Audio output control circuit and electronic equipment

Abstract

The invention discloses an audio output control circuit and electronic equipment, the circuit comprises an audio output circuit and a control circuit, the audio output circuit comprises an audio power amplifier and a loudspeaker, and the control circuit comprises a first switch piece and a switch control sub-circuit; the first output end of the audio power amplifier is connected with the first end of the loudspeaker, the second output end of the audio power amplifier is connected with the first end of the first switch piece, and the second end of the first switch piece is connected with the second end of the loudspeaker. The input end of the audio power amplifier is connected with the first end of the switch control sub-circuit, and the second end of the switch control sub-circuit is connected with the control end of the first switch piece; and the switch control sub-circuit is used for controlling the first switch piece to be switched on or switched off by detecting the existence condition of an audio signal at the input end of the audio power amplifier.

Description

Technical Field

[0001] The present application belongs to the field of electronic technology, and specifically relates to an audio output control circuit and an electronic device. Background Art

[0002] With the rapid development of electronic technology, electronic devices have been widely used. Speakers are usually deployed in electronic devices to provide audio output.

[0003] Other devices can also be deployed on electronic devices. These devices may intermittently draw large currents when working. These large current draws will generate corresponding changing magnetic fields in the designed circuit loop. The changing magnetic field will affect the coil of the speaker. In this way, when there is no audio signal input, the speaker and the audio amplifier will also form a low-resistance closed loop, causing a "sizzling" current sound phenomenon, resulting in poor audio output quality of the speaker. Summary of the invention

[0004] The purpose of the embodiments of the present application is to provide an audio output control circuit and an electronic device to solve the technical problem of poor audio output quality of a speaker in an electronic device, thereby improving the audio output quality of a speaker in an electronic device.

[0005] In a first aspect, an embodiment of the present application provides an audio output control circuit, including an audio output circuit and a control circuit, wherein the audio output circuit includes an audio power amplifier and a speaker, and the control circuit includes a first switch element and a switch control subcircuit;

[0006] The first output terminal of the audio power amplifier is connected to the first terminal of the speaker, the second output terminal of the audio power amplifier is connected to the first terminal of the first switch element, the second terminal of the first switch element is connected to the second terminal of the speaker, the input terminal of the audio power amplifier is connected to the first terminal of the switch control subcircuit, and the second terminal of the switch control subcircuit is connected to the control terminal of the first switch element;

[0007] The switch control subcircuit controls the first switch element to be turned on or off by detecting the presence of an audio signal at the input end of the audio power amplifier.

[0008] In a second aspect, an embodiment of the present application provides an electronic device, comprising the audio output control circuit as described in the first aspect.

[0009] In an embodiment of the present application, a control circuit is set in an audio output control circuit, and the control circuit includes a first switch and a switch control subcircuit, wherein the first output end of the audio power amplifier in the audio output control circuit is connected to the first end of the speaker in the audio output control circuit, the second output end of the audio power amplifier is connected to the first end of the first switch, the second end of the first switch is connected to the second end of the speaker, the input end of the audio power amplifier is connected to the first end of the switch control subcircuit, and the second end of the switch control subcircuit is connected to the control end of the first switch. The switch control subcircuit controls the first switch to be turned on or off by detecting the presence of an audio signal at the input end of the audio power amplifier. In this way, the switch control subcircuit can control the first switch to be turned on when an audio signal is detected at the input end of the audio power amplifier, so that the audio power amplifier and the speaker form a loop and output audio, and when it is detected that there is no audio signal at the input end of the audio power amplifier, the first switch is controlled to be turned off to disconnect the loop between the audio power amplifier and the speaker, thereby avoiding the "sizzling" current sound phenomenon, thereby improving the audio output quality of the speaker. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] Figure 1 It is one of the structural schematic diagrams of the audio output control circuit provided in the embodiment of the present application;

[0011] Figure 2 This is the second structural diagram of the audio output control circuit provided in the embodiment of the present application;

[0012] Figure 3 It is a schematic diagram of the waveform of the audio signal before and after it is amplified by the amplifier sub-circuit;

[0013] Figure 4 It is a schematic diagram of the waveform before and after half-wave rectification by the rectifier circuit;

[0014] Figure 5 It is a schematic diagram of a DC signal obtained by integrating a half-sine wave signal;

[0015] Figure 6 It is a schematic diagram of the relationship between the intermittent input audio signal and the output signal of the discharge electronic circuit;

[0016] Figure 7 It is a structural diagram of the audio output control circuit provided in an embodiment of the present application. DETAILED DESCRIPTION

[0017] The following will be combined with the drawings in the embodiments of the present application to clearly describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, rather than all the embodiments. All other embodiments obtained by ordinary technicians in this field based on the embodiments in the present application belong to the scope of protection of this application.

[0018] The terms "first", "second", etc. in the specification and claims of the present application are used to distinguish similar objects, and are not used to describe a specific order or sequence. It should be understood that the terms used in this way are interchangeable where appropriate, so that the embodiments of the present application can be implemented in an order other than those illustrated or described herein, and the objects distinguished by "first", "second", etc. are generally of one type, and the number of objects is not limited. For example, the first object can be one or more. In addition, "and / or" in the specification and claims represents at least one of the connected objects, and the character " / " generally indicates that the objects associated with each other are in an "or" relationship.

