and the high-frequency compensation network are connected to the first carrier frequency selection and gain adjustment module, the second carrier frequency selection and gain adjustment module, and the power switch, respectively. The microcontroller is connected to the communication bus, the power switch, and the second carrier frequency selection and gain adjustment module, respectively. The first carrier frequency selection and gain adjustment module is connected to the second carrier frequency selection and gain adjustment module, the second ADC, and the third ADC, respectively.

[0039] It should be noted that the line input module sends the balanced or single-ended input directly to the line output without any processing. After isolation by a small-signal transformer, the balanced or single-ended input is buffered and then output to the first analog-to-digital converter circuit. The line output module connects the original audio source signal from the line input module to the normally closed terminal and the output signal from the analog-to-digital converter circuit to the normally open terminal. These two input signals are then switched between two and output to the next power amplifier, i.e., the external power amplifier.

[0040] The first analog-to-digital converter (ADC) circuit converts the signal output from the line input module into a digital signal, which is then output to the digital signal processor (DSP). The second ADC circuit converts the power output signal of the reference power amplifier (after gain adjustment by the first carrier frequency selection and gain adjustment module) into a digital signal, which is then output to the DSP as a reference signal for audio phase detection. The third ADC circuit converts the power output signal of the local power amplifier (after gain adjustment) into a digital signal, which is then output to the DSP as a correction signal for audio phase detection.

[0041] The digital signal processor (DSP) performs gain adjustment, phase adjustment, EQ adjustment, compression and limiting, and volume adjustment on the input digital audio signal, and then outputs it to the digital-to-analog converter (DAC). During the power-on parallel mode process, the reference amplifier (such as...) Figure 1 The digital signal processor of the power amplifier 1) outputs a 1kHz signal with a continuous on / off cycle of 1 second according to the instructions of the microcontroller. The line output module also simultaneously outputs this signal to the non-reference power amplifier (such as...) Figure 1 In the power amplifier 2, the power switch of power amplifier 2 remains off. The digital signal processor compares the phase of the audio phase detection reference signal and the signal to be corrected, adjusting the phase of the signal to be corrected to be consistent with the reference signal within a certain error range. Based on the parameters of the microcontroller, the digital signal processor outputs a modulator clock signal with a specific frequency and phase to the modulator, and works with the microcontroller to adjust the frequency and phase of the local modulator clock based on the carrier frequency and phase of the reference power amplifier, ensuring that the carrier frequency and phase of the local power amplifier are consistent with the reference amplifier within a certain error range.

[0042] The digital-to-analog converter circuit converts the digital signal output by the digital signal processor into an analog signal, with one output to the line output module and the other output to the error comparator.

[0043] The error comparator performs error correction on the voltage feedback from the first carrier frequency selection and gain adjustment module, the integrated pulse signal, and the analog signal from the digital-to-analog converter circuit to reduce distortion and determine the power amplifier gain. The error comparator also performs error correction on the output current feedback from the first LC filter and high-frequency compensation network, comparing it with the analog signal output from the digital signal processor. This determines the maximum output current of the power amplifier, ensuring that when power amplifiers are connected in parallel, the maximum output current of each amplifier will not exceed its own maximum output current, thus preventing abnormal protection or damage.

[0044] The integrating circuit integrates the high-frequency pulses from the power transistor and feeds them back to the error comparator to reduce distortion.

[0045] The modulator converts the modulated clock signal from the digital signal processor into a triangular wave, and then modulates the audio signal from the error comparator into a pulse width modulated signal.

[0046] The pulse width modulation input half-bridge output stage converts the pulse width modulation signal into drive signals for the upper and lower power transistors after dead-time control, driving the half-bridge output pulse width modulation power signal.

[0047] The first LC filter and the high-frequency compensation network filter the pulse width modulated power signal to obtain the power signal.

[0048] The power switch receives different logic from the microcontroller during the parallel connection establishment phase and after successful establishment, and controls the power signal output to turn on and off.

