Two-microphone insertion detection and channel switching circuit

Abstract

The utility model provides a two-microphone insertion detection and channel switching circuit. The two-microphone insertion detection and channel switching circuit comprises a first microphone socket J6, a second microphone socket J5 and an audio channel switching chip U1, a second pin of the first microphone socket J6 is connected with a MICDET pin and a fourth pin of the audio channel switching chip U1 through diodes D1 and D2, and the first microphone socket J6 is used for detecting insertion of a microphone and controlling channel switching; the second pin of the second microphone socket J5 is connected to the MICDET pin and is used for detecting the insertion of a second microphone; and the audio channel switching chip U1 selects which microphone outputs the audio signal of the microphone to the audio output channel according to the level state of the fourth pin of the audio channel switching chip U1. According to the utility model, only one IO port is used to realize insertion detection of two microphones, and automatic switching of channels can be realized without software logic processing, thereby greatly saving MCU software and hardware resources, reducing product cost, and simplifying software design logic.

Description

Technical Field

[0001] This utility model relates to the field of circuit design technology, and in particular to a two-channel microphone insertion detection and channel switching circuit. Background Technology

[0002] In existing circuit designs, implementing dual-microphone insertion detection and audio channel switching requires at least three GPIO resources from the MCU. Additionally, software logic processing is needed to handle the channel switching, consuming significant MCU hardware and software resources. When the device's MCU resources are limited, resource shortages can occur. Using an MCU with more resources can avoid this, but it increases costs.

[0003] Therefore, how to effectively detect the insertion of two microphones and switch audio channels without increasing costs is an urgent problem to be solved.

[0004] The background description provided herein is for the purpose of generally presenting the context of this disclosure. Unless otherwise indicated herein, the material described in this section is not prior art to the claims of this application and should not be acknowledged as prior art by virtue of its inclusion in this section. Summary of the Invention

[0005] In view of the above-mentioned technical problems in related technologies, this utility model proposes a two-channel microphone insertion detection and channel switching circuit, which uses only one IO port to realize the two-channel microphone insertion detection, and can realize automatic channel switching without software logic processing, saving MCU resources and simplifying software design logic.

[0006] This utility model provides a two-channel microphone insertion detection and channel switching circuit, which includes a first microphone socket J6, a second microphone socket J5, and an audio channel switching chip U1;

[0007] The first microphone jack J6 includes pin 1, pin 2, and pin 3; pin 1 of the first microphone jack J6 is grounded; pin 2 of the first microphone jack J6 is connected to the cathodes of the first diode D1 and the second diode D2 respectively; the anode of the first diode D1 is connected to the first power supply through the first resistor R1, and to pin 4 of the audio channel switching chip U1 through the second resistor R2; the anode of the second diode D2 is connected to the MIC_DET pin; pin 3 of the first microphone jack J6 is connected to pin 3 of the audio channel switching chip U1 as the first audio input MIC_IN.

[0008] The second microphone jack J5 includes pins 1, 2, 3, 4, and 5. Pin 1 of the second microphone jack J5 is connected to the first power supply through a third resistor R3. Pin 2 of the second microphone jack J5 is connected to the MIC_DET pin and grounded through a first resistor R4. Pin 4 of the second microphone jack J5 is grounded. Pin 5 of the second microphone jack J5 is connected to pin 1 of the audio channel switching chip U1 as the second audio input MIC2_IN through a second capacitor C2. Pin 3 of the second microphone jack J5 is left floating and not used.

[0009] The audio channel switching chip U1 includes pins 1, 2, 3, 4, 5, and 6. Pin 2 of the audio channel switching chip U1 is connected to ground and connected to a second power supply through a third capacitor C3. Pin 5 of the audio channel switching chip U1 is connected to the second power supply and grounded through a third capacitor C3. Pin 6 of the audio channel switching chip U1 is connected to the MIC_AUDIO pin through a fourth capacitor C4. Pin 4 of the audio channel switching chip U1 is the MIC_SW pin. Pin 6 of the audio channel switching chip U1 is the audio output channel.

