Differential power amplifier circuit, control method, chip and electronic equipment

Abstract

The invention relates to the technical field of circuits, and discloses a differential power amplifier circuit, a control method, a chip and electronic equipment, the differential power amplifier circuit comprises a control module, a switch module, a differential power amplifier and a first capacitor unit; the first end of the differential power amplifier is used for receiving audio signals, the second end of the differential power amplifier is connected with the first end of the first capacitor unit, the second end of the first capacitor unit is connected with the first end of the switch module, and the second end of the switch module is connected with the audio device; the control module is used for controlling the first capacitor unit to be charged through the state of the switch module when detecting that the differential power amplifier is powered on, and controlling the differential power amplifier to output an audio signal to the audio device through the state of the switch module after the first capacitor unit is charged; and when the pre-power-off of the differential power amplifier is detected, the first capacitor unit is controlled to discharge through the state of the switch module, and the conduction of the audio device is cut off. Based on the above scheme, POP sound and bottom noise can be reduced.

Description

Technical Field

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

[0002] A differential power amplifier, or differential power amplifier for short, is an electronic amplifier that amplifies the voltage difference between the two input terminals of the amplifier with a fixed gain. The input modes of a differential power amplifier include single-ended input and dual-ended input. Among them, a single-ended input differential power amplifier circuit refers to a circuit in which the input signal enters one input terminal of the differential power amplifier, and the other input terminal is grounded. A dual-ended input differential power amplifier circuit refers to a circuit in which the input signal enters the two input terminals of the differential power amplifier. The output modes of a differential power amplifier include single-ended output and differential output (i.e., dual-ended output). Among them, a single-ended output differential power amplifier circuit refers to a circuit in which the output signal is input from one output terminal of the differential power amplifier to an audio device connected to the differential power amplifier, and the other output terminal is grounded. A dual-ended output differential power amplifier circuit refers to a circuit in which the output signal is input from the two output terminals of the differential power amplifier to an audio device.

[0003] At present, in a differential power amplifier circuit with single-ended input and single-ended output, when the differential power amplifier is powered on or off, due to the sudden change in voltage of components in the circuit, the audio devices connected to the components in the circuit will have problems of high background noise (a type of noise) and POP sound (a type of explosive sound). Summary of the invention

[0004] In order to solve the above problems, the embodiments of the present application provide a differential power amplifier circuit, a control method, a chip and an electronic device.

[0005] In a first aspect, an embodiment of the present application provides a differential power amplifier circuit, comprising a control module, a switch module, a differential power amplifier and a first capacitor unit; the first end of the differential power amplifier is used to receive an audio signal, the second end of the differential power amplifier is connected to the first end of the first capacitor unit, the second end of the first capacitor unit is connected to the first end of the switch module, and the second end of the switch module is connected to an audio device; the control module is used to detect that when the differential power amplifier is powered on, control the charging of the first capacitor unit through the state of the switch module, and after the first capacitor unit is charged, control the differential power amplifier to output an audio signal to the audio device through the state of the switch module, and the control module is also used to detect that when the differential power amplifier is pre-powered off, control the discharge of the first capacitor unit through the state of the switch module, and disconnect the conduction between the differential power amplifier and the audio device.

[0006] In the present application, in a differential power amplifier circuit with single-ended input and single-ended output, a switch module is added to the output end of the differential power amplifier. When the differential power amplifier is powered on and off, the state of the switch module, that is, the opening and closing sequence and the opening and closing state of each switch in the switch module, is controlled, so that the voltage of the first capacitor unit connected to the differential power amplifier changes slowly, thereby reducing the background noise and POP sound of the audio device in the circuit.

[0007] In a possible implementation of the first aspect above, the first capacitor unit includes a first capacitor, the switch module includes a first switch component and a second switch component, the first end of the first switch component is connected to the second end of the first capacitor and the first end of the second switch component, and the second end of the first switch component is grounded; the first end of the second switch component is connected to the second end of the first capacitor, and the second end of the second switch component is connected to the audio device.

[0008] In a possible implementation of the first aspect above, the control module is used to: when it is detected that the differential power amplifier is powered on, control the first switch component to close and the second switch component to open, so as to charge the first capacitor; and after the first capacitor is charged, control the first switch component to open and the second switch component to close, so as to enable the differential power amplifier to output an audio signal to the audio device.