[0049] The gain adjustment section of the first carrier frequency selection and gain adjustment module and the second carrier frequency selection and gain adjustment module are used to attenuate the feedback signal to a suitable level. The carrier frequency selection section is used to filter the carrier from the power signal of the reference power amplifier, attenuate it to a suitable level, and send it to the microcontroller for phase and frequency measurement, as well as to adjust the phase and frequency of its own power amplifier.

[0050] The communication bus is responsible for communication between the reference power amplifier and other power amplifiers. The communication bus can be a proprietary protocol bus, a network bus, a CAN bus, or an RS485 bus.

[0051] The microcontroller determines the reference power amplifier and other power amplifiers through different settings, and establishes the parallel connection process of the power amplifiers through the communication bus, coordinating all power amplifiers to establish parallel connection. The establishment process is as follows: The reference power amplifier is powered on for x seconds (if there is a sequencer, this time needs to be longer than the power amplifier's last power amplifier power-on time). If no normal power amplifier is detected on the communication bus after all power amplifiers are powered on, power amplifier 2 is automatically set as the reference power amplifier, and so on until a normal reference power amplifier appears; the reference power amplifier turns on its power switch and outputs a 1kHz signal with a continuous on and off cycle of 1 second. The line output module also simultaneously cascades and outputs this signal to the non-reference power amplifiers, while the non-reference power amplifiers keep their power switches off; the non-reference power amplifiers are controlled by their respective digital signal processors to continuously power on and off the reference power amplifier. In the off state, a 1kHz signal with a 1-second period is detected. In the on state, the phase and gain of the 1kHz signal are detected, and the phase and gain of the input 1kHz signal are adjusted to match those of the reference power amplifier. In the off state, each microcontroller detects the phase and frequency of the carrier wave and adjusts the phase and frequency of the modulation clock signal to match those of the reference power amplifier. After all non-reference power amplifiers complete the above adjustments, they notify the reference power amplifier via the bus. The reference power amplifier then turns off the test signal, restoring the signal source to the connection of all power amplifiers. Then, the communication bus informs the other power amplifiers, and which of the other power amplifiers turns on its power switch to achieve parallel output of the power amplifiers.

[0052] The microcontroller uses the phase and frequency of the reference power amplifier to adjust the frequency and phase of the modulator clock signal of the digital signal processor to match the reference power amplifier; the microcontroller controls the digital signal processor to adjust the volume, EQ, compression, gain and phase of the input signal.

[0053] like Figure 2 As shown, the parallel-connectable constant-voltage digital audio power amplifier provided in this embodiment of the invention can realize the parallel connection of single-channel constant-voltage digital audio power amplifiers. When connected in parallel, the audio source is connected to the input terminal of the line input module of the reference power amplifier (power amplifier 1), the power switch of the reference power amplifier is connected to the input terminal of the constant-voltage speaker, the line output module of the reference power amplifier is connected to the line input module of the non-reference power amplifier 2, the power switch of the non-reference power amplifier is connected to the constant-voltage speaker, the line output module of the non-reference power amplifier 2 is connected to the line input module of the non-reference power amplifier 3, and so on up to the non-reference power amplifier N.

[0054] like Figure 3 As shown, the parallel-connectable constant-voltage digital audio power amplifier provided in this embodiment of the invention can realize the parallel connection of multiple channels of parallel-connectable constant-voltage digital audio power amplifiers within the same host. In parallel connection, the line input module of channel 1 of the multi-channel power amplifier 1 is connected to the audio source, the line output module of channel 1 is connected to the line input module of channel 2, and the power switches of channel 1 and channel 2 are respectively connected to constant-voltage speakers.

[0055] like Figure 4As shown, the parallel-connectable constant-voltage digital audio power amplifier provided in this embodiment of the invention can realize the parallel connection of a single-channel constant-voltage digital audio power amplifier with another multi-channel parallel-connectable constant-voltage digital audio power amplifier. In parallel connection, the line output module of the single-channel constant-voltage digital audio power amplifier is connected to the line input module of channel 1 (reference power amplifier channel) of the other multi-channel parallel-connectable constant-voltage digital audio power amplifier. The power switch of channel 1 is connected to a constant-voltage speaker. The remaining channels of the other multi-channel parallel-connectable constant-voltage digital audio power amplifier are similarly connected through line output modules. The power switches of all channels of the other multi-channel parallel-connectable constant-voltage digital audio power amplifier are respectively connected to constant-voltage speakers.

