A multi-functional earphone circuit and earphone

Abstract

This application discloses a multifunctional headphone circuit and a headphone. The headphone circuit includes: a connector for connecting to an audio device; a first headset interface for connecting to the connector; and a second headset interface for connecting to the connector, including a microphone input detection signal path and a microphone input signal path. When a four-segment headphone is connected, the first and second headset interfaces input sound through the left and right channel input paths within the first headset interface. This solves the technical problem that existing headphone circuits cannot simultaneously support both three-segment and four-segment headphone inputs, and that LINE IN recording input cannot be connected when a four-segment headphone is connected, thus limiting the applicability of the audio input device. It achieves compatibility with both three-segment and four-segment headphone inputs, and allows LINE IN recording input when a four-segment headphone is connected, thereby improving the applicability of the audio input device.

Description

Technical Field

[0001] This application relates to the technical field of audio devices, and in particular to a multifunctional headphone circuit and headphones. Background Technology

[0002] With the widespread use of multimedia devices, headphones have become an indispensable audio device in daily life. Headphones are divided into integrated and independent types. Traditional headphone interfaces are mainly divided into three-segment (TRS) and four-segment (TRRS) types. Three-segment (without microphone) headphones are usually used for pure audio playback and have three contacts. From the top segment, they are the left channel, right channel, and common ground. Headphone plugs come in 3.5mm and 2.5mm versions. Currently, most headphone interfaces use 3.5mm, but the two are not interchangeable. A 3.5mm headphone needs an adapter to be used with a 2.5mm headphone jack device. Four-segment (with microphone) headphones have four contacts. That is, the ground segment is split into two parts, adding a microphone channel to support voice input and call functions. From the top segment, four-segment headphones are the left channel, right channel, common ground, and Mic (digital signal). Due to compatibility issues between different devices, existing technologies often have the problem that headphones cannot be simultaneously compatible with both three-segment and four-segment headphones. This is especially true when microphone functionality is supported, which may lead to signal loss or functional limitations, affecting the headphone's adaptability and failing to meet users' needs in various scenarios, such as voice calls, recording, and high-quality audio playback.

[0003] However, in the process of implementing the inventive technical solution in the embodiments of this application, the inventors of this application discovered that the above-mentioned technology has at least the following technical problems:

[0004] The existing headphone circuitry cannot simultaneously support both three-segment and four-segment headset inputs, and when a four-segment headset is connected, it cannot connect to LINE IN recording input, thus limiting the applicability of audio input devices. Summary of the Invention

[0005] This application provides a multifunctional headphone circuit and headphone, solving the technical problems in the prior art where headphone circuits cannot simultaneously support three-segment and four-segment headset inputs, and where LINE IN recording input cannot be connected when a four-segment headset is connected, thus limiting the applicability of audio input devices. It achieves the technical effect of being compatible with three-segment and four-segment headset inputs, and allowing LINE IN recording input when a four-segment headset is connected, thereby improving the applicability of audio input devices.

[0006] This application provides a multi-functional headphone circuit, comprising: a connector for connecting to an audio device; a first headphone jack for connecting to the connector; and a second headphone jack for connecting to the connector, including a microphone input detection signal path and a microphone input signal path; wherein, when a four-segment headphone is connected, the first and second headphone jacks input sound through the left channel input path and the right channel input path within the first headphone jack.

[0007] Preferably, the connector is connected to a CODEC signal, which includes a first signal path set and a second signal path set. The first signal path set is connected to the first headset interface and includes the left channel input path and the right channel input path. The second signal path set is connected to the second headset interface and includes the microphone input detection signal path and the microphone input signal path.

[0008] Preferably, the first headset interface includes: a sound input detection signal path, a left channel input path, and a right channel input path; wherein, when a four-segment headset is connected, the sound input signal is detected through the sound input detection signal path, and the sound is input through the left channel input path and the right channel input path within the first headset interface.

[0009] Preferably, the first headset interface further includes: a first sound output detection signal path, a first left channel output path, a first right channel output path, a microphone input detection signal path, a second left channel output path, and a second right channel output path.

[0010] Preferably, the second headset interface further includes: a third left channel output path, a third right channel output path, and a headset access detection signal path.

