Audio power amplifier device and loudspeaker

Abstract

The invention provides an audio power amplifier device and a loudspeaker, and relates to the technical field of power amplifiers, the audio power amplifier device comprises an audio power amplifier, and a current detection circuit is used for detecting a power tube current of the audio power amplifier and outputting a corresponding current detection signal; the temperature detection circuit is used for detecting the temperature of a power tube of the audio power amplifier and outputting a corresponding temperature detection signal; the control circuit is connected with the controlled end of the audio power amplifier; the control circuit is used for determining a current threshold value according to the temperature detection signal; the control circuit is also used for controlling the working state of the audio power amplifier according to the current threshold and the current detection signal; the change trend of the temperature and the current threshold of the power tube is that the lower the temperature of the power tube is, the larger the current threshold is. According to the invention, the output current range of the power amplifier can be dynamically adjusted, so that better tone quality experience is realized.

Description

Technical Field

[0001] The present application relates to the technical field of power amplifiers, and in particular to an audio power amplifier device and a loudspeaker. Background Art

[0002] The current protection mechanism of the existing Class D audio amplifier (digital amplifier) ​​will trigger protection when it recognizes a music signal with large dynamic low-frequency components, causing the audio output to be paused or the sound quality to be reduced. Summary of the invention

[0003] The main purpose of the present invention is to provide an audio power amplifier device, aiming to dynamically adjust the output current range of the power amplifier, thereby achieving a better sound quality experience.

[0004] To achieve the above object, the present invention provides an audio power amplifier device, the audio power amplifier device comprising an audio power amplifier, the audio power amplifier device further comprising: A current detection circuit, the current detection circuit is used to detect the power tube current of the audio power amplifier and output a corresponding current detection signal; A temperature detection circuit, the temperature detection circuit is used to detect the temperature of the power tube of the audio power amplifier and output a corresponding temperature detection signal; A control circuit, the control circuit being connected to a controlled end of the audio power amplifier; the control circuit being used to determine a current threshold value according to the temperature detection signal; The control circuit is also used to control the working state of the audio power amplifier according to the current threshold and the current detection signal; wherein the change trend of the power tube temperature and the current threshold is: the lower the power tube temperature, the larger the current threshold.

[0005] Optionally, the control circuit is used to match the current threshold and the current detection signal. If the current detection signal is greater than or equal to the current threshold, the audio power amplifier is controlled to be shut down; if the current detection signal is less than the current threshold, the audio power amplifier is controlled to operate normally.

[0006] Optionally, the current detection circuit includes: A first resistor, the first resistor is connected in series with a power tube of the audio power amplifier; A first operational amplifier, wherein a first input terminal of the first operational amplifier is connected to a first terminal of the first resistor, a second input terminal of the first operational amplifier is connected to a second terminal of the first resistor, and an output terminal of the first operational amplifier outputs a current detection signal.

[0007] Optionally, the temperature detection circuit includes: A temperature sensor, wherein the temperature sensor is arranged close to a power tube of the audio power amplifier; A second operational amplifier, wherein a first input terminal of the second operational amplifier is connected to a first terminal of the temperature sensor, a second input terminal of the second operational amplifier is connected to a second terminal of the temperature sensor, and an output terminal of the second operational amplifier outputs a corresponding temperature detection signal.

[0008] Optionally, the control circuit includes: A controller, wherein an input end of the controller is connected to an output end of the temperature detection circuit; A comparison circuit, wherein a first input terminal of the comparison circuit is connected to an output terminal of the current detection circuit, a second input terminal of the comparison circuit is connected to an output terminal of the controller, and the comparison circuit is used to control the working state of the audio power amplifier according to the current threshold and the current detection signal.

[0009] Optionally, the comparison circuit comprises: A comparator, a third resistor is connected in series between the non-phase terminal of the comparator and the output terminal of the current detection circuit, and a fourth resistor is connected in series between the inverting terminal of the comparator and the output terminal of the controller.

