Analog switch implementation of a sound head pointing switching circuit

Abstract

This utility model relates to the field of audio circuit technology and discloses an analog switch circuit for achieving microphone pointing switching, comprising: a signal input module, including a left channel interface MIC-L, a right channel interface MIC-R, and a rear channel interface MIC-B; a signal amplification module, connected to the signal input module, each having an amplifier corresponding to each channel interface for outputting amplified signals corresponding to each channel interface; a pointing switching module, connected to the signal amplification module, including a controller U1, a first analog switch U2, a second analog switch U3, and a third analog switch U4, the first analog switch U2, the second analog switch U3, and the third analog switch U4 being connected to the amplifiers respectively, for controlling the on / off state of the multi-stage analog switches according to the level change of the AB pin of the controller U1; and a signal output module, for receiving and merging the output signals of the multi-stage analog switches and amplifying and transmitting them to the output interface OUT-L / R. This application achieves multi-point pointing switching function of the microphone through analog switches.

Description

Technical Field

[0001] This utility model belongs to the field of audio circuit technology, specifically relating to an analog switch circuit for switching the direction of the microphone head. Background Technology

[0002] In the field of audio acquisition technology, with the continuous development of technology, the performance requirements for audio acquisition equipment are increasing. Currently, single-capacitor audio acquisition devices are widely used in various products, such as microphones, pickups, and other audio equipment.

[0003] Currently, most single-capture audio devices can only perform one directional function, while multi-capture devices cannot flexibly switch directional functions according to actual needs during operation. This makes it difficult for existing devices to meet diverse usage requirements in complex and ever-changing audio acquisition scenarios. Furthermore, in some traditional audio circuits, achieving directional switching often requires individual control via hardware switches. This control method is difficult to achieve dynamic real-time adjustment, and the addition of hardware switches increases the size and complexity of the device, hindering miniaturization and integration. At the same time, frequent manual operation of hardware switches can easily lead to malfunctions such as poor contact, reducing the device's lifespan and stability. Utility Model Content

[0004] This application provides a circuit for implementing a microphone pointer switching function using an analog switch, which can solve the problem that the microphone cannot dynamically adjust the switching function.

[0005] This application discloses an analog switch circuit for switching the position of a microphone, the circuit comprising:

[0006] The signal input module includes a left channel interface MIC-L, a right channel interface MIC-R, and a rear channel interface MIC-B;

[0007] The signal amplification module is connected to the output terminal of the signal input module and is equipped with amplifiers corresponding to each channel interface to output amplified signals corresponding to each channel interface.

[0008] A directional switching module is connected to the output of the signal amplification module. The directional switching module includes a controller U1, a first analog switch U2, a second analog switch U3, and a third analog switch U4. The first analog switch U2, the second analog switch U3, and the third analog switch U4 are respectively connected to the amplifier and are used to control the on / off state of the multi-stage analog switches according to the level changes of the AB pins of the controller U1.

[0009] The signal output module is used to receive and merge the output signals of the multi-stage analog switches and amplify them before transmitting them to the output interface OUT-L / R.

[0010] In one embodiment, the amplifier includes a first amplifier U5, a second amplifier U6, and a third amplifier U7. The left channel interface MIC-L is connected to the input terminal of the first amplifier U5, the right channel interface MIC-R is connected to the input terminal of the second amplifier U6, and the rear channel interface MIC-B is connected to the input terminal of the third amplifier U7.

[0011] In one embodiment, the first input terminal U2_8, the second input terminal U2_3, and the third input terminal U2_1 of the first analog switch U2 are all connected to the output terminal of the first amplifier U5, and the fourth input terminal U2_2 of the first analog switch U2 is left floating.

[0012] The first input terminal U3_8 and the fourth input terminal U3_2 of the second analog switch U3 are both connected to the output terminal of the third amplifier U7, and the second input terminal U3_3 and the third input terminal U3_1 of the second analog switch U3 are both connected to the low potential potential.

[0013] The third input terminal U4_1 of the third analog switch U4 is connected to the output terminal of the third amplifier U7, and the first input terminal U4_8, the second input terminal U4_3 and the fourth input terminal U4_2 of the third analog switch U4 are all connected to the low potential potential.

