Earphone circuit, debugging method of earphone circuit, chip and electronic device

Abstract

The earphone circuit includes a first signal processing circuit, a second signal processing circuit, a switch circuit, a voltage comparison circuit, a differential operational amplifier circuit and a gain amplification circuit. The first signal processing circuit is configured to convert an input first digital signal into a first analog signal and amplify the first analog signal. The second signal processing circuit is configured to convert an input second digital signal into a second analog signal and amplify the second analog signal. The switch circuit is configured to control the conduction or disconnection of the first signal processing circuit or the second signal processing circuit and a printed circuit board module. The voltage comparison circuit is configured to control the gain amplification circuit by comparing a voltage signal output by the differential operational amplifier circuit with a preset voltage. The differential operational amplifier circuit is configured to operate the voltage signal transmitted by the gain amplification circuit. The gain amplification circuit is configured to amplify the voltage signal input by the printed circuit board module. The application further discloses a debugging method of the earphone circuit, a chip with the earphone circuit and an electronic device.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of circuit, in particular to an earphone circuit, a debugging method of the earphone circuit, a chip and an electronic device. BACKGROUND

[0002] With the increasing popularity of mobile networks, audio and video multimedia are widely loved by consumers. When enjoying multimedia content through electronic devices such as mobile phones, PADs, personal digital assistants (PDAs), etc., the earphone mode is gradually favored and used by more and more users due to its delicate sound quality, realistic stereo effect and other advantages. With the increasing demand for sound quality, users hope to eliminate the problem of sound quality reduction caused by earphone crosstalk as much as possible.

[0003] To ensure good stereo effect, the left and right channels of the earphone need a certain degree of isolation, that is, the crosstalk between the left and right channels needs to be less than a certain standard. Generally, when the earphone is connected with the electronic device, a Type C (C-type Universal Serial Bus (USB)) interface is generally used in combination with an adapter to connect. Specifically, the Type C interface of the electronic device is connected with the Type C interface of one end of the adapter, and the earphone interface of the other end of the adapter is connected with the earphone, so as to send the audio signal output by the electronic device to the earphone through the adapter.

[0004] However, when the earphone is used, due to the impedance of the adapter itself and the contact impedance when the adapter and the Type C interface of the electronic device are connected, the earphone ground wire has impedance, which generates a voltage division, and the voltage division crosstalks to the other channel of the earphone, thereby affecting the stereo effect of the earphone and reducing the sound quality of the earphone output audio signal. Therefore, it is a technical problem to be solved by those skilled in the art to find a solution to solve the problem of voltage division crosstalk to the other channel due to the voltage division caused by the impedance of the adapter itself and the contact impedance when the adapter and the Type C interface of the electronic device are connected. SUMMARY

[0005] The present application provides an earphone circuit, a debugging method of the earphone circuit, a chip and an electronic device, which are beneficial to reduce the signal crosstalk between the left and right channels of the earphone caused by voltage division.

[0006] In a first aspect, the earphone circuit includes a first signal processing circuit, a second signal processing circuit, a voltage comparison circuit, a differential operational amplifier circuit, a gain amplification circuit, and a switch circuit. The first signal processing circuit converts an input first digital signal into a first analog signal, amplifies the first analog signal, and transmits the amplified first analog signal to a printed circuit board module. The second signal processing circuit is electrically connected to the first signal processing circuit, converts an input second digital signal into a second analog signal, amplifies the second analog signal, and transmits the amplified second analog signal to the printed circuit board module. The switch circuit is electrically connected to the printed circuit board module, controls the conduction or disconnection of the first signal processing circuit or the second signal processing circuit and the printed circuit board module, and controls the conduction or disconnection of the first signal processing circuit or the second signal processing circuit and the printed circuit board module. The voltage comparison circuit is electrically connected to the differential operational amplifier circuit and the gain amplification circuit, and controls the gain amplification circuit by comparing a voltage signal output by the differential operational amplifier circuit with a preset voltage. The differential operational amplifier circuit is electrically connected to the first signal processing circuit, the second signal processing circuit, the switch circuit, the voltage comparison circuit, and the gain amplification circuit, operates on a voltage signal transmitted by the gain amplification circuit, and transmits the operated voltage signal to the voltage comparison circuit. The gain amplification circuit is electrically connected to the first signal processing circuit, the second signal processing circuit, the differential operational amplifier circuit, and the printed circuit board module, amplifies a voltage signal input by the printed circuit board module, and transmits the amplified voltage signal to the differential operational amplifier circuit and the second signal processing circuit.

[0007] In the earphone circuit, the differential operational amplifier circuit and the gain amplification circuit compensate for the voltage input by the printed circuit board module to reduce the voltage difference across the signal output assembly, thereby reducing the signal crosstalk between the left and right channels caused by voltage division of the signal output assembly, improving the stereo sound effect of the earphone, and increasing the sound quality of the audio signal output by the earphone, thereby providing a user with a required audio signal.

[0008] In a possible implementation, the first signal processing circuit is electrically connected with the printed circuit board module, the first signal processing circuit comprises a first amplifier, wherein a non-inverting input terminal of the first amplifier inputs the first digital signal, an inverting input terminal of the first amplifier is electrically connected with the second signal processing circuit, the differential operational amplifier circuit and the gain amplification circuit, and an output terminal of the first amplifier is electrically connected with the printed circuit board module, the first amplifier is configured to convert the first digital signal into a first analog signal, amplify the first analog signal, and transmit the amplified second analog signal to the printed circuit board module.

[0009] In a possible implementation, the second signal processing circuit is electrically connected with the printed circuit board module through the switch circuit, the second signal processing circuit comprises a second amplifier, wherein a non-inverting input terminal of the second amplifier inputs the second digital signal, an inverting input terminal of the second amplifier is electrically connected with the inverting input terminal of the first amplifier, the differential operational amplifier circuit and the gain amplification circuit, and an output terminal of the second amplifier is electrically connected with the printed circuit board module through the switch circuit, the second amplifier is configured to convert the second digital signal into a second analog signal, amplify the second analog signal, and transmit the amplified second analog signal to the printed circuit board module through the switch circuit.

[0010] In a possible implementation, the voltage comparison circuit comprises a comparator, wherein an input terminal of the comparator is electrically connected with the differential operational amplifier circuit, and an output terminal of the comparator is electrically connected with the gain amplification circuit, and the comparator is configured to control the gain amplification circuit.