[0009] In a possible implementation of the first aspect above, the control module is used to: when it is detected that the differential power amplifier is pre-powered off, control the first switch component to close and the second switch component to open in sequence, power off the differential power amplifier, and disconnect the first switch component, so as to disconnect the conduction between the differential power amplifier and the audio device.

[0010] In a possible implementation of the first aspect above, the differential power amplifier circuit includes a background noise pre-reduction module, a signal filtering module, a first protection module, a second protection module, and a background noise adjustment module; the first end of the background noise pre-reduction module is used to receive an audio signal, and the second end of the background noise pre-reduction module is connected to the differential power amplifier; the first end of the signal filtering module is connected to the first output interface of the differential power amplifier, and the second end of the signal filtering module is connected to the first end of the first protection module; the second end of the first protection module is connected to the first end of the first capacitor, the second end of the first capacitor is connected to the first end of the switch module, the second end of the switch module is connected to the first end of the second protection module, the second end of the second protection module is connected to the first end of the background noise adjustment module, and the second end of the background noise adjustment module is connected to the audio device.

[0011] In the present application, the protection modules are connected in series at the first and second ends of the differential power amplifier, respectively, so that the series protection modules reduce the voltage of the differential power amplifier, thereby reducing the gain of the differential power amplifier, which can further reduce the background noise and POP sound of the audio device in the circuit. At the same time, when overvoltage occurs in the differential power amplifier circuit, the series protection modules are used to divide the voltage, alleviate the problem of voltage overshoot in the differential power amplifier circuit, and improve the EMI protection capability of the differential power amplifier circuit.

[0012] In a possible implementation of the first aspect above, the background noise pre-reduction module includes a first resistor, a second resistor and a third resistor, and the differential power amplifier circuit also includes a second capacitor and a third capacitor; the first end of the first resistor is used to receive an audio signal, the second end of the first resistor is respectively connected to the first end of the third resistor and the first end of the second capacitor, the second end of the second capacitor is connected to the first input interface of the differential power amplifier, the second end of the third resistor is respectively connected to the first end of the second resistor and the first end of the third capacitor, the second end of the third capacitor is connected to the second input interface of the differential power amplifier, and the second end of the second resistor is grounded.

[0013] In a possible implementation of the first aspect above, the signal filtering module includes a first inductor and a fourth capacitor; the first end of the first inductor is connected to the first output interface of the differential power amplifier, the second end of the first inductor is respectively connected to the first end of the fourth capacitor and the first end of the first protection module, and the second end of the fourth capacitor is grounded.

[0014] In a possible implementation of the first aspect above, the first protection module includes a fifth capacitor, a sixth capacitor and a fourth resistor; the first end of the fifth capacitor is respectively connected to the second end of the first inductor, the first end of the fourth capacitor, the first end of the fourth resistor and the first end of the first capacitor, and the second end of the fifth capacitor is grounded; the second end of the fourth resistor is connected to the first end of the sixth capacitor, and the second end of the sixth capacitor is grounded.

[0015] In a possible implementation of the first aspect above, the second protection module includes a seventh capacitor, an eighth capacitor and a fifth resistor; the first end of the seventh capacitor is respectively connected to the second end of the switch module, the first end of the fifth resistor and the background noise adjustment module, and the second end of the seventh capacitor is grounded; the second end of the fifth resistor is connected to the first end of the eighth capacitor, and the second end of the eighth capacitor is grounded.

[0016] In a possible implementation of the first aspect above, the background noise adjustment module includes a sliding rheostat, a first end of the sliding rheostat is respectively connected to the first end of the fifth resistor, the first end of the seventh capacitor, and the second end of the second switch component, and a second end of the sliding rheostat is connected to the audio device.

[0017] In a second aspect, the present application provides a control method, which is applied to the differential power amplifier circuit of the first aspect and any possible implementation of the first aspect, the method comprising: when detecting that the differential power amplifier is powered on, controlling the first switch component to close and the second switch component to open, so as to realize charging of the first capacitor unit, and after the charging of the first capacitor unit is completed, controlling the first switch component to open and the second switch component to close, so as to realize the differential power amplifier to output an audio signal to the audio device;

[0018] When the differential power amplifier is detected to be pre-powered off, the first switch component is controlled to be closed and the second switch component is controlled to be opened in sequence, the differential power amplifier is powered off, and the first switch component is opened to disconnect the conduction between the differential power amplifier and the audio device.