[0014] The first output terminal U2_9 of the first analog switch U2, the first output terminal U3_9 of the second analog switch U3, and the first output terminal U3_9 of the third analog switch U4 are all connected to the signal output module.

[0015] In one embodiment, the controller U1 includes an enable pin KEY, an A pin, and a B pin. The controller U1 is used to control the A pin and the B pin to output high and low levels according to the enable signal input by the enable pin KEY.

[0016] In one embodiment, the first analog switch U2, the second analog switch U3, and the third analog switch U4 are all provided with logic units for connecting to the A pin and the B pin.

[0017] In one embodiment, the signal output module includes a left channel amplifier U8-A, a right channel amplifier U8-B, resistor R13, and resistor R23. The positive input terminal of the left channel amplifier U8-A is connected to the positive input terminal of the right channel amplifier U8-B, and the negative input terminal of the left channel amplifier U8-A is connected to the negative input terminal of the right channel amplifier U8-B. The power supply VCC33 is connected to the positive input terminal of the left channel amplifier U8-A through resistor R13, and the power supply VCC33 is connected to the positive input terminal of the right channel amplifier U8-B through resistor R23.

[0018] The output terminal of the first amplifier U5 and the output terminal of the third analog switch U4 are both connected between the negative input terminal of the left channel amplifier U8-A and the negative input terminal of the right channel amplifier U8-B. The output terminal of the second analog switch U3 is connected between the positive input terminal of the left channel amplifier U8-A and the positive input terminal of the right channel amplifier U8-B.

[0019] The output terminal of the first amplifier U5 is connected to the negative input terminal of the left channel amplifier U8-A, and the output terminal of the second amplifier U6 is connected to the negative input terminal of the right channel amplifier U8-B.

[0020] In one embodiment, the left channel amplifier U8-A is provided with a resistor R1 and a capacitor C1. One end of the resistor R1 is connected to the negative input terminal of the left channel amplifier U8-A, and the other end of the resistor R1 is connected to the output terminal of the left channel amplifier U8-A. The capacitor C1 is connected in parallel with the resistor R1.

[0021] The right channel amplifier U8-B is equipped with a resistor R2 and a capacitor C2. One end of the resistor R2 is connected to the negative input terminal of the right channel amplifier U8-B, and the other end of the resistor R2 is connected to the output terminal of the right channel amplifier U8-B. The capacitor C2 is connected in parallel with the resistor R2.

[0022] In one embodiment, the right channel amplifier U8-B includes a VCC terminal and a VSS terminal, the VCC terminal being connected to the power supply VCC33, and the VSS terminal being connected to a low potential.

[0023] In one embodiment, the left channel interface MIC-L, the right channel interface MIC-R, and the rear channel interface MIC-B are all the same input unit. The input unit includes a V+ pin, a MIC pin, and a GND pin for grounding. The V+ pin is used to connect to the power supply MVCC, and the MIC pin is used to output the corresponding audio signal. The V+ pin, MIC pin, and GND pin are each provided with their corresponding test points.

[0024] In some embodiments, the directivity of the signal output module is stereo, omnidirectional, cardioid, or figure-eight.

[0025] As described above, the analog switch in this application implements a microphone polarity switching circuit. Through the coordinated operation of the signal input module, signal amplification module, polarity switching module, and signal output module, it uses the left channel interface MIC-L, right channel interface MIC-R, and rear channel interface MIC-B to collect omnidirectional audio signals. The audio signals are amplified by the signal amplification module and then enter the polarity switching module. The controller U1 controls the multi-stage analog switches to achieve the on / off and merging of the audio signals, enabling the signal output module to flexibly switch between various polarity modes such as stereo, omnidirectional, cardioid, and figure-eight polarity. This makes operation simpler, more efficient, and easier to automate and intelligently control. This application uses an analog switch circuit to achieve polarity switching. Compared with traditional hardware switch control methods, this reduces the use of physical hardware switches, effectively reducing the size and complexity of the device, which is beneficial for miniaturization and thinner design of the product. It also improves the reliability of the circuit and reduces malfunctions caused by frequent operation of hardware switches. Attached Figure Description

[0026] Figure 1 This is a schematic diagram illustrating the principle of the analog switch circuit for switching the tone pointer provided in the embodiments of this application.