[0011] In a possible implementation, the differential operational amplifier circuit comprises a third amplifier, a first resistor, a second resistor, a third resistor and a fourth resistor, wherein the inverting input terminal of the third amplifier is electrically connected with the first resistor and the second resistor, the non-inverting input terminal of the third amplifier is electrically connected with the third resistor and the fourth resistor, the output terminal of the third amplifier is electrically connected with the input terminal of the comparator, and the third amplifier is configured to operate on the voltage signal output by the gain amplification circuit; the first resistor is electrically connected between the inverting input terminal of the third amplifier and the output terminal of the third amplifier, the first end of the second resistor is electrically connected with the second end of the first resistor and the inverting input terminal of the third amplifier, the second end of the second resistor is electrically connected with the switch circuit, the first end of the third resistor is electrically connected with the non-inverting input terminal of the third amplifier and the fourth resistor, the second end of the third resistor is electrically connected with the gain amplification circuit and the inverting input terminals of the first amplifier and the second amplifier, and the first end of the fourth resistor is electrically connected between the non-inverting input terminal of the third amplifier and the first end of the third resistor, and the second end of the fourth resistor is grounded.

[0012] In a possible implementation, the gain amplification circuit comprises a fourth amplifier, wherein the input terminal of the fourth amplifier is electrically connected with the printed circuit board module, the control terminal of the fourth amplifier is electrically connected with the output terminal of the comparator, and the output terminal of the fourth amplifier is electrically connected with the inverting input terminal of the first amplifier, the inverting input terminal of the second amplifier and the second end of the third resistor, and is configured to amplify the voltage signal transmitted by the printed circuit board module.

[0013] In a possible implementation, the switch circuit comprises a first switch and a second switch, wherein the first switch is connected between the output terminal of the second amplifier and the printed circuit board module, and is configured to control the on or off of the path between the second signal processing circuit and the printed circuit board module; the first end of the second switch is electrically connected with the second end of the first switch, and the second end of the second switch is electrically connected with the second end of the second resistor, and is configured to control the on or off of the path between the second signal processing circuit and the printed circuit board module.

[0014] In a possible implementation, the earphone circuit further comprises a fifth resistor, wherein the first end of the fifth resistor is electrically connected with the input terminal of the fourth amplifier and the earphone connection assembly, and the second end of the fifth resistor is grounded.

[0015] In a possible implementation, the earphone circuit further includes a sixth resistor, a seventh resistor, and an eighth resistor, wherein the sixth resistor, the seventh resistor, and the eighth resistor are electrically connected between the earphone connection component and the signal output component, and the eighth resistor is electrically connected with the first end of the fifth resistor.

[0016] In a possible implementation, the signal output component includes a ninth resistor, a tenth resistor, and an eleventh resistor, wherein the first end of the ninth resistor is electrically connected with the second end of the eighth resistor, the second end of the ninth resistor is electrically connected with the second end of the tenth resistor and the second end of the eleventh resistor, the first end of the tenth resistor is electrically connected with the second end of the seventh resistor, the second end of the tenth resistor is electrically connected with the second end of the ninth resistor, the first end of the eleventh resistor is electrically connected with the second end of the sixth resistor, and the second end of the eleventh resistor is electrically connected with the second end of the ninth resistor.

[0017] In a possible implementation, when the first end of the second switch is electrically connected with the second end of the second switch, the first switch is in an off state, the inverting input end of the third amplifier is electrically connected with the printed circuit board module through the second resistor, the voltage at the second end of the second switch is equal to the voltage at the first end of the second switch, and the voltage at the first end of the second switch is equal to the voltage at the first end of the tenth resistor.

[0018] In a possible implementation, the earphone circuit further includes the printed circuit board module, the earphone connection component, and the signal output component, which are electrically connected in sequence, wherein the printed circuit board module is configured to transmit the amplified first analog signal transmitted by the first signal processing circuit and the amplified second analog signal transmitted by the second signal processing circuit through the switch circuit to the earphone connection component; the earphone connection component is configured to transmit the first analog signal and the second analog signal transmitted by the printed circuit board module to the signal output component; and the signal output component is configured to output the first analog signal and the second analog signal transmitted by the earphone connection component.

[0019] In a possible implementation, the earphone circuit includes a signal processing module, the signal processing module includes the first signal processing circuit, the second signal processing circuit, the voltage comparison circuit, the differential operational amplifier circuit, the gain amplifier circuit, and the switch circuit, the signal processing module is a codec chip, the earphone connection component is an earphone seat, and the signal output component is an earphone wire.

[0020] In a second aspect, the application further provides a debugging method of an earphone circuit, which is used for debugging the earphone circuit, and the debugging method comprises the following steps: playing an audio source with a preset frequency; electrically connecting a first end of a second switch with a second end of the second switch, and a first switch is in an off state; powering on a third amplifier; setting a threshold voltage of a comparator as a preset voltage; adjusting a fourth amplifier; the voltage of an output end of the third amplifier is less than the preset voltage of the threshold voltage of the comparator; electrically connecting the first end of the first switch with the second end of the first switch, and the second switch is in an off state; powering off the third amplifier.

[0021] In a third aspect, the application further provides a chip, which comprises an audio output unit and the earphone circuit, and the earphone circuit compensates the voltage signal input by the printed circuit board module through the differential operational amplifier circuit and the gain amplifier circuit.

[0022] In a fourth aspect, the application further provides an electronic device, which comprises a user design module and the chip. BRIEF DESCRIPTION OF DRAWINGS

[0023] In order to more clearly illustrate the technical solutions in the embodiments of the application, the following will briefly introduce the drawings needed to be used in the embodiment description. Obviously, the drawings in the following description are only some embodiments of the application, and for those skilled in the art, other drawings can also be obtained from these drawings without creative labor.

[0024] Figure 1 FIG. 1 is a schematic structural diagram of an earphone circuit provided by an embodiment of the application;

[0025] Figure 2 FIG. 2 is a schematic circuit structural diagram of an earphone circuit provided by an embodiment of the application;

[0026] Figure 3 FIG. 3 is a schematic work flow diagram of a debugging method of an earphone circuit provided by an embodiment of the application;

[0027] Figure 4 FIG. 4 is a schematic structural diagram of a chip provided by an embodiment of the application;

[0028] Figure 5 FIG. 5 is a schematic structural diagram of an electronic device provided by an embodiment of the application. DETAILED DESCRIPTION

[0029] With reference to the drawings and the embodiments of the present application, the technical solutions in the embodiments of the present application will be described clearly and completely. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments of the present application. Based on the embodiments of the present application, all the other embodiments obtained by those skilled in the art without creative work fall within the scope of the present application.

[0030] The terms used in the following embodiments of the present application are only for the purpose of describing the specific embodiments, and are not intended to be limiting of the present application. As used in the specification and the appended claims of the present application, the singular forms "a," "an," and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms "and / or" as used herein refer to and encompass any or all possible combinations of one or more of the associated listed items.