[0019] In a third aspect, an embodiment of the present application provides a chip, the chip comprising the first aspect and any possible implementation of the differential power amplifier circuit of the first aspect.

[0020] In a fourth aspect, an embodiment of the present application provides an electronic device, comprising the chip mentioned in the third aspect above. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 According to some embodiments of the present application, a schematic diagram of a differential power amplifier circuit with single-ended input and differential output is shown;

[0022] Figure 2 According to some embodiments of the present application, a schematic diagram of a differential power amplifier circuit with single-ended input and single-ended output in a comparative embodiment is shown;

[0023] Figure 3 According to some embodiments of the present application, a structural schematic diagram of a differential power amplifier circuit with single-ended input and single-ended output is shown;

[0024] Figure 4a According to some embodiments of the present application, a structural schematic diagram of a differential power amplifier circuit is shown;

[0025] Figure 4b According to some embodiments of the present application, a structural schematic diagram of a differential power amplifier circuit is shown;

[0026] Figure 5 According to some embodiments of the present application, a flow chart of a control method is shown. DETAILED DESCRIPTION

[0027] The illustrative embodiments of the present application include, but are not limited to, a differential power amplifier circuit, a control method, a chip, a storage medium, and an electronic device.

[0028] The following is an introduction to the terms mentioned in the embodiments of the present application:

[0029] (1)POP sound

[0030] POP sound refers to a short explosive sound that appears in the sound effect. It usually occurs when the audio device is powered on, off or powered off. The sudden change in voltage causes the audio device to make a popping noise.

[0031] (2) Noise Background

[0032] Noise floor, also known as background noise, refers to the total noise in an audio device other than the useful signal, including the noise of the audio device itself and the noise of the playback environment. A larger noise floor will make a rustling sound, while a smaller noise floor is not easily perceived by the human ear.

[0033] (3) Headphone amplifier

[0034] A headphone amplifier, or amp for short, is an audio amplifier specially designed to drive headphones.

[0035] (4) Electromagnetic Interference (EMI)

[0036] EMI is electronic noise that interferes with cable signals and degrades signal integrity. EMI is typically generated by sources that generate electromagnetic radiation, such as noise generated by motors and machinery.

[0037] (5) Amplifier gain

[0038] The gain of an amplifier is the logarithm of the ratio of the amplifier output power to the input power, and is used to indicate the degree of power amplification.

[0039] The technical solution of the present application is introduced below in conjunction with the accompanying drawings.

[0040] The differential power amplifier mentioned in this application is any type of power amplifier, including but not limited to Class A power amplifier, Class B power amplifier, Class C power amplifier and Class D power amplifier.

[0041] The input modes of differential power amplifiers include single-ended input and dual-ended input. Among them, a single-ended input differential power amplifier circuit refers to a circuit in which the input signal enters one input terminal of the differential power amplifier, and the other input terminal is grounded. A dual-ended input differential power amplifier circuit refers to a circuit in which the input signal enters both input terminals of the differential power amplifier. The output modes of differential power amplifiers include single-ended output and differential output (i.e., dual-ended output). Among them, a single-ended output differential power amplifier circuit refers to a circuit in which the output signal is input from one output terminal of the differential power amplifier to an audio device connected to the differential power amplifier, and the other output terminal is grounded. A dual-ended output differential power amplifier circuit refers to a circuit in which the output signal is input from both output terminals of the differential power amplifier to an audio device.

[0042] Figure 1FIG. 1 is a schematic diagram showing a differential power amplifier circuit with single-ended input and differential output. Figure 1 As shown, the input interfaces of the differential power amplifier are INP and INN, wherein the input interface INP is connected in series with capacitor C1 and connected to the differential power amplifier circuit, and the input interface INN is grounded. The output interfaces of the differential power amplifier are OUTP and OUTN, wherein the output interfaces OUTP and OUTN are connected to audio devices (such as headphones or speakers, etc.).

[0043] Figure 2 FIG. 2 shows a schematic diagram of a differential power amplifier circuit with single-ended input and single-ended output in a comparative embodiment. Figure 2 As shown, the input interface INN of the differential power amplifier is connected in series with the capacitor C1 and connected to the differential power amplifier circuit, and the input interface INP is grounded (not shown in the figure). The output interface OUTP of the differential power amplifier is connected in series with the capacitor C2 and connected to an audio device (such as headphones or speakers, etc.), and the output interface OUTN is grounded (not shown in the figure). In some embodiments, the output mode of the headphone amplifier is single-ended output, and the output mode of the three-section (left channel section, right channel section and ground section) headphones is single-ended output.