[0010] When pin 4 of audio channel switching chip U1 is high, the audio signal from pin 1 of audio channel switching chip U1 is output from pin 6 of audio channel switching chip U1, and the audio signal from pin 3 of audio channel switching chip U1 is disconnected.

[0011] When pin 4 of audio channel switching chip U1 is low, the audio from pin 3 of audio channel switching chip U1 is output from pin 6 of audio channel switching chip U1, and the audio from pin 1 of audio channel switching chip U1 is disconnected.

[0012] Specifically, the second pin of the first microphone socket J6 is an insertion detection pin; when the microphone is not inserted into the first microphone socket J6, the second pin of the first microphone socket J6 is in a floating state; when the microphone is inserted into the first microphone socket J6, the second pin of the first microphone socket J6 is shorted to the first pin of the first microphone socket J6.

[0013] Specifically, pin 2 of the second microphone socket J5 is an insertion detection pin; when the microphone is not inserted into the second microphone socket J5, pin 1 of the second microphone socket J5 is shorted to pin 2 of the second microphone socket J5; when the microphone is inserted into the second microphone socket J5, pin 1 of the second microphone socket J5 is disconnected from pin 2 of the second microphone socket J5.

[0014] Specifically, when no microphone is plugged into either channel, pin 2 of the first microphone socket J6 is in a floating state; pin 2 of the second microphone socket J5 is shorted to pin 1 and pulled up to the first power supply.

[0015] The MIC_SW pin is pulled up to the first power supply through the second resistor R2 and the first resistor R1, and is at a high level. The audio output channel is connected to MIC2_IN by default.

[0016] The MIC_DET pin is connected between the fourth resistor R4 and the third resistor R3. By dividing the voltage between the two resistors, the voltage of the MIC_DET pin can be half of the second power supply, which is a high level.

[0017] Specifically, when a microphone is inserted into the first microphone socket J6 and not into the second microphone socket J5, the second pin of the first microphone socket J6 is shorted to the first pin and pulled down to ground; the second pin of the second microphone socket J5 is shorted to the first pin and pulled up to the first power supply.

[0018] The MIC_SW pin is pulled down to ground through the second resistor R2 and the first diode D1. Due to the clamping effect of the diode, even if the MIC_SW pin is pulled up to the first power supply through the first resistor R1, its voltage is still clamped to the forward voltage drop VF of the first diode D1, so that the fourth pin of the audio channel switching chip U1 detects a low level, and the audio output channel is switched from MIC2_IN to MIC1_IN.

[0019] The MIC_DET pin is pulled down to ground through the parallel circuit of the fourth resistor R4 and the second diode D2, and simultaneously pulled up to the first power supply through the third resistor R3. Due to the clamping effect of the second diode D2, the voltage of the MIC_DET pin is clamped to the forward voltage drop VF2 of the second diode D2, which is a low level.

[0020] Specifically, when the first microphone socket J6 is not inserted and the second microphone socket J5 is inserted, the second pin of the first microphone socket J6 is floating; the second pin of the second microphone socket J5 is disconnected from the first pin, the pull-up is canceled, and it is pulled down to ground through the fourth resistor R4.

[0021] The MIC_SW pin is pulled up to the first power supply through the second resistor R2 and the first resistor R1, and is at a high level. The audio channel is switched to MIC2_IN.

[0022] The MIC_DET pin is pulled down to ground through the fourth resistor R4, and the MIC_DET pin behaves as a low level.

[0023] Specifically, when microphones are inserted into both the first microphone socket J6 and the second microphone socket J5, the second pin of the first microphone socket J6 is shorted to the first pin and pulled down to ground; the second pin of the second microphone socket J5 is disconnected from the first pin, the pull-up is eliminated, and it is pulled down to ground through the fourth resistor R4.

[0024] The MIC_SW pin is pulled down to ground through the second resistor R2 and the first diode D1. Due to the clamping effect of the diode, even if the MIC_SW pin is pulled up to the first power supply through the first resistor R1, its voltage is still clamped to the forward voltage drop VF of the first diode D1, so that pin 4 of the audio channel switching chip U1 detects a low level and the output channel is switched to MIC1_IN.