[0010] Optionally, the audio power amplifier device comprises: A signal conditioning circuit, wherein the input end of the signal conditioning circuit is connected to the output end of the current detection circuit, the output end of the signal conditioning circuit is connected to the input end of the control circuit, and the signal conditioning circuit is used to filter out the peak noise part of the power tube current.

[0011] Optionally, the signal conditioning circuit includes: a third operational amplifier, wherein a non-inverting terminal of the third operational amplifier is grounded, and a second resistor is connected in series between an inverting terminal of the third operational amplifier and an output terminal of the current detection circuit; A first capacitor, wherein a first end of the first capacitor is connected to an inverting end of the third operational amplifier, and a second end of the first capacitor is connected to an output end of the third operational amplifier.

[0012] Optionally, the control circuit subtracts the power tube temperature from the maximum allowable junction temperature of the power tube to obtain a corresponding temperature difference, and determines the current threshold according to the temperature difference and a preset current-temperature coefficient.

[0013] In addition, to achieve the above-mentioned purpose, the present invention also provides a speaker, which includes the audio power amplifier device as described above.

[0014] The embodiment of the present invention is provided with a current detection circuit to detect the power tube current of the audio power amplifier and output a corresponding current detection signal, and then provided with a temperature detection circuit to detect the power tube temperature of the audio power amplifier and output a corresponding temperature detection signal. Finally, a control circuit is provided to be connected to the controlled end of the audio power amplifier, and the current threshold is determined according to the temperature detection signal. The working state of the audio power amplifier can be controlled according to the current threshold and the current detection signal to dynamically adjust the output current range of the power amplifier, maximize the dynamic power output range of the power amplifier, and achieve a better sound quality experience. Among them, since a Class D audio amplifier will have short-term large dynamic low-frequency signals when playing music, and these signals usually do not cause abnormal temperature rise of the power tube, and will not damage the power tube, the power tube temperature and current thresholds can be set to the lower the power tube temperature, the larger the current threshold. When a short-term large dynamic low-frequency signal appears, the power tube will not have a large temperature rise and will be allowed to pass the overload, thereby achieving higher output power when the power tube temperature is low, effectively avoiding the false triggering of the protection mechanism resulting in pause of audio output or reduction of sound quality. When the large current signal flowing through the power tube is long-term, the current threshold can be reduced in time to avoid excessive temperature rise caused by long-term overcurrent, which may cause overheating and damage of the power tube, thereby improving the stability and reliability of the entire audio amplifier device. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the present application and, together with the description, serve to explain the principles of the present application.

[0016] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0017] Figure 1 is a circuit structure block diagram of an audio power amplifier device according to an embodiment of the present invention; Figure 2 is a circuit structure block diagram of an audio power amplifier device according to another embodiment of the present invention; Figure 3 for Figure 2 A circuit diagram of an audio power amplifier device; Figure 4 A circuit structure block diagram of an audio power amplifier device according to another embodiment of the present invention; Figure 5 for Figure 4 Circuit diagram of an audio power amplifier device.

[0018] Description of Figure Numbers:

[0019] The realization of the purpose, functional features and advantages of the present invention will be further explained in conjunction with embodiments and with reference to the accompanying drawings. DETAILED DESCRIPTION

[0020] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments, and the well-known modules, units and their connections, links, communications or operations are not shown or described in detail. In addition, the described features, architectures or functions can be combined in any way in one or more embodiments. It should be understood by those skilled in the art that the various embodiments described below are only for illustration and not for limiting the scope of protection of the present invention. It can also be easily understood that the modules or units or processing methods in the various embodiments described herein and shown in the drawings can be combined and designed according to various different configurations. Based on the embodiments in the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0021] The limitations of various nouns or methods referred to in the following embodiments, except for those that are logically untenable, are generally based on the broad concepts that can be implemented under the premise of the disclosure in the embodiments. Under such understanding, the various specific subordinate specific limitations of the nouns or methods should be regarded as the inventive content of the present invention, and should not be understood narrowly or interpreted in a biased manner on the grounds that the specification does not disclose the specific limitations. Similarly, under the premise that it can be implemented logically, the order of the steps in the method is flexible and changeable, and the specific subordinate specific limitations in the broad concepts of various nouns or methods all fall within the scope of protection of the present invention.