[0019] The audio output control circuit provided in the embodiment of the present application is described in detail below through specific embodiments and application scenarios in conjunction with the accompanying drawings.

[0020] Figure 1 is one of the structural diagrams of the audio output control circuit provided in the embodiment of the present application, such as Figure 1 As shown, the audio output control circuit includes an audio output circuit 11 and a control circuit 12, wherein the audio output circuit 11 includes an audio power amplifier 111 and a speaker 112, and the control circuit 12 includes a first switch element 121 and a switch control subcircuit 122;

[0021] The first output terminal of the audio power amplifier 111 is connected to the first terminal of the speaker 112, the second output terminal of the audio power amplifier 111 is connected to the first terminal of the first switch element 121, the second terminal of the first switch element 121 is connected to the second terminal of the speaker 112, the input terminal of the audio power amplifier 111 is connected to the first terminal of the switch control subcircuit 122, and the second terminal of the switch control subcircuit 122 is connected to the control terminal of the first switch element 121;

[0022] The switch control subcircuit 122 controls the first switch element 121 to be turned on or off by detecting the presence of an audio signal at the input end of the audio power amplifier 111 .

[0023] The audio output circuit 11 may include an audio power amplifier 111 and a speaker 112. When the audio power amplifier 111 and the speaker 112 form a loop, current will pass through the speaker 112. When the current passes through the coil in the speaker 112, a magnetic field will be generated around it, and the magnetic field can drive the diaphragm of the speaker, thereby causing the speaker 112 to produce sound.

[0024] The audio power amplifier 111 is a device for amplifying the power of an audio signal. The audio signal can be provided by the central processing unit (CPU) of the electronic device. When the electronic device has an audio output requirement, the CPU can control the audio power amplifier 111 to turn on, and when audio output is required, the audio signal is input to the audio power amplifier 111, so that the audio power amplifier 111 amplifies the power of the audio signal, and based on the loop of the audio power amplifier 111 and the speaker 112, provides the audio signal of the power amplifier to drive the speaker 112 to output audio.

[0025] Among them, the speaker 112 is a device for outputting audio, and the speaker 112 can be composed of a coil, and its coil will be affected by the magnetic field. In some scenarios, when a third-party application in the software installed in the electronic device is opened, although audio playback is not provided to the outside, due to the need to provide audio output requirements to the third-party application, the CPU will be triggered to turn on the audio power amplifier. In this scenario, if the device deployed by the electronic device generates a corresponding changing magnetic field in the designed circuit loop when working, and the changing magnetic field affects the coil of the speaker, in the absence of an audio signal input, the speaker and the audio power amplifier will also form a low-resistance closed loop, resulting in a "sizzling" current sound phenomenon. This phenomenon is more obvious in electronic devices with increasingly compact layout space. For example, if the speaker in the electronic device is close to the motherboard, or even directly arranged in the projection area of ​​the motherboard, this "sizzling" current sound phenomenon is more obvious, which will bring a bad experience to the user.

[0026] In the related art, in order to prevent the interference signal from affecting the normal operation of the speaker, a resistor is usually connected in series with the circuit where the speaker is located, so as to reduce the current of the interference signal. However, the solution of connecting a resistor in series with the circuit where the speaker is located will reduce the current of the audio signal input to the speaker, which will reduce the loudness of the audio played by the speaker.

[0027] In the related art, the interference source of the speaker can also be sampled, a compensation signal is generated by a processing module, and the compensation signal is output to the speaker. The compensation signal and the interference signal cancel each other out, so that the speaker works normally. This solution will lead to some defects. For example, if there are many interference sources of the speaker, the process of sampling multiple interference sources and generating compensation signals by the processing module is very complicated. Once the phase of the compensation signal and the interference signal is not aligned, the compensation signal will become an interference signal, which will make the interference sound of the speaker more serious.

[0028] In this embodiment, a first switch element 121 is provided in the middle of the circuit between the audio power amplifier 111 and the speaker 112. The first switch element 121 can be controlled by a switch control subcircuit 122. The switch control subcircuit 122 controls the first switch element 121 to be turned on or off by detecting the presence of an audio signal at the input end of the audio power amplifier 111.

[0029] The first switch 121 is turned on or off to control the connection or disconnection of the line between the audio power amplifier 111 and the speaker 112. When the first switch 121 is turned on, the line between the audio power amplifier 111 and the speaker 112 is turned on, a closed loop can be generated to output sound. When the first switch 121 is turned off, the line between the audio power amplifier 111 and the speaker 112 can be controlled to be disconnected, so that the closed loop generated by the line between the audio power amplifier 111 and the speaker 112 can be disconnected, so that the "sizzling" current sound phenomenon will not occur.

[0030] The first switch 121 being turned on means that the first end and the second end of the first switch 121 are in a turned-on state, and the first switch 121 being turned off means that the first end and the second end of the first switch 121 are in a turned-off state.

[0031] In some embodiments, since the audio signal is an AC signal, the first switch element 121 may be a bidirectional switch, that is, the first switch element 121 may be a device that conducts current bidirectionally.

