Power amplifier circuit and electronic equipment

Abstract

The utility model discloses a power amplifier circuit and electronic equipment. The power amplifier circuit comprises a power supply module; the power supply end of the power amplification module is connected with the power supply module, and the output end is connected with an external loudspeaker; the signal detection module is connected with the output end of the power amplification module and the power supply module; wherein the signal detection module is configured to detect an audio signal of the output end of the power amplification module, and the power supply module is configured to provide a first voltage signal for the power amplification module when the signal detection module does not detect the audio signal and provide a second voltage signal for the power amplification module when the signal detection module detects the audio signal. A second voltage signal is provided for the power amplification module, and the voltage value of the second voltage signal is larger than that of the first voltage signal. Through the mode, the power supply voltage can be reduced when the power amplification module has no audio output, the circuit energy consumption is reduced, the heating is reduced, and the service life of the power amplifier is further prolonged.

Description

Technical Field

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

[0002] The full name of the amplifier is power amplifier. Its function is to amplify the weak signal input by the sound source equipment and generate a large enough current to drive the speaker to reproduce the sound. With the development of society and the improvement of people's living standards, listeners begin to pay attention to better music experience, and gradually begin to pursue audio with better restoration.

[0003] As a type of power amplifier, the boost amplifier has greatly improved the sound quality. The improvement in sound quality is also accompanied by an increase in power. To ensure that the speaker has sufficient driving power, the voltage of the sound signal needs to be increased to the required voltage value through a boost circuit. The car amplifier consumes the car battery. The boost circuit is always on, causing energy waste and causing the amplifier to continue to heat up, affecting the performance and service life of the amplifier. Utility Model Content

[0004] The present application at least provides a power amplifier circuit and electronic device, which can reduce the power supply voltage, reduce circuit energy consumption, reduce heat generation, and thus extend the service life of the power amplifier when the power amplifier module has no audio output.

[0005] In order to solve the above technical problems, a technical solution adopted in the present application is: to provide a power amplifier circuit, which includes: a power supply module; a power amplifier module, whose power supply end is connected to the power supply module, and whose output end is connected to an external speaker; a signal detection module, which is connected to the output end of the power amplifier module and the power supply module; wherein the signal detection module is configured to detect an audio signal at the output end of the power amplifier module, and the power supply module is configured to provide a first voltage signal to the power amplifier module when the signal detection module does not detect the audio signal, and to provide a second voltage signal to the power amplifier module when the signal detection module detects the audio signal, and the voltage value of the second voltage signal is greater than the voltage value of the first voltage signal.

[0006] Among them, the power supply module includes: a boost unit, whose input end is connected to an external power supply, and whose output end is connected to the power supply end of the power amplifier module; a control unit, connected to the signal detection module and the boost unit, and the control unit is configured to control the boost unit to output a first voltage signal provided by the external power supply when the signal detection module does not detect an audio signal, and to control the boost unit to boost the first voltage signal provided by the external power supply and output a second voltage signal after the boost processing when the signal detection module detects an audio signal.

[0007] The boost unit includes: an inductor, a first end of which is connected to an external power supply, and a second end of which is connected to the power supply end of the power amplifier module; a first switch, a first end of which is connected to the second end of the inductor, a second end of which is grounded, and a control end of which is connected to the control unit; wherein the control unit is configured to control the first switch to be disconnected when the signal detection module does not detect an audio signal, and to control the first switch to be alternately turned on and off based on a preset frequency when the signal detection module detects an audio signal.

[0008] The power supply module further includes a second switch, a first end of which is connected to the second end of the inductor, a second end of which is connected to the power supply end of the power amplifier module, and a control end of which is connected to the control unit.

[0009] The power supply module further includes a first capacitor, a first end of which is connected to the second end of the inductor, and a second end of which is grounded.