[0022] The main solution of the embodiment of the present application is: by providing a current detection circuit to detect the power tube current of the audio power amplifier and output a corresponding current detection signal, then providing a temperature detection circuit to detect the power tube temperature of the audio power amplifier and output a corresponding temperature detection signal, and finally providing a control circuit connected to the controlled end of the audio power amplifier, and determining the current threshold according to the temperature detection signal, and being able to control the working state of the audio power amplifier according to the current threshold and the current detection signal.

[0023] Because the current protection mechanism of the Class D audio amplifier (digital amplifier) ​​in the prior art will trigger the protection when it identifies a music signal with a large dynamic low-frequency component, resulting in the suspension of audio output or the reduction of sound quality.

[0024] This application provides a solution to dynamically adjust the output current range of the power amplifier to achieve a better sound quality experience.

[0025] It should be understood that when a Class D audio amplifier plays music, there will be short-term large dynamic low-frequency signals, and these signals usually do not cause abnormal temperature rise of the power tube, and will not damage the power tube. Therefore, the power tube temperature and current thresholds can be set to the lower the power tube temperature, the larger the current threshold. When a short-term large dynamic low-frequency signal appears, the power tube will not have a large temperature rise and will be allowed to pass the overload, thereby achieving higher output power when the power tube temperature is low, effectively avoiding the false triggering of the protection mechanism, resulting in the suspension of audio output or the reduction of sound quality. When the large current signal flowing through the power tube is long-term, the current threshold can be reduced in time to avoid excessive temperature rise caused by long-term overcurrent, which may cause overheating and damage to the power tube, thereby improving the stability and reliability of the entire audio amplifier device.

[0026] It should be understood that the audio power amplification device includes an audio power amplifier.

[0027] Reference Figure 1 In one embodiment of the present invention, the audio power amplifier device includes a current detection circuit 10, a temperature detection circuit 20 and a control circuit 30, wherein: The current detection circuit 10 is used to detect the power tube current of the audio power amplifier and output a corresponding current detection signal; the temperature detection circuit 20 is used to detect the power tube temperature of the audio power amplifier and output a corresponding temperature detection signal; the control circuit 30 is connected to the controlled end of the audio power amplifier; the control circuit 30 is used to determine the current threshold according to the temperature detection signal; the control circuit 30 is also used to control the working state of the audio power amplifier according to the current threshold and the current detection signal; wherein, the change trend of the power tube temperature and the current threshold is: the lower the power tube temperature, the larger the current threshold.

[0028] In this embodiment, the current detection circuit 10 can be a Hall effect sensor, a resistor sampling circuit, a resistor divider or other current sensing device. The temperature detection circuit 20 can be a thermistor, a thermocouple or other temperature sensing device. The control circuit 30 can be implemented by a main controller, such as an MCU (Micro controller Unit), a DSP (Digital Signal Process), an FPGA (Field Programmable Gate Array), a SOC (System On Chip), etc.

[0029] Through the coordinated work of the current detection circuit 10, the temperature detection circuit 20 and the control circuit 30, the current detection circuit 10 mainly continuously detects the power tube current of the audio power amplifier, while the temperature detection circuit 20 is the basis for setting the current threshold, and the control circuit 30 is responsible for determining the current threshold based on the temperature detection signal output by the temperature detection circuit 20, and adjusting the working state of the audio power amplifier according to the determined current threshold. When the temperature of the power tube is low, the current threshold can be set to a higher value to avoid the short-term appearance of a large dynamic low-frequency signal causing the suspension of audio output or the reduction of sound quality, and when the temperature of the power tube is high, the current threshold needs to be set to a lower threshold to prevent the power tube from being damaged by overheating due to long-term overcurrent and abnormal temperature rise. The audio power amplifier can dynamically adjust its output according to the real-time temperature and current conditions, thereby providing a wider dynamic range and better sound quality without damaging the power transistor.