[0032] In some embodiments, the first switch 121 can be controlled by a wireless signal. In some embodiments, since the voltage peak of the audio signal is relatively large after being amplified by the audio power amplifier 111, the first switch 121 can be controlled by a relatively large voltage value to turn it on, that is, the first switch 121 can be controlled by a high voltage signal conducted by the line.

[0033] In some embodiments, the first switch element 121 may be a packaged device of a bidirectional switch, and the packaged device may lead out a control terminal, and the control terminal may be controlled by the switch control subcircuit 122 .

[0034] In some embodiments, the first switch element 121 may be a circuit composed of some devices. In some embodiments, the first switch element 121 may include a first switch unit and a second switch unit, and the first switch unit and the second switch unit may be N-type metal oxide semiconductor (N Metal Oxide Semiconductor, NMOS) tubes or devices of the same type as NMOS tubes.

[0035] In some embodiments, the first switch unit and the second switch unit are NMOS tubes as an example, the gates of the two NMOS tubes can be connected together, the sources of the two NMOS tubes can be connected together, and the drains of the two NMOS tubes can be respectively connected between the lines of the audio power amplifier 111 and the speaker 112, that is, the drain of one NMOS tube can be connected to the second output terminal of the audio power amplifier 111, and the drain of one NMOS tube can be connected to the second terminal of the speaker 112. In this way, when the gate voltage of the NMOS tube is relatively large, so that the voltage difference between the gate and the source is greater than the threshold voltage, the first switch unit and the second switch unit will be controlled to be turned on at the same time, and when the gate voltage of the NMOS tube is relatively small, so that the voltage difference between the gate and the source is less than the threshold voltage, the first switch unit and the second switch unit will be controlled to be turned off at the same time, so that the gate voltage of the NMOS tube can be controlled to control the on or off of the first switch.

[0036] In some embodiments, the switch control subcircuit 122 may be a controller, which may control the first switch element 121 by sending a wireless signal.

[0037] In some embodiments, the switch control subcircuit 122 may also be a circuit composed of some devices, which can control the first switch element 121 by conducting a voltage signal through a line.

[0038] In some embodiments, the switch control subcircuit 122 can determine whether there is an audio signal at the input end of the audio power amplifier 111 by detecting the signal voltage value at the input end of the audio power amplifier 111. For example, when it is detected that the signal voltage value at the input end is greater than zero, it is determined that there is an audio signal at the input end of the audio power amplifier 111, and when it is detected that the signal voltage value at the input end is equal to zero, it is determined that there is no audio signal at the input end of the audio power amplifier 111.

[0039] In some embodiments, the switch control subcircuit 122 can also detect the presence of an audio signal at the input end of the audio power amplifier 111 by detecting the signal waveform at the input end of the audio power amplifier 111. In this way, the presence of the audio signal can be detected with the help of the waveform characteristics of the sinusoidal wave of the audio signal.

[0040] In some embodiments, the switch control subcircuit 122 can detect the presence of the audio signal at the input end of the audio power amplifier 111 through the second switch element. For example, the second switch element can have different on or off states according to the presence of the audio signal at the input end of the audio power amplifier 111. When there is an audio signal at the input end of the audio power amplifier 111, the second switch element is turned on, and when there is no audio signal at the input end of the audio power amplifier 111, the second switch element is turned off. In this way, the control signal of the first switch element 121 can be affected according to the different signals conducted by the line when the second switch element is turned on or off, so that the first switch element 121 can be switched on and off under different control signals conducted by the switch control subcircuit 122.

[0041] In some embodiments, when the switch control subcircuit 122 detects that there is no audio signal at the input end of the audio power amplifier 111, the first switch element 121 can be controlled to disconnect, thereby disconnecting the closed loop between the audio power amplifier 111 and the speaker 112, thereby preventing the changing magnetic field generated by other components of the electronic device from affecting the coil of the speaker, causing a "sizzling" current sound phenomenon to occur.

[0042] In some embodiments, when the switch control subcircuit 122 detects that there is an audio signal at the input end of the audio power amplifier 111, it can control the first switch element 121 to be turned on, thereby forming a closed loop between the audio power amplifier 111 and the speaker 112, and outputting audio corresponding to the audio signal.

[0043] In this embodiment, a control circuit 12 is provided in the audio output control circuit, and the control circuit 12 includes a first switch element 121 and a switch control subcircuit 122, wherein a first output terminal of an audio power amplifier 111 in the audio output control circuit is connected to a first terminal of a speaker 112 in the audio output control circuit, a second output terminal of the audio power amplifier 111 is connected to a first terminal of the first switch element 121, a second terminal of the first switch element 121 is connected to a second terminal of the speaker 112, an input terminal of the audio power amplifier 111 is connected to a first terminal of the switch control subcircuit 122, and a second terminal of the switch control subcircuit 122 is connected to a control terminal of the first switch element 121. The switch control subcircuit 122 controls the first switch element 121 to be turned on or off by detecting the presence of an audio signal at the input terminal of the audio power amplifier 111. In this way, the switch control sub-circuit can be used to control the first switch element to be turned on when an audio signal is detected at the input end of the audio power amplifier, so that the audio power amplifier and the speaker form a loop to output audio. When it is detected that no audio signal is present at the input end of the audio power amplifier, the first switch element is controlled to be turned off to disconnect the loop between the audio power amplifier and the speaker, thereby avoiding the "sizzling" current sound phenomenon, thereby improving the audio output quality of the speaker.