[0025] Specifically, the audio channel switching chip U1 is a 2-to-1 channel selection circuit.

[0026] Specifically, the audio channel switching chip U1 is model SGM3157.

[0027] Specifically, the first power supply is a 3.3V power supply; the second power supply is a 5V power supply.

[0028] Specifically, the first resistor R1 is 20kΩ, the second resistor R2 is 22Ω, the third resistor R3 is 1kΩ, and the fourth resistor R4 is 10kΩ.

[0029] Specifically, the first capacitor C1 is 10uF, the second capacitor C2 is 10uF, the third capacitor C3 is 10uF, and the fourth capacitor C4 is 10uF; wherein the first capacitor C1, the second capacitor C2, and the fourth capacitor C4 are AC coupling capacitors, transmitting AC audio signals and isolating DC voltage; the third capacitor C3 is a filter capacitor at the power supply end of the channel switching chip U1, filtering out voltage noise at the power supply port.

[0030] Specifically, the first diode D1 and the second diode D2 are of type SS24; the forward voltage drop VF of the first diode D1 is 0.3V; the forward voltage drop VF2 of the second diode D2 is 0.3V.

[0031] This invention provides a dual-channel microphone insertion detection and channel switching circuit, including a first microphone socket J6, a second microphone socket J5, and an audio channel switching chip U1. Pin 2 of the first microphone socket J6 is connected to the MIC_DET pin and pin 4 of the audio channel switching chip U1 via diodes D1 and D2, used to detect microphone insertion and control channel switching. Pin 2 of the second microphone socket J5 is connected to the MIC_DET pin, used to detect the insertion of the second microphone. The audio channel switching chip U1 selects which microphone's audio signal to output to the audio output channel based on the level of pin 4. When pin 4 of the audio channel switching chip U1 is high, the audio signal of the first microphone is output; when pin 4 of the audio channel switching chip U1 is low, the audio signal of the second microphone is output. This invention uses only one I / O port to implement dual-channel microphone insertion detection, achieving automatic channel switching without software logic processing, greatly saving MCU hardware and software resources, reducing product costs, and simplifying software design logic. Attached Figure Description

[0032] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0033] Figure 1 A schematic diagram of a two-channel microphone insertion detection and channel switching circuit provided for an embodiment of this utility model;

[0034] Figure 2 This is a schematic diagram of a two-channel microphone insertion detection and channel switching circuit provided for an embodiment of the present utility model. Detailed Implementation

[0035] The present invention can be explained in detail through the following embodiments. The purpose of disclosing the present invention is to protect all technical improvements within the scope of the present invention. In the description of the present invention, it should be understood that if there are terms such as "upper", "lower", "front", "rear", "left", "right" indicating the orientation or positional relationship, they are only corresponding to the drawings of this application for the convenience of describing the present invention, and do not indicate or imply that the device or element referred to must have a specific orientation.

[0036] In the description of this utility model, it should be understood that the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc., indicating the orientation or positional relationship are based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this utility model and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this utility model.

[0037] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this utility model, "a plurality of" means two or more, unless otherwise explicitly specified.

[0038] To make the technical problems, technical solutions and advantages of this utility model clearer, a detailed description will be given below in conjunction with the accompanying drawings and specific embodiments.

[0039] Example 1

[0040] refer to Figure 1-2 This embodiment provides a two-channel microphone insertion detection and channel switching circuit;

[0041] in, Figure 1 This embodiment provides a simplified technical diagram of a two-channel microphone insertion detection and channel switching circuit.

[0042] When either the first channel MIC1 or the second channel MIC2 is inserted, the MIC detection signal needs to be pulled low. Simultaneously, when the first channel MIC1 is inserted, the channel switching signal needs to be pulled low, and when the second channel MIC2 is inserted, the channel switching signal needs to be pulled high. This invention, through a specific circuit design, multiplexes the MIC detection signal into a channel switching signal, and sets the first channel MIC1 as the main channel. When the first channel MIC1 and the second channel MIC2 are inserted simultaneously, only the first channel MIC1 is effective. The channel switching module selects either the first channel MIC1 audio signal MIC1_IN or the second channel MIC1 audio signal MIC2_IN as the final MIC audio output (MIC_AUDIO) based on the channel switching signal.

