Port supports both open and closed microphone circuits

Abstract

The utility model provides a kind of circuit of port supports empty microphone and switch microphone, belong to integrated circuit technical field, comprising: common port, oscillation module, identification logic module and multiplexer;Identification logic module is used to identify the output signal of oscillation module determines microphone type, when microphone type is empty microphone, multiplexer enables first input end, output frequency signal, when microphone type is switch microphone, multiplexer enables second input end, output logic level signal. Through single common port, the necessity that two sets of independent interface circuit is designed for empty microphone and switch microphone is saved, significantly reduce the number of peripheral components, simplify circuit structure, reduce system cost and volume.

Description

Technical Field

[0001] This utility model relates to the field of integrated circuit technology, and in particular to a circuit that supports both empty microphone and switch microphone at the port. Background Technology

[0002] In the consumer electronics field, there are two main types of microphones: open microphones (capacitive microphones) and switch microphones (button microphones). An open microphone outputs a capacitance value that changes with sound, while a switch microphone outputs a simple logic level signal. Existing circuit solutions typically require designing two independent interface circuits and processing paths for these two physically distinct microphones, leading to an increase in the number of components, complex circuit board layout, and overall cost. Although some microcontroller solutions attempt to identify and adapt via software programs, these solutions are not only expensive, but their recognition speed and system stability are also susceptible to program crashes or electromagnetic interference.

[0003] Therefore, how to provide a circuit that is simple in structure, low in cost, and whose ports simultaneously support both empty and switched microphones has become a technical problem that urgently needs to be solved by those skilled in the art. Utility Model Content

[0004] This invention provides a circuit that supports both empty and switched microphones at the port, thereby overcoming the shortcomings of existing solutions that simultaneously support both empty and switched microphones, which are complex and costly.

[0005] In a first aspect, this utility model provides a circuit that supports both empty and switched microphones, comprising: a shared port, an oscillation module, an identification logic module, and a multiplexer;

[0006] The input terminal of the common port is used to connect an empty microphone or a switch microphone, and the output terminal is connected to the input terminal of the oscillation module. The output terminal of the oscillation module is connected to the input terminal of the identification logic module, and the output terminal of the identification logic module is connected to the selection terminal of the multiplexer. The first input terminal of the multiplexer is connected to the output terminal of the oscillation module, and the second input terminal of the multiplexer is connected to the output terminal of the common port through the control module.

[0007] The identification logic module is used to identify the output signal of the oscillation module to determine the microphone type. When the microphone type is an empty microphone, the multiplexer selects the first input terminal and outputs a frequency signal. When the microphone type is a switch microphone, the multiplexer selects the second input terminal and outputs a logic level signal.

[0008] According to the present invention, a circuit that supports both empty and switched microphones is provided, wherein the identification logic module includes a frequency detection unit and a latch;

[0009] The input terminal of the frequency detection unit is connected to the output terminal of the oscillation module, the output terminal of the frequency detection unit is connected to the input terminal of the latch, and the output terminal of the latch is connected to the selection terminal of the multiplexer.

[0010] The frequency detection unit is used to detect the output frequency of the oscillation module and compare it with a preset threshold. The latch is used to latch the comparison result and output the microphone type.

[0011] According to the present invention, a circuit that supports both empty and switched microphones is provided, wherein the frequency detection unit includes: a counting component and a comparator;

[0012] The input terminal of the counting component is connected to the output terminal of the oscillation module to count the oscillation pulses;

[0013] The first input terminal of the comparator is connected to the output terminal of the counting component, and the second input terminal of the comparator is connected to a reference count value as the preset threshold.

[0014] According to the present invention, a circuit that supports both empty and switched microphones is provided, wherein the counting component includes: an oscillator, a frequency divider, and a counter;

[0015] The oscillator is connected to the counter via the frequency divider;

[0016] The oscillator is used to generate a high-frequency signal, the frequency divider is used to reduce the high-frequency signal to a low-frequency signal, and the counter is used to count the low-frequency signal.

[0017] According to the present invention, a circuit that supports both empty and switched microphones is provided, wherein the counter is an asynchronous binary counter composed of multiple cascaded D flip-flops.

[0018] According to the present invention, a circuit that supports both empty and switched microphones is provided, wherein the reference count value is provided by a built-in register or generated by a fixed resistor voltage divider network connected to a power supply.

[0019] According to the present invention, a circuit that supports both empty and switched microphones is provided. The latch is a D flip-flop, and the clock terminal of the D flip-flop is driven by a fixed frequency clock signal or a power-on delay signal to latch the output result of the comparator at a specific moment.

[0020] According to the present invention, a circuit is provided that supports both empty microphone and switched microphone at the port, the circuit further includes a pull-up resistor;

[0021] One end of the pull-up resistor is connected to the power supply, and the other end is connected between the common port and the input terminal of the oscillator.

[0022] According to the present invention, a circuit is provided that supports both empty and switched microphones at a port. The shared port is also used to select whether to connect to the oscillation module or the control module.