[0044] That is, the first switch 121 is used to control the on and off of the speaker 112 path. When the audio power amplifier 111 has an input signal, the first switch 121 is turned on, the speaker 112 path forms a closed loop, and the speaker 112 can work normally. At this time, even the current sound generated by the external interference magnetic field will be covered by the normal audio output, so that the "sizzling" current sound cannot be heard. When the first switch 121 is disconnected, the speaker 112 path is disconnected, the speaker 112 cannot work normally, and the external interference magnetic field cannot interfere with the coil of the speaker 112 to generate the "sizzling" current sound.

[0045] In some embodiments, the switch control subcircuit 122 can control the first switch element 121 by conducting a line voltage signal. Figure 2 FIG. 2 is a second structural diagram of the audio output control circuit provided in an embodiment of the present application. Figure 2 As shown, the switch control subcircuit 122 includes a first conversion subcircuit 1221 and a second conversion subcircuit 1222; the input end of the audio power amplifier 111 is connected to the first end of the first conversion subcircuit 1221, the second end of the first conversion subcircuit 1221 is connected to the first end of the second conversion subcircuit 1222, and the second end of the second conversion subcircuit 1222 is connected to the control end of the first switch element 121;

[0046] Among them, the first conversion sub-circuit 1221 is used to convert the audio signal at the input end of the audio power amplifier 111 into a DC signal to obtain a first DC signal, and the second conversion sub-circuit 1222 is used to perform level conversion on a first level value in the first DC signal to obtain a second DC signal, the second DC signal includes a second level value converted based on the first level value, the first level value is a level value converted based on the audio signal, the second level value is greater than the first level value, and the second DC signal is used to control the first switch 121 to be turned on.

[0047] In some embodiments, the audio signal may be a sine wave voltage signal, and its signal value is usually relatively small, such as an audio signal may be a small sine wave signal of a few millivolts (mV) to several hundred mV. In order to enable the first switch element 121 to remain in a conducting state when an audio signal is input, the control signal of the first switch element 121 may be a DC signal. Therefore, the audio signal at the input end of the audio power amplifier 111 may be converted into a DC signal by the first conversion subcircuit 1221 to obtain a first DC signal.

[0048] In some embodiments, the control voltage value of the first switch element 121 is usually relatively large, and in order to keep the first switch element 121 continuously in the on state, the control voltage of the first switch element 121 usually needs to always maintain a high voltage state. Therefore, the first level value in the first DC signal can be level-converted by the second conversion subcircuit 1222 to obtain a second DC signal, and the second level value in the second DC signal is greater than the first level value.

[0049] In this way, when there is an audio signal at the input end of the audio power amplifier 111, the first conversion subcircuit 1221 and the second conversion subcircuit 1222 can be used to convert the audio signal to obtain a second DC signal to control the first switch 121 to be turned on. In this way, the audio signal can be first converted into a low-voltage signal that is easier to generate, and then converted into a DC signal by the first conversion subcircuit 1221, so as to control the first switch 121 to be continuously turned on. After that, the low-voltage signal is converted into a high-voltage signal by the second conversion subcircuit 1222, so that the high-voltage signal used to control the first switch 121 can be converted into a low-voltage signal that is easier to generate, thereby simplifying the control of the first switch 121.

[0050] In some embodiments, when there is no audio signal at the input end of the audio power amplifier 111, the first conversion subcircuit 1221 and the second conversion subcircuit 1222 may not work, so that the control signal of the first switch element 121 at the rear end cannot turn on the first switch element 121. In some embodiments, a discharge subcircuit may be provided after the first conversion subcircuit 1221 or the second conversion subcircuit 1222, so that when the first switch element 121 is in the on state, if it is detected that there is no audio signal at the input end of the audio power amplifier 111, the discharge subcircuit may be used to discharge to control the first switch element 121 to be turned off.

[0051] In some embodiments, a branch circuit may be further provided. When it is detected that no audio signal is present at the input end of the audio power amplifier 111, if the first switch element 121 is turned on, the branch circuit may be used to control the first switch element 121 to be turned off. Alternatively, if the first switch element 121 is turned off, the branch circuit may be used to prevent the control signal of the rear-end first switch element 121 from turning on the first switch element 121.

[0052] In some embodiments, the first conversion subcircuit 1221 can convert the audio signal into a DC signal through an integration subcircuit. Figure 2 As shown, the first conversion subcircuit 1221 includes an amplifying subcircuit 12211 and an integrating subcircuit 12212; the input end of the audio power amplifier 111 is connected to the first end of the amplifying subcircuit 12211, the second end of the amplifying subcircuit 12211 is connected to the first end of the integrating subcircuit 12212, and the second end of the integrating subcircuit 12212 is connected to the first end of the second conversion subcircuit 1222;

[0053] The amplifying subcircuit 12211 is used to amplify the audio signal to obtain an audio AC signal, and the integrating subcircuit 12212 is used to integrate the audio AC signal to obtain the first DC signal.

