Audio power amplification circuit

Abstract

The present disclosure provides an audio power amplification circuit, comprising: an input module configured to generate a current signal corresponding to an input voltage according to the input voltage and a feedback voltage, the feedback voltage being generated according to an output signal of an output end of the audio power amplification circuit; the conversion module is configured to convert the type of the current signal, amplify the current signal, generate a voltage amplification signal and send the voltage amplification signal to the power amplification module; the bias module is configured to change the bias voltage output to the power amplification module by changing the resistance value of the bias module; and the power amplification module is provided with a complete complementary framework and is configured to output a voltage output signal consistent with the voltage amplification signal when the power amplification module is in a preset working state according to the bias voltage and generate a current amplification signal based on the voltage amplification signal. By adopting the technical scheme, the static bias degree and the stability of the audio power amplification circuit under high voltage and large current can be improved.

Description

Technical Field

[0001] The present invention relates to the field of circuit technologies, and particularly to an audio power amplifier circuit. Background Art

[0002] An operational amplifier is an important electronic component and is widely used in audio devices, especially in speaker systems. The operational amplifier can process, amplify, and adjust audio signals, thereby improving the quality and performance of audio output.

[0003] However, in some application scenarios, affected by the supply voltage at the power supply end or other factors, the performance of the audio power amplifier circuit will be significantly reduced. Especially in high-voltage and high-current application scenarios, the stability of the audio power amplifier circuit will be significantly reduced. Summary of the Invention

[0004] In view of this, the present invention provides an audio power amplifier circuit, which can improve the static bias degree and stability of the audio power amplifier circuit under high voltage and high current.

[0005] The present invention provides an audio power amplifier circuit, including: an input module, a conversion module, a bias module, and a power amplification module, where:

[0006] The input module is configured to generate a current signal corresponding to the input voltage according to the input voltage and the feedback voltage, where the feedback voltage is generated according to the output signal at the output end of the audio power amplifier circuit;

[0007] The conversion module is configured to convert the type of the current signal and perform amplification processing to generate a voltage amplification signal;

[0008] The bias module is configured to change the bias voltage output to the power amplification module by changing its own resistance value;

[0009] The power amplification module has a fully complementary architecture and is configured to output a voltage output signal consistent with the voltage amplification signal when in a preset working state according to the bias voltage, and generate a current amplification signal based on the voltage amplification signal.

[0010] Optionally, the input module includes: a differential input unit, a clamping unit, and a current adjustment unit, where:

[0011] The differential input unit includes a first differential branch and a second differential branch. The first differential branch is respectively coupled to the clamping unit, the current adjustment unit, and the second differential branch, and is configured to output the current signal to the conversion module; the second differential branch is respectively coupled to the clamping unit and the current adjustment unit;

[0012] The clamping unit is configured to make the current signal on the first differential branch the same as the current signal on the second differential branch;

[0013] The current regulation unit is configured to adjust the current signals of the first differential branch and the second differential branch in response to the change in the difference between the feedback voltage and the input voltage, so that the current signals have a preset amplitude.

[0014] Optionally, the audio power amplifier circuit satisfies at least one or more of the following:

[0015] The first differential branch includes a first differential transistor, a first resistor, a second resistor, and a second differential transistor, where: the base of the first differential transistor is adapted to input the input voltage, the collector of the first differential transistor is respectively coupled to the first end of the second resistor and the base of the second differential transistor, the emitter of the first differential transistor is respectively coupled to the second end of the first resistor and the collector of the second differential transistor; the emitter of the second differential transistor is respectively coupled to the second end of the second resistor and the clamping unit; the first end of the first resistor is respectively coupled to the current regulation unit and the second differential branch;

[0016] The second differential branch includes a third differential transistor, a third resistor, a fourth resistor, and a fourth differential transistor, where: the base of the third differential transistor is adapted to input the feedback voltage, the collector of the first differential transistor is respectively coupled to the first end of the fourth resistor and the base of the fourth differential transistor, the emitter of the third differential transistor is respectively coupled to the second end of the third resistor and the collector of the fourth differential transistor; the emitter of the fourth differential transistor is respectively coupled to the second end of the fourth resistor and the clamping unit; the first end of the third resistor is respectively coupled to the current regulation unit and the first differential branch;

[0017] The clamping unit includes a current mirror, and the current mirror includes a first mirror branch composed of a first mirror transistor and a first mirror resistor, and a second mirror branch composed of a second mirror transistor and a second mirror resistor. Wherein, the base of the first mirror transistor is respectively coupled to the base of the second mirror transistor, the collector of the second mirror transistor, and the second differential branch, the collector of the first mirror transistor is respectively coupled to the first differential branch and the conversion module, the emitter of the first mirror transistor is coupled to the first end of the first mirror resistor; the second end of the first mirror resistor is coupled to the second end of the second mirror resistor; the emitter of the second mirror transistor is coupled to the first end of the second mirror resistor;

[0018] The current regulation unit includes: a first voltage source, a first transistor, and a fifth resistor. Among them, the first end of the first voltage source is coupled to the first end of the fifth resistor, and the second end of the first voltage source is coupled to the base of the first transistor; the emitter of the first transistor is coupled to the second end of the fifth resistor, and the collector of the first transistor is coupled to the first differential branch and the second differential branch respectively.

[0019] Optionally, the conversion module includes: a first-stage conversion unit and a second-stage conversion unit. The first-stage conversion unit is coupled to the input module and the second-stage conversion unit respectively, and the second-stage conversion unit is coupled to the bias module and the power amplification module respectively.

[0020] Optionally, the audio power amplification circuit satisfies at least one or more of the following:

[0021] The first-stage conversion unit includes: a first conversion transistor and a first conversion resistor. The base of the first conversion transistor is coupled to the input module, the collector of the first conversion transistor is grounded, and the emitter of the first conversion transistor is coupled to the second-stage conversion unit and the first end of the first conversion resistor respectively;

[0022] The second-stage conversion unit includes: a second conversion transistor and a second conversion resistor. The collector of the second conversion transistor is coupled to the bias module and the power amplification module respectively, and the emitter of the second conversion transistor is coupled to the first end of the second conversion resistor;

[0023] A filter capacitor is coupled to the base of the first conversion transistor and the collector of the second conversion transistor respectively.

[0024] Optionally, the bias module includes: a reference current unit and a bias unit, where:

[0025] The reference current unit, which is coupled to the bias unit, is configured to provide a reference current;

[0026] The bias unit, which is coupled to the power amplification module, is configured to provide a corresponding bias voltage to the power amplification module according to the adjusted resistance value and the reference current.