[0043] in, Figure 2This embodiment provides a schematic diagram of a two-channel microphone insertion detection and channel switching circuit, which includes a first microphone socket J6, a second microphone socket J5, and an audio channel switching chip U1;

[0044] It is understood that the first microphone socket J6 corresponds to the first channel MIC1 mentioned above; the second microphone socket J5 corresponds to the first channel MIC2 mentioned above; and the audio channel switching chip U1 corresponds to the channel switch module mentioned above.

[0045] The first microphone socket J6 is a 6.35mm microphone socket; the second microphone socket J5 is a 3.5mm microphone socket.

[0046] The model number of the second microphone socket J5 is CK-3.5-168;

[0047] The first microphone jack J6 includes pin 1, pin 2, and pin 3; pin 1 of the first microphone jack J6 is grounded; pin 2 of the first microphone jack J6 is connected to the cathodes of the first diode D1 and the second diode D2 respectively; the anode of the first diode D1 is connected to the first power supply through the first resistor R1, and to pin 4 of the audio channel switching chip U1 through the second resistor R2; the anode of the second diode D2 is connected to the MIC_DET pin; pin 3 of the first microphone jack J6 is connected to pin 3 of the audio channel switching chip U1 as the first audio input MIC_IN.

[0048] The second pin of the first microphone socket J6 is an insertion detection pin; when the microphone is not inserted into the first microphone socket J6, the second pin of the first microphone socket J6 is in a floating state; when the microphone is inserted into the first microphone socket J6, the second pin of the first microphone socket J6 is shorted to the first pin of the first microphone socket J6.

[0049] In this embodiment, the second pin of the first microphone socket J6 is simultaneously multiplexed for MIC_SW and MIC_DET functions, and is isolated using the second diode D2 and the first diode D1.

[0050] The first microphone socket J6 also includes pins 4, 5, 6, 7, and 8; in this embodiment, pins 4 to 8 of the first microphone socket J6 are left unused.

[0051] The second microphone jack J5 includes pins 1, 2, 3, 4, and 5. Pin 1 of the second microphone jack J5 is connected to the first power supply through a third resistor R3. Pin 2 of the second microphone jack J5 is connected to the MIC_DET pin and grounded through a first resistor R4. Pin 4 of the second microphone jack J5 is grounded. Pin 5 of the second microphone jack J5 is connected to pin 1 of the audio channel switching chip U1 as the second audio input MIC2_IN through a second capacitor C2. Pin 3 of the second microphone jack J5 is left floating and not used.

[0052] The second microphone socket J5 has a second pin that is an insertion detection pin. When the microphone is not inserted into the second microphone socket J5, the first pin of the second microphone socket J5 is shorted to the second pin of the second microphone socket J5. When the microphone is inserted into the second microphone socket J5, the first pin of the second microphone socket J5 is disconnected from the second pin of the second microphone socket J5.

[0053] The audio channel switching chip U1 is a 2-to-1 channel selection circuit, including pins 1, 2, 3, 4, 5, and 6. Pin 2 of the audio channel switching chip U1 is connected to ground and connected to the second power supply through the third capacitor C3. Pin 5 of the audio channel switching chip U1 is connected to the second power supply and grounded through the third capacitor C3. Pin 6 of the audio channel switching chip U1 is connected to the MIC_AUDIO pin through the fourth capacitor C4. Pin 4 of the audio channel switching chip U1 is the MIC_SW pin, i.e., the channel control signal pin.

[0054] Specifically, pins 1 and 3 of the audio channel switching chip U1 are two audio input channels, respectively; pin 6 of the audio channel switching chip U1 is the audio output channel.

[0055] When pin 4 of audio channel switching chip U1 is high, the audio signal from pin 1 of audio channel switching chip U1 is output from pin 6 of audio channel switching chip U1, and the audio signal from pin 3 of audio channel switching chip U1 is disconnected.