[0030] The control circuit 30 can pre-set a reference temperature threshold. When the detected power tube temperature is lower than the reference temperature, the current threshold will be increased accordingly, allowing the audio power amplifier to output a larger current within a safe range to cope with large dynamic low-frequency signals. On the contrary, if the power tube temperature rises, the control circuit 30 will lower the current threshold to avoid overheating of the power transistor and ensure stable operation of the device.

[0031] Optionally, the control circuit 30 is used to match the current threshold and the current detection signal. If the current detection signal is greater than or equal to the current threshold, the audio power amplifier is controlled to be turned off. If the current detection signal is less than the current threshold, the audio power amplifier is controlled to operate normally.

[0032] In this embodiment, after the control circuit 30 sets the current threshold according to the temperature detection signal, the control circuit 30 may need to dynamically adjust the output power of the audio power amplifier; first, the current detection signal is compared with the current threshold determined by the control circuit 30 to determine whether to trigger protection and output a control signal to the audio power amplifier. When the current detection signal is less than the current threshold, it means that the power transistor is operating within a safe operating range and the power amplifier is operating normally. At this time, the audio power amplifier is controlled to operate normally; when the current detection signal is greater than or equal to the current threshold, it means that the power transistor is at risk of damage. At this time, the protection should be triggered and a control signal should be output to the audio power amplifier to cut off the output of the audio power amplifier to protect the power amplifier from over-temperature and over-current damage.

[0033] Optionally, the control circuit 30 subtracts the power tube temperature from the maximum allowable junction temperature of the power tube to obtain a corresponding temperature difference, and determines the current threshold according to the temperature difference and a preset current-temperature coefficient.

[0034] In this embodiment, in order to more accurately determine the current threshold, it is necessary to determine the maximum allowable junction temperature of the power tube. This value can be determined according to the data sheet of the power tube of the audio power amplifier, and the maximum allowable junction temperature of the power tube is subtracted from the temperature detection signal output by the temperature detection circuit 20 to obtain a temperature difference. Then, based on the temperature difference, a conversion coefficient is multiplied to accurately and reliably determine the current threshold. The calculation formula of the current threshold is as follows: ; in, is the maximum allowable junction temperature of the power tube, k is the current-temperature coefficient, T It is the current power tube temperature.

[0035] Optionally, refer to Figure 3 Another embodiment of the present invention provides an audio power amplifier device, based on the above Figure 1 In the illustrated embodiment, the current detection circuit 10 includes a first resistor R1 and a first operational amplifier U1, wherein: The first resistor R1 is connected in series with the power tube of the audio power amplifier; the first input end of the first operational amplifier U1 is connected to the first end of the first resistor R1, the second input end of the first operational amplifier U1 is connected to the second end of the first resistor R1, and the output end of the first operational amplifier U1 outputs a current detection signal.

[0036] In this embodiment, the current detection signal is generated by amplifying the voltage difference between the two ends of the first resistor R1 by the first operational amplifier U1. Since a voltage drop is generated when the power tube current flows through the first resistor R1, and this voltage drop is proportional to the current flowing through, the output end of the first operational amplifier U1 can output a current detection signal proportional to the power tube current.

[0037] In order to ensure the accuracy and stability of the current detection signal, the first operational amplifier U1 can use a high-precision, low-drift amplifier chip. In addition, in order to reduce the impact of external interference on the current detection signal, the current detection circuit 10 can also include a filter circuit for filtering out high-frequency noise to ensure the purity of the current detection signal.