[0044] Currently, reference Figure 2 In a differential power amplifier circuit with single-ended input and single-ended output, when the differential power amplifier is powered on and off, the voltage of capacitor C2 changes suddenly, causing the audio device connected to capacitor C2 to have background noise and POP pitch problems.

[0045] In some embodiments, due to the parameters of the differential power amplifier itself, for example, the greater the gain of the differential power amplifier, the higher the background noise and POP sound of the audio device connected to the differential power amplifier in the differential power amplifier circuit.

[0046] To this end, the present application embodiment proposes a differential power amplifier circuit, such as Figure 3 As shown, it includes a control module (not shown), a switch module, a differential power amplifier and a first capacitor unit; the first end of the differential power amplifier is used to receive an audio signal, the second end of the differential power amplifier is connected to the first end of the first capacitor unit, the second end of the first capacitor unit is connected to the first end of the switch module, and the second end of the switch module is connected to the audio device; the control module is used to detect that the differential power amplifier is powered on, control the charging of the first capacitor unit through the state of the switch module, and after the first capacitor unit is charged, control the differential power amplifier to output an audio signal to the audio device through the state of the switch module, and the control module is also used to detect that the differential power amplifier is pre-powered off, control the discharge of the first capacitor unit through the state of the switch module, and disconnect the conduction between the differential power amplifier and the audio device.

[0047] In an embodiment of the present application, in a differential power amplifier circuit with single-ended input and single-ended output, a switch module is added to the second end (i.e., the output end) of the differential power amplifier. When the differential power amplifier is powered on and off, the state of the switch module, i.e., the opening and closing sequence and the opening and closing state of each switch in the switch module, is controlled, so that the voltage of the first capacitor unit connected to the differential power amplifier changes slowly, thereby reducing the background noise and POP sound of the audio device in the circuit.

[0048] The first capacitor unit may include a first capacitor, and the switch module includes a first switch component and a second switch component. The first end of the first switch component is connected to the second end of the first capacitor and the first end of the second switch component, and the second end of the first switch component is grounded; the first end of the second switch component is connected to the second end of the first capacitor, and the second end of the second switch component is connected to the audio device.

[0049] The control module is used to: when detecting that the differential power amplifier is powered on, first control the first switch component to close and the second switch component to open, so as to realize charging of the first capacitor, and after the first capacitor is charged, control the first switch component to open and the second switch component to close, so as to realize the differential power amplifier outputting the audio signal to the audio device. It can be understood that when the differential power amplifier needs to be turned on, the initial default state of the first switch component and the second switch component is the open state.

[0050] The control module is also used to: when detecting that the differential power amplifier is pre-powered off, control the first switch component to close and the second switch component to open in sequence, the differential power amplifier is powered off, and the first switch component is opened to disconnect the conduction between the differential power amplifier and the audio device. It can be understood that when the differential power amplifier needs to be turned off, the initial default state of the first switch component is the open state, and the initial default state of the second switch component is the closed state.

[0051] The first capacitor unit may include a first capacitor, or may be composed of a plurality of capacitors connected in series, which is not limited in the present application.

[0052] Combine the following Figure 4a , introduces the structure of the differential power amplifier circuit with single-ended input and single-ended output in this application. Figure 4a As shown, the differential power amplifier circuit includes a differential power amplifier, a first capacitor unit, a noise floor pre-reduction module, a signal filtering module, a first protection module, a second protection module and a noise floor adjustment module.

[0053] Among them, the first end of the background noise pre-reduction module is used to receive the audio signal, and the second end of the background noise pre-reduction module is connected to the differential power amplifier; the first end of the signal filtering module is connected to the first output interface of the differential power amplifier, and the second end of the signal filtering module is connected to the first end of the first protection module; the second end of the first protection module is connected to the first end of the first capacitor unit, the second end of the first capacitor unit is connected to the first end of the switch module, the second end of the switch module is connected to the first end of the second protection module, the second end of the second protection module is connected to the first end of the background noise adjustment module, and the second end of the background noise adjustment module is connected to the audio device.