[0027] Figure 2 This is a schematic diagram of the structure of the analog switch circuit for switching the tone pointer provided in the embodiment of this application. Detailed Implementation

[0028] The preferred embodiments of this application will now be described in detail with reference to the accompanying drawings, so that the advantages and features of this application can be more easily understood by those skilled in the art, thereby providing a clearer definition of the scope of protection of this application.

[0029] Please refer to the diagrams, where the same component symbols represent the same components. The principles of this application are illustrated by way of example implementation in a suitable computing environment. The following description is based on the specific embodiments of this application exemplified, and should not be construed as limiting other specific embodiments not detailed herein.

[0030] Please see Figure 1 The figure shows a schematic diagram of the analog switch circuit for switching the tone pointer provided in an embodiment of this application.

[0031] like Figure 1 As shown, the analog switch realizes the tone pointer switching circuit, which includes a signal input module 10, a signal amplification module 20, a directivity switching module 30, and a signal output module 40.

[0032] The signal input module 10 includes a left channel interface MIC-L, a right channel interface MIC-R, and a rear channel interface MIC-B. It receives audio signals from three directions through three microphones. The microphones are connected to analog switches via the left channel interface MIC-L, right channel interface MIC-R, and rear channel interface MIC-B to realize a microphone switching circuit. Each channel interface is connected to the input terminal of the corresponding amplifier in the signal amplification module 20 to output the amplified signal corresponding to each channel interface. The polarization switching module 30 is connected to the output terminal of the signal amplification module 20. The amplified audio signal enters the polarization switching module 30, and the MUC processor of the polarization switching module 30 outputs a logic signal to control the conduction state of the analog switch in the polarization switching module 30, thereby completing the operation of switching on or off or combining the audio signal to realize the switching of different polarization modes. The combined audio signal is output to the signal output module 40, and after further processing by the amplifier, it is output to the output interface OUT-L / R, thus achieving the purpose of dynamic adjustment of the multi-polarity of the microphone.

[0033] The signal input module 10 may have three input heads, but is not limited to three, in order to form the required directional function. Multiple input heads can be selected according to the actual situation, and the number of analog switches can also be adjusted accordingly. This application does not limit the number of input heads.

[0034] Please see Figure 2 The figure shows a structural diagram of the analog switch circuit for switching the tone pointer according to an embodiment of this application.

[0035] Furthermore, such as Figure 2 As shown, the directional switching module 30 includes a controller U1, a first analog switch U2, a second analog switch U3, and a third analog switch U4. The first analog switch U2, the second analog switch U3, and the third analog switch U4 are respectively connected to the amplifier. The controller U1 controls the on / off state of the multi-level analog switches by changing the AB pin level, which can flexibly switch between multiple directional modes and improve the adaptability of the audio acquisition device to different usage scenarios.

[0036] The working principle of the analog switch implementation of the microphone pointing switching circuit in this application is as follows: the signal is collected by an external device and connected to the left channel interface MIC-L, the right channel interface MIC-R, and the rear channel interface MIC-B. The signal of each channel is amplified by the corresponding amplifier and transmitted to the pointing switching module 30 so that it obtains an audio signal with sufficient intensity so that the audio signal can switch between different pointing modes. The controller U1 can output the corresponding AB level signal according to the user selection or the program preset to control the conduction state of each analog switch. The switched audio signal is output and combined and amplified by the output module before being output to the external device through the output interface OUT-L / R.

[0037] like Figure 2 As shown, the amplifiers within the signal amplification module 20 include a first amplifier U5, a second amplifier U6, and a third amplifier U7. The left channel interface MIC-L is connected to the input terminal of the first amplifier U5, the right channel interface MIC-R is connected to the input terminal of the second amplifier U6, and the rear channel interface MIC-B is connected to the input terminal of the third amplifier U7. The first amplifier U5 includes a resistor R5 and a capacitor C5. The positive input terminal of the first amplifier U5 is connected to the power supply pin VREF1, which provides a stable reference voltage for the first amplifier U5. The negative input terminal of the first amplifier U5 is connected to the left channel interface MIC-L. One end of the resistor R5 is connected to the negative input terminal of the first amplifier U5, and the other end is connected to the output terminal of the first amplifier U5. The amplification factor of the first amplifier U5 is changed by adjusting the resistance value of the resistor R5. Additionally, the capacitor C5 is connected in parallel with the resistor R5 to compensate for the phase of the operational amplifier circuit, prevent the effects of self-oscillation, ensure the stable operation of the first amplifier U5, and also filter out high-frequency noise or interference signals in the input signal, improving the processing quality of the audio signal.

