Power amplifier control circuit and active sound box

Abstract

The invention relates to a power amplifier control circuit and an active sound box. The power amplifier control circuit comprises a power supply module, a first MOS tube, a second MOS tube, a switch module, a power amplifier module and a loudspeaker, the grid electrode of the first MOS tube and the grid electrode of the second MOS tube are both electrically connected with the positive electrode end of the power supply module, the power supply module is suitable for transmitting constant voltage to the first MOS tube and the second MOS tube, the source electrode of the first MOS tube is electrically connected with the source electrode of the second MOS tube, the drain electrode of the first MOS tube is electrically connected with the output of the power amplifier module, and the drain electrode of the second MOS tube is electrically connected with the positive end of the loudspeaker; the input end of the power amplifier module and the negative end of the loudspeaker are grounded; the grid electrode of the first MOS tube and the grid electrode of the second MOS tube are electrically connected with the first end of the switch module, and the second end of the switch module is grounded so as to control the on-off of the first MOS tube and the second MOS tube. According to the power amplifier control circuit, the condition of signal distortion can be effectively avoided.

Description

Technical Field

[0001] The present application relates to the technical field of power amplifier control, and in particular to a power amplifier control circuit and an active speaker. Background Art

[0002] When using audio equipment such as speakers, a control circuit is generally used to control the power amplifier.

[0003] In the power amplifier control circuit in the related art, when the audio signal is small, there may be a situation where the power amplifier and the speaker are not fully connected, which may cause the problem of small signal distortion. Summary of the invention

[0004] An embodiment of the present application provides a power amplifier control circuit that can avoid signal distortion and at least partially solve the above technical problems.

[0005] In order to achieve the above-mentioned object, according to a first aspect of the present application, a power amplifier control circuit is provided, including a power module, a first MOS transistor, a second MOS transistor, a switch module, a power amplifier module and a speaker;

[0006] The gate of the first MOS tube and the gate of the second MOS tube are both electrically connected to the positive terminal of the power module, the power module is suitable for transmitting a constant voltage to the first MOS tube and the second MOS tube, the source of the first MOS tube is electrically connected to the source of the second MOS tube, the drain of the first MOS tube is electrically connected to the output of the power amplifier module, and the drain of the second MOS tube is electrically connected to the positive terminal of the speaker;

[0007] The input terminal of the power amplifier module and the negative terminal of the speaker are both grounded;

[0008] The gate of the first MOS tube and the gate of the second MOS tube are both electrically connected to the first end of the switch module, and the second end of the switch module is grounded to control the on and off of the first MOS tube and the second MOS tube.

[0009] Optionally, the switch module includes a switch tube, the gate of the first MOS tube and the gate of the second MOS tube are both electrically connected to the output end of the switch tube, the ground end of the switch tube is grounded, and the control end of the switch tube is used to receive a control signal.

[0010] Optionally, the switch module further includes a first resistor, a first end of the first resistor is electrically connected to the output end of the switch tube, and a gate of the first MOS tube and a gate of the second MOS tube are both electrically connected to a second end of the first resistor.

[0011] Optionally, the switch module further includes a second resistor, a first end of the second resistor is electrically connected to the control end of the switch tube, and a second end of the second resistor is used to receive a control signal.

[0012] Optionally, the power amplifier control circuit also includes a third resistor and a fourth resistor, the third resistor is electrically connected between the power module and the gate of the first MOS tube, and the fourth resistor is electrically connected between the third resistor and the source of the first MOS tube.

[0013] Optionally, the power amplifier control circuit further includes a voltage stabilizing module, a first end of the voltage stabilizing module is electrically connected to the gate of the first MOS tube, and a second end of the voltage stabilizing module is electrically connected to the source of the first MOS tube.

[0014] Optionally, the voltage stabilizing module includes a voltage stabilizing diode, a positive terminal of the voltage stabilizing diode is electrically connected to the gate of the first MOS tube, and a negative terminal of the voltage stabilizing diode is electrically connected to the source of the first MOS tube.