[0038] The first resistor R1 can be a low-resistance high-precision resistor to ensure that the voltage drop introduced during the current detection process is as small as possible, thereby reducing the impact on the performance of the audio power amplifier. In addition, in order to improve the accuracy of current detection, the temperature coefficient of the first resistor R1 should be as low as possible to avoid the change in resistance value caused by temperature changes affecting the accuracy of current detection.

[0039] In the embodiment of the present invention, a current detection circuit 10 is provided to detect the power tube current of the audio power amplifier and output a corresponding current detection signal, and a temperature detection circuit 20 is provided to detect the power tube temperature of the audio power amplifier and output a corresponding temperature detection signal. Finally, a control circuit 30 is provided to be connected to the controlled end of the audio power amplifier, and a current threshold is determined according to the temperature detection signal. The working state of the audio power amplifier can be controlled according to the current threshold and the current detection signal to dynamically adjust the output current range of the power amplifier, maximize the dynamic power output range of the power amplifier, and achieve a better sound quality experience. Among them, since a Class D audio amplifier will have short-term large dynamic low-frequency signals when playing music, and these signals usually do not cause abnormal temperature rise of the power tube, and will not damage the power tube, the power tube temperature and current thresholds can be set to the lower the power tube temperature, the larger the current threshold. When a short-term large dynamic low-frequency signal appears, the power tube will not have a large temperature rise and will be allowed to pass the overload, thereby achieving higher output power when the power tube temperature is low, effectively avoiding the false triggering of the protection mechanism resulting in pause of audio output or reduction of sound quality. When the large current signal flowing through the power tube is long-term, the current threshold can be reduced in time to avoid excessive temperature rise caused by long-term overcurrent, which may cause overheating and damage of the power tube, thereby improving the stability and reliability of the entire audio amplifier device.

[0040] Optionally, refer to Figure 3 Another embodiment of the present invention provides an audio power amplifier device, based on the above Figure 1 In the embodiment shown, the temperature detection circuit 20 includes a temperature sensor NTC and a second operational amplifier U2, wherein: The temperature sensor NTC is arranged close to the power tube of the audio power amplifier; the first input end of the second operational amplifier U2 is connected to the first end of the temperature sensor NTC, the second input end of the second operational amplifier U2 is connected to the second end of the temperature sensor NTC, and the output end of the second operational amplifier U2 outputs a corresponding temperature detection signal.

[0041] In this embodiment, the temperature sensor NTC can be a high-precision temperature detection element, such as an NTC thermistor or a PTC thermistor, for real-time monitoring of the temperature of the power tube. The temperature sensor NTC is arranged close to the power tube to ensure fast response and high precision of temperature detection, thereby providing accurate temperature information for the control circuit 30.

[0042] The temperature detection signal is generated by amplifying the voltage difference between the two ends of the temperature sensor NTC through the second operational amplifier U2. Since the resistance value of the temperature sensor NTC changes with temperature, the output end of the second operational amplifier U2 can output a temperature detection signal proportional to the temperature of the power tube. In order to ensure the accuracy and stability of the temperature detection signal, the second operational amplifier U2 can use a high-precision, low-drift amplifier chip.

[0043] Optionally, refer to Figure 2 Another embodiment of the present invention provides an audio power amplifier device, based on the above Figure 1 In the embodiment shown, the control circuit 30 includes a controller 31 and a comparison circuit 32, wherein: The input end of the controller 31 is connected to the output end of the temperature detection circuit 20; the first input end of the comparison circuit 32 is connected to the output end of the current detection circuit 10, and the second input end of the comparison circuit 32 is connected to the output end of the controller 31. The comparison circuit 32 is used to control the working state of the audio power amplifier according to the current threshold and the current detection signal.