[0038] It is worth noting that the second amplifier U6 and the third amplifier U7 are configured similarly to the first amplifier U5. The power supply pin VREF1 is connected to the positive input terminal of the second amplifier U6 and the positive input terminal of the third amplifier U7, respectively. Resistor R6 and capacitor C6 are connected in parallel to the negative input terminal and the output terminal of the second amplifier U6, and resistor R7 and capacitor C7 are connected in parallel to the negative input terminal and the output terminal of the third amplifier U7. In addition, the first amplifier U5, the second amplifier U6, and the third amplifier U7 all have power supply pins and ground pins. The power supply pin OPVCC is connected to these power supply pins to provide a stable power supply for the amplifiers.

[0039] like Figure 2 As shown, in the directional switching module 30, the controller U1 includes an enable pin KEY, an A pin, and a B pin. The controller U1 is used to control the output high and low levels of the A pin and the B pin according to the enable signal input by the enable pin KEY, so that the user can configure the controller U1 through a program or preset operation according to the needs of the actual scenario, so as to control each analog switch and realize the switching needs of audio acquisition directional in different scenarios.

[0040] In addition, the first analog switch U2, the second analog switch U3, and the third analog switch U4 are all analog switches of the same specification. The first input terminal U2_8, the second input terminal U2_3, and the third input terminal U2_1 of the first analog switch U2 are all connected to the output terminal of the first amplifier U5, and the fourth input terminal U2_2 of the first analog switch U2 is left floating. The first input terminal U3_8 and the fourth input terminal U3_2 of the second analog switch U3 are both connected to the output terminal of the third amplifier U7, and the second input terminal U4 of the second analog switch U4 is left floating. Both the third input terminal U3_3 and the third input terminal U3_1 are connected to the low potential potential; the third input terminal U4_1 of the third analog switch U4 is connected to the output terminal of the third amplifier U7, and the first input terminal U4_8, the second input terminal U4_3 and the fourth input terminal U4_2 of the third analog switch U4 are all connected to the low potential potential; wherein, the first output terminal U2_9 of the first analog switch U2, the first output terminal U3_9 of the second analog switch U3 and the first output terminal U4_9 of the third analog switch U4 are all connected to the input terminal of the signal output module 40.

[0041] It is worth noting that the first analog switch U2, the second analog switch U3, and the third analog switch U4 are all equipped with logic units for connecting to the A pin and the B pin. The conduction state of the analog switches is controlled according to the level signals of the A and B pins. This logic unit can simplify the control logic of the analog switches and enable the three analog switches to be controlled in a unified manner. By designing the connection of different input terminals of the analog switches, the operation of audio signal on / off and merging is realized, allowing the directional switching module 30 to switch between four modes. The four modes are A, B=00 / 01 / 10 / 11.

[0042] In some implementations, the signal output module 40 is stereo, omnidirectional, cardioid, or figure-eight directional.

[0043] The working principle of the directional switching module 30 is as follows: the controller U1 outputs the level signal of the AB pin. When A and B=00, the first output terminal of the three analog switches is connected to the first input terminal. Among them, the first analog switch U2 makes the left channel audio signal and the right channel audio signal merge. The second analog switch U3 is turned on to output the back audio signal, and the third analog switch U4 is connected to the low potential position, so that the directional switching module 30 merges and outputs the 8-digit directional signal through the signal output module 40.

[0044] When A and B=01, the first output terminal of each of the three analog switches is connected to the third input terminal. The first analog switch U2 merges the left channel audio signal with the right channel audio signal, the second analog switch U3 is connected to the low potential position, and the third analog switch U4 outputs the back channel audio signal, so that the direction switching module 30 merges and outputs omnidirectional signals through the signal output module 40.

[0045] When A and B=10, the first output terminal of each of the three analog switches is connected to the second input terminal. The first analog switch U2 merges the left channel audio signal with the right channel audio signal. The second analog switch U3 and the third analog switch U4 are both connected to a low potential, so that the back audio signal is not connected in the circuit. The pointing switching module 30 merges and outputs a cardioid pointing signal through the signal output module 40.