[0056] like Figure 5 As shown, the parallel-connectable constant-voltage digital audio power amplifier provided in this embodiment of the invention can realize the parallel connection of a multi-channel parallel-connectable constant-voltage digital audio power amplifier with another multi-channel parallel-connectable constant-voltage digital audio power amplifier. In parallel connection, the audio source is connected to the line input module of channel 1 (reference amplifier channel) of one multi-channel parallel-connectable constant-voltage digital audio power amplifier. The power switch of channel 1 is connected to the constant-voltage speaker. The remaining channels of one multi-channel parallel-connectable constant-voltage digital audio power amplifier are similarly connected through line output modules. The line output module of one non-reference amplifier channel of one multi-channel parallel-connectable constant-voltage digital audio power amplifier is connected to the line input module of channel 1 (reference amplifier channel) of another multi-channel parallel-connectable constant-voltage digital audio power amplifier. The remaining channels of the other multi-channel parallel-connectable constant-voltage digital audio power amplifier are similarly connected through line output modules.

[0057] The parallel-connectable constant-voltage digital audio power amplifier provided by this invention includes a line input module, a line output module, a first analog-to-digital converter (ADC), a second ADC, a third ADC, a digital signal processor, a microcontroller, a digital-to-analog converter (DAC), an error comparator, a modulator, an integrator, a pulse-width modulation (PWM) input half-bridge output stage, a first carrier frequency selection and gain adjustment module, a second carrier frequency selection and gain adjustment module, a first LC filter and a high-frequency compensation network, a communication bus, and a power switch. This parallel-connectable constant-voltage digital audio power amplifier enables parallel connection of single-channel constant-voltage digital audio power amplifiers and multi-channel... This invention enables parallel connection of constant-voltage digital audio power amplifiers within the same host unit, parallel connection of a single-channel constant-voltage digital audio power amplifier with another multi-channel constant-voltage digital audio power amplifier, and parallel connection of a multi-channel constant-voltage digital audio power amplifier with another multi-channel constant-voltage digital audio power amplifier. It is not limited to parallel connection between different channels within the same power amplifier, thus solving the technical limitations of existing multi-channel parallel-connectable constant-voltage digital power amplifiers, which are limited to power amplifier channels within the same power amplifier and where the parallel connection method can only use the first channel as the master power amplifier and the others as slave power amplifiers.

[0058] In one embodiment, such as Figure 6 As shown, the parallel constant voltage digital audio power amplifier provided by the present invention further includes an inverting pulse width modulation input half-bridge output stage, a second LC filter and a high-frequency compensation network, a first differential receiver amplifier, a second differential receiver amplifier, a third differential receiver amplifier, a fourth differential receiver amplifier, a fifth differential receiver amplifier and a sixth differential receiver amplifier.

[0059] The inverting pulse width modulation input half-bridge output stage is connected to the modulator and the second LC filter and the high-frequency compensation network, respectively. The second LC filter and the high-frequency compensation network are connected to the power switch.

[0060] The non-inverting input of the first differential receiver amplifier is connected to the output of the pulse width modulation input half-bridge output stage, the inverting input of the first differential receiver amplifier is connected to the output of the inverting pulse width modulation input half-bridge output stage, and the output of the first differential receiver amplifier is connected to the integrating circuit.

[0061] The non-inverting input of the second differential receiver amplifier is connected to the output of the first LC filter and the high-frequency compensation network, the inverting input of the second differential receiver amplifier is connected to the output of the second LC filter and the high-frequency compensation network, and the output of the second differential receiver amplifier is connected to the error comparator.

[0062] The non-inverting input of the third differential receiver amplifier is connected to the output of the first LC filter and high-frequency compensation network, the inverting input of the third differential receiver amplifier is connected to the output of the second LC filter and high-frequency compensation network, and the output of the third differential receiver amplifier is connected to the input of the first carrier frequency selection and gain adjustment module.