[0044] In this embodiment, the controller 31 can be implemented by MCU (Micro controller Unit), DSP (Digital Signal Process), FPGA (Field Programmable Gate Array), SOC (System On Chip), etc.; the comparison circuit 32 can use a high-precision analog comparator U4 chip to ensure that the comparison result between the current threshold and the current detection signal is accurate. The controller 31 dynamically adjusts the current threshold according to the real-time temperature information provided by the temperature detection circuit 20 to adapt to different working environments and conditions. When the temperature rises, the controller 31 will reduce the current threshold accordingly to prevent the power transistor from being damaged due to overheating. Conversely, when the temperature decreases, the controller 31 will increase the current threshold to maximize the dynamic power output range of the power amplifier, thereby achieving a better sound quality experience.

[0045] Optionally, refer to Figure 3 Another embodiment of the present invention provides an audio power amplifier device, based on the above Figure 2 In the illustrated embodiment, the comparison circuit 32 includes a comparator U4, wherein: A third resistor R3 is connected in series between the non-phase terminal of the comparator U4 and the output terminal of the current detection circuit 10 , and a fourth resistor R5 is connected in series between the inverting terminal of the comparator U4 and the output terminal of the controller 31 .

[0046] In this embodiment, the resistance values ​​of the third resistor R3 and the fourth resistor R5 can be selected as needed to ensure that the input voltage difference of the comparator U4 is within a suitable range, thereby ensuring the normal operation of the comparator U4. Through the voltage division effect of the third resistor R3 and the fourth resistor R5, the threshold voltage of the comparator U4 can be adjusted, so that the comparator U4 can accurately determine whether the current threshold is reached when receiving the current detection signal and the signal output by the controller 31.

[0047] In this embodiment, the output end of the comparator U4 is connected to the control circuit 30 of the audio power amplifier, and is used to control the working state of the power amplifier. When the comparator U4 detects that the current detection signal exceeds the current threshold set by the controller 31, the comparator U4 outputs a signal, which can be used to trigger the protection mechanism of the power amplifier, such as reducing the output power or shutting down the amplifier to prevent the power tube from being damaged due to overcurrent, which can effectively protect the power tube from damage caused by overcurrent or overheating, and ensure that the audio power amplifier can provide stable and high-quality audio output under various working environments.

[0048] Optionally, refer to Figure 4 Another embodiment of the present invention provides an audio power amplifier device, based on the above Figures 1 to 3 In any of the illustrated embodiments, the audio power amplifier device includes a signal conditioning circuit 40, wherein: The input end of the signal conditioning circuit 40 is connected to the output end of the current detection circuit 10 , and the output end of the signal conditioning circuit 40 is connected to the input end of the control circuit 30 . The signal conditioning circuit 40 is used to filter out the peak noise part of the power tube current.

[0049] In this embodiment, the signal conditioning circuit 40 can process the current signal through different types of filters such as low-pass filters, high-pass filters or band-pass filters. Low-pass filters can remove high-frequency noise, while high-pass filters can filter out low-frequency interference, and band-pass filters can optimize signals within a specific frequency range. Through a carefully designed filter circuit, it can be ensured that the current signal output by the signal conditioning circuit 40 is smoother, reducing misoperation or damage caused by current spike noise.

[0050] The signal conditioning circuit 40 can also be implemented by an MCU, and a corresponding filtering algorithm is provided in the MCU to improve the flexibility and accuracy of signal processing. In addition, the signal conditioning circuit 40 can also be an operational amplifier, which can provide the required linear processing capability and flexibility to achieve effective signal filtering, and the operational amplifier has high gain and stability, and can adjust the frequency response characteristics of the filter through an appropriate feedback network to achieve a variety of functions such as low-pass, high-pass, band-pass or band-stop filters, ensuring that the control circuit 30 can accurately receive and process the current detection signal.