[0046] When A and B=11, the first output terminals of the three analog switches are all connected to the fourth input terminal. The first analog switch U2 is connected to the unconnected pin, and the left channel audio signal and the right channel audio signal are output to the signal output module 40 independently. The second analog switch U3 is turned on and outputs the back audio signal. The third analog switch U4 is connected to the low potential position, so that the direction switching module 30 outputs stereo direction through the signal output module 40.

[0047] like Figure 2 As shown, the signal output module 40 includes a left channel amplifier U8-A, a right channel amplifier U8-B, resistors R13 and R23. The positive input terminal of the left channel amplifier U8-A is connected to the positive input terminal of the right channel amplifier U8-B, and the negative input terminal of the left channel amplifier U8-A is connected to the negative input terminal of the right channel amplifier U8-B. The power supply VCC33 is connected to the positive input terminal of the left channel amplifier U8-A through resistor R13, and the power supply VCC33 is connected to the positive input terminal of the right channel amplifier U8-B through resistor R23.

[0048] Understandably, the positive and negative inputs of the left channel amplifier U8-A and the right channel amplifier U8-B are connected together to form a differential amplifier structure. This design can suppress common-mode noise in the two signals, amplifying only the differential signal component and improving the signal-to-noise ratio. Power supply VCC33 is connected between the positive inputs of the left channel amplifier U8-A and the right channel amplifier U8-B to provide a bias voltage, which suppresses common-mode signals and further enhances anti-interference capabilities.

[0049] Furthermore, power supply VCC33 is connected to the positive input of the left channel amplifier U8-A via resistor R13, and to the positive input of the right channel amplifier U8-B via resistor R23. Resistors R13 and R23, working in symmetrical configuration, form a differential circuit, amplifying the difference between the two channel signals and resulting in a clearer sense of space and layering in the sound. Additionally, when power supply VCC33 experiences ripple interference, the differential circuit can cancel its effect on the left and right channels, preventing noise from mixing into the audio.

[0050] The output terminals of the first amplifier U5 and the third analog switch U4 are both connected between the negative input terminal of the left channel amplifier U8-A and the negative input terminal of the right channel amplifier U8-B. The output terminal of the second analog switch U3 is connected between the positive input terminal of the left channel amplifier U8-A and the positive input terminal of the right channel amplifier U8-B. The output terminal of the first amplifier U5 is connected to the negative input terminal of the left channel amplifier U8-A, and the output terminal of the second amplifier U6 is connected to the negative input terminal of the right channel amplifier U8-B.

[0051] The first analog switch U2 is used to adjust the conduction state of the left and right channel signals to complete the directional function of stereo and other mixed signals. The second analog switch U3 and the third analog switch U4 are used to switch whether to introduce the back channel audio signal to adjust the composition of the left and right channel signals, so that the output left and right channels can form a mixture according to the introduced back channel signal, realizing the switching of various directional modes.

[0052] like Figure 2 As shown, the left channel amplifier U8-A has a resistor R1 and a capacitor C1. One end of the resistor R1 is connected to the negative input terminal of the left channel amplifier U8-A, and the other end of the resistor R1 is connected to the output terminal of the left channel amplifier U8-A. The capacitor C1 is connected in parallel with the resistor R1. The right channel amplifier U8-B has a resistor R2 and a capacitor C2. One end of the resistor R2 is connected to the negative input terminal of the right channel amplifier U8-B, and the other end of the resistor R2 is connected to the output terminal of the right channel amplifier U8-B. The capacitor C2 is connected in parallel with the resistor R2.

[0053] Furthermore, the signal output module 40 also includes resistors R11, R12, R21, and R22, and capacitors R11, R12, R21, and R22. The first amplifier U5 is connected to the negative input terminal of the left channel amplifier U8-A via resistor R11, the second amplifier U6 is connected to the negative input terminal of the right channel amplifier U8-B via resistor R21, the output terminal of the third analog switch U4 is connected to the negative input terminal of the left channel amplifier U8-A via capacitor C11 and resistor R12, the output terminal of the third analog switch U4 is connected to the negative input terminal of the right channel amplifier U8-B via capacitor C21 and resistor R22, the output terminal of the second analog switch U3 is connected to the positive input terminal of the left channel amplifier U8-A via capacitor C12, and the output terminal of the second analog switch U3 is connected to the positive input terminal of the right channel amplifier U8-B via capacitor C22.