[0011] Preferably, each signal path within the first and second headset interfaces is connected to a TVS diode and a filter capacitor.

[0012] Preferably, the digital signals in the first and second headset interfaces use digital ground as the reference ground, and the analog signals use analog ground as the reference ground, with the digital ground and analog ground connected by a capacitor.

[0013] This application also provides an earphone, including any one of the following multifunctional earphone circuits.

[0014] One or more technical solutions provided in the embodiments of this application have at least the following technical effects or advantages:

[0015] This application provides a multifunctional headphone circuit and headphone, including a connector for connecting audio devices; a first headset interface connected to the connector; and a second headset interface connected to the connector, comprising a microphone input detection signal path and a microphone input signal path. When a four-segment headphone is connected, the first and second headset interfaces input sound through the left and right channel input paths within the first headset interface. This solves the technical problem that existing headphone circuits cannot simultaneously support three-segment and four-segment headphone inputs, and that LINE IN recording input cannot be connected when a four-segment headphone is connected, thus limiting the applicability of audio input devices. It achieves compatibility with both three-segment and four-segment headphone inputs, and allows LINE IN recording input when a four-segment headphone is connected, thereby improving the applicability of audio input devices.

[0016] The above description is only an overview of the technical solution of this application. In order to better understand the technical means of this application and to implement it in accordance with the contents of the specification, and to make the above and other objects, features and advantages of this application more obvious and understandable, the following are specific embodiments of this application. Attached Figure Description

[0017] To more clearly illustrate the technical solutions in this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0018] Figure 1 This is a schematic diagram of a connector for a multifunctional headphone circuit provided in an embodiment of this application.

[0019] Figure 2 This is a schematic diagram of the first headphone interface of a multifunctional headphone circuit provided in an embodiment of this application.

[0020] Figure 3 This is a schematic diagram of a second headphone interface for a multifunctional headphone circuit provided in an embodiment of this application.

[0021] Figure 4 This is a schematic diagram of the signal path connection reference ground for a multifunctional headphone circuit provided in an embodiment of this application.

[0022] Figure 5 This is a schematic diagram showing the connection between the digital ground and analog ground of a multifunctional headphone circuit provided in an embodiment of this application. Detailed Implementation

[0023] To make the above-mentioned objectives, features, and advantages of this application more apparent and understandable, the technical solutions in the embodiments of this application will be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of them. It should be understood that this application is not limited to the exemplary embodiments described herein. All other embodiments obtained by those skilled in the art based on the embodiments of this application without creative effort are within the scope of protection of this application. It should also be noted that, for ease of description, only the parts related to this application are shown in the accompanying drawings, not all of them.

[0024] The terms "first" and "second" in the specification and claims of this application may explicitly or implicitly include one or more of the features. In the description of this application, unless otherwise stated, "multiple" means two or more. Furthermore, "and / or" in the specification and claims indicates at least one of the connected objects, and the character " / " generally indicates that the preceding and following objects are in an "or" relationship.

[0025] In the description of this application, it should be understood that the terms "vertical", "horizontal", "perpendicular", "parallel", "clockwise", "counterclockwise", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application.

[0026] In the description of this application, it should be noted that, unless otherwise expressly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection between two components. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.

[0027] Technical concept

[0028] This application provides a multifunctional headphone circuit and headphone, which solves the technical problem that existing headphone circuits cannot simultaneously support three-segment headphones and four-segment headsets, and cannot connect LINE IN recording input when a four-segment headset is connected, thus limiting the applicability of audio input devices.

[0029] The multi-functional headphone circuit in this application has the following overall structure: a connector for connecting audio devices; a first headset interface for connecting the connector; and a second headset interface for connecting the connector, including a microphone input detection signal path and a microphone input signal path. When a four-segment headphone is connected, the first and second headset interfaces input sound through the left and right channel input paths within the first headset interface, thereby achieving compatibility with both three-segment and four-segment headphone inputs. Furthermore, when a four-segment headphone is connected, LINE IN recording input can be connected, thus improving the applicability of the audio input device.