[0010] Wherein, the signal detection module includes a comparator, whose first input terminal is configured to input a reference voltage signal, whose second input terminal is connected to the output terminal of the power amplifier module, and whose output terminal is connected to the power supply module; wherein the power supply module is configured to provide a first voltage signal to the power amplifier module when the voltage of the signal received at the second input terminal of the comparator is less than the voltage of the reference voltage signal, and to provide a second voltage signal to the power amplifier module when the voltage of the signal received at the second input terminal of the comparator is greater than the voltage of the reference voltage signal.

[0011] The signal detection module further includes a second capacitor, a first end of which is connected to the output end of the power amplification module, and a second end of which is connected to the second input end of the comparator.

[0012] The signal detection module further includes a diode, an anode of which is connected to the second end of the second capacitor, and a cathode of which is connected to the second input end of the comparator.

[0013] The power amplifier circuit further includes: a third capacitor, a first end of which is connected to an external power supply and a second end of which is connected to the output end of the signal detection module; a resistor, a first end of which is connected to the second end of the third capacitor and a second end of which is grounded.

[0014] In order to solve the above technical problem, another technical solution adopted by the present application is: to provide an electronic device, which includes the above power amplifier circuit.

[0015] The beneficial effect of the present application is that, different from the prior art, the power supply module of the present application provides a first voltage signal to the power amplifier module when the signal detection module does not detect an audio signal; and provides a second voltage signal with a voltage value greater than the first voltage signal to the power amplifier module when an audio signal is detected at the output end of the power amplifier module. This reduces the power supply voltage when the power amplifier module has no audio output, reduces circuit energy consumption, reduces heat generation, and thus extends the service life of the power amplifier. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 It is a structural schematic diagram of the first embodiment of the power amplifier circuit of the present application;

[0017] Figure 2 It is a flow chart of the second embodiment of the power amplifier circuit of the present application;

[0018] Figure 3 It is a structural schematic diagram of an embodiment of the electronic device of the present application. DETAILED DESCRIPTION

[0019] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are only some embodiments of the present application, not all embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of this application.

[0020] This application first proposes a power amplifier circuit, such as Figure 1 As shown, Figure 1 1 is a schematic diagram of the structure of the first embodiment of the power amplifier circuit of the present application. The power amplifier circuit 100 of this embodiment includes:

[0021] A power supply module 120; a power amplifier module 130, whose power supply end is connected to the power supply module 120, and whose output end is connected to the external speaker 140; a signal detection module 110, connected to the output end of the power amplifier module 130 and the power supply module 120; wherein the signal detection module 110 is configured to detect an audio signal at the output end of the power amplifier module 130, and the power supply module 120 is configured to provide a first voltage signal to the power amplifier module 130 when the signal detection module 110 does not detect an audio signal, and to provide a second voltage signal to the power amplifier module 130 when the signal detection module 110 detects an audio signal, and a voltage value of the second voltage signal is greater than a voltage value of the first voltage signal.

[0022] Specifically, the input end of the power amplifier module 130 can be connected to an audio input signal, and the power amplifier module 130 can be a power amplifier circuit or a PA chip. The audio signal output by the power amplifier unit can be an AC signal superimposed with a DC bias signal.

[0023] In this embodiment, the input end of the signal detection module 110 is connected to the output end of the power amplifier module 130 for detecting an audio signal. When the signal detection unit does not detect an audio signal, the power supply module 120 provides a first voltage signal to the power amplifier module 130. When the signal detection unit detects an audio signal, the power supply module 120 provides a second voltage signal having a voltage value greater than the first voltage signal to the power amplifier module 130. This reduces the power supply voltage when the power amplifier module 130 has no audio output, reduces circuit energy consumption, reduces heat generation, and thereby extends the service life of the power amplifier.

[0024] Optionally, in one embodiment, the power amplifier circuit 100 further includes a third capacitor C3 and a resistor R1, wherein a first end of the third capacitor C3 is connected to an external power supply, and a second end of the third capacitor C3 is connected to an output end of the signal detection module 110. A first end of the resistor R1 is connected to a second end of the third capacitor C3, and a second end of the resistor R1 is grounded. The third capacitor C3 and the resistor R1 constitute a delay module, and the third capacitor C3 is charged when a signal is output from the output end of the signal detection module 110, and when the output end of the signal detection module 110 stops outputting a signal, the third capacitor C3 is discharged, so that the output end signal of the signal detection module 110 continues for a period of time.