[0015] Optionally, the power amplifier control circuit further includes a capacitor module, a first end of the capacitor module is electrically connected to the gate of the first MOS tube, and a second end of the capacitor module is electrically connected to the source of the first MOS tube.

[0016] Optionally, the power module includes a power amplifier power supply and a boost power supply, and the power amplifier power supply and the boost power supply are arranged in series between the gate of the first MOS tube and the ground.

[0017] According to a second aspect of the present application, there is also provided an active speaker, comprising the power amplifier control circuit as described above.

[0018] In the power amplifier control circuit of the embodiment of the present application, the power module is used to transmit the conduction voltage to the first MOS tube and the second MOS tube, and at the same time, the switch module is used to control the on-off between the gate of the first MOS tube and the second MOS tube and the ground. When the switch module connects the gate of the first MOS tube to the ground and the gate of the second MOS tube to the ground, the first MOS tube and the second MOS tube are in a disconnected state, and the power amplifier module and the speaker are in a disconnected state at this time. When the switch module disconnects the first MOS tube and the ground and the second MOS tube and the ground, the first MOS tube and the second MOS tube are in a conducting state under the action of the constant voltage provided by the power module, and the power amplifier module and the speaker are in a connected state. That is to say, the present application can realize the control of the on-off state of the first MOS tube and the second MOS tube through the power module and the switch module, and then control the on-off between the power amplifier module and the speaker. The size of the audio signal output by the power amplifier module will not affect the on-off of the first MOS tube and the second MOS tube. Regardless of the size of the audio signal, the power amplifier module can be guaranteed to be connected to the speaker, which can effectively avoid the occurrence of signal distortion.

[0019] Other features and advantages of the present application will be described in detail in the subsequent specific implementation section. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present application, and those skilled in the art can obtain other drawings based on these drawings without creative work.

[0021] In order to more completely understand the present application and its beneficial effects, the following description will be given in conjunction with the accompanying drawings, wherein the same figure numbers represent the same parts in the following description.

[0022] Figure 1 is a schematic diagram of a power amplifier control circuit provided in an exemplary embodiment of the present disclosure;

[0023] Figure 2 is one of the circuit diagrams of the power amplifier control circuit provided in the exemplary embodiment of the present disclosure;

[0024] Figure 3 is a second circuit diagram of a power amplifier control circuit provided in an exemplary embodiment of the present disclosure;

[0025] Figure 4 This is the third circuit diagram of the power amplifier control circuit provided in the exemplary embodiment of the present disclosure.

[0026] Description of reference numerals:

[0027] 1. Power module; 2. First MOS tube; 3. Second MOS tube; 4. Switch module; 5. Power amplifier module; 6. Speaker; 7. Voltage regulator module; 8. Capacitor module. DETAILED DESCRIPTION

[0028] The technical solutions in the embodiments of the present application will be described clearly and completely below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative work are within the scope of protection of the present application.

[0029] According to the first aspect of this application, see Figure 1 and Figure 2 The present disclosure provides a power amplifier control circuit. The power amplifier control circuit includes a power module 1, a first MOS tube 2, a second MOS tube 3, a switch module 4, a power amplifier module 5 and a speaker 6;

[0030] The gate of the first MOS transistor 2 and the gate of the second MOS transistor 3 are both electrically connected to the positive terminal of the power module 1. The power module 1 is suitable for transmitting a constant voltage to the first MOS transistor 2 and the second MOS transistor 3. The source of the first MOS transistor 2 is electrically connected to the source of the second MOS transistor 3. The drain of the first MOS transistor 2 is electrically connected to the output of the power amplifier module 5. The drain of the second MOS transistor 3 is electrically connected to the positive terminal of the speaker 6.

[0031] The input of the power amplifier module 5 and the negative terminal of the speaker 6 are both grounded;

[0032] The gate of the first MOS transistor 2 and the gate of the second MOS transistor 3 are both electrically connected to the first end of the switch module 4 , and the second end of the switch module 4 is grounded to control the on and off of the first MOS transistor 2 and the second MOS transistor 3 .