[0030] Example 1

[0031] This application provides a multifunctional headphone circuit, the headphone circuit comprising:

[0032] A connector for connecting audio devices; a first headset jack for connecting to the connector; a second headset jack for connecting to the connector, including a microphone input detection signal path and a microphone input signal path; wherein, when connecting a four-segment headphone, the first and second headset jacks input sound through the left channel input path and the right channel input path within the first headset jack.

[0033] Furthermore, the first headset interface includes: a sound input detection signal path, a left channel input path, and a right channel input path; wherein, when a four-segment headset is connected, the sound input signal is detected through the sound input detection signal path, and the sound is input through the left channel input path and the right channel input path within the first headset interface.

[0034] Furthermore, the first headset interface also includes: a first sound output detection signal path, a first left channel output path, a first right channel output path, a microphone input detection signal path, a second left channel output path, and a second right channel output path.

[0035] Furthermore, the second headset interface also includes: a third left channel output path, a third right channel output path, and a headset access detection signal path.

[0036] Specifically, the connector is a four-segment plug (TRRS) used to connect external audio devices (such as mobile phones, computers, or players). It contains the following four signal channels: Tip (T), left channel audio signal (L); Ring 1 (R1), right channel audio signal (R); Ring 2 (R2), microphone signal (MIC); and Sleeve (S), common ground (GND). The connector's function is to transmit the audio device's signals to the headphones through the circuitry, ensuring the normal operation of the audio signal input and output functions. The first headset jack is directly connected to the connector and is mainly used to handle the headphone's audio signal input, including the left and right channel input paths. That is, through the connector's Tip (T), the audio signal is transmitted to the headphone's left channel speaker; and through the connector's Ring 1 (R1), the audio signal is transmitted to the headphone's right channel speaker. The second headset jack connects to Ring 2 (R2) and Sleeve (S) of the connector and focuses on handling the headset's microphone-related functions, including determining whether the headset supports microphone functionality (i.e., whether it is a four-segment headset) by detecting changes in voltage or impedance along the microphone signal path; and transmitting the microphone's audio signal from the headset to the audio device for voice input (such as recording or making calls).

[0037] Specifically, when connecting a four-segment headphone, the left channel input path of the first headset jack originates from the headphone's tip and is used to transmit the left channel audio signal. The right channel input path of the first headset jack originates from Ring 1 of the headphone and is used to transmit the right channel audio signal. The left and right channel signals are transmitted to the audio device through these paths, completing the stereo sound signal input. The first left channel output path and the first right channel output path are responsible for transmitting the left and right channel audio signals output by the audio processing device to the headphones, respectively. The left channel signal is transmitted to the left channel speaker of the headphones through the first left channel output path, and the right channel signal is transmitted to the right channel speaker of the headphones through the first right channel output path. The second left channel output path and the second right channel output path provide left and right channel audio signal paths for the second headset device. When the headset device has multiple output units (such as dual-output speakers or parallel output), they provide audio signals to the second output device. The second left channel output path transmits the left channel audio signal to the second device, and the second right channel output path transmits the right channel audio signal to the second device; the third left channel output path and the third right channel output path are used for the transmission of left and right channel audio signals of a third device (such as a spare headset or an external audio device), allowing multiple headsets or audio devices to be connected and used simultaneously. The third left channel output path transmits the left channel audio signal to the external device, and the third right channel output path transmits the right channel audio signal to the external device. They are usually connected to the target device through an additional pin of the headphone jack (such as an expansion interface).

[0038] Specifically, the first left channel output path and the first right channel output path correspond to PORT-D_L and PORT-D_R, respectively; the second left channel output path and the second right channel output path correspond to PORT-C_L and PORT-C_R, respectively; the third left channel output path and the third right channel output path correspond to HP_OUT_L_1 and HP_OUT_R_1, respectively; the first sound output detection signal path and the microphone input detection signal path correspond to LINEO_SW_D and RMIC_SW_C, respectively; the sound input detection signal path, the left channel input path, and the right channel input path correspond to LINEIN_SW_E, PORT-E_L, and PORT-E_R, respectively; the headphone input detection signal path corresponds to HPOUT_JD; SLEEVE_R and RING2_R are both microphone input and output signal paths.