[0031] It should be noted that the terms "first", "second", "third", etc. in the specification and claims of the present application and in the above-described drawings are used to distinguish similar objects, and do not necessarily have to describe a specific order or sequence. It should be understood that the data thus used can be interchanged under appropriate circumstances, so that the embodiments of the present application described herein can be implemented in an order other than that illustrated or described herein. In addition, the term "comprising" and any variation thereof is intended to cover non-exclusive inclusion, for example, a process, method, system, product or server comprising a series of steps or units does not have to be limited to those steps or units clearly listed, but can include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0032] With the increasing popularity of mobile networks, audio and video multimedia are widely favored by consumers. When enjoying multimedia content through electronic devices such as mobile phones, PADs, personal digital assistants (PDAs), etc., the earphone mode is gradually favored and used by more and more users due to its delicate sound quality, realistic stereo sound effect, etc. With the increasing demand for sound quality, users hope to eliminate the problem of sound quality reduction caused by earphone crosstalk as much as possible. To ensure good stereo sound effect, the left and right channels of the earphone need a certain degree of isolation, that is, the crosstalk between the left and right channels needs to be less than a certain standard. Generally, when the earphone is connected with the electronic device, a Type C interface is usually used in conjunction with an adapter (for example, a Type-C to 3.5mm earphone jack adapter) to connect. Specifically, the Type C interface of the electronic device is connected with the Type C interface at one end of the adapter, and the earphone interface at the other end of the adapter is connected with the earphone to send the audio signal output by the electronic device to the earphone through the adapter. However, during the use of the earphone, due to the impedance of the adapter itself and the contact impedance when the adapter and the Type C interface of the electronic device are connected, the earphone ground wire has impedance, which generates a voltage division, and the voltage division crosstalks to the other channel of the earphone, thereby affecting the stereo sound effect of the earphone and reducing the sound quality of the audio signal output by the earphone. Therefore, it is a technical problem that needs to be solved by those skilled in the art to find a solution to solve the problem of voltage division crosstalk to the other channel due to the voltage division caused by the impedance of the adapter (for example, a Type-C to 3.5mm earphone jack adapter) itself and the contact impedance generated when the adapter and the Type C interface of the electronic device are connected, thereby affecting the stereo sound effect of the earphone and reducing the sound quality of the audio signal output by the earphone.

[0033] Based on this, the present application hopes to provide a solution that can solve the above technical problems, which can solve the problem of voltage division crosstalk to the other channel due to the voltage division caused by the impedance of the adapter (for example, a Type-C to 3.5mm earphone jack adapter) itself and the contact impedance generated when the adapter and the Type C interface of the electronic device are connected, thereby affecting the stereo sound effect of the earphone and reducing the sound quality of the audio signal output by the earphone. The detailed content will be described in the subsequent embodiments. The detailed description of the earphone circuit, the debugging method of the earphone circuit, the chip and the electronic device of the present application solution.

[0034] Please refer to Figure 1 , which is a schematic diagram of an earphone circuit structure according to an embodiment of the present application. As shown in Figure 1As shown, the earphone circuit 100 provided in the present application comprises a signal processing module 110, a printed circuit board (PCB) module 120, an earphone connecting assembly 130 and a signal output assembly 140. The signal processing module 110 is electrically connected with the PCB module 120, the PCB module 120 is electrically connected with the earphone connecting assembly 130, and the earphone connecting assembly 130 is electrically connected with the signal output assembly 140, that is, the signal processing module 110, the PCB module 120, the earphone connecting assembly 130 and the signal output assembly 140 are electrically connected in sequence.

[0035] In the embodiment of the present application, the PCB module 120 can be a PCB board. It can be understood that in the exemplary embodiment, the signal processing module 110 can be integrated or integrated on the PCB module 120 and electrically connected with the corresponding electronic components on the PCB module 120.

[0036] In the embodiment of the present application, the signal processing module 110 converts the input signal into a corresponding audio signal, amplifies the audio signal and transmits it to the PCB module 120, the PCB module 120 processes the audio signal transmitted by the signal processing module 110, and transmits the processed signal to the signal output assembly 140 through the earphone connecting assembly 130, the signal output assembly 140 outputs the signal transmitted by the earphone connecting assembly 130, thereby providing the user with the required audio signal. At the same time, the signal processing module 110 performs voltage compensation on the signal output assembly 140 to reduce the voltage difference across the signal output assembly 140, thereby reducing the signal crosstalk between the left and right channels of the signal output assembly 140 due to voltage division, improving the stereo sound effect of the earphone, and facilitating the increase of the sound quality of the audio signal output by the earphone.

[0037] In the embodiment of the present application, the signal processing module 110 comprises a first signal processing circuit 111, a second signal processing circuit 112, a voltage comparison circuit 115, a differential operational amplifier circuit 116, a gain amplification circuit 117 and a switch circuit 114, wherein the first signal processing circuit 111 is electrically connected with the second signal processing circuit 112, the differential operational amplifier circuit 116, the gain amplification circuit 117 and the PCB module 120, the first signal processing circuit 111 is used for converting the input first digital signal into a first analog signal, amplifying the first analog signal, and transmitting the amplified first analog signal to the PCB module 120. The second signal processing circuit 112 is electrically connected with the first signal processing circuit 111, the differential operational amplifier circuit 116, the gain amplification circuit 117 and the switch circuit 114, the second signal processing circuit 112 is used for converting the input second digital signal into a second analog signal, amplifying the second analog signal, and transmitting the amplified second analog signal to the PCB module 120 through the switch circuit 114. The switch circuit 114 is electrically connected with the second signal processing circuit 112 and the PCB module 120, the switch circuit 114 is used for controlling the conduction or disconnection of the second signal processing circuit 112 and the PCB module 120. The voltage comparison circuit 115 is electrically connected with the differential operational amplifier circuit 116 and the gain amplification circuit 117, the voltage comparison circuit 115 is used for controlling the gain amplification circuit 117 by comparing the voltage signal output by the differential operational amplifier circuit 116 with a preset voltage. The differential operational amplifier circuit 116 is electrically connected with the first signal processing circuit 111, the second signal processing circuit 112, the switch circuit 114, the voltage comparison circuit 115 and the gain amplification circuit 117, the differential operational amplifier circuit 116 is used for operating the voltage signal transmitted by the gain amplification circuit 117, and transmitting the operated voltage signal to the voltage comparison circuit 115. The gain amplification circuit 117 is electrically connected with the first signal processing circuit 111, the second signal processing circuit 112, the differential operational amplifier circuit 116 and the PCB module 120, the gain amplification circuit 117 is used for amplifying the voltage signal input by the PCB module 120, and transmitting the amplified voltage signal to the differential operational amplifier circuit 116 and the second signal processing circuit 112.

[0038] In the embodiment of the present application, the signal processing module 110 can be a codec chip.