[0051] The output signal of the signal conditioning circuit 40 is then transmitted to the control circuit 30. The control circuit 30 comprehensively determines the working state of the audio power amplifier device based on the processed current signal and the temperature information provided by the temperature detection circuit 20, thereby being able to better determine whether the audio power amplifier triggers protection, with greater reliability and stability.

[0052] Optionally, refer to Figure 5 Another embodiment of the present invention provides an audio power amplifier device, based on the above Figure 4 In the illustrated embodiment, the signal conditioning circuit 40 includes a third operational amplifier U3 and a first capacitor C1, wherein: The non-inverting terminal of the third operational amplifier U3 is grounded, and a second resistor R2 is connected in series between the inverting terminal of the third operational amplifier U3 and the output terminal of the current detection circuit 10; the first end of the first capacitor C1 is connected to the inverting terminal of the third operational amplifier U3, and the second end of the first capacitor C1 is connected to the output terminal of the third operational amplifier U3.

[0053] In this embodiment, the inverting terminal of the third operational amplifier U3 receives the current signal from the current detection circuit 10, and the third operational amplifier U3 is protected by the second resistor R2 and the first capacitor C1, so that the high-frequency noise and spike noise in the current signal can be better filtered out. Since the non-phase terminal of the third operational amplifier U3 is grounded, the voltage of its inverting terminal will change with the input signal, but will be affected by the charging and discharging of the first capacitor C1, thereby achieving a low-pass filtering effect.

[0054] The output end of the third operational amplifier U3 is connected to the control circuit 30 to provide a filtered current signal. The control circuit 30 can more accurately determine the working state of the audio power amplifier device based on the signal and the temperature information provided by the temperature detection circuit 20, thereby triggering a protection mechanism when necessary to prevent the power tube from being damaged due to overcurrent or overheating.

[0055] In addition, the gain of the third operational amplifier U3 can be adjusted by selecting a suitable feedback resistor to meet different filtering requirements. For example, by increasing the resistance of the feedback resistor, the cutoff frequency of the filter can be increased, thereby allowing more high-frequency signals to pass through; conversely, reducing the resistance of the feedback resistor can reduce the cutoff frequency and better filter out high-frequency noise. Through effective signal processing, the audio power amplifier device can provide clearer and more stable audio output, thereby achieving a better sound quality experience.

[0056] The present invention further provides a loudspeaker, which includes the audio power amplifier device as described in the above embodiment.

[0057] It is worth noting that since the speaker of the present invention is based on the above-mentioned audio power amplifier device, the embodiments of the speaker of the present invention include all technical solutions of all embodiments of the above-mentioned audio power amplifier device, and the technical effects achieved are also exactly the same, which will not be repeated here.

[0058] It should be noted that, in this article, the terms "include", "comprises" or any other variations thereof are intended to cover non-exclusive inclusion, so that a process, method, article or system including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or system. In the absence of further restrictions, an element defined by the sentence "includes a ..." does not exclude the existence of other identical elements in the process, method, article or system including the element.

[0059] The serial numbers of the above embodiments of the present invention are only for description and do not represent the advantages or disadvantages of the embodiments.

[0060] Through the description of the above implementation methods, those skilled in the art can clearly understand that the above-mentioned embodiment methods can be implemented by means of software plus a necessary general hardware platform, and of course by hardware, but in many cases the former is a better implementation method. Based on such an understanding, the technical solution of the present invention is essentially or the part that contributes to the prior art can be embodied in the form of a software product, and the computer software product is stored in a storage medium (such as ROM / RAM, magnetic disk, optical disk) as described above, including a number of instructions for enabling a terminal device (which can be a mobile phone, a computer, a server, or a network device, etc.) to execute the methods described in each embodiment of the present invention.

[0061] The above are only preferred embodiments of the present invention, and are not intended to limit the patent scope of the present invention. Any equivalent structure or equivalent process transformation made using the contents of the present invention specification and drawings, or directly or indirectly applied in other related technical fields, are also included in the patent protection scope of the present invention.