[0054] Since the audio signal has a small signal value, the audio signal can be amplified by the amplifier subcircuit 12211. In some embodiments, the amplifier subcircuit 12211 can amplify the small sine wave signal to a large sine wave signal of 1 to 2 volts (V), so that after level conversion by the second conversion subcircuit 1222, the control voltage height that turns on the first switch element 121 can be reached.

[0055] Figure 3 It is a waveform diagram of the audio signal before and after amplification by the amplifier sub-circuit, such as Figure 3As shown, curve 301 is the sine wave waveform before amplification, and curve 302 is the sine wave waveform after amplification. The signal value of the amplified sine wave is significantly greater than the signal value of the sine wave before amplification.

[0056] In some embodiments, the amplified sine wave can be integrated by the integration sub-circuit 12212 to convert the AC signal into a DC signal. In this way, by converting the AC signal into a DC signal that can continuously control the conduction of the first switch element 121, the control stability of the first switch element 121 can be ensured.

[0057] If the sine wave signal is directly passed through the integrator circuit 12212, the level amplitude of the obtained DC signal may be relatively small. Figure 2 As shown, the first conversion sub-circuit 1221 further includes a rectifier circuit 12213; the second end of the amplification sub-circuit 12211 is connected to the first end of the integration sub-circuit 12212 through the rectifier circuit 12213;

[0058] The rectifier circuit 12213 is used to perform half-wave rectification on the audio AC signal to obtain a half-wave shaped signal, and the integration subcircuit 12212 is specifically used to integrate the half-wave shaped signal to obtain the first DC signal.

[0059] That is, in this embodiment, a half-wave rectifier can be added between the amplifying sub-circuit 12211 and the integrating sub-circuit 12212 to intercept the negative half cycle of the sine wave, so that the DC level obtained by integrating the integrating sub-circuit 12212 will be closer to the peak value of the sine wave.

[0060] like Figure 4 As shown, it is a schematic diagram of the waveform before and after half-wave rectification by the rectifier circuit, such as Figure 4 As shown, curve 401 is a waveform without half-wave shaping, and curve 402 is a waveform after half-wave rectification. Compared with the waveform of curve 401, the negative half cycle of the sine wave of curve 402 is intercepted, that is, the voltage value of the negative half cycle is converted to zero level.

[0061] Afterwards, the half-sine wave signal after half-wave rectification can be converted into a DC signal with smaller sawtooth through the integrator circuit 12212, so as to continuously control the on and off of the first switch element 121 at the rear end. Figure 5 As shown in the figure, a half-sine wave signal with a short duration or interruption time can be Figure 5 As shown in the middle left figure, after the integration processing by the integration sub-circuit 12212, a sawtooth-shaped DC signal can be output as Figure 5As shown in the middle right figure, the signal value is relatively large, so after the level conversion by the second conversion sub-circuit 1222, a high-voltage signal with a relatively large voltage can be output, so that the first switch element 121 at the rear end is continuously kept in the on state, so that when there is an audio signal at the input end of the audio power amplifier 111, continuous control of the first switch element 121 can be achieved.

[0062] In some embodiments, Figure 2 As shown, the first conversion sub-circuit 1221 further includes a discharge sub-circuit 12214; the second end of the integration sub-circuit 12212 is connected to the first end of the second conversion sub-circuit 1222 through the discharge sub-circuit 12214;

[0063] The discharge subcircuit 12214 is used for discharging based on the first DC signal to control the first switch 121 to be disconnected when there is no audio signal at the input end of the audio power amplifier.

[0064] In some embodiments, the electronic device does not continuously output audio. If the audio output needs to be turned off after an audio signal is input, the first switch 121 needs to be disconnected within a set time to switch the output circuit of the speaker. In this scenario, a discharge subcircuit 12214 can be set after the integration subcircuit 12212 to discharge based on the first DC signal when there is no audio signal at the input end of the audio power amplifier 111.

[0065] Since the voltage value at the first end of the second conversion subcircuit 1222 is the first DC signal, in the discharge process, the second level value converted by the second conversion subcircuit 1222 cannot turn on the first switch 121, and the first switch 121 is disconnected accordingly. When the voltage value at the first end of the second conversion subcircuit 1222 is discharged to be lower than a certain value, the second conversion subcircuit 1222 cannot realize its level conversion function, which may cause the control terminal voltage of the first switch 121 to be unable to turn on the first switch 121, and the first switch 121 is disconnected accordingly.

[0066] Figure 6 This is a schematic diagram of the relationship between the intermittent input audio signal and the output signal of the discharge electronic circuit, such as Figure 6As shown, in the case of intermittent input of the audio signal 601, it is necessary to dynamically control the first switch element 121 to be turned on or off. At the audio signal input moment 602, the integration sub-circuit 12212 can integrate the audio signal, and its discharge sub-circuit 12214 does not work, and its output can be the same as the output signal of the integration sub-circuit 12212. At the end of the audio signal input, or at the beginning of the negative half cycle before the end of the audio signal input 603, the discharge sub-circuit 12214 can start discharging based on the first DC signal until it is discharged to the zero level.