[0025] Different from the prior art, the power amplifier circuit 100 of the present application detects whether there is an audio output at the output end of the power amplifier module 130 through the signal detection module 110, and the power supply module 120 is based on the detection result; if the detection result is that no audio output is detected, the power supply module 120 provides a first voltage signal to the power amplifier module 130; if the detection result is that the audio output is detected, the power supply module 120 provides a second voltage signal with a voltage value greater than the first voltage signal to the power amplifier module 130. The power supply voltage of the power amplifier circuit is adjusted to avoid continuous high-voltage power supply when the power amplifier circuit has no audio output, resulting in energy waste, while causing the power amplifier to heat up and affect the performance of the power amplifier. The present application can also extend the duration of the output end signal of the signal detection module 110 by cooperating with the third capacitor C3 and the resistor R1, and avoid the influence of the fluctuation of the power supply voltage on the subsequent modules by signal delay. The delay time can be controlled by adjusting the capacitance of the third capacitor C3 and / or the resistance of the resistor R1.

[0026] Alternatively, if Figure 2 As shown, Figure 21 is a schematic diagram of the structure of the second embodiment of the power amplifier circuit 100 of the present application. The power supply module 120 of this embodiment includes a boost unit, whose input end is connected to the external power supply 160, and whose output end is connected to the power supply end of the power amplifier module 130; a control unit 221, connected to the signal detection module 110 and the boost unit, and the control unit 221 is configured to control the boost unit to output the first voltage signal provided by the external power supply 160 when the signal detection module 110 does not detect the audio signal, and to control the boost unit to boost the first voltage signal provided by the external power supply 160 and output the second voltage signal after the boost processing when the signal detection module 110 detects the audio signal.

[0027] The external power supply 160 provides a first voltage signal. In this embodiment, the input end of the control unit 221 is connected to the signal detection module 110, and the output end is connected to the boost unit. The input end of the boost unit is connected to the external power supply 160, the output end is connected to the power supply end of the power amplifier module 130, and the control end is connected to the output end of the control unit 221. In a specific embodiment, the control unit 221 can be a control chip, and the control unit 221 is configured to output a control signal to control the boost unit to output the first voltage signal provided by the external power supply 160 when the signal detection module 110 does not detect an audio signal, and output a control signal to control the boost unit to boost the first voltage signal provided by the external power supply 160 and output a second voltage signal after the boost processing when the signal detection module 110 detects an audio signal. The control signal may include a signal indicating a boost process and a signal indicating a non-boost process. For example, the control signal may be a low-level signal and a high-level signal. When the signal detection module 110 does not detect an audio signal, the output terminal of the control unit 221 outputs a low-level signal, and the boost unit control terminal receives the low-level signal and outputs the first voltage signal provided by the external power supply 160; when the signal detection module 110 detects an audio signal, the output terminal of the control unit 221 outputs a high-level signal, and the boost unit control terminal receives the high-level signal to boost the first voltage signal provided by the external power supply 160 and output the second voltage signal after the boost process. For another example, the control signal may be an I2C, I2S, or SPI signal; when the usage scenario is a vehicle-mounted power amplifier, the control signal may also be a CAN signal, which is not limited here.

[0028] Alternatively, if Figure 2As shown, the boost unit of this embodiment includes: an inductor 222, a first end of which is connected to the external power supply 160, and a second end of which is connected to the power supply end of the power amplification module 130; a first switch Q1, a first end of which is connected to the second end of the inductor 222, a second end of which is grounded, and a control end of which is connected to the control unit 221; wherein the control unit 221 is configured to control the first switch Q1 to be disconnected when the signal detection module 110 does not detect an audio signal, and to control the first switch Q1 to be alternately turned on and off based on a preset frequency when the signal detection module 110 detects an audio signal.