[0063] The non-inverting input of the fourth differential receiver amplifier is connected to the output of the first LC filter and high-frequency compensation network, the inverting input of the fourth differential receiver amplifier is connected to the output of the second LC filter and high-frequency compensation network, and the output of the fourth differential receiver amplifier is connected to the input of the first carrier frequency selection and gain adjustment module.

[0064] The non-inverting input of the fifth differential receiver amplifier is connected to the first output of the power switch, the inverting input of the fifth differential receiver amplifier is connected to the second output of the power switch, and the output of the fifth differential receiver amplifier is connected to the input of the first carrier frequency selection and gain adjustment module.

[0065] The non-inverting input of the sixth differential receiver amplifier is connected to the first output of the power switch, the inverting input of the sixth differential receiver amplifier is connected to the second output of the power switch, and the output of the sixth differential receiver amplifier is connected to the input of the second carrier frequency selection and gain adjustment module.

[0066] It should be noted that the parallel-connectable constant-voltage digital audio power amplifier provided by this invention can be applied not only to... Figure 1 The half-bridge power architecture shown can also be applied to a full-bridge power architecture. For example... Figure 6 As shown, in Figure 1 Based on the half-bridge architecture, an inverting half-bridge output is added to form a bridged output connected in parallel with other power amplifiers to drive a constant-voltage speaker. Voltage feedback, current feedback, integrating circuit, audio phase detection, and carrier phase frequency detection all require the addition of differential receiving amplifiers to convert the signals into single-ended signals. The flow of other control and signal processing logic is similar to... Figure 1 The half-bridge structure shown is the same.

[0067] For easier understanding, please refer to Figure 2 The present invention provides a broadcasting system, which includes any of the parallel constant voltage digital audio power amplifiers provided in the embodiments of the present invention, wherein the parallel constant voltage digital audio power amplifiers include at least two single-channel constant voltage digital audio power amplifiers.

[0068] The line output module of the preamplifier that can be connected in parallel to the constant voltage digital audio power amplifier is connected to the line input module of the subsequent amplifier that can be connected in parallel to the constant voltage digital audio power amplifier. The amplifiers that can be connected in parallel to each other communicate with each other through a communication bus.

[0069] For easier understanding, please refer to Figure 4 The present invention provides a broadcasting system, which includes any of the parallel-connectable constant voltage digital audio power amplifiers provided in the embodiments of the present invention. The parallel-connectable constant voltage digital audio power amplifiers include at least one single-channel constant voltage digital audio power amplifier and at least one multi-channel parallel-connectable constant voltage digital audio power amplifier.

[0070] The line output module of the single-channel constant voltage digital audio power amplifier is connected to the line input module of one channel of the multi-channel constant voltage digital audio power amplifier that can be connected in parallel. Among the line output modules of the remaining channels of the multi-channel constant voltage digital audio power amplifier that can be connected in parallel, the line output module of the preamp channel is connected to the line input module of the amp channel. The constant voltage digital audio power amplifiers that can be connected in parallel communicate with each other through a communication bus.

[0071] For easier understanding, please refer to Figure 5 The present invention provides a broadcasting system, which includes any of the parallel-connectable constant voltage digital audio power amplifiers provided in the embodiments of the present invention, wherein the parallel-connectable constant voltage digital audio power amplifiers include multi-channel parallel-connectable constant voltage digital audio power amplifiers in at least two different hosts;

[0072] The line output module of one channel of the preamplifier multi-channel parallel constant voltage digital audio power amplifier is connected to the line input module of one channel of the postamplifier multi-channel parallel constant voltage digital audio power amplifier. Among the line output modules of the remaining channels of the multi-channel parallel constant voltage digital audio power amplifier, the line output module of the preamplifier channel is connected to the line input module of the postamplifier channel. The channels communicate with each other through a communication bus.

[0073] For easier understanding, please refer to Figure 3 The present invention provides a broadcasting system, which includes any of the parallel-connectable constant voltage digital audio power amplifiers provided in the embodiments of the present invention, wherein the parallel-connectable constant voltage digital audio power amplifiers include at least two multi-channel parallel-connectable constant voltage digital audio power amplifiers in the same host.