[0054] It can be understood that resistors R1 and R2 accurately set the amplification factors of the two amplifiers, while capacitors C1 and C2 provide phase compensation, effectively preventing operational amplifier self-oscillation. Resistor R1 and capacitor C1 form a feedback loop with the left channel amplifier U8-A; changing the value of R1 adjusts the amplification of the input signal by the left channel amplifier U8-A, and capacitor C1 filters out high-frequency noise or interference signals from the input signal. Similarly, resistors R2 and C2 form a feedback loop with the right channel amplifier U8-B; changing the value of R2 adjusts the amplification of the input signal by the right channel amplifier U8-B, and capacitor C2 filters out high-frequency noise or interference signals from the input signal. Additionally, resistors R11 and R21 limit the current flowing into the amplifiers, while resistors R12 and R22, in conjunction with capacitors C11 and C21 respectively, filter out some high-frequency or low-frequency noise from the input audio signal.

[0055] like Figure 2 As shown, the right channel amplifier U8-B includes a VCC terminal and a VSS terminal. The VCC terminal is connected to the power supply VCC33, and the VSS terminal is connected to the low potential potential.

[0056] Correspondingly, the right channel amplifier U8-B has an independent power supply, namely power supply VCC33 connected to the VCC terminal of the right channel amplifier U8-B, in order to prevent power supply noise from the left channel circuit from being coupled to the right channel through the power bus and to enhance channel separation.

[0057] like Figure 2 As shown, in the signal input module 10, the left channel interface MIC-L, the right channel interface MIC-R, and the rear channel interface MIC-B are all the same input unit. The input unit includes a V+ pin, a MIC pin, and a GND pin for grounding. The V+ pin is used to connect to the power supply MVCC, and the MIC pin is used to output the corresponding audio signal. The V+ pin, the MIC pin, and the GND pin are respectively provided with their corresponding test points.

[0058] This test point setup can be used to measure the pin voltage of each interface, enabling rapid fault diagnosis. It only requires connecting the test probe to complete the testing of each interface, reducing maintenance time. It also facilitates batch testing during production, enabling consistency checks on products. In addition, it facilitates product aging tests.

[0059] As used herein, the term "module" can refer to a software or hardware object that executes on the computing system. The various components, modules, engines, and services described herein can be implementations on the computing system. The apparatuses and methods described herein can be implemented in software or hardware, both of which are within the scope of this application.

[0060] In this document, the term "embodiment" means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this application. The appearance of this phrase in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment mutually exclusive with other embodiments. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.

[0061] 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, an electrical connection, or a connection that allows communication between them; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication between two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0062] The embodiments of this application have been described in detail above with reference to the accompanying drawings. However, this application is not limited to the above embodiments. Within the scope of knowledge possessed by those skilled in the art, various changes can be made without departing from the spirit of this application.

Claims

1. A circuit for switching the position of a tone head using an analog switch, characterized in that, The circuit includes: The signal input module includes a left channel interface MIC-L, a right channel interface MIC-R, and a rear channel interface MIC-B; The signal amplification module is connected to the output terminal of the signal input module and is equipped with amplifiers corresponding to each channel interface to output amplified signals corresponding to each channel interface. A directional switching module is connected to the output of the signal amplification module. The directional switching module includes a controller U1, a first analog switch U2, a second analog switch U3, and a third analog switch U4. The first analog switch U2, the second analog switch U3, and the third analog switch U4 are respectively connected to the amplifier and are used to control the on / off state of the multi-stage analog switches according to the level changes of the AB pins of the controller U1. The signal output module is used to receive and merge the output signals of the multi-stage analog switches and amplify them before transmitting them to the output interface OUT-L / R.

2. The analog switch circuit for switching the tone pointer as described in claim 1, characterized in that, The amplifier includes a first amplifier U5, a second amplifier U6, and a third amplifier U7. The left channel interface MIC-L is connected to the input terminal of the first amplifier U5, the right channel interface MIC-R is connected to the input terminal of the second amplifier U6, and the rear channel interface MIC-B is connected to the input terminal of the third amplifier U7.