[0039] In the embodiment of the present application, the PCB module 120 is electrically connected with the first signal processing circuit 111, the gain amplification circuit 117, the switch circuit 114 and the earphone connecting assembly 130. The PCB module 120 is configured to transmit the amplified first analog signal transmitted by the first signal processing circuit 111 and the amplified second analog signal transmitted by the second signal processing circuit 112 through the switch circuit 114 to the earphone connecting assembly 130.

[0040] In the embodiment of the present application, the earphone connecting assembly 130 is electrically connected with the PCB module 120 and the signal output assembly 140, and transmits the first analog signal and the second analog signal transmitted by the PCB module 120 to the signal output assembly 140.

[0041] In the embodiment of the present application, the earphone connecting assembly 130 can be an earphone seat.

[0042] In the embodiment of the present application, the signal output assembly 140 is electrically connected with the earphone connecting assembly 130, and is configured to output the first analog signal and the second analog signal transmitted by the earphone connecting assembly 130.

[0043] In the embodiment of the present application, the signal output assembly 140 can be an earphone wire, and the signal output assembly 140 can be mechanically connected to the earphone connecting assembly 130. The signal output assembly 140 can include a first sound channel and a second sound channel. The first analog signal can be output through the first sound channel or the second sound channel, and the second analog signal can be output through the second sound channel or the first sound channel. The first analog signal and the second analog signal are output through different sound channels respectively. In an exemplary embodiment, the first sound channel can be a left sound channel of an earphone, configured to output a first audio signal, and the second sound channel can be a right sound channel of the earphone, configured to output a second audio signal. It can be understood that the first sound channel can also be a right sound channel of an earphone, configured to output a first audio signal, and the second sound channel can be a left sound channel of the earphone, configured to output a second audio signal.

[0044] In other embodiments of this application, the second signal processing circuit 112 is directly electrically connected to the printed circuit board module 120, and the switching circuit 114 is electrically connected between the second signal processing circuit 112 and the PCB module 120, and is electrically connected to the differential operational amplifier circuit 116. It is used to control the on or off state of the second signal processing circuit 112 and the PCB module 120, and the on or off state of the differential operational amplifier circuit 116 and the PCB module 120, respectively. That is, the switching circuit 114 is used to selectively control the on or off state of the second signal processing circuit 112 or the differential operational amplifier circuit 116 and the PCB module 120.

[0045] Therefore, in the headphone circuit 100 of this application, the voltage input to the PCB module 120 is compensated by the differential operational amplifier circuit 116 and the gain amplifier circuit 117 to reduce the voltage difference across the signal output component 140. This reduces signal crosstalk between the left and right channels caused by voltage division in the signal output component 140, improves the stereo effect of the headphones, and enhances the sound quality of the audio signal output by the headphones, thereby providing users with a satisfactory audio signal. Moreover, the headphone circuit of this application is based on the principle of crosstalk. Starting from the hardware design, it can eliminate problems such as PCB traces and mechanical contact impedance, solve the crosstalk problem at the headphone end, and enable the headphone end to obtain the isolation of the chip output, ensuring a better stereo effect.

[0046] Please see Figure 2 , it is Figure 1 The circuit diagram shown is a schematic of the headphone circuit. Figure 2 As shown, the first signal processing circuit 111 in the headphone circuit 100 provided in this application includes a first amplifier 1111. The non-inverting input terminal of the first amplifier 1111 is used to input the first digital signal. The inverting input terminal of the first amplifier 1111 is electrically connected to the second signal processing circuit 112, the differential operational amplifier circuit 116, and the gain amplifier circuit 117. The output terminal of the first amplifier 1111 is electrically connected to the PCB module 120. The first amplifier 1111 is used to convert the first digital signal into a first analog signal, amplify the first analog signal, and transmit the amplified second analog signal to the PCB module 120.

[0047] In this embodiment of the application, the first amplifier 1111 may be a power amplifier (PA).

[0048] In the embodiment of the present application, the second signal processing circuit 112 comprises a second amplifier 1121, wherein the non-inverting input terminal of the second amplifier 1121 is configured to input the second digital signal, the inverting input terminal of the second amplifier 1121 is electrically connected with the inverting input terminal of the first amplifier 1111, the differential operational amplifier circuit 116 and the gain amplification circuit 117, and the output terminal of the second amplifier 1121 is electrically connected with the PCB module 120 through the switch circuit 114. The second amplifier 1121 is configured to convert the second digital signal into a second analog signal, amplify the second analog signal, and transmit the amplified second analog signal to the PCB module 120 through the switch circuit 114.

[0049] In the embodiment of the present application, the second amplifier 1121 can be a power amplifier.

[0050] In the embodiment of the present application, the voltage comparison circuit 115 comprises a comparator 1151, wherein the input terminal of the comparator 1151 is electrically connected with the differential operational amplifier circuit 116, and the output terminal of the comparator 1151 is electrically connected with the gain amplification circuit 117, and the comparator 1151 is configured to control the gain amplification circuit 117. The differential operational amplifier circuit 116 comprises a third amplifier 1161, a first resistor 1162, a second resistor 1163, a third resistor 1164 and a fourth resistor 1165, wherein the inverting input terminal of the third amplifier 1161 is electrically connected with the first resistor 1162 and the second resistor 1163, the non-inverting input terminal of the third amplifier 1161 is electrically connected with the third resistor 1164 and the fourth resistor 1165, the output terminal of the third amplifier 1161 is electrically connected with the input terminal of the comparator 1151, and the third amplifier 1161 is configured to operate the voltage signal output by the gain amplification circuit 117. The first resistor 1162 is electrically connected between the inverting input terminal of the third amplifier 1161 and the output terminal of the third amplifier 1161, the first end of the second resistor 1163 is electrically connected with the second end of the first resistor 1162 and the inverting input terminal of the third amplifier 1161, the second end of the second resistor 1163 is electrically connected with the switch circuit 114, the first end of the third resistor 1164 is electrically connected with the non-inverting input terminal of the third amplifier 1161 and the fourth resistor 1165, the second end of the third resistor 1164 is electrically connected with the gain amplification circuit 117 and the inverting input terminals of the first amplifier 1111 and the second amplifier 1121, the first end of the fourth resistor 1165 is electrically connected between the non-inverting input terminal of the third amplifier 1161 and the first end of the third resistor 1164, and the second end of the fourth resistor 1165 is grounded.

[0051] In the embodiment of the present application, the third amplifier 1161 can be a gate-level comparator.

[0052] In the embodiment of the present application, the gain amplification circuit 117 includes a fourth amplifier 1171, wherein an input end of the fourth amplifier 1171 is electrically connected with the PCB module 120, a control end of the fourth amplifier 1171 is electrically connected with an output end of the comparator 1151, and an output end of the fourth amplifier 1171 is electrically connected with an inverting input end of the first amplifier 1111, an inverting input end of the second amplifier 1121 and a second end of the third resistor 1164, for amplifying the voltage signal transmitted by the PCB module 120.