[0023] According to the present invention, a circuit that supports both empty and switched microphones at a port further includes: a selection switch;

[0024] One end of the selection switch is connected to the input terminal of the common port, and the other end is connected to the oscillation module;

[0025] The selection switch is composed of a transmission gate, and the control electrode of the transmission gate is controlled by a power-on reset signal, which is used to connect the common port to the input terminal of the oscillation module when the system is powered on.

[0026] According to the present invention, a circuit that supports both empty and switched microphones is provided, wherein the shared port, the oscillation module, the identification logic module, and the multiplexer are integrated on the same chip.

[0027] This invention provides a circuit that supports both empty and switched microphones, comprising: a shared port, an oscillation module, an identification logic module, and a multiplexer. The input of the shared port is used to connect either an empty or switched microphone, and its output is connected to the input of the oscillation module. The output of the oscillation module is connected to the input of the identification logic module, and the output of the identification logic module is connected to the selection terminal of the multiplexer. The first input of the multiplexer is connected to the output of the oscillation module, and the second input of the multiplexer is connected to the output of the shared port via a control module. The identification logic module identifies the output signal of the oscillation module to determine the microphone type. When the microphone type is empty, the multiplexer selects the first input and outputs a frequency signal; when the microphone type is switched, the multiplexer selects the second input and outputs a logic level signal. By using a single shared port, the necessity of designing two separate interface circuits for empty and switched microphones is eliminated, significantly reducing the number of external components, simplifying the circuit structure, and lowering system cost and size. Attached Figure Description

[0028] To more clearly illustrate the technical solutions in this utility model 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 utility model. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0029] Figure 1 This is a schematic diagram of the circuit that supports both empty and switched microphones provided in this embodiment. Detailed Implementation

[0030] To make the objectives, technical solutions, and advantages of this utility model clearer, the technical solutions of this utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this utility model, not all embodiments. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this utility model.

[0031] Figure 1 This is a schematic diagram of the circuit that supports both empty and switched microphones provided in this embodiment.

[0032] like Figure 1 As shown in the figure, this utility model embodiment provides a circuit that supports both empty and switched microphones, including: a common port 1, an oscillation module 2, an identification logic module 3, and a multiplexer 4. The input terminal of the common port 1 is used to connect to either an empty or switched microphone, and its output terminal is connected to the input terminal of the oscillation module 2. The output terminal of the oscillation module 2 is connected to the input terminal of the identification logic module 3, and the output terminal of the identification logic module 3 is connected to the selection terminal of the multiplexer 4. The first input terminal of the multiplexer 4 is connected to the output terminal of the oscillation module 2, and the second input terminal of the multiplexer 4 is connected to the output terminal of the common port 1 via a control module 5. The identification logic module 3 is used to identify the output signal of the oscillation module 2 to determine the microphone type. When the microphone type is an empty microphone, the multiplexer 4 selects the first input terminal and outputs a frequency signal; when the microphone type is a switched microphone, the multiplexer 4 selects the second input terminal and outputs a logic level signal. The common port is also used to select whether to connect to the oscillation module or the control module under the control of the SEL signal.

[0033] In a specific implementation, common port 1 is used to connect either an empty microphone or a switch microphone. The output signal of common port 1 is then fed into identification logic module 3 after passing through oscillation module 2. Identification logic module 3 determines the type of microphone connected to common port 1 based on the output signal and outputs a selection control signal to multiplexer 4 based on the microphone type. Multiplexer 4 controls the corresponding path to be turned on according to the selection control signal. The output of multiplexer 4 is the output of the entire circuit, while the input corresponds to different paths. If one path corresponds to an empty microphone connected to common port 1, multiplexer 4 outputs a frequency signal; if another path corresponds to a switch microphone connected to common port 1, multiplexer 4 outputs a logic level signal.

[0034] Further, in this embodiment, the identification logic module 3 includes a frequency detection unit 31 and a latch 32; the input of the frequency detection unit 31 is connected to the output of the oscillation module 2, the output of the frequency detection unit 31 is connected to the input of the latch 32, and the output of the latch 32 is connected to the selection terminal of the multiplexer 4; the frequency detection unit 31 is used to detect the output frequency of the oscillation module 2 and compare it with a preset threshold, and the latch 32 is used to latch the comparison result and output the microphone type. The frequency detection unit 31 includes a counting component 311 and a comparator 312; the input of the counting component 311 is connected to the output of the oscillation module 2 to count the oscillation pulses; the first input of the comparator 312 is connected to the output of the counting component 311, and the second input of the comparator 312 is connected to a reference count value as a preset threshold. The counting component 311 includes an oscillator 3113, a frequency divider 3112, and a counter 3111. The oscillator 3113 is connected to the counter 3111 via the frequency divider 3112. The oscillator 3113 generates a high-frequency signal, the frequency divider 3112 reduces the high-frequency signal to a low-frequency signal, and the counter 3111 counts the low-frequency signal. The counter 3111 is an asynchronous binary counter, composed of multiple cascaded D flip-flops. The reference count value is provided by a built-in register or generated by a fixed-resistor voltage divider network connected to the power supply. The latch 32 is a D flip-flop, whose clock input is driven by a fixed-frequency clock signal or a power-on delay signal, used to latch the output of the comparator 312 at a specific time.