[0033] It can be understood that the first MOS transistor 2 and the second MOS transistor 3 are arranged in series between the power amplifier module 5 and the speaker 6, that is, the on-off of the power amplifier module 5 and the speaker 6 can be controlled by controlling the on-off of the first MOS transistor 2 and the second MOS transistor 3.

[0034] The power module 1 is used to transmit the conduction voltage to the first MOS tube 2 and the second MOS tube 3. At the same time, the switch module 4 controls the on-off between the gate of the first MOS tube 2 and the second MOS tube 3 and the ground. When the switch module 4 connects the gate of the first MOS tube 2 and the ground and the gate of the second MOS tube 3 and the ground, the first MOS tube 2 and the second MOS tube 3 are in a disconnected state, and at this time, the power amplifier module 5 and the speaker 6 are in a disconnected state. When the switch module 4 disconnects the first MOS tube 2 and the ground and the second MOS tube 3 and the ground, the first MOS tube 2 and the second MOS tube 3 are in a conducting state under the action of the constant voltage provided by the power module 1, and at this time, the power amplifier module 5 and the speaker 6 are in a connected state. That is to say, the present application can realize the control of the on-off state of the first MOS tube 2 and the second MOS tube 3 through the power module 1 and the switch module 4, and then can control the on-off between the power amplifier module 5 and the speaker 6. The size of the audio signal output by the power amplifier module 5 will not affect the on-off of the first MOS tube 2 and the second MOS tube 3. Regardless of the size of the audio signal, it can ensure that the power amplifier module 5 is connected to the speaker 6, which can effectively avoid the occurrence of signal distortion.

[0035] It can be understood that the present application controls the on and off of the first MOS tube 2 and the second MOS tube 3 through the switch module 4, so that the first MOS tube 2 and the second MOS tube 3 can remain normally turned on, that is, the power amplifier module 5 and the speaker 6 are normally connected to respond to sudden audio signals.

[0036] In some embodiments, see Figure 1 and Figure 2 The switch module 4 includes a switch tube Q1, the gate of the first MOS tube 2 and the gate of the second MOS tube 3 are both electrically connected to the output end of the switch tube Q1, the ground end of the switch tube Q1 is grounded, and the control end of the switch tube Q1 is used to receive a control signal.

[0037] It can be understood that the control end of the switch tube Q1 is used to receive a control signal, and the control signal can control the on and off of the switch tube Q1. When the switch tube Q1 is turned off, the gate of the first MOS tube 2 will not be grounded through the switch tube Q1, and the gate of the second MOS tube 3 will not be grounded through the switch tube Q1. Then, the voltage provided by the power module 1 can make the voltage difference between the gate and the source of the first MOS tube 2 and the second MOS tube 3 reach the conduction voltage, and the first MOS tube 2 and the second MOS tube 3 are in the on state, so that the power amplifier module 5 and the speaker 6 are connected; when the switch tube Q1 is connected, the gate of the first MOS tube 2 is grounded through the switch tube Q1, and the gate of the second MOS tube 3 is grounded through the switch tube Q1. At this time, the voltage difference between the gate and the source of the first MOS tube 2 and the second MOS tube 3 will not reach the conduction voltage, and the first MOS tube 2 and the second MOS tube 3 are in the off state, and the power amplifier module 5 and the speaker 6 are disconnected, so that the on and off state of the first MOS tube 2 and the second MOS tube 3 is controlled by the switch tube Q1.

[0038] In some examples, the control end of the switch tube Q1 can be used to be electrically connected to a processor, and the on and off of the switch tube Q1 can be controlled by the processor sending a corresponding control signal to the control end of the switch tube Q1.

[0039] In some examples, the switch tube Q1 is, for example, a field effect transistor.

[0040] In some embodiments, the switch tube Q1 includes a triode, the gate of the first MOS tube 2 and the gate of the second MOS tube 3 are both electrically connected to the collector of the triode, the emitter of the triode is grounded, and the base of the triode is used to receive a control signal.