[0067] In this way, by setting the discharge subcircuit 12214 in the first conversion subcircuit 1221, the presence of the audio signal at the input end of the audio power amplifier 111 can be detected by setting only one branch in the switch control subcircuit 122, and the conduction and shutdown of the first switch element 121 can be dynamically controlled according to the presence of the audio signal at the input end of the audio power amplifier 111, and the circuit design is simple.

[0068] In some embodiments, Figure 7 is a schematic diagram of the structure of the audio output control circuit provided in the embodiment of the present application, such as Figure 7 As shown, the amplifying subcircuit 12211 includes a second switch element 122111; the input end of the audio power amplifier 111 is connected to the control end of the second switch element 122111, the first end of the second switch element 122111 is respectively connected to the first voltage source 122112 and the first end of the integrating subcircuit 12212, and the second end of the second switch element 122111 is connected to the ground end;

[0069] In which, when there is an audio signal at the input end of the audio power amplifier 111, the audio signal can control the second switch 122111 to be turned on, so as to amplify the audio signal and obtain an audio AC signal.

[0070] The voltage value of the first voltage source may be 3V.

[0071] In this embodiment, the amplification subcircuit 12211 detects whether there is an audio signal at the input end of the audio power amplifier 111 through the second switch element 122111. When there is an audio signal at the input end of the audio power amplifier 111, the second switch element 122111 is turned on, and when there is no audio signal at the input end of the audio power amplifier 111, the second switch element 122111 is turned off. When the second switch element 122111 is turned on, the audio signal can be amplified.

[0072] The second switch element 122111 may be an NPN transistor or other devices of the same type as the NPN transistor. Taking the NPN transistor as an example, the control end of the second switch element 122111 may be a base, the first end of the first switch element 122111 may be a collector, and the second end of the first switch element 122111 may be an emitter. When an audio signal is input to the base end, the voltage between the base and the emitter exceeds the conduction threshold of the second switch element 122111, the second switch element 122111 is turned on, the amplifier subcircuit 12211 can amplify the audio signal, the first conversion subcircuit 1221 and the second conversion subcircuit 1222 start to work, and control the first switch element 121 to be turned on. When no audio signal is input to the base terminal, the second switch element 122111 is disconnected, the amplifying subcircuit 12211 may not work, the first converting subcircuit 1221 and the second converting subcircuit 1222 may not work, and the discharging subcircuit 12214 starts to work and controls the first switch element 121 to be disconnected.

[0073] In this way, by setting the second switch element 122111 in the amplifying sub-circuit 12211, the presence of the audio signal at the input end of the audio power amplifier 111 can be detected through the second switch element 122111, and the amplifying sub-circuit 12211 can simultaneously have the functions of detecting and amplifying the audio signal.

[0074] In some embodiments, Figure 7 As shown, the amplifier subcircuit 12211 may also include a second capacitor 122113, a third capacitor 122114, a third resistor 122115, a fourth resistor 122116 and a fifth resistor 122117. The second capacitor 122113 is connected between the input end of the audio power amplifier 111 and the control end of the second switch 122111, and its function is to limit current. The third capacitor 122114 is connected to the first end of the second switch 122111 and one end of the rectifier subcircuit 12213. The third resistor 122115 is connected between the first voltage source 122112 and the first end of the second switch 122111, and its function is to limit current. The fourth resistor 122116 is connected between the second end of the second switch 122111 and the ground end, and its function is to limit current. One end of the fifth resistor 122117 is connected to the control end of the second switch 122111, and the other end is connected to one end of the first voltage source 122112, and its function is to stabilize voltage.

[0075] In some embodiments, Figure 7 As shown, the rectifier circuit 12213 is a half-wave rectifier, which is a packaged device.

[0076] In some embodiments, Figure 7As shown, the integrating sub-circuit 12212 includes a first resistor 122121 and a first capacitor 122122, and the discharging sub-circuit 12214 includes a second resistor 122141; one end of the first resistor 122121 is connected to the second end of the amplifying sub-circuit 12211, the other end of the first resistor 122121 is connected in series with the first capacitor 122122, and the second resistor 122141 is connected in parallel with the first capacitor 122122; the second resistor 122141 is connected in parallel between the first end of the second converting sub-circuit 1222 and the ground end.

[0077] In this way, the design of the integrator sub-circuit 12212 and the discharge sub-circuit 12214 is simple. The implementation method is a pure hardware control design, which can avoid complex software designs such as phase control and amplitude compensation.

[0078] In some embodiments, Figure 7 As shown, the second conversion subcircuit 1222 includes a third switch element 12221 and a fourth switch element 12222, the second end of the first conversion subcircuit 1221 is connected to the control end of the third switch element 12221, the first end of the third switch element 12221 is respectively connected to the second voltage source 12223 and the control end of the fourth switch element 12222, the first end of the fourth switch element 12222 is respectively connected to the second voltage source 12223 and the control end of the first switch element 121, and the second end of the third switch element 12221 and the second end of the fourth switch element 12222 are respectively connected to the ground end;

[0079] In which, when there is an audio signal at the input end of the audio power amplifier 111, the second level value of the control end of the fourth switch element 12222 can control the first switch element 121 to be turned on, and when there is no audio signal at the input end of the audio power amplifier, the third level value of the control end of the fourth switch element 12222 can control the first switch element 121 to be turned off.