Claims

1. An audio power amplifier device, comprising an audio power amplifier, characterized in that: The audio power amplifier device also includes: A current detection circuit, the current detection circuit is used to detect the power tube current of the audio power amplifier and output a corresponding current detection signal; A temperature detection circuit, the temperature detection circuit is used to detect the temperature of the power tube of the audio power amplifier and output a corresponding temperature detection signal; A control circuit, the control circuit being connected to a controlled end of the audio power amplifier; the control circuit being used to determine a current threshold value according to the temperature detection signal; The control circuit is also used to control the working state of the audio power amplifier according to the current threshold and the current detection signal; wherein the change trend of the power tube temperature and the current threshold is: the lower the power tube temperature, the larger the current threshold.

2. The audio power amplifier device according to claim 1, characterized in that: The control circuit is used to match the current threshold and the current detection signal. If the current detection signal is greater than or equal to the current threshold, the audio power amplifier is controlled to be turned off. If the current detection signal is less than the current threshold, the audio power amplifier is controlled to operate normally.

3. The audio power amplifier device according to claim 1, characterized in that: The current detection circuit comprises: A first resistor, the first resistor is connected in series with a power tube of the audio power amplifier; A first operational amplifier, wherein a first input terminal of the first operational amplifier is connected to a first terminal of the first resistor, a second input terminal of the first operational amplifier is connected to a second terminal of the first resistor, and an output terminal of the first operational amplifier outputs a current detection signal.

4. The audio power amplifier device according to claim 1, characterized in that: The temperature detection circuit comprises: A temperature sensor, wherein the temperature sensor is arranged close to a power tube of the audio power amplifier; A second operational amplifier, wherein a first input terminal of the second operational amplifier is connected to a first terminal of the temperature sensor, a second input terminal of the second operational amplifier is connected to a second terminal of the temperature sensor, and an output terminal of the second operational amplifier outputs a corresponding temperature detection signal.

5. The audio power amplifier device according to claim 1, characterized in that: The control circuit comprises: A controller, wherein an input end of the controller is connected to an output end of the temperature detection circuit; A comparison circuit, wherein a first input terminal of the comparison circuit is connected to an output terminal of the current detection circuit, a second input terminal of the comparison circuit is connected to an output terminal of the controller, and the comparison circuit is used to control the working state of the audio power amplifier according to the current threshold and the current detection signal.

6. The audio power amplifier device as claimed in claim 5, characterized in that: The comparison circuit comprises: A comparator, a third resistor is connected in series between the non-phase terminal of the comparator and the output terminal of the current detection circuit, and a fourth resistor is connected in series between the inverting terminal of the comparator and the output terminal of the controller.

7. The audio power amplifier device according to any one of claims 1 to 6, characterized in that: The audio power amplifier device comprises: A signal conditioning circuit, wherein the input end of the signal conditioning circuit is connected to the output end of the current detection circuit, the output end of the signal conditioning circuit is connected to the input end of the control circuit, and the signal conditioning circuit is used to filter out the peak noise part of the power tube current.

8. The audio power amplifier device as claimed in claim 7, characterized in that: The signal conditioning circuit comprises: a third operational amplifier, wherein a non-inverting terminal of the third operational amplifier is grounded, and a second resistor is connected in series between an inverting terminal of the third operational amplifier and an output terminal of the current detection circuit; A first capacitor, wherein a first end of the first capacitor is connected to an inverting end of the third operational amplifier, and a second end of the first capacitor is connected to an output end of the third operational amplifier.

9. The audio power amplifier device according to any one of claims 1 to 6, characterized in that: The control circuit subtracts the power tube temperature from the maximum allowable junction temperature of the power tube to obtain a corresponding temperature difference, and determines a current threshold value according to the temperature difference and a preset current-temperature coefficient.

10. A loudspeaker, characterized in that: The speaker comprises the audio power amplifier device according to any one of claims 1 to 9.

Images