[0041] In some embodiments, see Figure 1 and Figure 3 The switch module 4 also includes a first resistor R1, a first end of the first resistor R1 is electrically connected to the output end of the switch tube Q1, and a gate of the first MOS tube 2 and a gate of the second MOS tube 3 are both electrically connected to a second end of the first resistor R1.

[0042] It is understandable that when the switch tube Q1 is in the on state, the first resistor R1 can prevent the gate of the first MOS tube 2 from being directly grounded, that is, it can prevent the positive terminal of the power module 1 from being directly grounded, and the first resistor R1 can play a role in protecting the circuit.

[0043] In some examples, the resistance of the first resistor R1 is, for example, 100 ohms.

[0044] In some examples, when the switch tube Q1 is a transistor, the first end of the first resistor R1 is electrically connected to the collector of the transistor, and the gate of the first MOS tube 2 and the gate of the second MOS tube 3 are both electrically connected to the second end of the first resistor R1.

[0045] In some embodiments, see Figure 1 and Figure 3 The switch module 4 further includes a second resistor R2, a first end of the second resistor R2 is electrically connected to the control end of the switch tube Q1, and a second end of the second resistor R2 is used to receive a control signal.

[0046] It can be understood that, by electrically connecting the second resistor R2 to the control end of the switch tube Q1 , the second resistor R2 can limit the current flowing to the control end, thereby preventing the switch tube Q1 from being damaged due to excessive current.

[0047] In some examples, the resistance of the second resistor R2 is, for example, 10k ohms.

[0048] In some examples, when the switch tube Q1 is a triode, the first end of the second resistor R2 is electrically connected to the base of the triode, and the second end of the second resistor R2 is used to receive a control signal. The second resistor R2 limits the magnitude of the base current to prevent the current from being too large, thereby protecting the triode from damage and helping to stabilize the working point of the triode.

[0049] In some embodiments, see Figure 1 and Figure 3 The power amplifier control circuit also includes a third resistor R3 and a fourth resistor R4, the third resistor R3 is electrically connected between the power module 1 and the gate of the first MOS tube 2, and the fourth resistor R4 is electrically connected between the third resistor R3 and the source of the first MOS tube 2.

[0050] It can be understood that the power module 1, the third resistor R3 and the fourth resistor R4 are connected in series in sequence, and the third resistor R3 and the fourth resistor R4 play a role of voltage division. The gate of the first MOS tube 2 and the gate of the second MOS tube 3 are both electrically connected to one end of the fourth resistor R4, and the source of the first MOS tube 2 and the source of the second MOS tube 3 are both electrically connected to the other end of the fourth resistor R4. The voltage difference between the two ends of the fourth resistor R4 is the voltage difference between the gate and the source of the first MOS tube 2 and the gate and the source of the second MOS tube 3. That is, in this embodiment, the first MOS tube 2 and the second MOS tube 3 are provided with a conduction voltage through the voltage division of the third resistor R3 and the fourth resistor R4.

[0051] In some examples, the resistance of the third resistor R3 is 100k ohms, and the resistance of the fourth resistor R4 is 470k ohms.

[0052] In some embodiments, see Figure 1 and Figure 4 The power amplifier control circuit also includes a voltage stabilizing module 7, a first end of the voltage stabilizing module 7 is electrically connected to the gate of the first MOS tube 2, and a second end of the voltage stabilizing module 7 is electrically connected to the source of the first MOS tube 2.

[0053] It can be understood that the gate of the first MOS tube 2 and the gate of the second MOS tube 3 are both electrically connected to the first end of the voltage stabilizing module 7, and the source of the first MOS tube 2 and the source of the second MOS tube 3 are both electrically connected to the second end of the voltage stabilizing module 7. The voltage stabilizing module 7 can stabilize the voltage between the gate and the source of the first MOS tube 2 and the voltage between the gate and the source of the second MOS tube 3, so that the voltage between the gate and the source of the first MOS tube 2 and the voltage between the gate and the source of the second MOS tube 3 remain stable, so that the first MOS tube 2 and the second MOS tube 3 can maintain a stable conduction state.