[0080] The third switch element 12221 may be an NMOS tube, or may be a device of the same type as the NMOS tube, and the fourth switch element 12222 may also be an NMOS tube, or may be a device of the same type as the NMOS tube.

[0081] In some embodiments, the control end of the third switch element 12221 may be a gate of an NMOS tube, the first end of the third switch element 12221 may be a drain, and the second end of the third switch element 12221 may be a source.

[0082] In some embodiments, the control end of the fourth switch element 12222 may be the gate of the NMOS tube, the first end of the fourth switch element 12222 may be the drain of the NMOS tube, and the second end of the fourth switch element 12222 may be the source of the NMOS tube.

[0083] In some embodiments, when there is an audio signal at the input end of the audio power amplifier 111, the output signal of the discharge sub-circuit 12214 is the same as the output signal of the integration sub-circuit 12212, which is the first DC signal. At this time, the third switch element 12221 is turned on, the fourth switch element 12222 is turned off, the drain of the fourth switch element 12222 outputs a high level, and the first switch element 121 is turned on. When there is no audio signal at the input end of the audio power amplifier 111, the discharge sub-circuit 12214 discharges based on the first DC signal. When the discharge reaches a certain level, the third switch element 12221 is turned off, the fourth switch element 12222 is turned on, and the drain of the fourth switch element 12222 outputs a low level, and the first switch element 121 is turned off.

[0084] The voltage value of the second voltage source may be greater than the voltage value of the first voltage source, which may be 9V.

[0085] In some embodiments, Figure 7 As shown, the second conversion subcircuit 1222 may further include a sixth resistor 12224 and a seventh resistor 12225, the sixth resistor 12224 and the seventh resistor 12225 are connected in series, one end of the sixth resistor 12224 is connected to the second voltage source 12223, and one end of the seventh resistor 12225 is connected to the drain of the third switch element 12221. The sixth resistor 12224 and the seventh resistor 12225 function to limit current.

[0086] In some embodiments, the first switch element 121 includes a first switch unit 1211 and a second switch unit 1212, the control end of the first switch unit 1211 and the control end of the second switch unit 1212 are both connected to the second end of the switch control subcircuit 122, the first end of the first switch unit 1211 is connected to the second output end of the audio power amplifier 111, the first end of the second switch unit 1212 is connected to the second end of the speaker 112, and the second end of the first switch unit 1211 is connected to the second end of the second switch unit 1212;

[0087] When both the first switch unit 1211 and the second switch unit 1212 are turned on, the first switch element 121 is turned on; when either the first switch unit 1211 or the second switch unit 1212 is turned off, the first switch element 121 is turned off.

[0088] In some embodiments, the control end of the first switch unit 1211 may be a gate of an NMOS tube, the first end of the first switch unit 1211 may be a drain, and the second end of the first switch unit 1211 may be a source.

[0089] In some embodiments, the control end of the second switch unit 1212 may be a gate of an NMOS tube, the first end of the second switch unit 1212 may be a drain of the NMOS tube, and the second end of the second switch unit 1212 may be a source of the NMOS tube.

[0090] In some embodiments, the first switch element 121 may also include an eighth resistor 1213 and a fourth capacitor 1214, the eighth resistor 1213 and the fourth capacitor 1214 are connected in series, one end of the eighth resistor 1213 is connected to the first end of the first switch unit 1211, and one end of the fourth capacitor 1214 is connected to the control end of the first switch unit 1211, and the function of the eighth resistor 1213 and the fourth capacitor 1214 is voltage stabilization.

[0091] An embodiment of the present application further provides an electronic device, which may include the audio output control circuit provided by the above embodiment, and the audio output control circuit may provide audio output for the electronic device.

[0092] It should be noted that, in this article, the terms "comprise", "include" or any other variant thereof are intended to cover non-exclusive inclusion, so that the process, method, article or device including a series of elements includes not only those elements, but also includes other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, the elements defined by the sentence "comprise one..." do not exclude the presence of other identical elements in the process, method, article or device including the element. In addition, it should be pointed out that the scope of the methods and devices in the embodiments of the present application is not limited to performing functions in the order shown or discussed, and may also include performing functions in a substantially simultaneous manner or in reverse order according to the functions involved, for example, the described method may be performed in an order different from that described, and various steps may also be added, omitted, or combined. In addition, the features described with reference to certain examples may be combined in other examples.

[0093] Through the description of the above implementation methods, those skilled in the art can clearly understand that the above-mentioned embodiment methods can be implemented by means of software plus a necessary general hardware platform, and of course by hardware, but in many cases the former is a better implementation method. Based on such an understanding, the technical solution of the present application, or the part that contributes to the prior art, can be embodied in the form of a computer software product, which is stored in a storage medium (such as ROM / RAM, a magnetic disk, or an optical disk), and includes a number of instructions for enabling an electronic device (which can be a mobile phone, a computer, a server, or a network device, etc.) to execute the methods described in each embodiment of the present application.

[0094] The embodiments of the present application are described above in conjunction with the accompanying drawings, but the present application is not limited to the above-mentioned specific implementation methods. The above-mentioned specific implementation methods are merely illustrative and not restrictive. Under the guidance of the present application, ordinary technicians in this field can also make many forms without departing from the purpose of the present application and the scope of protection of the claims, all of which are within the protection of the present application.