[0056] When pin 4 of audio channel switching chip U1 is low, the audio from pin 3 of audio channel switching chip U1 is output from pin 6 of audio channel switching chip U1, and the audio from pin 1 of audio channel switching chip U1 is disconnected;

[0057] The first power supply is a 3.3V power supply; the second power supply is a 5V power supply;

[0058] The audio channel switching chip U1 is model SGM3157;

[0059] The first resistor R1 is 20kΩ, the second resistor R2 is 22Ω, the third resistor R3 is 1kΩ, and the fourth resistor R4 is 10kΩ;

[0060] The first capacitor C1 is 10uF, the second capacitor C2 is 10uF, the third capacitor C3 is 10uF, and the fourth capacitor C4 is 10uF; wherein the first capacitor C1, the second capacitor C2, and the fourth capacitor C4 are AC coupling capacitors, which transmit AC audio signals and isolate DC voltage; the third capacitor C3 is a filter capacitor at the power supply end of the channel switching chip U1, which filters out voltage noise at the power supply port.

[0061] The first diode D1 and the second diode D2 are both SS24 type; the forward voltage drop VF of the first diode D1 is 0.3V; the forward voltage drop VF2 of the second diode D2 is 0.3V.

[0062] This embodiment provides the audio channel output with and without a microphone plugged into the two-channel sockets. Specifically:

[0063] ① When no microphone is plugged into either channel, pin 2 of the first microphone socket J6 is in a floating state; pin 2 of the second microphone socket J5 is shorted to pin 1 and pulled up to the first power supply 3.3V;

[0064] The MIC_SW pin is pulled up to the first power supply of 3.3V through the second resistor R2 and the first resistor R1, and is at a high level. The audio output channel is connected to MIC2_IN by default.

[0065] The MIC_DET pin is connected between the fourth resistor R4 and the third resistor R3. Through the voltage division of the two resistors, the voltage of the MIC_DET pin can be 3V, which is a high level.

[0066] The second diode D2 can prevent 3.3V from being forward-biased through the first resistor R1 and the first diode D1 to conduct MIC_DET, thereby affecting the level of MIC_DET; the high level uses a voltage of 3V, which is greater than the high level threshold of 1.5V of the MIC_SW pin of the audio channel switching chip U1.

[0067] ② When a microphone is inserted into the first microphone socket J6 and not into the second microphone socket J5, the second pin of the first microphone socket J6 is shorted to the first pin and pulled down to ground; the second pin of the second microphone socket J5 is shorted to the first pin and pulled up to the first power supply 3.3V.

[0068] The MIC_SW pin is pulled down to ground through the second resistor R2 and the first diode D1. Due to the clamping effect of the diode, even if the MIC_SW pin is pulled up to the first power supply 3.3V through the first resistor R1, its voltage is still clamped to the forward voltage drop VF of the first diode D1, so that the fourth pin of the audio channel switching chip U1 detects a low level, and the audio output channel is switched from MIC2_IN to MIC1_IN.

[0069] The MIC_DET pin is pulled down to ground through the parallel circuit of the fourth resistor R4 and the second diode D2, and simultaneously pulled up to the first power supply 3.3V through the third resistor R3; similar to the switching principle of the MIC_SW pin above, due to the clamping effect of the second diode D2, the voltage of the MIC_DET pin is clamped to the forward voltage drop VF2 (0.3V) of the second diode D2, which is a low level.

[0070] ③ When the first microphone socket J6 is not inserted and the second microphone socket J5 is inserted, the second pin of the first microphone socket J6 is floating; the second pin of the second microphone socket J5 is disconnected from the first pin, the pull-up is canceled, and it is pulled down to ground through the fourth resistor R4;

[0071] The MIC_SW pin is pulled up to the first power supply of 3.3V through the second resistor R2 and the first resistor R1, and is at a high level. The audio channel is switched to MIC2_IN.

[0072] The MIC_DET pin is pulled down to ground through the fourth resistor R4, and the MIC_DET pin behaves as a low level.