[0027] Optionally, the audio power amplification circuit satisfies at least one or more of the following:

[0028] The reference current unit includes: a second voltage source, a second transistor and a sixth resistor, wherein a first end of the second voltage source is coupled to a first end of the sixth resistor, a second end of the second voltage source is coupled to a base of the second transistor; an emitter of the second transistor is coupled to a second end of the sixth resistor, and a collector of the second transistor is coupled to the bias unit;

[0029] The bias unit includes: a third transistor, a seventh resistor, an eighth resistor, a ninth resistor and an adjustable resistor, wherein: the base of the third transistor is connected to the second end of the seventh resistor and the first end of the eighth resistor respectively, the collector of the third transistor is coupled to the second end of the ninth resistor and the power amplifier module respectively, the emitter of the third transistor is coupled to the second end and the third end of the adjustable resistor respectively; the first end of the seventh resistor is coupled to the first end of the ninth resistor and the reference current unit respectively; the second end of the eighth resistor is coupled to the first end of the adjustable resistor.

[0030] Optionally, the power amplification module includes: a first amplification unit and a second amplification unit having the fully complementary architecture and being turned on in time-sharing manner, wherein the first amplification unit is enabled when the voltage amplification signal is in a positive half-cycle; and the second amplification unit is enabled when the voltage amplification signal is in a negative half-cycle, and when in the enabled state, in response to the bias voltage, the audio power amplifier circuit operates in a Class AB state while generating the current amplification signal and the output voltage signal.

[0031] Optionally, the audio power amplifier circuit satisfies at least one or more of the following:

[0032] The first amplifying unit includes a first power tube, a second power tube, a third power tube, a first power resistor, a second power resistor, a third power resistor and a fourth power resistor, wherein the base of the first power tube is coupled to the bias module, the collector of the first power tube is coupled to the second end of the first power resistor and the base of the second power tube respectively, the emitter of the first power tube is coupled to the first end of the second power resistor; the collector of the second power tube is coupled to the second end of the third power resistor; the emitter of the second power tube is coupled to the first end of the fourth power resistor and the base of the third power tube respectively; the collector of the third power tube is coupled to the first end of the first power resistor and the first end of the third power resistor respectively; the emitter of the third power tube is coupled to the second end of the second power resistor, the second end of the fourth power resistor and the second amplifying unit respectively;

[0033] The second amplification unit includes a fourth power transistor, a fifth power transistor, a sixth power transistor, a fifth power resistor, a sixth power resistor, a seventh power resistor, and an eighth power resistor. Among them, the base of the fourth power transistor is respectively coupled to the bias module and the conversion module. The collector of the fourth power transistor is respectively coupled to the first end of the first power resistor and the base of the fifth power transistor. The emitter of the fourth power transistor is coupled to the first end of the sixth power resistor. The collector of the fifth power transistor is respectively coupled to the second end of the seventh power resistor and the base of the sixth power transistor. The emitter of the fifth power transistor is coupled to the first end of the eighth power resistor. The collector of the sixth power transistor is respectively coupled to the second end of the eighth power resistor and the second end of the fifth power resistor. The emitter of the sixth power transistor is respectively coupled to the second end of the sixth power resistor and the first end of the seventh power resistor.

[0034] Optionally, the audio power amplifier circuit further includes at least one or more of the following:

[0035] A voltage division module, respectively coupled to the output end of the audio power amplifier circuit and the input module, and configured to divide the output voltage of the output end of the audio power amplifier circuit to obtain the feedback voltage;

[0036] A first buffer resistor, disposed between the bias module and the power amplification module;

[0037] A second buffer resistor, disposed between the conversion module and the power amplification module;

[0038] A compensation module, disposed at the output end of the audio power amplifier circuit, and configured to compensate the current amplification signal to improve the stability of the current amplification signal;

[0039] Among them, the voltage division module includes a first voltage division resistor, a second voltage division resistor, and a feedback capacitor. Among them, the first end of the first voltage division resistor is coupled to the output end of the audio power amplifier circuit. The second end of the first voltage division resistor is respectively coupled to the first end of the second voltage division resistor and the input module. The second end of the second voltage division resistor is coupled to the first end of the feedback capacitor. The second end of the feedback capacitor is grounded;

[0040] The compensation module includes a compensation inductor and a compensation resistor connected in parallel.

[0041] Compared with the prior art, the technical solution of the invention embodiment has the following advantages:

[0042] The audio power amplifier circuit provided by the invention embodiment can generate a current signal corresponding to the input voltage according to the input voltage and the feedback voltage. Since the feedback voltage is generated according to the output signal at the output end of the audio power amplifier circuit, the current signal can more accurately reflect the change of the output signal at the output end. In this way, through the signal conversion and amplification functions of the conversion module, a voltage amplification signal can be generated. At the same time, the bias module can output different bias voltages to the power amplification module by changing its own resistance value, and the power amplification module has a fully complementary architecture. In this way, under the action of the bias voltage, the voltage amplification signal can be symmetrically processed in different cycles, reducing signal distortion and making the current amplification signal have better linearity. In this way, when the output end of the power amplification module is used as the output end of the audio power amplifier circuit, the feedback voltage has better linearity. In other words, both the input signal and the output signal of the audio power amplifier circuit have good linearity, which enables the audio power amplifier circuit to still have good static bias and stability even under high voltage and large current. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the drawings in the following description are only the embodiments of the present application. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained according to the provided drawings.

[0044] Figure 1 The structural schematic diagram of an audio power amplifier circuit in an embodiment of the present invention is shown;

[0045] Figure 2 The specific structural schematic diagram of an audio power amplifier circuit in the first embodiment of the present invention is shown;

[0046] Figure 3 The specific structural schematic diagram of an audio power amplifier circuit in the second embodiment of the present invention is shown. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0047] As described in the background art, in high-voltage and high-current application scenarios, the stability of operational amplifiers will be significantly reduced.

[0048] To solve the above technical problems, the present invention provides an audio power amplifier circuit, which can generate a current signal corresponding to the input voltage according to the input voltage and the feedback voltage. Since the feedback voltage is generated according to the output signal at the output end of the audio power amplifier circuit, the current signal can more accurately reflect the change of the output signal at the output end. In this way, through the signal conversion and amplification of the conversion module, a voltage amplification signal can be generated. At the same time, the bias module can output different bias voltages to the power amplification module by changing its own resistance value, and the power amplification module has a fully complementary architecture. In this way, under the action of the bias voltage, the voltage amplification signal can be symmetrically processed in different cycles, reducing signal distortion and making the current amplification signal have better linearity. In this way, when the output end of the power amplification module is used as the output end of the audio power amplifier circuit, the feedback voltage has better linearity. In other words, both the input signal and the output signal of the audio power amplifier circuit have good linearity, which enables the audio power amplifier circuit to still have good static bias and stability even under high voltage and large current.