3. The analog switch circuit for switching the tone pointer as described in claim 2, characterized in that, The first input terminal U2_8, the second input terminal U2_3, and the third input terminal U2_1 of the first analog switch U2 are all connected to the output terminal of the first amplifier U5, and the fourth input terminal U2_2 of the first analog switch U2 is left floating. The first input terminal U3_8 and the fourth input terminal U3_2 of the second analog switch U3 are both connected to the output terminal of the third amplifier U7, and the second input terminal U3_3 and the third input terminal U3_1 of the second analog switch U3 are both connected to the low potential potential. The third input terminal U4_1 of the third analog switch U4 is connected to the output terminal of the third amplifier U7, and the first input terminal U4_8, the second input terminal U4_3 and the fourth input terminal U4_2 of the third analog switch U4 are all connected to the low potential potential. The first output terminal U2_9 of the first analog switch U2, the first output terminal U3_9 of the second analog switch U3, and the first output terminal U3_9 of the third analog switch U4 are all connected to the input terminal of the signal output module.

4. The analog switch circuit for switching the tone pointer as described in claim 1, characterized in that, The controller U1 includes an enable pin KEY, an A pin, and a B pin. The controller U1 is used to control the output of the A pin and the B pin to be high or low level according to the enable signal input by the enable pin KEY.

5. The analog switch circuit for switching the tone pointer as described in claim 4, characterized in that, The first analog switch U2, the second analog switch U3 and the third analog switch U4 are all provided with logic units for connecting to the A pin and the B pin.

6. The analog switch circuit for switching the tone pointer as described in claim 5, characterized in that, The signal output module includes a left channel amplifier U8-A, a right channel amplifier U8-B, resistor R13, and resistor R23. The positive input terminal of the left channel amplifier U8-A is connected to the positive input terminal of the right channel amplifier U8-B, and the negative input terminal of the left channel amplifier U8-A is connected to the negative input terminal of the right channel amplifier U8-B. The power supply VCC33 is connected to the positive input terminal of the left channel amplifier U8-A through resistor R13, and the power supply VCC33 is connected to the positive input terminal of the right channel amplifier U8-B through resistor R23. The output terminal of the first amplifier U5 and the output terminal of the third analog switch U4 are both connected between the negative input terminal of the left channel amplifier U8-A and the negative input terminal of the right channel amplifier U8-B. The output terminal of the second analog switch U3 is connected between the positive input terminal of the left channel amplifier U8-A and the positive input terminal of the right channel amplifier U8-B. The output terminal of the first amplifier U5 is connected to the negative input terminal of the left channel amplifier U8-A, and the output terminal of the second amplifier U6 is connected to the negative input terminal of the right channel amplifier U8-B.

7. The analog switch circuit for switching the tone pointer as described in claim 6, characterized in that, The left channel amplifier U8-A is provided with a resistor R1 and a capacitor C1. One end of the resistor R1 is connected to the negative input terminal of the left channel amplifier U8-A, and the other end of the resistor R1 is connected to the output terminal of the left channel amplifier U8-A. The capacitor C1 is connected in parallel with the resistor R1. The right channel amplifier U8-B is equipped with a resistor R2 and a capacitor C2. One end of the resistor R2 is connected to the negative input terminal of the right channel amplifier U8-B, and the other end of the resistor R2 is connected to the output terminal of the right channel amplifier U8-B. The capacitor C2 is connected in parallel with the resistor R2.

8. The analog switch circuit for switching the tone pointer as described in claim 7, characterized in that, The right channel amplifier U8-B includes a VCC terminal and a VSS terminal. The VCC terminal is connected to the power supply VCC33, and the VSS terminal is connected to a low potential.

9. The analog switch circuit for switching the tone pointer as described in claim 1, characterized in that, The left channel interface MIC-L, the right channel interface MIC-R, and the rear channel interface MIC-B are all the same input unit. The input unit includes a V+ pin, a MIC pin, and a GND pin for grounding. The V+ pin is used to connect to the power supply MVCC, and the MIC pin is used to output the corresponding audio signal. The V+ pin, MIC pin, and GND pin are each provided with their corresponding test points.

10. The analog switch circuit for switching the tone pointer as described in claim 1, characterized in that, The signal output module is stereo, omnidirectional, cardioid, or figure-eight directional.

Images