[0074] In the multi-channel constant voltage digital audio power amplifier, the line output module of the preamplifier channel is connected to the line input module of the power amplifier channel, and the channels communicate with each other through a communication bus.

[0075] The broadcasting system provided in this invention includes any of the parallel-connectable constant-voltage digital audio power amplifiers in the embodiments of this invention, and can achieve the same technical effects as the parallel-connectable constant-voltage digital audio power amplifiers provided in this invention, which will not be described in detail here.

[0076] The above-described embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit it. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A parallelable constant-voltage digital audio power amplifier, characterized by comprising: The circuit comprises a line input module, a line output module, a first analog-digital conversion circuit, a second analog-digital conversion circuit, a third analog-digital conversion circuit, a digital signal processor, a single-chip microcomputer, an analog-digital conversion circuit, an error comparator, a modulator, an integration circuit, a pulse width modulation input half-bridge output stage, a first carrier frequency selection and gain adjustment module, a second carrier frequency selection and gain adjustment module, a first LC filter and high-frequency compensation network, a communication bus and a power switch; The line input module is connected with the first analog-digital conversion circuit and the line output module, the line output module is connected with the analog-digital conversion circuit, the first analog-digital conversion circuit is connected with the digital signal processor, the digital signal processor is connected with the second analog-digital conversion circuit, the third analog-digital conversion circuit, the analog-digital conversion circuit and the single-chip microcomputer, the analog-digital conversion circuit is connected with the error comparator, the error comparator is connected with the integration circuit, the modulator, the first LC filter and high-frequency compensation network and the first carrier frequency selection and gain adjustment module, the modulator is connected with the single-chip microcomputer and the pulse width modulation input half-bridge output stage, the pulse width modulation input half-bridge output stage is connected with the integration circuit and the first LC filter and high-frequency compensation network, the first LC filter and high-frequency compensation network is connected with the first carrier frequency selection and gain adjustment module, the second carrier frequency selection and gain adjustment module and the power switch, the single-chip microcomputer is connected with the communication bus, the power switch and the second carrier frequency selection and gain adjustment module, and the first carrier frequency selection and gain adjustment module is connected with the second carrier frequency selection and gain adjustment module, the second analog-digital conversion circuit and the third analog-digital conversion circuit.

2. The parallelable constant-voltage digital audio power amplifier according to claim 1, wherein, The circuit further comprises an inverse pulse width modulation input half-bridge output stage, a second LC filter and high-frequency compensation network, a first differential receiving amplifier, a second differential receiving amplifier, a third differential receiving amplifier, a fourth differential receiving amplifier, a fifth differential receiving amplifier and a sixth differential receiving amplifier; The inverse pulse width modulation input half-bridge output stage is connected with the modulator and the second LC filter and high-frequency compensation network, and the second LC filter and high-frequency compensation network is connected with the power switch. The non-inverting input end of the first differential receiving amplifier is connected with the output end of the pulse width modulation input half-bridge output stage, the inverting input end of the first differential receiving amplifier is connected with the output end of the inverse pulse width modulation input half-bridge output stage, and the output end of the first differential receiving amplifier is connected with the integration circuit. The non-inverting input end of the second differential receiving amplifier is connected with the output end of the first LC filter and high-frequency compensation network, the inverting input end of the second differential receiving amplifier is connected with the output end of the second LC filter and high-frequency compensation network, and the output end of the second differential receiving amplifier is connected with the error comparator. The non-inverting input end of the third differential receiving amplifier is connected with the output end of the first LC filter and high-frequency compensation network, the inverting input end of the third differential receiving amplifier is connected with the output end of the second LC filter and high-frequency compensation network, and the output end of the third differential receiving amplifier is connected with the input end of the first carrier frequency selection and gain adjustment module. The non-inverting input terminal of the fourth differential receiving amplifier is connected with the output terminal of the first LC filter and high frequency compensation network, the inverting input terminal of the fourth differential receiving amplifier is connected with the output terminal of the second LC filter and high frequency compensation network, and the output terminal of the fourth differential receiving amplifier is connected with the input terminal of the first carrier frequency selection and gain adjustment module; The non-inverting input terminal of the fifth differential receiving amplifier is connected with the first output terminal of the power switch, the inverting input terminal of the fifth differential receiving amplifier is connected with the second output terminal of the power switch, and the output terminal of the fifth differential receiving amplifier is connected with the input terminal of the first carrier frequency selection and gain adjustment module; The non-inverting input terminal of the sixth differential receiving amplifier is connected with the first output terminal of the power switch, the inverting input terminal of the sixth differential receiving amplifier is connected with the second output terminal of the power switch, and the output terminal of the sixth differential receiving amplifier is connected with the input terminal of the second carrier frequency selection and gain adjustment module.