[0054] Combine the following Figure 4b , introduces the detailed structure of the differential power amplifier circuit in this application. Figure 4b As shown, the differential power amplifier circuit includes a differential power amplifier, a first capacitor C2, a second capacitor C1 and a third capacitor C3, a noise floor pre-reduction module, a signal filtering module, a first protection module, a second protection module and a noise floor adjustment module.

[0055] The differential power amplifier includes an input interface INP (the first input interface mentioned in this application), an input interface INN (the second input interface mentioned in this application), an output interface OUTP (the first output interface mentioned in this application), and an output interface OUTN. The input interface INP is used to receive an audio signal. The output interface OUTP is used to transmit a signal to an audio device. The output interface OUTN is grounded.

[0056] The noise floor pre-reduction module includes a first resistor R1, a second resistor R2 and a third resistor R3. In the noise floor pre-reduction module, the first end of the first resistor R1 is used to receive the input audio signal, the second end of the first resistor R1 is respectively connected to the first end of the third resistor R3 and the first end of the second capacitor C1, the second end of the second capacitor C1 is connected to the input interface INP of the differential power amplifier, the second end of the third resistor R3 is connected to the first end of the second resistor R2, and the second end of the second resistor R2 is grounded. The first end of the second resistor R2 is also connected to the second end of the third capacitor C3. In the differential power amplifier circuit, the noise floor pre-reduction module is connected in series with the differential power amplifier to reduce the voltage of the differential power amplifier, thereby reducing the gain of the differential power amplifier, which can reduce the noise floor and POP sound of the audio device in the circuit.

[0057] The signal filtering module includes a first inductor L1 and a fourth capacitor C4. In the signal filtering module, the first end of the first inductor L1 is connected to the output interface OUTP of the differential power amplifier, the second end of the first inductor L1 is connected to the first end of the fourth capacitor C4 and the first end of the first protection module, and the second end of the fourth capacitor C4 is grounded. In the differential power amplifier circuit, the signal filtering module is used to convert the pulse width modulation (PWM) waveform in the output signal of the differential power amplifier into a sine wave, that is, to convert a digital signal into an analog signal.

[0058] The first protection module includes a fifth capacitor C5, a sixth capacitor C6 and a fourth resistor R4. In the first protection module, the first end of the fifth capacitor C5 is respectively connected to the second end of the first inductor, the first end of the fourth capacitor, the first end of the fourth resistor R4 and the first end of the first capacitor C2, and the second end of the fifth capacitor C5 is grounded. The second end of the fourth resistor R4 is connected to the first end of the sixth capacitor C6, and the second end of the sixth capacitor C6 is grounded. In the differential power amplifier circuit, the fourth resistor R4 plays a role of current limiting, and the fifth capacitor C5 and the sixth capacitor C6 have the ability to store charge. When an overvoltage occurs at the second end of the differential power amplifier in the circuit, the fourth resistor R4 will limit the flow of current, and the fifth capacitor C5 and the sixth capacitor C6 will absorb the excess charge caused by the overvoltage, thereby effectively protecting the safety of the differential power amplifier.

[0059] The switch module includes a first switch component S1 and a second switch component S2. In the switch module, the first end of the first switch component S1 is connected to the second end of the first capacitor C2 and the first end of the second switch component, and the second end of the first switch component S1 is grounded; the first end of the second switch component S2 is connected to the second end of the first capacitor C2, and the second end of the second switch component S2 is connected to the audio device. In the differential power amplifier circuit, by controlling the opening and closing states and opening and closing sequences of the first switch component S1 and the second switch component S2 in the switch module, the voltage of the first capacitor C2 changes slowly when the differential power amplifier is powered on and off, thereby reducing the background noise and POP sound of the audio device in the circuit.

[0060] Specifically, the first switch component S1 and the second switch component S2 are turned on by default. When the differential power amplifier is powered on, the control circuit first controls the first switch component S1 to be closed, so that the first capacitor C2 is charged to avoid a sudden change in the capacitance of the first capacitor C2. Then the second switch component S2 is closed and the first switch component S1 is opened, so that the signal of the differential power amplifier is input to the audio device.