[0049] To enable those skilled in the art to better understand and implement the present disclosure, the following refers to the accompanying drawings, and the specific solutions, principles, advantages, and effects of the present disclosure are described in detail through specific embodiments.

[0050] See Figure 1 In a schematic structural diagram of an audio power amplifier circuit according to an embodiment of the present invention shown in Figure 1 As shown, the audio power amplifier circuit may include: an input module 110, a conversion module 120, a bias module 130, and a power amplification module 140, where:

[0051] The input module 110 is coupled to the conversion module 120 and is configured to generate a current signal corresponding to the input voltage Vin according to the input voltage Vin and the feedback voltage Vfb, where the feedback voltage Vfb is generated according to the output signal at the output end of the audio power amplifier circuit;

[0052] The conversion module 120 is respectively coupled to the bias module 130 and the power amplification module 140 and is configured to convert the type of the current signal and perform amplification processing to generate a voltage amplification signal (it can be understood that the voltage amplification signal is transmitted to the power amplification module 140);

[0053] The bias module 130 is coupled to the power amplification module 140 and is configured to change the bias voltage Vb output to the power amplification module 140 by changing its own resistance value;

[0054] The power amplification module 140 has a fully complementary architecture and is configured to output a voltage output signal consistent with the voltage amplification signal and generate a current amplification signal based on the voltage amplification signal when in a preset operating state according to the bias voltage Vb.

[0055] It should be noted that the current amplification signal is generally provided for use in a speaker. Therefore, by generating the current amplification signal, the audio power is increased.

[0056] Combined with Figure 1 , the working principle of the audio power amplification circuit in the embodiment of the present invention will be briefly described:

[0057] When the feedback voltage Vfb does not change, the audio power amplification circuit is in a steady state, that is, the current signal is in a steady state, and the voltage amplification signal and the current amplification signal are both in a stable state. In this way, when the audio power amplification circuit is applied to a speaker device, the performance and user experience of the speaker device can be improved.

[0058] When affected by other factors and the feedback voltage Vfb changes, in response to the changed feedback voltage Vfb and the input voltage Vin, the input module 110 can generate a current signal corresponding to the input voltage Vin.

[0059] Since the feedback voltage is generated based on the output signal at the output end of the audio power amplification circuit, the current signal can more accurately reflect the change in the output signal at the output end. In this way, through the signal conversion and amplification functions of the conversion module 120, a voltage amplification signal can be generated.

[0060] At the same time, the bias module 130 can output different bias voltages to the power amplification module 140 by changing its own resistance value, and the power amplification module 140 has a fully complementary architecture. In this way, under the action of the bias voltage, the power amplification module 140 can symmetrically process the voltage amplification signal in different cycles, reducing signal distortion and making the current amplification signal have better linearity.

[0061] In this way, when the output end of the power amplification module 140 is used as the output end of the audio power amplification circuit, the feedback voltage Vfb has better linearity, and the change in the current signal with the fluctuation of the feedback voltage Vfb is smaller.

[0062] In other words, through the cooperation between the above-mentioned modules with mutual interaction, both the input signal and the output signal of the audio power amplification circuit are good, which enables the audio power amplification circuit to still have good static bias and stability even under high voltage and large current.

[0063] Combined with Figure 1 , see Figure 2The specific structural schematic diagram of an audio power amplifier circuit in the first embodiment of the present invention shown is composed of Figure 2 As can be seen, the input module 110 may include: a differential input unit 112, a clamping unit 114, and a current regulation unit 116, where:

[0064] The differential input unit 112 includes a first differential branch (not marked in the figure) and a second differential branch (not marked in the figure). The first differential branch is respectively coupled to the clamping unit 114, the current regulation unit 116, and the second differential branch, and is configured to output the current signal to the conversion module 120; the second differential branch is respectively coupled to the clamping unit 114 and the current regulation unit 116;

[0065] The clamping unit 114 is configured to make the current signal on the first differential branch the same as the current signal on the second differential branch;

[0066] The current regulation unit 116 is configured to respond to the change in the difference between the feedback voltage Vfb and the input voltage Vin, and adjust the current signals of the first differential branch and the second differential branch, so that the current signal has a preset amplitude.

[0067] In some embodiments, when the differential input unit 112 receives the input voltage Vin, based on the first differential branch and the second differential branch, the input voltage Vin can be converted into a current signal, that is: both the first differential branch and the second differential branch generate a current signal. And, under the action of the clamping unit 114, the current signal on the first differential branch is made the same as the current signal on the second differential branch.

[0068] In this way, even when the feedback voltage Vfb changes, the current regulation unit 116 can adaptively adjust the current signal based on the change trend of the feedback voltage Vfb, so that the current signal has a preset amplitude. That is: the current signal on the first differential branch is the same as the current signal on the second differential branch.

[0069] For example, when the feedback voltage Vfb becomes larger, the currents on the first differential branch and the second differential branch will become larger, and under the action of the current regulation unit 116, the currents on the first differential branch and the second differential branch will decrease, so that through the cancellation effect, the current signal remains unchanged.

[0070] Also for example, when the feedback voltage Vfb becomes smaller, the currents on the first differential branch and the second differential branch will become smaller, and under the action of the current regulation unit 116, the currents on the first differential branch and the second differential branch will increase, so that through the cancellation effect, the current signal remains unchanged.

[0071] Thus, by adopting the input module with the above structure, the currents on the first differential branch and the second differential branch are kept the same and are a constant value.

[0072] It should be noted that the "constant value" in this solution means that the currents on the first differential branch and the second differential branch remain unchanged when the input voltage is constant. When the input voltage increases or decreases, the currents on the first differential branch and the second differential branch will change.

[0073] In some embodiments, referring to Figure 2 , the first differential branch may include a first differential transistor Q9, a first resistor R9, a second resistor R23, and a second differential transistor Q10, where:

[0074] The base of the first differential transistor Q9 is adapted to input the input voltage Vin. The collector of the first differential transistor Q9 is respectively coupled to the first end of the second resistor R23 and the base of the second differential transistor Q11. The emitter of the first differential transistor Q9 is respectively coupled to the second end of the first resistor R9 and the collector of the second differential transistor Q11. The emitter of the second differential transistor Q11 is respectively coupled to the second end of the second resistor R23 and the clamping unit 114. The first end of the first resistor R9 is respectively coupled to the current regulation unit 116 and the second differential branch.