Claims

1. An audio output control circuit, characterized in that: It includes an audio output circuit and a control circuit, wherein the audio output circuit includes an audio power amplifier and a speaker, and the control circuit includes a first switch element and a switch control subcircuit; The first output terminal of the audio power amplifier is connected to the first terminal of the speaker, the second output terminal of the audio power amplifier is connected to the first terminal of the first switch element, the second terminal of the first switch element is connected to the second terminal of the speaker, the input terminal of the audio power amplifier is connected to the first terminal of the switch control subcircuit, and the second terminal of the switch control subcircuit is connected to the control terminal of the first switch element; The switch control subcircuit controls the first switch element to be turned on or off by detecting the presence of an audio signal at the input end of the audio power amplifier.

2. The circuit according to claim 1, characterized in that The switch control subcircuit includes a first conversion subcircuit and a second conversion subcircuit; the input end of the audio power amplifier is connected to the first end of the first conversion subcircuit, the second end of the first conversion subcircuit is connected to the first end of the second conversion subcircuit, and the second end of the second conversion subcircuit is connected to the control end of the first switch element; Among them, the first conversion sub-circuit is used to convert the audio signal at the input end of the audio power amplifier into a DC signal to obtain a first DC signal, and the second conversion sub-circuit is used to perform level conversion on a first level value in the first DC signal to obtain a second DC signal, the second DC signal includes a second level value converted based on the first level value, the first level value is a level value converted based on the audio signal, the second level value is greater than the first level value, and the second DC signal is used to control the first switch to be turned on.

3. The circuit according to claim 2, characterized in that The first conversion subcircuit includes an amplifying subcircuit and an integrating subcircuit; the input end of the audio power amplifier is connected to the first end of the amplifying subcircuit, the second end of the amplifying subcircuit is connected to the first end of the integrating subcircuit, and the second end of the integrating subcircuit is connected to the first end of the second conversion subcircuit; The amplifying subcircuit is used to amplify the audio signal to obtain an audio AC signal, and the integrating subcircuit is used to integrate the audio AC signal to obtain the first DC signal.

4. The circuit according to claim 3, characterized in that The amplification subcircuit includes a second switch element; the input end of the audio power amplifier is connected to the control end of the second switch element, the first end of the second switch element is respectively connected to the first voltage source and the first end of the integration subcircuit, and the second end of the second switch element is connected to the ground end; Wherein, when there is an audio signal at the input end of the audio power amplifier, the audio signal can control the second switch to be turned on, so as to amplify the audio signal and obtain an audio AC signal.

5. The circuit according to claim 3, characterized in that The first conversion sub-circuit further includes a rectifier circuit; the second end of the amplification sub-circuit is connected to the first end of the integration sub-circuit through the rectifier circuit; The rectifier circuit is used to perform half-wave rectification on the audio AC signal to obtain a half-wave shaped signal, and the integrator circuit is specifically used to perform integration on the half-wave shaped signal to obtain the first DC signal.

6. The circuit according to any one of claims 3 to 5, characterized in that The first conversion subcircuit further includes a discharge subcircuit; the second end of the integration subcircuit is connected to the first end of the second conversion subcircuit through the discharge subcircuit; The discharge subcircuit is used for discharging based on the first DC signal to control the first switch to be disconnected when there is no audio signal at the input end of the audio power amplifier.

7. The circuit according to claim 6, characterized in that The integrating subcircuit includes a first resistor and a first capacitor, and the discharging subcircuit includes a second resistor; one end of the first resistor is connected to the second end of the amplifying subcircuit, the other end of the first resistor is connected in series with the first capacitor, and the second resistor is connected in parallel with the first capacitor; the second resistor is connected in parallel between the first end of the second converting subcircuit and the ground end.

8. The circuit according to claim 2, characterized in that The second conversion subcircuit comprises a third switch element and a fourth switch element, the second end of the first conversion subcircuit is connected to the control end of the third switch element, the first end of the third switch element is respectively connected to the second voltage source and the control end of the fourth switch element, the first end of the fourth switch element is respectively connected to the second voltage source and the control end of the first switch element, and the second end of the third switch element and the second end of the fourth switch element are respectively connected to the ground end; In which, when there is an audio signal at the input end of the audio power amplifier, the second level value of the control end of the fourth switch element can control the first switch element to be turned on, and when there is no audio signal at the input end of the audio power amplifier, the third level value of the control end of the fourth switch element can control the first switch element to be turned off.

9. The circuit according to claim 1, characterized in that The first switch element includes a first switch unit and a second switch unit, the control end of the first switch unit and the control end of the second switch unit are both connected to the second end of the switch control subcircuit, the first end of the first switch unit is connected to the second output end of the audio power amplifier, the first end of the second switch unit is connected to the second end of the speaker, and the second end of the first switch unit is connected to the second end of the second switch unit; When both the first switch unit and the second switch unit are turned on, the first switch element is turned on, and when either the first switch unit or the second switch unit is turned off, the first switch element is turned off.

10. An electronic device, characterized in that: The method comprises the audio output control circuit as claimed in any one of claims 1 to 9.

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