[0053] In the embodiment of the present application, the resistance value of the first resistor 1162 and the resistance value of the fourth resistor 1165 can both be Rf, and the resistance value of the second resistor 1163 and the resistance value of the third resistor 1164 can both be Rin. The fourth amplifier 1171 can be a programmable gain amplifier (PGA), and the amplification multiple of the fourth amplifier 1171 can be controlled by program as needed.

[0054] In the embodiment of the present application, the switch circuit 114 includes a first switch 1141 and a second switch 1143, wherein a first end of the first switch 1141 is electrically connected with an output end of the second amplifier 1121, and a second end of the first switch 1141 is electrically connected with the PCB module 120, that is, the first switch 1141 is connected between the output end of the second amplifier 1121 and the PCB module 120, for controlling the on or off of the path between the second signal processing circuit 112 and the PCB module 120. A first end of the second switch 1143 is electrically connected with the second end of the first switch 1141, that is, the second end of the first switch 1141 and the first end of the second switch 1143 share one end, and a second end of the second switch 1143 is electrically connected with a second end of the second resistor 1163, for controlling the on or off of the path between the differential operational amplifier circuit 116 and the PCB module 120.

[0055] In the embodiment of the present application, the PCB module 120 includes a fifth resistor 121, a first end of the fifth resistor 121 is electrically connected with an input end of the fourth amplifier 1171 and the earphone connection assembly 130, and a second end of the fifth resistor 121 is grounded.

[0056] In the embodiment of the present application, the earphone circuit 100 further comprises a fifth resistor 121, the fifth resistor 121 is located on the PCB module 120, a first end of the fifth resistor 121 is electrically connected with an input end of the fourth amplifier 1171 and the earphone connecting assembly 130, and a second end of the fifth resistor 121 is grounded. Wherein, the fifth resistor 121 can be a PCB wiring impedance and a frequency modulation (FM) ground magnetic bead, and a resistance value of the fifth resistor 121 can be Rg3. The fifth resistor 121 is used for shielding interference between signals, and is also used for suppressing high-frequency interference and noise, and improving signal-to-noise ratio.

[0057] In the embodiment of the present application, the earphone circuit 100 further comprises a sixth resistor 131, a seventh resistor 132 and an eighth resistor 133, wherein the sixth resistor 131, the seventh resistor 132 and the eighth resistor 133 are electrically connected between the earphone connecting assembly 130 and the signal output assembly 140. Specifically, a first end of the sixth resistor 131 is electrically connected with the earphone connecting assembly 130, and a second end of the sixth resistor 131 is electrically connected with the signal output assembly 140, that is, the sixth resistor 131 is electrically connected between the earphone connecting assembly 130 and the signal output assembly 140. A first end of the seventh resistor 132 is electrically connected with the earphone connecting assembly 1300, and a second end of the seventh resistor 132 is electrically connected with the signal output assembly 140, that is, the seventh resistor 132 is electrically connected between the earphone connecting assembly 130 and the signal output assembly 140. A first end of the eighth resistor 133 is electrically connected with the earphone connecting assembly 130, and a second end of the eighth resistor 133 is electrically connected with the signal output assembly 140, that is, the eighth resistor 133 is electrically connected between the earphone connecting assembly 130 and the signal output assembly 140.

[0058] In the embodiment of the present application, the sixth resistor 131, the seventh resistor 132 and the eighth resistor 133 are equivalent resistors between the earphone connecting assembly 130 and the signal output assembly 140. The eighth resistor 133 can be an earphone seat contact impedance, and a resistance value of the eighth resistor 133 can be Rg2.

[0059] In the embodiment of the present application, the signal output component 140 comprises a ninth resistor 141, a tenth resistor 142 and an eleventh resistor 143, wherein a first end of the ninth resistor 141 is electrically connected with a second end of the eighth resistor 133, and a second end of the ninth resistor 141 is electrically connected with a second end of the tenth resistor 142 and a second end of the eleventh resistor 143. A first end of the tenth resistor 142 is electrically connected with a second end of the seventh resistor 132, and a second end of the tenth resistor 142 is electrically connected with the second end of the ninth resistor 141. A first end of the eleventh resistor 143 is electrically connected with a second end of the sixth resistor 131, and a second end of the eleventh resistor 143 is electrically connected with the second end of the ninth resistor 141.

[0060] In the embodiment of the present application, the ninth resistor 141 can be the impedance of the earphone wire, and the resistance value of the ninth resistor 141 can be Rg1. The resistance value of the tenth resistor 142 and the resistance value of the eleventh resistor 143 can both be R.

[0061] Please refer to Figure 3 , which is a work flow diagram of the debugging method of the earphone circuit as shown in Figure 2 . The work flow is used to reduce the crosstalk of the earphone circuit in the embodiment shown in Figures 1-2 , thereby effectively improving the stereo sound effect of the earphone. It should be noted that, in order to facilitate the description of the working principle of the earphone circuit, the earphone circuit of the present application is described by taking the right channel as an example, which is also applicable to the left channel of the earphone, and the present application does not make specific limitations thereto. It should also be noted that, all crosstalk tests below are based on the left channel full amplitude signal and the right channel mute signal. As shown in Figure 3 , the work flow of the debugging method of the earphone circuit at least comprises the following steps.

[0062] S10, playing an audio source of a preset frequency.

[0063] Specifically, playing an audio source of a preset frequency, the earphone circuit 100 is turned on, the voltage at the first end (i.e., the fourth point as shown in Figure 2 ) of the fifth resistor 121 can be V4=V1*Rg3 / (R+Rg1+Rg2+Rg3), and the voltage at the second end (i.e., the third point as shown in Figure 2 ) of the ninth resistor 141 can be V3=V1*(Rg1+Rg2+Rg3) / (R+Rg1+Rg2+Rg3). The signal processing module 110 selects the voltage at the first end (i.e., the fourth point as shown in Figure 2 ) of the fifth resistor 121 as the common voltage of the second amplifier 1121, and the output voltage of the second amplifier 1121 is the voltage at the first end (i.e., the fourth point as shown inFigure 2 The voltage of the fourth point shown in the first aspect.In an embodiment of the present application, the preset frequency can be 1K Hz. Figure 2 The signal of the fourth point shown in the first aspect can be used as a reference signal, which is taken inside the signal processing module 110 as a common-mode reference of the earphone power amplifier. The default level of the power amplifier output of the earphone will follow Figure 2 The voltage change of the fourth point shown in the first aspect.