[0075] The second differential branch may include a third differential transistor Q10, a third resistor R10, a fourth resistor R24, and a fourth differential transistor Q12, where: The base of the third differential transistor Q10 is adapted to input the feedback voltage Vfb. The collector of the third differential transistor Q10 is respectively coupled to the first end of the fourth resistor R24 and the base of the fourth differential transistor Q12. The emitter of the third differential transistor Q10 is respectively coupled to the second end of the third resistor R10 and the collector of the fourth differential transistor Q12. The emitter of the fourth differential transistor Q12 is respectively coupled to the second end of the fourth resistor R24 and the clamping unit 114. The first end of the third resistor R10 is respectively coupled to the current regulation unit 116 and the first differential branch.

[0076] In other words, the first differential branch and the second differential branch adopt a complementary feedback pair architecture, which can improve the linearity of the input stage.

[0077] The clamping unit 114 may include a current mirror, and the current mirror includes a first mirror branch composed of a first mirror transistor Q16 and a first mirror resistor R32, and a second mirror branch composed of a second mirror transistor Q17 and a second mirror resistor R33.

[0078] Among them, the base of the first mirror transistor Q16 is coupled to the base of the second mirror transistor Q17, the collector of the second mirror transistor Q17, and the second differential branch respectively. The collector of the first mirror transistor Q16 is coupled to the first differential branch and the conversion module 120 respectively. The emitter of the first mirror transistor Q16 is coupled to the first end of the first mirror resistor R32. The second end of the first mirror resistor R32 is coupled to the second end of the second mirror resistor R33. The emitter of the second mirror transistor Q17 is coupled to the first end of the second mirror resistor R33.

[0079] By adopting the current mirror method, the circuits on the first differential branch and the second differential branch are kept in the same state.

[0080] The current regulation unit 116 may include: a first voltage source U1, a first transistor Q4, and a fifth resistor R1. Among them, the first end of the first voltage source U1 is coupled to the first end of the fifth resistor R1. The second end of the first voltage source U1 is coupled to the base of the first transistor Q4. The emitter of the first transistor Q4 is coupled to the second end of the fifth resistor R1. The collector of the first transistor Q4 is coupled to the first differential branch and the second differential branch respectively.

[0081] The following combines Figure 2 , to illustrate the working mechanism of the input module.

[0082] Due to some reason, the feedback voltage becomes larger, causing the currents on the first differential transistor Q9 and the third differential transistor Q10 to become larger. Then, based on Kirchhoff's current law, the current on the collector of the first transistor Q4 also becomes larger. In this way, the potentials of the emitters of the first differential transistor Q9 and the third differential transistor Q10 will both become larger. While the base potentials of the first differential transistor Q9 and the third differential transistor Q10 are relatively fixed. Therefore, the base-emitter voltages of the first differential transistor Q9 and the third differential transistor Q10 will both decrease, thereby reducing the base currents of the first differential transistor Q9 and the third differential transistor Q10. Furthermore, the emitter currents of the first differential transistor Q9 and the third differential transistor Q10 are reduced, which offsets the change in the collector caused by the increase in temperature or voltage. Thus, the collector currents of the first differential transistor Q9 and the third differential transistor Q10 are basically kept unchanged, that is, the current signal output to the conversion module 120 remains unchanged.

[0083] In some embodiments, then refer to Figure 2, the conversion module 120 may include: a first-stage conversion unit 122 and a second-stage conversion unit 124. The first-stage conversion unit 122 is respectively coupled to the input module 110 and the second-stage conversion unit 124, and the second-stage conversion unit 124 is respectively coupled to the bias module 130 and the power amplification module 140.

[0084] Among them, the first-stage conversion unit 122 and the second-stage conversion unit 124 may form a follower-type voltage amplification stage, which can reduce the distortion phenomenon during the amplification process.

[0085] In some embodiments, the first-stage conversion unit 122 may include: a first conversion transistor Q14 and a first conversion resistor R34. The base of the first conversion transistor Q14 is coupled to the input module 110, the collector of the first conversion transistor Q14 is grounded, and the emitter of the first conversion transistor Q14 is respectively coupled to the second-stage conversion unit 124 and the first end of the first conversion resistor Q34.

[0086] The second-stage conversion unit 124 may include: a second conversion transistor Q18 and a second conversion resistor R35. The collector of the second conversion transistor Q18 is respectively coupled to the bias module 130 and the power amplification module 140, and the emitter of the second conversion transistor Q18 is coupled to the first end of the second conversion resistor R35.

[0087] In other words, the conversion module 120 may be an emitter follower-type voltage amplification stage, and the voltage amplification signal output to the power amplification module 140 is the voltage signal output from the collector of the second conversion transistor Q18.

[0088] In some embodiments, the audio power amplification circuit may further include a filter capacitor C12, which is respectively coupled to the base of the first conversion transistor Q14 and the collector of the second conversion transistor Q18.

[0089] By setting the filter capacitor C12, the clutter in the voltage amplification signal can be filtered out, and the quality of the voltage amplification signal can be improved.

[0090] In some embodiments, the bias module 130 may include: a reference current unit 132 and a bias unit 134, where:

[0091] The reference current unit 132, which is coupled to the bias unit 134, is configured to provide a reference current; the bias unit 134, which is coupled to the power amplification module 140, is configured to provide a corresponding bias voltage to the power amplification module 140 according to the adjusted resistance value and the reference current.

[0092] In other words, by adjusting the resistance value in the bias unit 134, a bias voltage corresponding to the resistance value can be output, enabling the power amplification module 140 to enter a preset operating state (such as class AB operating state) and avoiding crossover distortion.

[0093] In some embodiments, the bias voltage refers to the equivalent voltage generated by the equivalent resistance value of the bias unit 134 after adjustment and the reference current.

[0094] In some embodiments, the reference current unit 132 may include: a second voltage source U2, a second transistor Q2, and a sixth resistor R3. Among them, the first end of the second voltage source U2 is coupled to the first end of the sixth resistor R3, and the second end of the second voltage source U2 is coupled to the base of the second transistor Q2; the emitter of the second transistor Q2 is coupled to the second end of the sixth resistor R3, and the collector of the second transistor Q2 is coupled to the bias unit 134.

[0095] In other words, when the second transistor Q2 is turned on, the reference current provided by the reference current unit 132 is the ratio between the second voltage source U2 and the sixth resistor R3.