[0029] The first end of the inductor 222 is connected to the external power supply 160, and the second end is connected to the power supply end of the power amplifier module 130. When the first switch Q1 is turned off, the external power supply 160 is connected to the power supply end of the power amplifier module 130 through the inductor 222, and the external power supply 160 provides a first voltage signal, so the power supply end of the power amplifier module 130 receives the first voltage signal. When the first switch Q1 is alternately turned on and off based on a preset frequency, based on the characteristic of the inductor 222 maintaining current, the first voltage signal provided by the external power supply 160 is boosted and a second voltage signal after the boosting is output.

[0030] Alternatively, if Figure 2 As shown, the first switch Q1 may be a transistor, the first end of the transistor (i.e., the drain of the transistor) is connected to the second end of the inductor 222, the second end of the transistor (i.e., the source of the transistor) is grounded, and the control end of the transistor (i.e., the gate of the transistor) is connected to the control unit 221. In other embodiments, the first switch Q1 may also be other types of transistors, not limited to Figure 2 The type in .

[0031] It is understandable that the boost unit in the above embodiment uses an inductor boost circuit, which is a DC boost circuit that can make the output voltage higher than the input voltage. In other embodiments, other DC boost circuits can also be used, which are not limited here.

[0032] Optionally, the power supply module 120 further includes a second switch Q2 , a first end of which is connected to the second end of the inductor 222 , a second end of which is connected to the power supply end of the power amplification module 130 , and a control end of which is connected to the control unit 221 .

[0033] It can be understood that, in one embodiment, the second switch Q2 is always in the on state after the power amplifier circuit 100 is powered on.

[0034] Optionally, the second switch Q2 may be a transistor, a first end of the transistor (i.e., the source of the transistor) is connected to the second end of the inductor 222, a second end of the transistor (i.e., the drain of the transistor) is connected to the power supply terminal of the power amplifier module 130, and a control end of the transistor (i.e., the gate of the transistor) is grounded. The second switch Q2 may also be a diode, an anode of which is connected to the second end of the inductor 222, and a cathode of which is connected to the power supply terminal of the power amplifier module 130.

[0035] Optionally, the power supply module 120 further includes a first capacitor C1, one end of which is connected to the second end of the inductor 222, and the second end of which is grounded. The first capacitor C1 has a filtering effect.

[0036] Alternatively, if Figure 2 The power supply module 120 shown may include a second switch and a first capacitor C1 at the same time. The first end of the second switch is connected to the second end of the inductor 222, the second end thereof is connected to the power supply end of the power amplification module 130, and the control end thereof is connected to the control unit 221. The first end of the first capacitor C1 is connected to the second end of the second switch, and the second end of the first capacitor C1 is grounded.

[0037] In this embodiment, the signal detection module 110 includes a comparator 211, a first input terminal of which is configured to input a reference voltage signal, a second input terminal of which is connected to the output terminal of the power amplification module 130, and an output terminal of which is connected to the power supply module 120; wherein the power supply module 120 is configured to provide a first voltage signal to the power amplification module 130 when the voltage of the signal received at the second input terminal of the comparator 211 is less than the voltage of the reference voltage signal, and to provide a second voltage signal to the power amplification module 130 when the voltage of the signal received at the second input terminal of the comparator 211 is greater than the voltage of the reference voltage signal.

[0038] The first input terminal of the comparator 211 receives the voltage of the reference voltage signal, and the signal received by the second input terminal of the comparator 211 is the voltage of the output signal of the output terminal of the power amplifier module 130. The comparator 211 compares the signal received by the first input terminal with the signal received by the second output terminal. In this embodiment, the first input terminal of the comparator 211 is a positive input terminal, and the second input terminal of the comparator 211 is a negative input terminal. If the voltage of the signal received by the second input terminal of the comparator 211 is less than the voltage of the reference voltage signal, the output of the comparator 211 is a low level. In some other embodiments, the first input terminal of the comparator 211 may also be a negative input terminal, and the second input terminal of the comparator 211 may also be a positive input terminal. If the voltage of the signal received by the second input terminal of the comparator 211 is less than the reference voltage, the output of the comparator 211 may also be a high level, which is not limited here.