[0064] In an embodiment of the present application, when the earphone circuit 100 is adjusted, the voltage across the tenth resistor 142 is equal to the voltage difference between the first end (i.e., the second point shown in the first aspect) and the second end (i.e., the third point shown in the first aspect) of the tenth resistor 142, that is, V Figure 2 The voltage difference between the first end (i.e., the second point shown in the first aspect) and the second end (i.e., the third point shown in the first aspect) of the tenth resistor 142 will determine the crosstalk result. Figure 2 The voltage difference between the first end (i.e., the second point shown in the first aspect) and the second end (i.e., the third point shown in the first aspect) of the tenth resistor 142 will determine the crosstalk result. R The voltage difference between the first end (i.e., the second point shown in the first aspect) and the second end (i.e., the third point shown in the first aspect) of the tenth resistor 142 will determine the crosstalk result. 23 The voltage difference between the first end (i.e., the second point shown in the first aspect) and the second end (i.e., the third point shown in the first aspect) of the tenth resistor 142 will determine the crosstalk result. Figure 2 The voltage difference between the first end (i.e., the second point shown in the first aspect) and the second end (i.e., the third point shown in the first aspect) of the tenth resistor 142 will determine the crosstalk result. Figure 2 The voltage difference between the first end (i.e., the second point shown in the first aspect) and the second end (i.e., the third point shown in the first aspect) of the tenth resistor 142 will determine the crosstalk result.

[0065] S20, electrically connect the first end of the second switch 1143 to the second end of the second switch 1143, and the first switch 1141 is in an open state.

[0066] Specifically, the first end of the second switch 1143 is electrically connected to the second end of the second switch 1143, the inverting input end of the third amplifier 1161 is electrically connected to the PCB module 120 through the second resistor 1163, the voltage Vsw_2 of the second end of the second switch 1143 is equal to the voltage Vsw1 of the first end of the second switch 1143, and the voltage Vsw1 of the first end of the second switch 1143 is also equal to the voltage V2 of the first end (i.e., the second point shown in the first aspect) of the tenth resistor 142, that is, Vsw_2 = Vsw1 = V2. Figure 2

[0067] S30, power on the third amplifier 1161.

[0068] Specifically, since the first end of the second switch 1143 is electrically connected to the second end of the second switch 1143, the third amplifier 1161 is conductive with the PCB module 120 and forms a loop, and the voltage V O of the output end of the third amplifier 1161 is equal to the calculation process of the voltage V O of the output end of the third amplifier 1161 is as follows:

[0069]

[0070] and V3=V1*(Rg1+Rg2+Rg3) / (R+Rg1+Rg2+Rg3), V4=V1*Rg3 / (R+Rg1+Rg2+Rg3)

[0071]

[0072] wherein, V in1 is the voltage of the second end of the second resistor 1163, V in2 is the voltage of the second end of the third resistor 1164, PGA is the amplification of the fourth amplifier 1171, R f is the resistance of the first resistor 1162, R in is the resistance of the second resistor 1163.

[0073] S40, setting the threshold voltage Vth of the comparator 1151 as a preset voltage.

[0074] Specifically, the voltage V O of the output end of the third amplifier 1161 is transmitted to the input end of the comparator 1151, and the comparator 1151 sets the threshold voltage Vth, and sets the Vth as a preset voltage. In the embodiment of the application, the preset voltage can be 5uV.

[0075] S50, adjusting the fourth amplifier 1171.

[0076] Specifically, from the above formula (3), by adjusting the fourth amplifier 1171 and then adjusting PGA to change the voltage V O of the output end of the third amplifier 1161, adjusting PGA so that the voltage V O of the output end of the third amplifier 1161 is less than or equal to the preset voltage set by the threshold voltage Vth, that is, V O ≤Vth, and adjusting PGA to amplify the voltage V4 of the first end (i.e., the fourth point shown in FIG. 1) of the fifth resistor 121, so that the voltage V4 of the first end (i.e., the fourth point shown in FIG. 1) of the fifth resistor 121 approaches the voltage V3 of the second end (i.e., the third point shown in FIG. 1) of the ninth resistor 141, thereby reducing the voltage difference of the tenth resistor 142, thereby reducing the signal crosstalk problem between the two channels of the earphone caused by voltage division, and improving the stereo effect of the earphone. Figure 2 Figure 2 Figure 2

[0077] S60, the voltage V O of the output end of the third amplifier 1161 is less than the preset voltage set by the threshold voltage Vth of the comparator 1151.

[0078] ​​​It should be noted that when the voltage V at the output terminal of the third amplifier 1161 O When the voltage is less than the preset voltage of the comparator 1151, the headphone circuit can continue to operate. When the voltage V at the output of the third amplifier 1161... O When the voltage is not less than the preset voltage of the comparator 1151, the fourth amplifier 1171 needs to be further adjusted so that the voltage V at the output of the third amplifier 1161 is equal to the preset voltage of the comparator 1151. O The preset voltage is less than or equal to the threshold voltage Vth, i.e., V O ≤Vth, and simultaneously adjust the PGA to the first terminal of the fifth resistor 121 (i.e. Figure 2 The voltage V4 at point 4 (as shown) is amplified, so that the first terminal of the fifth resistor 121 (i.e. Figure 2 The voltage V4 at point 4 (as shown) is close to the second terminal of the ninth resistor 141 (i.e. Figure 2 The voltage V3 (as shown in point 3) reduces the voltage difference of the tenth resistor 142, thereby reducing the signal crosstalk between the two channels of the headphones caused by voltage division.

[0079] S70. Electrically connect the first terminal of the first switch 1141 to the second terminal of the first switch 1141, and the second switch 1143 is in the off state.

[0080] Specifically, the electrical connection between the first and second terminals of the second switch 1143 is disconnected, and the first and second terminals of the first switch 1141 are electrically connected. The resistance values ​​of the first resistor 1162 and the second resistor 1163 are equal, and the resistance values ​​of the third resistor 1164 and the fourth resistor 1165 are equal. This ensures that the output voltage of the second amplifier 1121 is equal to the output voltage Vin2 of the fourth amplifier 1171. The calculation process is as follows:

[0081] Since the resistance of the first resistor 1162 is equal to the resistance of the second resistor 1163, we can obtain the following result according to the above formula (1):

[0082] V O =V3-V in2 Formula (4)

[0083] At the same time, the voltage across the tenth resistor 142 is equal to the voltage across the first terminal of the tenth resistor 142 (i.e., Figure 2 Point 2 shown) and the second end (i.e. Figure 2 The voltage difference at point 3 (as shown), i.e., V R =V 23V3-V2, the first end of the tenth resistor 142 (i.e. Figure 4 As shown in the second point) V2 of the voltage of the first end of the tenth resistor 142 is equal to the output end of the fourth amplifier 1171, Vin2, that is:

[0084] V R =V in2 -V3 formula (5)

[0085] S80, the third amplifier 1161 is powered off.

[0086] Specifically, according to formula (6), the earphone end X-talk value can be calculated.