[0096] In some embodiments, the bias unit 134 may include: a third transistor Q8, a seventh resistor R6, an eighth resistor R14, a ninth resistor R7, and a variable resistor Rx. Among them: the base of the third transistor Q8 is respectively connected to the second end of the seventh resistor R6 and the first end of the eighth resistor R14, the collector of the third transistor Q8 is respectively coupled to the second end of the ninth resistor R7 and the power amplification module 140, and the emitter of the third transistor Q8 is respectively coupled to the second end and the third end of the variable resistor Rx; the first end of the seventh resistor R6 is respectively coupled to the first end of the ninth resistor R7 and the reference current unit 132; the second end of the eighth resistor R14 is coupled to the first end of the variable resistor Rx.

[0097] Specifically, by adjusting the variable resistor Rx, the voltage drop between the base and emitter of the third transistor Q8 is changed, thereby affecting the voltage drop between the collector and emitter of the third transistor Q8, and thus changing the bias voltage output to the power amplification module 140.

[0098] In some embodiments, the power amplification module 140 may be a common collector amplifier circuit, and the output voltage signal changes following the input voltage signal, playing a role in current amplification.

[0099] More specifically, the power amplification module 140 may include: a first amplification unit 142 and a second amplification unit 144 having the fully complementary architecture and being turned on in time-sharing manner, wherein when the voltage amplification signal is in a positive half-cycle, the first amplification unit 142 is enabled; when the voltage amplification signal is in a negative half-cycle, the second amplification unit 144 is enabled, and when in the enabled state, in response to the bias voltage Vb, the audio power amplifier circuit operates in a Class AB state while generating the current amplification signal and the output voltage signal.

[0100] In other words, it is in different cycles that the voltage amplification signal is symmetrically processed to reduce signal distortion, so that the current amplification signal has better linearity, so that when the output end of the power amplifier module is used as the output end of the audio power amplifier circuit, the feedback voltage has better linearity. This makes the input signal and output signal of the audio power amplifier circuit have good linearity, so that even under high voltage and high current, the audio power amplifier circuit still has good static bias and stability.

[0101] While generating the output voltage signal, when either the first amplifying unit 142 or the second amplifying unit 144 is turned on, it plays a role of current amplification.

[0102] In some embodiments, the first amplifying unit 142 may include a first power tube Q54, a second power tube Q5, a third power tube Q3, a first power resistor R107, a second power resistor R108, a third power resistor R4 and a fourth power resistor R106, wherein the base of the first power tube Q54 is coupled to the bias module 130, the collector of the first power tube Q54 is coupled to the second end of the first power resistor R107 and the base of the second power tube Q5, respectively, and the emitter of the first power tube Q54 is coupled to the first end of the second power resistor R108; The collector of the second power tube Q5 is coupled to the second end of the third power resistor R4, and the emitter of the second power tube Q5 is coupled to the first end of the fourth power resistor R106 and the base of the third power tube Q3 respectively; the collector of the third power tube Q3 is coupled to the first end of the first power resistor R107 and the first end of the third power resistor R4 respectively; the emitter of the third power tube Q3 is coupled to the second end of the second power resistor R108, the second end of the fourth power resistor R105, and the second amplification unit 144 respectively, and serves as the output end of the audio power amplifier circuit.

[0103] In other words, the first amplifying unit 142 can be regarded as a common collector amplification type NPN power transistor, that is, an NPN power transistor composed of a power transistor and its peripheral components.

[0104] In some embodiments, the second amplification unit 144 may include a fourth power transistor Q55, a fifth power transistor Q19, a sixth power transistor Q15, a fifth power resistor R109, a sixth power resistor R110, a seventh power resistor R105, and an eighth power resistor R36. Among them, the base of the fourth power transistor Q55 is respectively coupled to the bias module 130 and the conversion module 120. The collector of the fourth power transistor Q55 is respectively coupled to the first end of the first power resistor R109 and the base of the fifth power transistor Q19. The emitter of the fourth power transistor Q55 is coupled to the first end of the sixth power resistor R110. The collector of the fifth power transistor Q19 is respectively coupled to the second end of the seventh power resistor R105 and the base of the sixth power transistor Q15. The emitter of the fifth power transistor Q19 is coupled to the first end of the eighth power resistor R36. The collector of the sixth power transistor Q15 is respectively coupled to the second end of the eighth power resistor R36 and the second end of the fifth power resistor R109. The emitter of the sixth power transistor Q16 is respectively coupled to the second end of the sixth power resistor R110 and the first end of the seventh power resistor R106.

[0105] In other words, the second amplification unit 144 can be regarded as a common collector amplifier type PNP power triode, that is, an NPN power triode composed of a power transistor and its peripheral components.

[0106] In some embodiments, by adopting complementary PNP and NPN power transistors, crossover distortion can be reduced and the sound quality of the audio amplifier can be improved.

[0107] In some embodiments, the first amplification unit 142 may further include: a first feedback resistor R16, disposed between the output end of the first amplification unit 142 and the output end of the audio power amplification circuit.

[0108] By setting the negative feedback effect of the first feedback resistor R16, the static operating point of the first amplification unit 142 is stabilized, and the influence of factors such as temperature change on the first amplification unit 142 is reduced.

[0109] In some embodiments, the second amplification unit 144 may further include: a second feedback resistor R26, disposed between the output end of the second amplification unit 144 and the output end of the audio power amplification circuit.

[0110] By setting the negative feedback effect of the second feedback resistor R26, the static operating point of the second amplification unit 144 is stabilized, and the influence of factors such as temperature change on the second amplification unit 144 is reduced.

[0111] In some embodiments, the structure of the audio power amplifier circuit in the above examples can be further improved to further enhance the performance of the audio power amplifier circuit.

[0112] Next, referring to Figure 2 , the audio power amplifier circuit may further include a voltage dividing module (not shown in the figure), which is respectively coupled to the output end of the audio power amplifier circuit and the input module 110, and is configured to divide the output voltage of the output end of the audio power amplifier circuit to obtain the feedback voltage Vfb.

[0113] In other words, the feedback voltage Vfb is obtained by dividing the output voltage of the output end of the audio power amplifier circuit.

[0114] Moreover, the voltage division ratio of the voltage dividing module can be used as the gain of the entire audio power amplifier circuit.

[0115] In some embodiments, the voltage dividing module may include a first voltage dividing resistor R18, a second voltage dividing resistor R20, and a feedback capacitor C9. Among them, the first end of the first voltage dividing resistor R18 is coupled to the output end of the audio power amplifier circuit, the second end of the first voltage dividing resistor R18 is respectively coupled to the first end of the second voltage dividing resistor R20 and the input module 110, the second end of the second voltage dividing resistor R20 is coupled to the first end of the feedback capacitor C9, and the second end of the feedback capacitor C9 is grounded.