[0061] When the differential power amplifier is working normally, the first switch component S1 is opened and the second switch component S2 is closed. When the differential power amplifier is pre-powered off, the differential power amplifier is powered off with a delay through the control circuit. Specifically, the first switch component S1 is first controlled to be closed so that the first capacitor C2 starts to discharge to avoid a sudden change in the capacitance of the first capacitor C2, and then the second switch component S2 is opened and the differential power amplifier is powered off, and finally the first switch component S1 is opened to power off the differential power amplifier. When the differential power amplifier is in a power-off state, both the first switch component S1 and the second switch component S2 are in an open state. In some embodiments, the delayed power-off process of the differential power amplifier is in the millisecond level.

[0062] The second protection module includes a seventh capacitor C7, an eighth capacitor C8 and a fifth resistor R5. In the second protection module, the first end of the seventh capacitor C7 is respectively connected to the second end of the switch module, the first end of the fifth resistor R5 and the background noise adjustment module, and the second end of the seventh capacitor C7 is grounded. The second end of the fifth resistor R5 is connected to the first end of the eighth capacitor C8, and the second end of the eighth capacitor C8 is grounded. In the differential power amplifier circuit, the fifth resistor R5 plays a role of current limiting, and the seventh capacitor C7 and the eighth capacitor C8 have the ability to store charge. When an overvoltage appears at the input end of the audio device in the circuit, the fifth resistor R5 will limit the flow of current, and the seventh capacitor C7 and the eighth capacitor C8 will absorb the excess charge caused by the overvoltage, thereby effectively protecting the safety of the differential power amplifier.

[0063] The background noise adjustment module includes a sliding rheostat R6, the first end of which is respectively connected to the first end of the fifth resistor, the first end of the seventh capacitor, and the second end of the second switch component, and the second end of which is connected to the audio device. The background noise adjustment module changes the resistance of the series resistor in the differential power amplifier circuit by adjusting the resistance of the sliding rheostat R6. When the resistance of the resistor connected in series in the circuit is larger, the voltage of the sliding rheostat R6 is larger, thereby making the voltage of the differential power amplifier smaller, further reducing the background noise and POP sound in the audio device.

[0064] In some embodiments, the resistance range of the sliding resistor R6 is 0Ω-200Ω. In some embodiments, the resistance range of the sliding resistor R6 can be set as needed and is not limited here.

[0065] In the differential power amplifier circuit, when the audio device is a headphone, the power of the headphone is relatively small, generally in the mW level, and the resistance value of the sliding rheostat R6 connected to the circuit should be relatively large, such as 180Ω; when the audio device is a speaker, the power of the speaker is relatively large, and it is necessary to balance the background noise and POP sound in the audio device by changing the resistance value of the sliding rheostat R6.

[0066] In an embodiment of the present application, in a differential power amplifier circuit with single-ended input and single-ended output, a switch module is added to the output end of the differential power amplifier. When the differential power amplifier is powered on and off, the on and off state of the switch in the switch module is controlled so that the voltage of the components connected to the differential power amplifier changes slowly, thereby reducing the background noise and POP sound of the audio devices in the circuit.

[0067] In the differential power amplifier circuit of the embodiment of the present application, a noise floor pre-reduction module is provided in series with the differential power amplifier to reduce the voltage of the differential power amplifier, thereby reducing the gain of the differential power amplifier, and reducing the noise floor and POP sound of the audio device in the circuit.

[0068] In the embodiment of the present application, a first protection module and a second protection module are set in the differential power amplifier circuit. When an overvoltage phenomenon occurs in the differential power amplifier circuit, the series-connected protection modules are used to divide the voltage, thereby alleviating the problem of voltage overshoot in the differential power amplifier circuit, thereby improving the EMI protection capability of the differential power amplifier circuit.

[0069] In the differential power amplifier circuit of the embodiment of the present application, a background noise adjustment module is provided to further reduce the background noise and POP sound of the audio device in the circuit by adjusting the sliding rheostat.

[0070] Combine the following Figure 5 , introduces a control method mentioned in the present application, which can be used in the differential power amplifier circuit mentioned in the embodiment of the present application. Figure 5 A flow chart of a control method is shown. Figure 5 As shown, the method includes:

[0071] S101: When it is detected that the differential power amplifier is powered on, the first switch component S1 is controlled to be closed and the second switch component S2 is controlled to be opened to charge the first capacitor. After the first capacitor is charged, the first switch component S1 is controlled to be opened and the second switch component is controlled to be closed to enable the differential power amplifier to output an audio signal to the audio device.