[0087]

[0088] As can be seen from the above, in the earphone circuit of the present application, by adjusting the fourth amplifier 1171, when the comparator 1151 is set to a preset voltage Vth, the optimized earphone crosstalk test data is about -102db, which is about 49db higher than the optimized earphone crosstalk test data (about -52.3db), greatly improving the stereo effect of the earphone. Moreover, the earphone circuit of the present application compensates for the earphone line impedance (Rg1), earphone seat contact impedance (Rg2) and Rg3 (PCB trace, FM ground magnetic bead) three impedance in principle, so that the earphone end obtains the crosstalk performance of the chip output. In addition, Rg3 includes FM ground magnetic bead, which undertakes the function of isolating FM signal. Generally, the magnetic bead with good FM performance has high Directive Current Resistance (DCR), and balance between FM sensitivity and HP performance is required. The patent can ignore the influence of DCR on the earphone, and make the FM magnetic bead selection more flexible.

[0089] It can be understood that the earphone circuit of the present application is not limited to 3.5mm earphone seat, TypeC seat and other earphone forms, and has wide compatibility.

[0090] As Figure 4 shown, Figures 1 to 3 The chip 10 provided by the embodiment of the present application comprises an earphone circuit 100 and an audio output unit 200, wherein the earphone circuit 100 is specifically described above. Figure 5The description of the embodiments is not repeated here. In the earphone circuit 100, the voltage input by the PCB module 120 is compensated by the differential operational amplifier circuit 116 and the gain amplification circuit 117, the voltage difference between the two ends of the signal output assembly 140 is reduced, the signal crosstalk between the left and right channels caused by voltage division of the earphone circuit 100 is reduced, the stereo effect of the earphone is improved, the sound quality of the audio signal output by the earphone is improved, and the user is provided with the audio signal meeting the requirements.

[0091] As Figure 5 shown, Figure 4 The electronic device 20 includes the chip 10 and the user design module 11. The electronic device 20 can be used in Internet of Things scenarios such as smart wear, smart home, shared bicycles, etc. The chip 10 is specifically described in the above ​ The description of the embodiments is not repeated here. The user design module 11 is used to control the chip 10 to realize the preset function.

[0092] The various devices, products, and modules / units described in the above embodiments can be software modules / units or hardware modules / units, or part of them are software modules / units and part of them are hardware modules / units. For example, for various devices, products of application or integrated chip, each module / unit contained therein can be realized by hardware such as circuit, or at least part of the modules / units can be realized by software program, which runs in the integrated processor inside the chip, and the remaining part of the modules / units can be realized by hardware such as circuit; for various devices, products of application or integrated chip module, each module / unit contained therein can be realized by hardware such as circuit, and different modules / units can be located in the same component (such as chip, circuit module, etc.) or different components of the chip module, at least part of the modules / units can be realized by software program, which runs in the integrated processor inside the chip module, and the remaining part of the modules / units can be realized by hardware such as circuit; for various devices, products of application or integrated terminal, each module / unit contained therein can be realized by hardware such as circuit, and different modules / units can be located in the same component (such as chip, circuit module, etc.) or different components of the terminal, or at least part of the modules / units can be realized by software program, which runs in the integrated processor inside the terminal, and the remaining part of the modules / units can be realized by hardware such as circuit.

[0093] It should be noted that, for the foregoing method embodiments, for the sake of simple description, they are all described as a series of action combinations, but those skilled in the art should know that the present application is not limited to the action sequence described, because according to the present application, certain operations can be performed in other sequences or simultaneously. Secondly, those skilled in the art should know that the embodiments described in the specification all belong to preferred embodiments, and the actions and modules involved are not necessarily necessary for the present application.

[0094] The descriptions of the various embodiments provided by the present application can be mutually referred to, and the descriptions of the various embodiments each have a focus. The parts not described in detail in a certain embodiment can be referred to the relevant description of other embodiments. For the convenience and brevity of description, for example, the functions of the various devices and equipment provided by the embodiments of the present application and the operations performed can be referred to the relevant description of the method embodiments of the present application, and the various method embodiments can also be mutually referred to, combined or cited.

[0095] Finally, it should be noted that: the above embodiments are only used to illustrate the technical solutions of the present application, and not to limit them; although the present application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that: it can still modify the technical solutions recorded in the foregoing embodiments, or make equivalent replacement for part or all of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present application.

Claims

1. A headphone circuit, characterized by, The application relates to a signal processing circuit, which comprises a first signal processing circuit, a second signal processing circuit, a voltage comparison circuit, a differential operational amplifier circuit, a gain amplification circuit and a switch circuit. The first signal processing circuit is used for converting an input first digital signal into a first analog signal, amplifying the first analog signal and transmitting the amplified first analog signal to a first sound channel of a printed circuit board module. The second signal processing circuit is electrically connected with the first signal processing circuit, and is used for converting an input second digital signal into a second analog signal, amplifying the second analog signal and transmitting the amplified second analog signal to a second sound channel of the printed circuit board module. The ground path is directly connected with a ground end through a resistor, and is used for shielding signal interference, inhibiting high-frequency interference and noise and providing ground voltages corresponding to the first sound channel and the second sound channel. The switch circuit is electrically connected with the printed circuit board module, and is used for controlling the conduction or disconnection of the second signal processing circuit and the printed circuit board module. The voltage comparison circuit is electrically connected with the differential operational amplifier circuit and the gain amplification circuit, and is used for controlling the amplification multiple of the gain amplification circuit by comparing a voltage signal output by the differential operational amplifier circuit with a preset voltage and outputting a comparison result. The differential operational amplifier circuit is electrically connected with the first signal processing circuit, the second signal processing circuit, the switch circuit, the voltage comparison circuit and the gain amplification circuit, and is used for operating a voltage signal transmitted by the gain amplification circuit and a voltage of the second sound channel on the printed circuit board module, and transmitting the operated voltage signal to the voltage comparison circuit. ​ The gain amplification circuit is electrically connected with the first signal processing circuit, the second signal processing circuit, the differential operational amplifier circuit and the ground terminal of the printed circuit board module, and is configured to amplify the ground voltage input from the ground terminal of the printed circuit board module in real time according to the gain corresponding to the comparison result of the voltage comparison circuit, and transmit the amplified voltage signal to the differential operational amplifier circuit and the second signal processing circuit, so as to eliminate the crosstalk caused by the resistor on the ground terminal when the voltage of the second sound channel is close to the ground voltage provided by the ground terminal.

2. The earphone circuit according to claim 1, characterized in that, The first signal processing circuit is electrically connected with the printed circuit board module, and includes a first amplifier, wherein the non-inverting input terminal of the first amplifier is configured to input the first digital signal, the inverting input terminal of the first amplifier is electrically connected with the second signal processing circuit, the differential operational amplifier circuit and the gain amplification circuit, the output terminal of the first amplifier is electrically connected with the printed circuit board module, and the first amplifier is configured to convert the first digital signal into a first analog signal, amplify the first analog signal, and transmit the amplified second analog signal to the printed circuit board module.