3. The parallelable constant-voltage digital audio power amplifier according to claim 1, wherein The communication bus is a private protocol bus, a network bus, a CAN bus or an RS485 bus.

4. The parallelable constant-voltage digital audio power amplifier according to claim 1, wherein The line input module is used for directly sending balanced or single-ended input to the line output module without any processing, and is used for outputting balanced or single-ended input to the first analog-digital conversion circuit through a buffer circuit after isolation by a small signal transformer.

5. The parallelable constant-voltage digital audio power amplifier according to claim 1, wherein The line output module is used for connecting the signal from the line input module to a normally closed terminal, connecting the output signal of the digital-analog conversion circuit to a normally open terminal, and outputting the two signals to an external power amplifier through a two-select switch.

6. The parallelable constant-voltage digital audio power amplifier according to claim 1, wherein The modulator is used for converting the modulation clock signal from the digital signal processor into a triangular wave, and modulating the output signal of the error comparator into a pulse width modulation signal output to the pulse width modulation input half-bridge output stage.

7. A broadcast system characterized by comprising: The parallelable constant-voltage digital audio power amplifier comprises at least two single-channel constant-voltage digital audio power amplifiers. The line output module of the front-stage parallelable constant-voltage digital audio power amplifier is connected with the line input module of the rear-stage parallelable constant-voltage digital audio power amplifier, and the parallelable constant-voltage digital audio power amplifiers are connected through the communication bus for communication.

8. A broadcast system characterized by comprising: The parallelable constant-voltage digital audio power amplifier comprises at least one single-channel constant-voltage digital audio power amplifier and at least one multi-channel parallelable constant-voltage digital audio power amplifier. The line output module of the single-channel constant-voltage digital audio power amplifier is connected with the line input module of one channel of the multi-channel parallelable constant-voltage digital audio power amplifier, the line output modules of the remaining channels of the multi-channel parallelable constant-voltage digital audio power amplifier are connected, the line output module of the front-stage channel is connected with the line input module of the rear-stage channel, and the parallelable constant-voltage digital audio power amplifiers are connected through the communication bus for communication.

9. A broadcast system, characterized by The parallelable constant-voltage digital audio power amplifier comprises at least two multi-channel parallelable constant-voltage digital audio power amplifiers in different host computers. The line output module of one channel of the front-stage multi-channel parallel-connection constant-voltage digital audio power amplifier is connected with the line input module of one channel of the rear-stage multi-channel parallel-connection constant-voltage digital audio power amplifier, and the line output module of the front-stage channel is connected with the line input module of the rear-stage channel among the line output modules of the remaining channels of the multi-channel parallel-connection constant-voltage digital audio power amplifier, and the channels are connected through a communication bus for communication.

10. A broadcast system characterized by comprising: The parallel-connection constant-voltage digital audio power amplifier comprises at least two multi-channel parallel-connection constant-voltage digital audio power amplifiers in the same host. The line output module of one channel of the front-stage multi-channel parallel-connection constant-voltage digital audio power amplifier is connected with the line input module of one channel of the rear-stage multi-channel parallel-connection constant-voltage digital audio power amplifier, and the line output module of the front-stage channel is connected with the line input module of the rear-stage channel among the line output modules of the remaining channels of the multi-channel parallel-connection constant-voltage digital audio power amplifier, and the channels are connected through a communication bus for communication.

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