[0116] In some embodiments, through the voltage division of the first voltage dividing resistor R18 and the second voltage dividing resistor R20, the feedback voltage Vfb is the voltage drop across the second voltage dividing resistor R20. And during this process, the feedback capacitor C9 is used to provide a loop for the feedback voltage in the form of alternating current.

[0117] In some embodiments, the audio power amplifier circuit may further include a first buffer resistor R8, which is disposed between the bias module 130 and the power amplifier module 140.

[0118] More specifically, the first buffer resistor R8 is disposed between the bias module 130 and the first amplification unit 142, playing a protective role.

[0119] In some embodiments, the audio power amplifier circuit may further include a second buffer resistor R31, which is disposed between the conversion module 120 and the power amplifier module 140.

[0120] More specifically, the second buffer resistor R31 is disposed between the conversion module 120 and the second amplification unit 144, playing a protective role.

[0121] In some embodiments, the audio power amplifier circuit may further include a self-oscillation prevention module (not shown in the figure), which is disposed at the output end of the audio power amplifier circuit and is configured to prevent the electromotive force generated by the load from damaging the audio power amplifier circuit.

[0122] In some embodiments, the self-oscillation prevention module may include a compensation inductor L1 and a compensation resistor R19 connected in parallel.

[0123] More specifically, the compensation inductor L1 blocks high-frequency signals, and the compensation resistor R19 absorbs residual energy to eliminate the self-oscillation problem in the circuit.

[0124] In some embodiments, the inventors further found that when the audio power amplifier circuit operates for a long time, an overcurrent phenomenon may occur.

[0125] Based on this, referring to Figure 3 the structural schematic diagram of an audio power amplifier circuit in the second embodiment of the present invention shown in

[0126] Referring to Figure 3 , the audio power amplifier circuit may further include: a protection module (not shown in the figure), which is respectively coupled to the power amplifier module 140 and the output end of the audio power amplifier circuit, and is configured to detect the current amplification signal on the path between the output end of the power amplifier module 140 and the output end of the audio power amplifier circuit, and obtain a corresponding detection voltage value, and when the detection voltage value is greater than the voltage amplitude preset by the protection unit itself, select to turn on the path between the input end and the feedback end NFB of the power amplifier module 140.

[0127] In other words, since the current value is obtained from the path between the output end of the power amplifier module 140 and the output end of the audio power amplifier circuit, when it is determined that the voltage value corresponding to the current value is greater than the voltage amplitude preset by the protection unit itself, it indicates that an overcurrent phenomenon occurs, so that the path between the input end and the feedback end NFB of the power amplifier module 140 can be selected to turn on, so as to reduce the current value at the input end of the power amplifier module 140, and further reduce the current value output from the power amplifier module 140 to the output end.

[0128] In some embodiments, the protection module may include a first protection unit 152 and a second protection unit 154. The first protection unit 152 is respectively coupled to the power amplifier module 140 and the feedback end NFB, and the second protection unit 154 is respectively coupled to the power amplifier module 140 and the feedback end NFB, and is configured to, when the power amplifier module 140 is operating, one of the first protection unit 152 and the second protection unit 154 plays a detection role.

[0129] Specifically, as can be seen from the foregoing, when the voltage amplification signal is in the positive half cycle, the first amplification unit is enabled. At this time, one of the first protection unit 152 and the second protection unit 154 is used to detect the current amplification signal between the first amplification unit 142 and the output end; when the voltage amplification signal is in the negative half cycle, the second amplification unit is enabled. At this time, the other of the first protection unit 152 and the second protection unit 154 is used to detect the current amplification signal between the second amplification unit and the output end.

[0130] In an optional embodiment, the first protection unit 152 is correspondingly arranged with the first amplification unit 142 and is used to detect the current amplification signal between the first amplification unit 142 and the output end; the second protection unit 154 is correspondingly arranged with the second amplification unit 144 and is used to detect the current amplification signal between the second amplification unit 144 and the output end.

[0131] In some embodiments, the first protection unit 152 may include: a first detection branch (not shown in the figure) and a first discharge branch (not shown in the figure). Among them, the first detection branch is used to detect the current amplification signal between the first amplification unit 142 and the output end and generate a first detection voltage value; the first discharge branch is used to select or disconnect the path between the input end and the feedback end of the first amplification unit 142 according to the first detection voltage value and its own first voltage amplitude.

[0132] More specifically, if the first detection voltage value is greater than the first voltage amplitude, it indicates that an overcurrent phenomenon occurs, and the first discharge branch is selected, so that the driving strength of the input end of the first amplification unit 142 can be reduced, thereby weakening the overcurrent phenomenon; if the first detection voltage value is not greater than the first voltage amplitude, it indicates that no overcurrent phenomenon occurs, and the first discharge branch is disconnected.

[0133] In some embodiments, the first detection branch may include a first detection resistor R15 and a second detection resistor R11. Among them, the first end of the first detection resistor R15 is coupled to the output end of the first amplification unit 142, and the second end of the first detection resistor R15 is respectively coupled to the first end of the second detection resistor R11 and the first discharge branch; the second end of the second detection resistor R11 is connected to the feedback end.

[0134] In some embodiments, the first discharge branch may include a first diode D1 and a first discharge transistor Q1. Among them, the first end of the first diode D1 is coupled to the input end of the first amplification unit 142, and the second end of the first diode D1 is coupled to the collector of the first discharge transistor Q1; the base of the first discharge transistor Q1 is coupled to the first detection branch, and the emitter of the first discharge transistor Q1 is connected to the feedback end.

[0135] In other words, on the one hand, the first diode D1 defines the flow direction of the signal on the first discharge branch, such that the signal can only flow from the input end to the feedback end of the first amplification unit 142; on the other hand, based on the turn-on voltage of the first discharge transistor Q1 itself, it can be adaptively turned on or off according to the detected first detection voltage value, without adding additional circuits, reducing the use of components while meeting the detection performance.

[0136] Specifically, the first detection resistor R15, the second detection resistor R11, the first diode D1 and the first discharge transistor Q1 form an overcurrent protection circuit. When the first detection voltage value detected by the first detection resistor R15 and the second detection resistor R11 is greater than the turn-on voltage of the first discharge transistor Q1 (for example, 0.6V), the first discharge transistor Q1 is turned on, and thus, through the first diode D1, a part of the current at the input end of the first amplification unit 142 is diverted, thereby limiting the current value flowing through the first amplification unit 142 and improving the operating stability of the entire circuit.