[0054] In some embodiments, see Figure 1 and Figure 4 The voltage stabilizing module 7 includes a voltage stabilizing diode D1 , a positive terminal of the voltage stabilizing diode D1 is electrically connected to the gate of the first MOS tube 2 , and a negative terminal of the voltage stabilizing diode D1 is electrically connected to the source of the first MOS tube 2 .

[0055] It can be understood that the voltage stabilizing diode D1 can stabilize the first MOS transistor 2 and the second MOS transistor 3 , so that the first MOS transistor 2 and the second MOS transistor 3 can remain in a conducting state.

[0056] In some examples, the voltage regulator module 7 may also be an operational amplifier.

[0057] In some embodiments, see Figure 1 and Figure 4 The power amplifier control circuit also includes a capacitor module 8, a first end of the capacitor module 8 is electrically connected to the gate of the first MOS tube 2, and a second end of the capacitor module 8 is electrically connected to the source of the first MOS tube 2.

[0058] It can be understood that the gate of the first MOS tube 2 and the gate of the second MOS tube 3 are both electrically connected to the first end of the capacitor module 8, and the source of the first MOS tube 2 and the source of the second MOS tube 3 are both electrically connected to the second end of the capacitor module 8. The capacitor module 8 can improve the voltage stability between the gate and source of the first MOS tube 2 and the gate and source of the second MOS tube 3, and the capacitor module 8 can also filter out noise.

[0059] The present application controls the on / off of the first MOS tube 2 and the second MOS tube 3 by the switch module 4, so the power module 1 can remain in the on state. When controlling the first MOS tube 2 and the second MOS tube 3 to switch from the off state to the on state, the power module 1 does not need to be reopened, thereby improving the conduction speed of the first MOS tube 2 and the second MOS tube 3.

[0060] In the related art, before turning on the MOS tube, it is necessary to charge the capacitor electrically connected to the MOS tube. However, the power module 1 of the present application can remain in the on state, and the capacitor module 8 will remain in the fully charged state, that is, when the on and off states of the first MOS tube 2 and the second MOS tube 3 are controlled by the switch module 4, the capacitor module 8 does not need to be charged, thereby improving the conduction speed of the first MOS tube 2 and the second MOS tube 3.

[0061] In some examples, the capacitor module 8 includes at least one capacitor C1.

[0062] In some embodiments, see Figure 1 and Figure 2 The power module 1 includes a power amplifier power supply V1 and a boost power supply V2, and the power amplifier power supply V1 and the boost power supply V2 are arranged in series between the gate of the first MOS tube 2 and the ground.

[0063] It can be understood that by connecting two power supplies in series to supply power to the first MOS transistor 2 and the second MOS transistor 3 , the power supply voltage is increased, ensuring that the power module 1 can keep the first MOS transistor 2 and the second MOS transistor 3 in a conducting state.

[0064] According to a second aspect of the present application, the present disclosure provides an active speaker, which includes the above-mentioned power amplifier control circuit.

[0065] It can be understood that the power module 1 is used to transmit the conduction voltage to the first MOS tube 2 and the second MOS tube 3, and at the same time, the switch module 4 is used to control the on-off between the gate of the first MOS tube 2 and the second MOS tube 3 and the ground. When the switch module 4 connects the gate of the first MOS tube 2 and the ground and the gate of the second MOS tube 3 and the ground, the first MOS tube 2 and the second MOS tube 3 are in a disconnected state, and at this time, the power amplifier module 5 and the speaker 6 are in a disconnected state. When the switch module 4 disconnects the first MOS tube 2 and the ground and the second MOS tube 3 and the ground, the first MOS tube 2 and the second MOS tube 3 are in a conducting state under the action of the constant voltage provided by the power module 1, and at this time, the power amplifier module 5 and the speaker 6 are in a connected state. That is to say, the present application can realize the control of the on-off state of the first MOS tube 2 and the second MOS tube 3 through the power module 1 and the switch module 4, and then control the on-off between the power amplifier module 5 and the speaker 6. The size of the audio signal output by the power amplifier module 5 will not affect the on-off of the first MOS tube 2 and the second MOS tube 3. Regardless of the size of the audio signal, the power amplifier module 5 can be guaranteed to be connected with the speaker 6, which can effectively avoid the occurrence of signal distortion.