[0072] The first switch component S1 and the second switch component S2 are turned on by default. When it is detected that the differential power amplifier is powered on, the control circuit first controls the first switch component S1 to be closed, so that the first capacitor C2 is charged to avoid a sudden change in the capacitance of the first capacitor C2. Then the second switch component S2 is closed and the first switch component S1 is opened, so that the signal of the differential power amplifier is input to the audio device.

[0073] S102: When it is detected that the differential power amplifier is powered off, the first switch component S1 is controlled to close and the second switch component S2 is controlled to open in sequence, the differential power amplifier is powered off, and the first switch component S1 is opened to disconnect the conduction between the differential power amplifier and the audio device.

[0074] When the differential power amplifier is operating normally, the first switch component S1 is opened and the second switch component S2 is closed. When the differential power amplifier is detected to be powered off, the differential power amplifier is delayed to be powered off through the control circuit. Specifically, the first switch component S1 is first controlled to be closed so that the first capacitor C2 starts to discharge to avoid a sudden change in the capacitance of the first capacitor C2, and then the second switch component S2 is opened to disconnect the connection with the audio device, turn off the differential power amplifier, and finally the first switch component S1 is opened to power off the differential power amplifier. When the differential power amplifier is in the power-off state, the first switch component S1 and the second switch component S2 are both in the open state. In some embodiments, the delayed power-off process of the differential power amplifier is in the millisecond level.

[0075] An embodiment of the present application provides a chip, and the chip includes the differential power amplifier circuit mentioned in the embodiment of the present application.

[0076] An embodiment of the present application provides an electronic device, including the chip mentioned in the embodiment of the present application.

[0077] In the accompanying drawings, some structural or method features may be shown in a specific arrangement and / or order. However, it should be understood that such a specific arrangement and / or order may not be required. Instead, in some embodiments, these features may be arranged in a manner and / or order different from that shown in the illustrative drawings. In addition, the inclusion of structural or method features in a particular figure does not mean that such features are required in all embodiments, and in some embodiments, these features may not be included or may be combined with other features.

[0078] It should be noted that the units / modules mentioned in the various device embodiments of the present application are all logical units / modules. Physically, a logical unit / module can be a physical unit / module, or a part of a physical unit / module, or can be implemented as a combination of multiple physical units / modules. The physical implementation method of these logical units / modules themselves is not the most important. The combination of functions implemented by these logical units / modules is the key to solving the technical problems proposed by the present application. In addition, in order to highlight the innovative part of the present application, the above-mentioned device embodiments of the present application do not introduce units / modules that are not closely related to solving the technical problems proposed by the present application, which does not mean that there are no other units / modules in the above-mentioned device embodiments.

[0079] It should be noted that in the examples and description of this patent, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, the elements defined by the sentence "including one" do not exclude the existence of other identical elements in the process, method, article or device including the elements.

[0080] Although the present application has been illustrated and described with reference to certain preferred embodiments thereof, it will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the scope of the present application.

Claims

1. A differential power amplifier circuit, characterized in that: It includes a control module, a switch module, a differential power amplifier and a first capacitor unit; The first end of the differential power amplifier is used to receive an audio signal, the second end of the differential power amplifier is connected to the first end of the first capacitor unit, the second end of the first capacitor unit is connected to the first end of the switch module, and the second end of the switch module is connected to the audio device; The control module is used to control the charging of the first capacitor unit through the state of the switch module when detecting that the differential power amplifier is powered on, and after the charging of the first capacitor unit is completed, control the differential power amplifier to output an audio signal to the audio device through the state of the switch module, and, The control module is further configured to control the discharge of the first capacitor unit through the state of the switch module and disconnect the conduction between the differential power amplifier and the audio device when detecting that the differential power amplifier is pre-powered off.

2. The differential power amplifier circuit according to claim 1, characterized in that: The first capacitor unit includes a first capacitor, the switch module includes a first switch component and a second switch component, The first end of the first switch component is connected to the second end of the first capacitor and the first end of the second switch component, and the second end of the first switch component is grounded; the first end of the second switch component is connected to the second end of the first capacitor, and the second end of the second switch component is connected to the audio device.

3. The differential power amplifier circuit according to claim 2, characterized in that: The control module is used for: When it is detected that the differential power amplifier is powered on, the first switch component is controlled to be closed and the second switch component is controlled to be opened, so as to realize charging of the first capacitor; and after the first capacitor is completely charged, the first switch component is controlled to be opened and the second switch component is controlled to be closed, so as to realize the differential power amplifier outputting an audio signal to the audio device.