[0073] ④ When microphones are inserted into both the first microphone socket J6 and the second microphone socket J5, the second pin of the first microphone socket J6 is shorted to the first pin and pulled down to ground; the second pin of the second microphone socket J5 is disconnected from the first pin, the pull-up is eliminated, and it is pulled down to ground through the fourth resistor R4.

[0074] The MIC_SW pin is pulled down to ground through the second resistor R2 and the first diode D1. Due to the clamping effect of the diode, even if the MIC_SW pin is pulled up to the first power supply 3.3V through the first resistor R1, its voltage is still clamped to the forward voltage drop VF (0.3V) of the first diode D1, so that the 4th pin of the audio channel switching chip U1 detects a low level and the output channel is switched to MIC1_IN.

[0075] The forward voltage drop VF of the first diode D1 and the forward voltage drop VF2 of the second diode D2 are both 0.3V;

[0076] This embodiment also provides a circuit truth table showing the changes when a microphone is inserted and not inserted in the two-channel sockets, as shown in Table 1:

[0077] Table 1

[0078] MIC1 MIC2 MIC_SW MIC_DET Audio output channel x x 1 1 MIC2 o x 0 0 MIC1 x o 1 0 MIC2 o o 0 0 MIC1

[0079] In Table 1, x indicates that the microphone is not inserted, o indicates that the microphone is inserted; 1 indicates a high level, and 0 indicates a low level.

[0080] This embodiment provides a two-channel microphone insertion detection and channel switching circuit, including a first microphone socket J6, a second microphone socket J5, and an audio channel switching chip U1. Pin 2 of the first microphone socket J6 is connected to the MIC_DET pin and pin 4 of the audio channel switching chip U1 via diodes D1 and D2, used to detect microphone insertion and control channel switching. Pin 2 of the second microphone socket J5 is connected to the MIC_DET pin, used to detect the insertion of the second microphone. The audio channel switching chip U1 selects which microphone's audio signal to output to the audio output channel based on the level of pin 4. When pin 4 of the audio channel switching chip U1 is high, the audio signal of the first microphone is output; when pin 4 of the audio channel switching chip U1 is low, the audio signal of the second microphone is output. This invention uses only one I / O port to implement two-channel microphone insertion detection, achieving automatic channel switching without software logic processing, greatly saving MCU hardware and software resources, reducing product costs, and simplifying software design logic.

[0081] The parts of this utility model not described in detail are prior art. It is obvious to those skilled in the art that this utility model is not limited to the details of the above exemplary embodiments, and that this utility model can be implemented in other specific forms without departing from the spirit or basic characteristics of this utility model. Therefore, the embodiments should be regarded as exemplary and non-limiting in all respects, and are intended to include all changes that fall within the meaning and scope of equivalents within this utility model.

Claims

1. A two-way microphone plug-in detection and channel switching circuit, characterized by It includes the first microphone socket J6, the second microphone socket J5 and the audio channel switching chip U1; The first microphone socket J6 includes the first pin, the second pin and the third pin; the first pin of the first microphone socket J6 is grounded; the second pin of the first microphone socket J6 is connected with the cathode of the first diode D1 and the cathode of the second diode D2 respectively; the anode of the first diode D1 is connected with the first power supply through the first resistor R1 and connected with the fourth pin of the audio channel switching chip U1 through the second resistor R2; the anode of the second diode D2 is connected with the MIC_DET pin; the third pin of the first microphone socket J6 is connected with the audio channel switching chip U1 as the first audio input MIC_IN and the third pin of the audio channel switching chip U1; The second microphone socket J5 includes the first pin, the second pin, the fourth pin and the fifth pin; the first pin of the second microphone socket J5 is connected with the first power supply through the third resistor R3; the second pin of the second microphone socket J5 is connected with the MIC_DET pin and grounded through the first resistor R4; the fourth pin of the second microphone socket J5 is grounded; the fifth pin of the second microphone socket J5 is connected with the first pin of the audio channel switching chip U1 as the second audio input MIC2_IN through the second capacitor C2; The audio channel switching chip U1 includes the first pin, the second pin, the third pin, the fourth pin, the fifth pin and the sixth pin; the second pin of the audio channel switching chip U1 is connected with the ground; the fifth pin of the audio channel switching chip U1 is connected with the second power supply and grounded through the third capacitor C3; the sixth pin of the audio channel switching chip U1 is connected with the MIC_AUDIO pin through the fourth capacitor C4; the fourth pin of the audio channel switching chip U1 is the MIC_SW pin; the sixth pin of the audio channel switching chip U1 is the audio output channel; When the fourth pin of the audio channel switching chip U1 is high, the audio of the first pin of the audio channel switching chip U1 is output from the sixth pin of the audio channel switching chip U1, and the audio of the third pin of the audio channel switching chip U1 is disconnected; When the fourth pin of the audio channel switching chip U1 is low, the audio of the third pin of the audio channel switching chip U1 is output from the sixth pin of the audio channel switching chip U1, and the audio of the first pin of the audio channel switching chip U1 is disconnected.