3. The earphone circuit according to claim 2, wherein The second signal processing circuit is electrically connected with the printed circuit board module through the switch circuit, and includes a second amplifier, wherein the non-inverting input terminal of the second amplifier is configured to input the second digital signal, the inverting input terminal of the second amplifier is electrically connected with the inverting input terminal of the first amplifier, the differential operational amplifier circuit and the gain amplification circuit, the output terminal of the second amplifier is electrically connected with the printed circuit board module through the switch circuit, and the second amplifier is configured to convert the second digital signal into a second analog signal, amplify the second analog signal, and transmit the amplified second analog signal to the printed circuit board module through the switch circuit.

4. The earphone circuit according to claim 3, wherein The voltage comparison circuit includes a comparator, wherein the input terminal of the comparator is electrically connected with the differential operational amplifier circuit, and the output terminal of the comparator is electrically connected with the gain amplification circuit, and the comparator is configured to control the gain amplification circuit.

5. The earphone circuit according to claim 4, wherein The differential operational amplifier circuit includes a third amplifier, a first resistor, a second resistor, a third resistor and a fourth resistor, wherein, the inverting input terminal of the third amplifier is electrically connected with the first resistor and the second resistor, the non-inverting input terminal of the third amplifier is electrically connected with the third resistor and the fourth resistor, the output terminal of the third amplifier is electrically connected with the input terminal of the comparator, and the third amplifier is configured to operate the voltage signal output by the gain amplification circuit; The first resistor is electrically connected between the inverting input terminal of the third amplifier and the output terminal of the third amplifier, the first end of the second resistor is electrically connected with the second end of the first resistor and the inverting input terminal of the third amplifier, the second end of the second resistor is electrically connected with the switch circuit, the first end of the third resistor is electrically connected with the non-inverting input terminal of the third amplifier and the fourth resistor, the second end of the third resistor is electrically connected with the gain amplification circuit and the inverting input terminals of the first amplifier and the second amplifier, and the first end of the fourth resistor is electrically connected between the non-inverting input terminal of the third amplifier and the first end of the third resistor, and the second end of the fourth resistor is grounded.

6. The earphone circuit according to claim 5, wherein The gain amplification circuit comprises a fourth amplifier, wherein the input terminal of the fourth amplifier is electrically connected with the printed circuit board module, the control terminal of the fourth amplifier is electrically connected with the output terminal of the comparator, and the output terminal of the fourth amplifier is electrically connected with the inverting input terminal of the first amplifier, the inverting input terminal of the second amplifier and the second end of the third resistor, so as to amplify the voltage signal transmitted by the printed circuit board module.

7. The earphone circuit according to claim 6, wherein The switch circuit comprises a first switch and a second switch, wherein, the first switch is connected between the output terminal of the second amplifier and the printed circuit board module, and is used for controlling the on or off of the path between the second signal processing circuit and the printed circuit board module; the first end of the second switch is electrically connected with the second end of the first switch, and the second end of the second switch is electrically connected with the second end of the second resistor, so as to control the on or off of the path between the differential operational amplifier circuit and the printed circuit board module.

8. The earphone circuit according to claim 7, wherein The earphone circuit further comprises a fifth resistor, the first end of the fifth resistor is electrically connected with the input terminal of the fourth amplifier and the earphone connection assembly, and the second end of the fifth resistor is grounded.

9. The earphone circuit according to claim 8, wherein The earphone circuit further comprises a sixth resistor, a seventh resistor and an eighth resistor, wherein the sixth resistor, the seventh resistor and the eighth resistor are all electrically connected between the earphone connection assembly and the signal output assembly, and the eighth resistor is electrically connected with the first end of the fifth resistor.

10. The earphone circuit according to claim 9, wherein The signal output assembly comprises a ninth resistor, a tenth resistor and an eleventh resistor, wherein the first end of the ninth resistor is electrically connected with the second end of the eighth resistor, the second end of the ninth resistor is electrically connected with the second end of the tenth resistor and the second end of the eleventh resistor, the first end of the tenth resistor is electrically connected with the second end of the seventh resistor, the second end of the tenth resistor is electrically connected with the second end of the ninth resistor, the first end of the eleventh resistor is electrically connected with the second end of the sixth resistor, and the second end of the eleventh resistor is electrically connected with the second end of the ninth resistor.

11. The earphone circuit according to claim 10, wherein When the first end of the second switch is electrically connected with the second end of the second switch, the first switch is in an off state, the inverting input end of the third amplifier is electrically connected with the printed circuit board module through the second resistor, the voltage of the second end of the second switch is equal to the voltage of the first end of the second switch, and the voltage of the first end of the second switch is equal to the voltage of the first end of the tenth resistor.

12. A headphone circuit according to any one of claims 9-11, characterized in that, The earphone circuit further comprises the printed circuit board module, the earphone connecting assembly and the signal output assembly, and the printed circuit board module, the earphone connecting assembly and the signal output assembly are electrically connected in sequence, wherein, The printed circuit board module is configured to transmit the amplified first analog signal transmitted by the first signal processing circuit and the amplified second analog signal transmitted by the second signal processing circuit through the switch circuit to the earphone connecting assembly; The earphone connecting assembly is configured to transmit the first analog signal and the second analog signal transmitted by the printed circuit board module to the signal output assembly; The signal output assembly is configured to output the first analog signal and the second analog signal transmitted by the earphone connecting assembly.

13. The earphone circuit of claim 10, wherein, The earphone circuit comprises a signal processing module, the signal processing module comprises the first signal processing circuit, the second signal processing circuit, the voltage comparison circuit, the differential operational amplifier circuit, the gain amplification circuit and the switch circuit, the signal processing module is a codec chip, the earphone connecting assembly is an earphone seat, and the signal output assembly is an earphone wire.

14. A method of debugging an earphone circuit for debugging an earphone circuit as claimed in any one of claims 1-13, characterized in that, The debugging method comprises: playing a sound source with a preset frequency; closing the second switch of the switch circuit to be in a conduction state, and the first switch of the switch circuit is in an off state; powering on the third amplifier; setting the threshold voltage of the comparator to a preset voltage; adjusting the fourth amplifier; the voltage of the output end of the third amplifier is less than the preset voltage of the comparator; electrically connecting the first end of the first switch with the second end of the first switch, and the second switch is in an off state; powering off the third amplifier.

15. A chip, characterized by The earphone circuit comprises an audio output unit and an earphone circuit according to any one of claims 1-13, wherein the voltage signal input by the printed circuit board module is compensated through the differential operational amplifier circuit and the gain amplification circuit in the earphone circuit.

16. An electronic device, comprising: The chip comprises a user design module and the chip according to claim 15.

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