[0039] Optionally, the signal detection module 110 further includes a second capacitor C2, a first end of which is connected to the output end of the power amplification module 130, and a second end of which is connected to the second input end of the comparator 211. The second capacitor C2 serves to block direct current and pass alternating current.

[0040] Optionally, the signal detection module 110 further includes a diode D1, whose anode is connected to the second end of the second capacitor C2, and whose cathode is connected to the second input end of the comparator 211. The diode D1 can convert the alternating alternating current into a single-direction pulse direct current. The diode D1 can be used in conjunction with the comparator 211 that does not support positive and negative voltages.

[0041] In an application scenario summary, the power amplifier circuit 100 of the present application reduces the supply voltage when the power amplifier module 130 has no audio output, reduces circuit energy consumption, reduces heat generation, and thus extends the service life of the power amplifier. The working principle is as follows:

[0042] The detection results of the signal detection module 110 are divided into two situations:

[0043] 1. The signal detection module 110 detects that there is audio output at the output end of the power amplifier module 130. The audio output signal is transmitted to the speaker 140 in one way and to the second input end of the comparator 211 through the second capacitor C2 and the diode D1 in another way. The comparator 211 compares the signal voltage value received at the second input end with the reference voltage value received at its first input end. If the voltage of the audio output signal is greater than the reference voltage, the comparator 211 outputs a high level. The control unit 221 receives a high-level signal, controls the first switch Q1 to alternately turn on and off based on a preset frequency, and based on the characteristic of the inductor 222 maintaining current, performs a voltage boosting process on the first voltage signal provided by the external power supply 160 and outputs the second voltage signal after the voltage boosting process to the power amplifier module 130; at the same time, the third capacitor C3 is charged. When the power amplifier module 130 has audio output, the power supply module 120 provides the voltage boosting process to the power amplifier module 130, thereby improving the audio quality and sound effect of the power amplifier output.

[0044] 2. The power amplifier module 130 detects that there is no audio output at the output end of the power amplifier module 130. The comparator 211 compares the signal voltage value received at the second output end with the reference voltage value received at its first input end. If the voltage of the audio output signal is less than the reference voltage, the comparator 211 outputs a low level. The third capacitor C3 discharges, prolonging the time for the control unit 221 to receive the high-level signal, thereby prolonging the time for the power supply module 120 to provide the second voltage signal after the boost processing. Until the discharge voltage of the third capacitor C3 decreases, the signal received by the control unit 221 changes from a high level to a low level, and the power supply module 120 provides the first voltage signal to the power amplifier module. By delaying the signal, the influence of the fluctuation of the power supply voltage on the subsequent modules is avoided, and the power supply voltage is reduced when there is no audio output from the power amplifier module 130, the circuit energy consumption is reduced, and the heat is reduced, thereby extending the service life of the power amplifier.

[0045] The present application further proposes an electronic device, such as Figure 3 As shown, Figure 3 It is a schematic diagram of the structure of an embodiment of the electronic device of the present application.

[0046] The electronic device 300 of this embodiment includes a power amplifier circuit 100, an external power supply 160 and a speaker 140, and the power amplifier circuit 100 is connected to the external power supply 160 and the speaker 140. In other embodiments, the power amplifier circuit 100 may also be connected to a microphone 170 to receive an audio input signal from the microphone 170.