4. The differential power amplifier circuit according to claim 2, characterized in that: The control module is used for: When it is detected that the differential power amplifier is pre-powered off, the first switch component is controlled to close and the second switch component is controlled to open in sequence, the differential power amplifier is powered off, and the first switch component is opened, so as to disconnect the conduction between the differential power amplifier and the audio device.

5. The differential power amplifier circuit according to any one of claims 2 to 4, characterized in that: The differential power amplifier circuit also includes a noise floor pre-reduction module, a signal filtering module, a first protection module, a second protection module, and a noise floor adjustment module; The first end of the noise floor pre-reduction module is used to receive an audio signal, and the second end of the noise floor pre-reduction module is connected to the differential power amplifier; The first end of the signal filtering module is connected to the first output interface of the differential power amplifier, and the second end of the signal filtering module is connected to the first end of the first protection module; The second end of the first protection module is connected to the first end of the first capacitor, the second end of the first capacitor is connected to the first end of the switch module, the second end of the switch module is connected to the first end of the second protection module, the second end of the second protection module is connected to the first end of the background noise adjustment module, and the second end of the background noise adjustment module is connected to the audio device.

6. The differential power amplifier circuit according to claim 5, characterized in that: The noise floor pre-reduction module includes a first resistor, a second resistor and a third resistor, and the differential power amplifier circuit also includes a second capacitor and a third capacitor; The first end of the first resistor is used to receive an audio signal, the second end of the first resistor is respectively connected to the first end of the third resistor and the first end of the second capacitor, the second end of the second capacitor is connected to the first input interface of the differential power amplifier, the second end of the third resistor is respectively connected to the first end of the second resistor and the first end of the third capacitor, the second end of the third capacitor is connected to the second input interface of the differential power amplifier, and the second end of the second resistor is grounded.

7. The differential power amplifier circuit according to claim 6, characterized in that: The signal filtering module includes a first inductor and a fourth capacitor; the first end of the first inductor is connected to the first output interface of the differential power amplifier, the second end of the first inductor is respectively connected to the first end of the fourth capacitor and the first end of the first protection module, and the second end of the fourth capacitor is grounded.

8. The differential power amplifier circuit according to claim 7, characterized in that: The first protection module includes a fifth capacitor, a sixth capacitor and a fourth resistor; the first end of the fifth capacitor is respectively connected to the second end of the first inductor, the first end of the fourth capacitor, the first end of the fourth resistor and the first end of the first capacitor, and the second end of the fifth capacitor is grounded; the second end of the fourth resistor is connected to the first end of the sixth capacitor, and the second end of the sixth capacitor is grounded.

9. The differential power amplifier circuit according to claim 8, characterized in that: The second protection module includes a seventh capacitor, an eighth capacitor and a fifth resistor; the first end of the seventh capacitor is respectively connected to the second end of the switch module, the first end of the fifth resistor and the background noise adjustment module, and the second end of the seventh capacitor is grounded; the second end of the fifth resistor is connected to the first end of the eighth capacitor, and the second end of the eighth capacitor is grounded.

10. The differential power amplifier circuit according to claim 9, characterized in that: The background noise adjustment module includes a sliding rheostat, a first end of which is respectively connected to the first end of the fifth resistor, the first end of the seventh capacitor, and the second end of the second switch component, and a second end of which is connected to the audio device.

11. A control method, applied to the differential power amplifier circuit according to any one of claims 1 to 10, characterized in that: The method comprises: When it is detected that the differential power amplifier is powered on, the first switch component is controlled to be closed and the second switch component is controlled to be opened, so as to realize charging of the first capacitor unit; and after the first capacitor unit is completely charged, the first switch component is controlled to be opened and the second switch component is controlled to be closed, so as to realize that the differential power amplifier outputs an audio signal to the audio device; When it is detected that the differential power amplifier is pre-powered off, the first switch component is controlled to close and the second switch component is controlled to open in sequence, the differential power amplifier is powered off, and the first switch component is opened, so as to disconnect the conduction between the differential power amplifier and the audio device.

12. A chip, characterized in that: The chip comprises the differential power amplifier circuit according to any one of claims 1 to 10.

13. An electronic device, characterized in that: Comprising the chip as claimed in claim 12.

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