[0039] Specifically, such as Figure 1 As shown in the diagram, the multi-functional headphone circuit block diagram mainly realizes the signal input, output, and switching functions between the headphones and audio devices. CON1 is the core connector module, used to connect the external audio device to the headphone circuit. It contains 40 pins, each pin corresponding to a specific signal path, used to receive and distribute input signals from the audio device and output audio signals to the headphone device. GND is the system ground, used to provide a current loop and signal stability for the circuit. AUGND is the dedicated audio ground, used to reduce noise and interference in the audio signal and ensure audio quality.

[0040] Specifically, LINEIN_SW_E (line input switch) is connected to PORT-E_L and PORT-E_R via pins 11, 13, and 15, corresponding to the left and right channel input paths respectively, and is used to control the switching of line input signals; LINEO_SW_D (line output switch) is connected to PORT-D_L and PORT-D_R via pins 19, 21, and 23, corresponding to the left and right channel output paths respectively, and is used to control the switching of line output signals; RMIC_SW_C (microphone switch) is connected to pin... Pins 31, 33, and 35 are connected to PORT-C_L and PORT-C_R, corresponding to the left and right channels of the microphone signal, respectively, and are used to detect and switch the microphone input signal; HPOUT_JD (headphone plug type detection) is connected to the SLEEVE_R and RING2_R signal paths via pin 26, and is used to detect the type of headphone plug (three-segment or four-segment); HP_OUT_L_1 and HP_OUT_R_1 are connected to the headphone output terminals of the left and right channels via pins 38 and 40, respectively, to provide the left and right channel audio output signals of the headphones.

[0041] Specifically, such as Figure 2As shown, the audio signal input / output circuit includes Line In, Line Out, and Mic In signal paths. Its main functions are to process audio signal input, output, and protection, ensuring signal quality and stability. Line In receives input signals from external audio devices and transmits them to the internal audio processor via PORT-E_L and PORT-E_R signal paths. PORT-E_LL and PORT-E_RR are the filtered left / right channel signals, respectively. Line Out outputs the internally processed audio signal to external audio devices via PORT-D_L and PORT-D_R signal paths. PORT-D_LL and PORT-D_RR are the filtered left / right channel signals, respectively. The In (microphone input) port receives input signals from an external microphone and transmits them to the audio processor via the PORT-C_L and PORT-C_R signal paths. PORT-C_LL and PORT-C_RR are the filtered left and right channel signals, respectively. Specifically, FB58, FB59, FB61, FB62, FB63, and FB64 are inductor filters with specifications of 120Ω, 100MHz, 2.5A, FB_0603, used to suppress high-frequency interference signals and ensure the stability and integrity of signal transmission, especially in high-frequency noise environments (such as radio frequency interference); C1 263, C1264, C1270, C1271, C1272, and C1273 are filter capacitors, rated at 100pF, 50V, NPO, and packaged in a C_0402 package. They are used for high-frequency filtering to further reduce noise interference with audio signals, thereby ensuring audio signal stability and improving signal quality. R811, R812, R813, R814, R815, R816, R817, and R818 are shunt resistors, rated at 22kΩ and packaged in an R0402 package. They are used for signal shunt to protect subsequent circuits and to regulate signal levels, preventing signals from being too strong or too weak. The Audio 1A2 is an audio connector that provides signal connections with Line In, Line Out, and Mic In interfaces, supporting audio input, output, and microphone signal transmission.