[0137] In some embodiments, the second protection unit 154 may include: a second detection branch (not shown in the figure) and a second discharge branch (not shown in the figure), wherein the second detection branch is used to detect the second detection voltage value between the second amplification unit 144 and the output end; the second discharge branch is used to select or disconnect the path between the input end and the feedback end of the second amplification unit 141 according to the second detection voltage value and its own second voltage amplitude.

[0138] More specifically, if the second detection voltage value is greater than the second voltage amplitude (in some embodiments, the second voltage amplitude may be the same as the first voltage amplitude), it indicates that an overcurrent phenomenon occurs, and the second discharge branch is selected, thereby reducing the driving strength at the input end of the second amplification unit 144 and then weakening the overcurrent phenomenon; if the second detection voltage value is not greater than the second voltage amplitude, it indicates that no overcurrent phenomenon occurs, and the second discharge branch is disconnected.

[0139] In some embodiments, the second detection branch may include a third detection resistor R13 and a fourth detection resistor R12, wherein the first end of the third detection resistor R13 is coupled to the output end of the second amplification unit 144, and the second end of the third detection resistor R13 is respectively coupled to the first end of the fourth detection resistor R12 and the second discharge branch; the second end of the fourth detection resistor R12 is connected to the feedback end.

[0140] In some embodiments, the second discharging branch may include a second diode D2 and a second discharging transistor Q6. Wherein, a first end of the second diode D2 is coupled to a collector of the second discharging transistor Q6, and a second end of the second diode D2 is coupled to an input end of the second amplifying unit 144; a base of the second discharging transistor Q6 is coupled to the second detecting branch, and an emitter of the second discharging transistor Q6 is connected to the feedback end.

[0141] In other words, on the one hand, the second diode D2 defines the flowing direction of the signal on the second discharging branch, so that the signal can only flow from the feedback end of the second amplifying unit 144 to the input end; on the other hand, through the turn-on voltage of the second discharging transistor Q6 itself, it can be adaptively turned on or off based on the detected second detection voltage value, without adding additional circuits, reducing the use of components while meeting the detection performance.

[0142] Specifically, a third detection resistor R13, a fourth detection resistor R12, the second diode D2 and the second discharging transistor Q6 form an overload protection circuit. When the second detection voltage value detected by the third detection resistor R13 and the fourth detection resistor R12 is greater than the turn-on voltage of the second discharging transistor Q6 (for example, 0.6V), the second discharging transistor Q6 is turned on, so that a part of the current at the input end of the second amplifying unit 144 is diverted through the first diode D1, thereby limiting the current value flowing through the second amplifying unit 142 and improving the operating stability of the entire circuit.

[0143] In some embodiments, a resistor R2 is further coupled to the base of the first differential transistor Q9. This resistor R2 plays a role in current limiting and reliable cut-off, ensuring that there is no mis-turn-on problem when there is no signal at the base of the first differential transistor Q9. And the parallel resistor R2 at the base of the first differential transistor Q9 provides a bias voltage to raise the input signal level and ensure the normal operation of the first differential transistor Q9.

[0144] It should be noted that Figure 3 The input end IN and the output end OUT of the audio power amplifying circuit are also shown.

[0145] It can be understood that the above describes multiple embodiment solutions provided by the embodiments of the present disclosure. Each optional manner introduced in each embodiment solution can be combined and cross-referenced with each other without conflict, so as to extend multiple possible embodiment solutions, all of which can be considered as the embodiment solutions disclosed and made public by the present disclosure.

[0146] Although the embodiments of the present disclosure are disclosed as above, the present invention is not limited thereto. Any person skilled in the art can make various changes and modifications without departing from the spirit and scope of the present invention. Therefore, the protection scope of the present invention should be subject to the scope defined by the claims.

Claims

1. An audio power amplifier circuit, characterized in that: include: Input module, conversion module, bias module and power amplifier module, wherein: The input module is configured to generate a current signal corresponding to the input voltage according to the input voltage and the feedback voltage, wherein the feedback voltage is generated according to the output signal of the output terminal of the audio power amplifier circuit; The conversion module is configured to convert the type of the current signal and perform amplification processing to generate a voltage amplified signal; The bias module is configured to change the bias voltage output to the power amplifier module by changing its own resistance value; The power amplifier module has a fully complementary architecture and is configured to output a voltage output signal consistent with the voltage amplification signal when in a preset working state according to the bias voltage, and to generate a current amplification signal based on the voltage amplification signal.

2. The audio power amplifier circuit according to claim 1, characterized in that: The input module comprises: a differential input unit, a clamping unit and a current regulating unit, wherein: The differential input unit comprises a first differential branch and a second differential branch, wherein the first differential branch is coupled to the clamping unit, the current regulating unit and the second differential branch respectively, and is configured to output the current signal to the conversion module; the second differential branch is coupled to the clamping unit and the current regulating unit respectively; The clamping unit is configured to make the current signal on the first differential branch path the same as the current signal on the second differential branch path; The current regulating unit is configured to regulate the current signals of the first differential branch and the second differential branch in response to a change in the difference between the feedback voltage and the input voltage, so that the current signals have a preset amplitude.

3. The audio power amplifier circuit according to claim 2, characterized in that: Satisfy at least one or more of the following: The first differential branch includes a first differential transistor, a first resistor, a second resistor and a second differential transistor, wherein: the base of the first differential transistor is suitable for inputting the input voltage, the collector of the first differential transistor is coupled to the first end of the second resistor and the base of the second differential transistor respectively, the emitter of the first differential transistor is coupled to the second end of the first resistor and the collector of the second differential transistor respectively; the emitter of the second differential transistor is coupled to the second end of the second resistor and the clamping unit respectively; the first end of the first resistor is coupled to the current regulating unit and the second differential branch respectively; The second differential branch includes a third differential transistor, a third resistor, a fourth resistor and a fourth differential transistor, wherein: the base of the third differential transistor is suitable for inputting the feedback voltage, the collector of the first differential transistor is coupled to the first end of the fourth resistor and the base of the fourth differential transistor respectively, the emitter of the third differential transistor is coupled to the second end of the third resistor and the collector of the fourth differential transistor respectively; the emitter of the fourth differential transistor is coupled to the second end of the fourth resistor and the clamping unit respectively; the first end of the third resistor is coupled to the current regulating unit and the first differential branch respectively; The clamping unit comprises a current mirror, the current mirror comprises a first mirror branch consisting of a first mirror transistor and a first mirror resistor, and a second mirror branch consisting of a second mirror transistor and a second mirror resistor, wherein the base of the first mirror transistor is coupled to the base of the second mirror transistor, the collector of the second mirror transistor and the second difference branch respectively, the collector of the first mirror transistor is coupled to the first difference branch and the conversion module respectively, the emitter of the first mirror transistor is coupled to the first end of the first mirror resistor; the second end of the first mirror resistor is coupled to the second end of the second mirror resistor; the emitter of the second mirror transistor is coupled to the first end of the second mirror resistor; The current regulating unit includes: a first voltage source, a first transistor and a fifth resistor, wherein the first end of the first voltage source is coupled to the first end of the fifth resistor, and the second end of the first voltage source is coupled to the base of the first transistor; the emitter of the first transistor is coupled to the second end of the fifth resistor, and the collector of the first transistor is coupled to the first differential branch and the second differential branch, respectively.