[0066] In the description of this application, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more features. In the description of this application, the meaning of "plurality" is two or more, unless otherwise clearly and specifically defined.

[0067] In the above embodiments, the description of each embodiment has its own emphasis. For parts that are not described in detail in a certain embodiment, reference can be made to the relevant descriptions of other embodiments.

[0068] The embodiments, implementation methods and related technical features of the present application can be combined and replaced with each other without conflict.

[0069] The above are only preferred embodiments of the present application and do not constitute any form of limitation to the present application. However, any simple modifications, equivalent changes and modifications made to the above embodiments based on the technical essence of the present application without departing from the content of the technical solution of the present application are still within the scope of the technical solution of the present application.

Claims

1. A power amplifier control circuit, characterized in that: It includes a power module, a first MOS tube, a second MOS tube, a switch module, a power amplifier module and a speaker; The gate of the first MOS tube and the gate of the second MOS tube are both electrically connected to the positive terminal of the power module, the power module is suitable for transmitting a constant voltage to the first MOS tube and the second MOS tube, the source of the first MOS tube is electrically connected to the source of the second MOS tube, the drain of the first MOS tube is electrically connected to the output of the power amplifier module, and the drain of the second MOS tube is electrically connected to the positive terminal of the speaker; The input of the power amplifier module and the negative terminal of the speaker are both grounded; The gate of the first MOS tube and the gate of the second MOS tube are both electrically connected to the first end of the switch module, and the second end of the switch module is grounded to control the on and off of the first MOS tube and the second MOS tube.

2. The power amplifier control circuit according to claim 1, characterized in that: The switch module includes a switch tube, the gate of the first MOS tube and the gate of the second MOS tube are both electrically connected to the output end of the switch tube, the ground end of the switch tube is grounded, and the control end of the switch tube is used to receive a control signal.

3. The power amplifier control circuit according to claim 2, characterized in that: The switch module further includes a first resistor, a first end of the first resistor is electrically connected to the output end of the switch tube, and a gate of the first MOS tube and a gate of the second MOS tube are both electrically connected to a second end of the first resistor.

4. The power amplifier control circuit according to claim 2, characterized in that: The switch module further includes a second resistor, a first end of the second resistor is electrically connected to the control end of the switch tube, and a second end of the second resistor is used to receive a control signal.

5. The power amplifier control circuit according to any one of claims 1 to 4, characterized in that: The power amplifier control circuit also includes a third resistor and a fourth resistor, the third resistor is electrically connected between the power module and the gate of the first MOS tube, and the fourth resistor is electrically connected between the third resistor and the source of the first MOS tube.

6. The power amplifier control circuit according to any one of claims 1 to 4, characterized in that: The power amplifier control circuit further includes a voltage stabilizing module, a first end of the voltage stabilizing module is electrically connected to the gate of the first MOS tube, and a second end of the voltage stabilizing module is electrically connected to the source of the first MOS tube.

7. The power amplifier control circuit according to claim 6, characterized in that: The voltage stabilizing module includes a voltage stabilizing diode, a positive terminal of the voltage stabilizing diode is electrically connected to the gate of the first MOS tube, and a negative terminal of the voltage stabilizing diode is electrically connected to the source of the first MOS tube.

8. The power amplifier control circuit according to any one of claims 1 to 4, characterized in that: The power amplifier control circuit further includes a capacitor module, a first end of the capacitor module is electrically connected to the gate of the first MOS tube, and a second end of the capacitor module is electrically connected to the source of the first MOS tube.

9. The power amplifier control circuit according to any one of claims 1 to 4, characterized in that: The power module comprises a power amplifier power supply and a boost power supply, and the power amplifier power supply and the boost power supply are arranged in series between the gate of the first MOS tube and the ground.

10. An active speaker, characterized in that: The invention comprises a power amplifier control circuit as claimed in any one of claims 1 to 9.

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