[0042] Specifically, such as Figure 3As shown, the headphone output (HP OUT) is used for the transmission, protection, and grounding management of the headphone audio signal. Specifically, it outputs the audio signals from the left and right channels (HP_OUT_L and HP_OUT_R) to the headphone speakers and supports the detection and transmission of microphone and ground (SLEEVE) signals. It uses filters and transient voltage suppressor diodes (TVS) to protect the headphone signal path from electrostatic discharge (ESD) or other voltage spikes. It also includes a detection signal path (HP_OUT_JD) to determine if the headphones are connected and to implement an automatic on / off function. Specifically, SLEEVE_R is the ground signal path used for audio grounding (AUGND), and RING2_R is the microphone signal path used to detect or transmit microphone signals. HP_OUT_L_1 and HP_OUT_R_1 are the audio signal paths for the left and right channels, respectively. HP_OUT_L_1 transmits the left channel audio signal, and HP_OUT_R_1 transmits the right channel audio signal. HP_OUT_JD is the detection signal path used to determine if headphones are plugged in. It can trigger a switch operation to automatically switch the audio signal output when headphones are plugged in. The inductor filters (A_FB13~A_FB17) are all 100R, 3A (inductors) used to suppress high-frequency noise, ensure signal integrity, and prevent interference signals from affecting audio quality. A_C34, A_C35, A_C44, A_C45, and A_C46 are filter capacitors, with a specification of 100... pF / 50V is used for high-frequency filtering to further eliminate high-frequency noise in the signal and ensure the stability of the audio signal; A_D16, A_D17, A_D18, A_D19, and A_D20 are transient voltage suppressor diodes (TVS), model BV-D505ZC, SOD_523 package, used for electrostatic discharge (ESD) protection. When a transient high voltage (such as electrostatic discharge) occurs on the signal path, it quickly conducts and introduces the overvoltage to ground, thereby protecting the subsequent circuits; AUDIO JACK2 (headphone jack) is used to connect the headphone plug, transmit audio signals, and detect the headphone insertion status.

[0043] Preferably, each signal path within the first and second headset interfaces is connected to a TVS diode and a filter capacitor.

[0044] Specifically, such as Figure 4As shown, the audio signal protection circuit protects the audio input and output signals (such as the left and right channels) from damage caused by overvoltage or electrostatic discharge (ESD). The protected signals are PORT-A_L and PORT-A_R (input signal paths for the left and right channels) and PORT-B_L and PORT-B_R (output signal paths for the left and right channels). Through an ESD protection diode array (TVS diodes) and grounding design, it achieves overvoltage protection for the signal paths, preventing damage from transient voltages or external interference. VRA23, VRA24, VRA25, and VRA26 represent TVS diodes used to suppress transient voltages (such as electrostatic discharge). The model number is SEU0501P1. They are transient voltage suppression devices. When an overvoltage occurs on the signal path, the TVS diode will quickly conduct, introducing the transient current to the common ground (GND), thereby protecting the subsequent circuit from damage. R0402_TVS indicates the package size of the device (0402 package, approximately 1.0mm × 0.5mm). It is used in conjunction with a TVS diode to filter out transient spike signals or reduce high-frequency interference.

[0045] Specifically, such as Figure 5 As shown, the decoupling capacitor array circuit provides power supply decoupling and filtering functions for the audio circuit, reducing power supply noise interference with the audio signal, thereby improving audio signal quality and circuit stability. Specifically, multiple parallel capacitors achieve power supply filtering and decoupling, suppressing power supply noise (such as high-frequency interference) and providing a stable power supply voltage for the audio circuit. Signal ground (GND) and audio-specific ground (AUGND) are connected separately to provide a clean reference point, avoiding the audio signal from being affected by noise. AUGND represents the audio-specific ground, mainly used for grounding the audio signal and reducing interference from power supply and other signals to the audio; GND represents the system common ground, the circuit's reference point, used to provide a path for all current loops; decoupling capacitors... (A_C36, A_C37, A_C38, A_C39, A_C40, A_C41, A_C42, A_C43), all capacitors are 0.1µF, 16V, used to remove high-frequency interference (such as switching noise, RF interference, etc.) on the power line, provide local current reserve, reduce voltage fluctuations caused by transient current changes, and ensure power supply stability. Multiple parallel capacitors achieve a wider frequency band noise suppression effect. The C_0402 package refers to the capacitor package size; 0402 indicates a size of 0.04 inches × 0.02 inches (approximately 1.0mm × 0.5mm). Each capacitor is connected in parallel with GND to form a low-pass filter, which can effectively filter out high-frequency noise signals on the power line.

[0046] Preferably, the connector is connected to a CODEC signal, which includes a first signal path set and a second signal path set. The first signal path set is connected to the first headset interface and includes the left channel input path and the right channel input path. The second signal path set is connected to the second headset interface and includes the microphone input detection signal path and the microphone input signal path.