[0047] The power amplifier circuit 100 includes a power supply module, a power amplifier module and a signal detection module. The power supply end of the power amplifier module is connected to the power supply module, and the output end thereof is connected to a speaker. The signal detection module is connected to the output section of the power amplifier module and the power supply module. The signal detection module is configured to detect the audio signal at the output end of the power amplifier module, and the power supply module is configured to provide a first voltage signal to the power amplifier module when the signal detection module does not detect the audio signal, and to provide a second voltage signal to the power amplifier module when the signal detection module detects the audio signal, and the voltage value of the second voltage signal is greater than the voltage value of the first voltage signal. The above description is only an embodiment of the present application, and does not limit the patent scope of the present application. Any equivalent structure or equivalent process transformation made using the contents of the specification and drawings of this application, or directly or indirectly used in other related technical fields, is similarly included in the patent protection scope of the present application.

Claims

1. A power amplifier circuit, characterized in that: The power amplifier circuit comprises: Power supply module; A power amplifier module, whose power supply end is connected to the power supply module and whose output end is connected to an external speaker; A signal detection module connected to the output end of the power amplification module and the power supply module; In which, the signal detection module is configured to detect the audio signal at the output end of the power amplification module, and the power supply module is configured to provide a first voltage signal to the power amplification module when the signal detection module does not detect the audio signal, and to provide a second voltage signal to the power amplification module when the signal detection module detects the audio signal, and the voltage value of the second voltage signal is greater than the voltage value of the first voltage signal.

2. The power amplifier circuit according to claim 1, characterized in that: The power supply module comprises: a boost unit, whose input end is connected to an external power supply, and whose output end is connected to a power supply end of the power amplifier module; A control unit is connected to the signal detection module and the boost unit, and the control unit is configured to control the boost unit to output the first voltage signal provided by the external power supply when the signal detection module does not detect the audio signal, and to control the boost unit to boost the first voltage signal provided by the external power supply and output a second voltage signal after the boost processing when the signal detection module detects the audio signal.

3. The power amplifier circuit according to claim 2, characterized in that: The boost unit comprises: an inductor, a first end of which is connected to the external power supply, and a second end of which is connected to the power supply terminal of the power amplifier module; A first switch, a first end of which is connected to the second end of the inductor, a second end of which is grounded, and a control end of which is connected to the control unit; The control unit is configured to control the first switch to be turned off when the signal detection module does not detect an audio signal, and to control the first switch to be turned on and off alternately based on a preset frequency when the signal detection module detects an audio signal.

4. The power amplifier circuit according to claim 3, characterized in that: The power supply module also includes a second switch, a first end of which is connected to the second end of the inductor, a second end of which is connected to the power supply end of the power amplifier module, and a control end of which is connected to the control unit.

5. The power amplifier circuit according to claim 3, characterized in that: The power supply module further includes a first capacitor, a first end of which is connected to the second end of the inductor, and a second end of which is grounded.

6. The power amplifier circuit according to claim 1, characterized in that: The signal detection module comprises a comparator, a first input end of which is configured to input a reference voltage signal, a second input end of which is connected to the output end of the power amplification module, and an output end of which is connected to the power supply module; In which, the power supply module is configured to provide a first voltage signal to the power amplification module when the voltage of the signal received at the second input terminal of the comparator is less than the voltage of the reference voltage signal, and to provide a second voltage signal to the power amplification module when the voltage of the signal received at the second input terminal of the comparator is greater than the voltage of the reference voltage signal.

7. The power amplifier circuit according to claim 6, characterized in that: The signal detection module further includes a second capacitor, a first end of which is connected to the output end of the power amplification module, and a second end of which is connected to the second input end of the comparator.

8. The power amplifier circuit according to claim 7, characterized in that: The signal detection module further includes a diode, an anode of which is connected to the second end of the second capacitor, and a cathode of which is connected to the second input end of the comparator.

9. The power amplifier circuit according to claim 1, characterized in that: The power amplifier circuit also includes: A third capacitor, a first end of which is connected to an external power supply, and a second end of which is connected to the output end of the signal detection module; A resistor, a first end of which is connected to the second end of the third capacitor, and a second end of which is grounded.

10. An electronic device, characterized in that: The electronic device comprises the power amplifier circuit as described in any one of claims 1-9.

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