4. The audio power amplifier circuit according to claim 1, characterized in that: The conversion module includes: a first-stage conversion unit and a second-stage conversion unit, the first-stage conversion unit is coupled to the input module and the second-stage conversion unit respectively, and the second-stage conversion unit is coupled to the bias module and the power amplification module respectively.

5. The audio power amplifier circuit according to claim 4, characterized in that: Satisfy at least one or more of the following: The first-stage conversion unit comprises: a first conversion transistor and a first conversion resistor, the base of the first conversion transistor is coupled to the input module, the collector of the first conversion transistor is grounded, and the emitter of the first conversion transistor is coupled to the second-stage conversion unit and the first end of the first conversion resistor respectively; The second-stage conversion unit includes: a second conversion transistor and a second conversion resistor, the collector of the second conversion transistor is coupled to the bias module and the power amplification module respectively, and the emitter of the second conversion transistor is coupled to the first end of the second conversion resistor; The filter capacitor is coupled to the base of the first conversion transistor and the collector of the second conversion transistor respectively.

6. The audio power amplifier circuit according to claim 1, characterized in that: The bias module comprises: a reference current unit and a bias unit, wherein: The reference current unit is coupled to the bias unit and is configured to provide a reference current; The bias unit is coupled to the power amplifier module and is configured to provide a corresponding bias voltage to the power amplifier module according to the adjusted resistance value and the reference current.

7. The audio power amplifier circuit according to claim 6, characterized in that: Satisfy at least one or more of the following: The reference current unit includes: a second voltage source, a second transistor and a sixth resistor, wherein a first end of the second voltage source is coupled to a first end of the sixth resistor, a second end of the second voltage source is coupled to a base of the second transistor; an emitter of the second transistor is coupled to a second end of the sixth resistor, and a collector of the second transistor is coupled to the bias unit; The bias unit includes: a third transistor, a seventh resistor, an eighth resistor, a ninth resistor and an adjustable resistor, wherein: the base of the third transistor is connected to the second end of the seventh resistor and the first end of the eighth resistor respectively, the collector of the third transistor is coupled to the second end of the ninth resistor and the power amplifier module respectively, the emitter of the third transistor is coupled to the second end and the third end of the adjustable resistor respectively; the first end of the seventh resistor is coupled to the first end of the ninth resistor and the reference current unit respectively; the second end of the eighth resistor is coupled to the first end of the adjustable resistor.

8. The audio power amplifier circuit according to claim 1, characterized in that: The power amplifier module includes: a first amplifier unit and a second amplifier unit having the fully complementary architecture and being turned on in time-sharing manner, wherein the first amplifier unit is enabled when the voltage amplification signal is in a positive half-cycle; the second amplifier unit is enabled when the voltage amplification signal is in a negative half-cycle, and when in the enabled state, in response to the bias voltage, the audio power amplifier circuit operates in a Class AB state while generating the current amplification signal and the output voltage signal.

9. The audio power amplifier circuit according to claim 8, characterized in that: Satisfy at least one or more of the following: The first amplifying unit includes a first power tube, a second power tube, a third power tube, a first power resistor, a second power resistor, a third power resistor and a fourth power resistor, wherein the base of the first power tube is coupled to the bias module, the collector of the first power tube is coupled to the second end of the first power resistor and the base of the second power tube respectively, the emitter of the first power tube is coupled to the first end of the second power resistor; the collector of the second power tube is coupled to the second end of the third power resistor; the emitter of the second power tube is coupled to the first end of the fourth power resistor and the base of the third power tube respectively; the collector of the third power tube is coupled to the first end of the first power resistor and the first end of the third power resistor respectively; the emitter of the third power tube is coupled to the second end of the second power resistor, the second end of the fourth power resistor and the second amplifying unit respectively; The second amplifying unit includes a fourth power tube, a fifth power tube, a sixth power tube, a fifth power resistor, a sixth power resistor, a seventh power resistor and an eighth power resistor, wherein the base of the fourth power tube is coupled to the bias module and the conversion module respectively, the collector of the fourth power tube is coupled to the first end of the first power resistor and the base of the fifth power tube respectively, the emitter of the fourth power tube is coupled to the first end of the sixth power resistor; the collector of the fifth power tube is coupled to the second end of the seventh power resistor and the base of the sixth power tube respectively; the emitter of the fifth power tube is coupled to the first end of the eighth power resistor; the collector of the sixth power tube is coupled to the second end of the eighth power resistor and the second end of the fifth power resistor respectively; the emitter of the sixth power tube is coupled to the second end of the sixth power resistor and the first end of the seventh power resistor respectively.

10. The audio power amplifier circuit according to claim 1, characterized in that: Also includes at least one or more of the following: A voltage dividing module, coupled to the output end of the audio power amplifier circuit and the input module respectively, and configured to divide the output voltage of the output end of the audio power amplifier circuit to obtain the feedback voltage; A first buffer resistor is arranged between the bias module and the power amplifier module; A second buffer resistor is arranged between the conversion module and the power amplification module; A compensation module, disposed at the output end of the audio power amplifier circuit, configured to compensate the current amplification signal to improve the stability of the current amplification signal; The voltage divider module includes a first voltage divider resistor, a second voltage divider resistor and a feedback capacitor, wherein the first end of the first voltage divider resistor is coupled to the output end of the audio power amplifier circuit, the second end of the first voltage divider resistor is coupled to the first end of the second voltage divider resistor and the input module respectively, the second end of the second voltage divider resistor is coupled to the first end of the feedback capacitor, and the second end of the feedback capacitor is grounded; The compensation module includes a compensation inductor and a compensation resistor connected in parallel.

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