[0047] Specifically, the CODEC signal is introduced into the headphone circuit through a connector and is divided into two signal path sets. The first signal path set is connected to the first headset interface and is responsible for transmitting the headphone's audio output (left and right channels) to the headphone speakers, including the left channel input path (transmitting the left channel audio signal) and the right channel input path (transmitting the right channel audio signal). The second signal path set is connected to the second headset interface and is responsible for processing the microphone input signal, including detecting and transmitting the microphone signal, including the microphone input detection signal path, used to detect whether the microphone is connected and whether the headphone is a four-segment headphone (TRRS); and the microphone input signal path, which transmits and processes the microphone's voice signal.

[0048] Preferably, the digital signals in the first and second headset interfaces use digital ground as the reference ground, and the analog signals use analog ground as the reference ground, with the digital ground and analog ground connected by a capacitor.

[0049] Specifically, digital ground (GND) is a reference potential provided for digital signals (such as logic level signals and digital audio signals). It is typically used to drive high-frequency switching signals in digital circuits (such as I²S, SPI, I²C, and other interface signals). Digital ground is usually used in conjunction with digital power supplies and is dedicated to digital signal processing. Analog ground (AUGND) is a reference potential provided for analog signals (such as analog audio signals). It is used to process continuously changing low-frequency or high-quality audio signals (such as left and right channel audio signals and microphone signals). Analog ground is typically used in conjunction with analog power supplies and is used for processing high-fidelity audio signals.

[0050] Example 2

[0051] This application also provides an earphone, including any of the multifunctional earphone circuits in Embodiment 1.

[0052] The multifunctional headphone circuit and headphone provided in this application embodiment have at least the following technical effects or advantages:

[0053] This application provides a multi-functional headphone circuit comprising: a connector for connecting an audio device; a first headset interface for connecting the connector; and a second headset interface for connecting the connector, including a microphone input detection signal path and a microphone input signal path. When a four-segment headphone is connected, the first and second headset interfaces input sound through the left and right channel input paths within the first headset interface. This solves the technical problem that existing headphone circuits cannot simultaneously support three-segment and four-segment headphone inputs, and that LINE IN recording input cannot be connected when a four-segment headphone is connected, thus limiting the applicability of the audio input device. This achieves compatibility with both three-segment and four-segment headphone inputs, and allows LINE IN recording input when a four-segment headphone is connected, thereby improving the applicability of the audio input device.

[0054] Although preferred embodiments of this application have been described, those skilled in the art, upon learning the basic inventive concept, can make other changes and modifications to these embodiments. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments as well as all changes and modifications falling within the scope of this application.

[0055] Obviously, those skilled in the art can make various modifications and variations to this application without departing from the spirit and scope of the embodiments of this application. Therefore, if these modifications and variations of this application fall within the scope of the claims of this application and their equivalents, this application also intends to include these modifications and variations.

Claims

1. A multifunctional headphone circuit, characterized in that, include: Connectors are used to connect audio devices; The first headset interface is connected to the connector; The second headset interface, connected to the connector, includes a microphone input detection signal path and a microphone input signal path; When connecting a four-segment headphone, the first and second headset interfaces input sound through the left and right channel input paths within the first headset interface. The first headset interface includes: Audio input detection signal path, left channel input path, right channel input path; When connecting a four-segment headphone, the sound input signal is detected through the sound input detection signal path, and the sound is input through the left channel input path and the right channel input path in the first headset interface; The connector is connected to a CODEC signal, which includes a first signal path set and a second signal path set. The first signal path set is connected to the first headset interface and includes the left channel input path and the right channel input path. The second signal path set is connected to the second headset interface and includes the microphone input detection signal path and the microphone input signal path. Each signal path within the first and second headset interfaces is connected to a TVS diode and a filter capacitor.

2. The multifunctional headphone circuit according to claim 1, characterized in that, The first headset interface also includes: First audio output detection signal path, first left channel output path, first right channel output path, microphone input detection signal path, second left channel output path, and second right channel output path.

3. The multifunctional headphone circuit according to claim 1, characterized in that, The second headset interface also includes: Third left channel output path, third right channel output path, headphone input detection signal path.

4. The multifunctional headphone circuit according to claim 1, characterized in that, The digital signals in the first and second headset interfaces use digital ground as the reference ground, and the analog signals use analog ground as the reference ground. The digital ground and the analog ground are connected by a capacitor.

5. An earphone, characterized in that, The earphone includes the multifunctional earphone circuit according to any one of claims 1-4.

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