2. The two-way microphone insertion detection and channel switching circuit according to claim 1, characterized in that The second pin of the first microphone socket J6 is the plug-in detection pin; when the microphone is not plugged into the first microphone socket J6, the second pin of the first microphone socket J6 is in floating state; when the microphone is plugged into the first microphone socket J6, the second pin of the first microphone socket J6 is shorted with the first pin of the first microphone socket J6.

3. The two-way microphone insertion detection and channel switching circuit of claim 1, wherein, The second pin of the second microphone socket J5 is the plug-in detection pin; when the microphone is not plugged into the second microphone socket J5, the first pin of the second microphone socket J5 is shorted with the second pin of the second microphone socket J5; when the microphone is plugged into the second microphone socket J5, the first pin of the second microphone socket J5 is disconnected with the second pin of the second microphone socket J5.

4. The two-way microphone plug-in detection and channel switching circuit according to any one of claims 1-3, wherein When neither of the two channels is inserted with a microphone, the second pin of the first microphone jack J6 is floating; the second pin of the second microphone jack J5 is shorted to the first pin and pulled up to the first power supply; The MIC_SW pin is pulled up to the first power supply through the second resistor R2 and the first resistor R1; the MIC_DET pin is connected between the fourth resistor R4 and the third resistor R3.

5. The two-way microphone insertion detection and channel switching circuit of claim 4, wherein, When the first microphone jack J6 is inserted with a microphone and the second microphone jack J5 is not inserted, the second pin of the first microphone jack J6 is shorted to the first pin and pulled down to the ground; the second pin of the second microphone jack J5 is shorted to the first pin and pulled up to the first power supply; The MIC_SW pin is pulled down to the ground through the second resistor R2 and the first diode D1; the MIC_DET pin is pulled down to the ground through the parallel circuit of the fourth resistor R4 and the second diode D2.

6. The two-channel microphone insertion detection and channel switching circuit according to claim 4, wherein, When the first microphone jack J6 is not inserted and the second microphone jack J5 is inserted with a microphone, the second pin of the first microphone jack J6 is floating; the second pin of the second microphone jack J5 is disconnected from the first pin and pulled down to the ground through the fourth resistor R4; The MIC_SW pin is pulled up to the first power supply through the second resistor R2 and the first resistor R1; the MIC_DET pin is pulled down to the ground through the fourth resistor R4.

7. The two-channel microphone insertion detection and channel switching circuit according to claim 4, wherein, When both the first microphone jack J6 and the second microphone jack J5 are inserted with microphones, the second pin of the first microphone jack J6 is shorted to the first pin and pulled down to the ground; the second pin of the second microphone jack J5 is disconnected from the first pin and pulled down to the ground through the fourth resistor R4; the MIC_SW pin is pulled down to the ground through the second resistor R2 and the first diode D1.

8. The two-way microphone insertion detection and channel switching circuit according to claim 1, wherein, The audio channel switching chip U1 is a 2-to-1 channel selection circuit.

9. The two-way microphone insertion detection and channel switching circuit according to claim 8, characterized in that The model of the audio channel switching chip U1 is SGM3157.

10. The two-way microphone insertion detection and channel switching circuit according to claim 1, wherein, The first power supply is a 3.3V power supply; and the second power supply is a 5V power supply.

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