[0035] Specifically, when a switch microphone is connected to common port 1, the output of the switch microphone to common port 1 is a logic level, either high or low; when an empty microphone is connected, common port 1 is equivalent to connecting a capacitor, the capacitance of which is affected by the pneumatic value.

[0036] After the system is powered on, the SEL signal is reset to 0, and the signal of the common port 1 is selected to the oscillation module 2. The capacitor connected to the input port is converted into the corresponding frequency. The core of the oscillation module 2 is to use the charging and discharging time difference of the capacitor to form a periodic oscillation. Its oscillation period is determined by the resistance and capacitor parameters of the charging and discharging circuit. Its oscillation period approximately satisfies formula (1):

[0037] T=K*RC (1)

[0038] Where T is the oscillation period, K is the circuit topology coefficient, R is the charging / discharging resistance, and C is the capacitance to be tested.

[0039] When the shared port 1 is connected to an empty microphone, the oscillation module 2 outputs a frequency signal. This frequency signal is processed by counter 3111 and then input to comparator 312 for comparison with the threshold value of the frequency counter 3111. The comparison result is latched by logic signal latch 32. After latching, a signal is fed back to select the output terminal. When the latched signal is 1, it indicates that the shared port 1 is connected to an empty microphone. The multiplexer 4 is connected to the output of the oscillation module 2, outputting a frequency signal. The frequency signal is determined by the empty microphone capacitor connected to the port.

[0040] When the common port 1 is connected as a switch microphone, the oscillation module 2 outputs a level signal. This level signal is processed by counter 3111 and then input to comparator 312 for comparison with the threshold of frequency counter 3111. The comparison result is latched by logic signal latch 32. After the signal is latched, the signal connected to the selection output terminal is fed back. When the latched signal is 0, it indicates that the common port 1 is connected to a switch microphone. The multiplexer 4 is connected to the output of the common port 1 through control module 5 and outputs a level signal.

[0041] Furthermore, this embodiment may also include a pull-up resistor and a selection switch; one end of the pull-up resistor is connected to the power supply, and the other end is connected between the common port 1 and the input terminal of the oscillator 3113. One end of the selection switch is connected to the input terminal of the common port 1, and the other end is connected to the oscillation module 2; the selection switch is composed of a transmission gate, and the control electrode of the transmission gate is controlled by a power-on reset signal, used to connect the common port 1 to the input terminal of the oscillation module 2 when the system is powered on.

[0042] This embodiment provides an overall description of the connection relationships and workflow.

[0043] I. Overall Circuit Structure and Component Connections

[0044] The circuit in this embodiment includes a common port 1, an oscillation module 2, an identification logic module 3, a multiplexer 4, pull-up resistors, a selection switch, and a control module 5. The specific structure and connection relationship of each component are as follows:

[0045] Common Port 1: Serves as the sole connection interface between the entire circuit and external microphones (empty microphone or switch microphone). Its input is used to connect an empty microphone (capacitive microphone) or a switch microphone (button microphone). The output is split into two paths: one path connects to the input of oscillation module 2 via a selector switch, and the other path connects directly to the input of control module 5. Simultaneously, the output of common port 1 and the input of oscillation module 2 are connected to the power supply VCC (e.g., a 3.3V DC power supply) via a pull-up resistor. The pull-up resistor R1 can be set to 10kΩ to provide a stable bias voltage for common port 1, ensuring normal operation when either an empty microphone or a switch microphone is connected.

[0046] The selector switch is constructed using a CMOS transmission gate. Its input is connected to the output of common port 1, and its output is connected to the input of oscillation module 2. The control gate is connected to the system's power-on reset signal. The power-on reset signal is provided by the system power management unit. When the system is powered on, it is high for 0-1ms and then becomes low after 1ms. The transmission gate is turned on under the high-level signal and remains on under the low-level signal (to ensure continuous signal transmission in the future). It is used to quickly establish a path between common port 1 and oscillation module 2 in the early stage of system power-on.

[0047] Oscillation Module 2: Employs an RC bridge oscillation circuit. Its input is connected to common port 1 via a selector switch, and its output is split into two paths: one connected to the input of identification logic module 3, and the other directly connected to the first input of multiplexer 4. The oscillation frequency of the RC oscillation circuit is determined by the external resistor and the equivalent capacitance of the microphone connected to common port 1. When an empty microphone is connected, its capacitance value changes the oscillation frequency; when a switched microphone is connected, its logic level suppresses the oscillation, significantly reducing the oscillation frequency.

[0048] Identification logic module 3 includes a frequency detection unit 31 and a latch 32. The specific structure and connections are as follows: Frequency detection unit 31 consists of a counting component 311 and a comparator 312. The counting component 311 includes a built-in high-frequency oscillator 3113, a frequency divider 3112, and a counter 3111. The built-in high-frequency oscillator 3113 is a crystal oscillator that outputs a high-frequency clock signal. Its output is connected to the input of the frequency divider 3112. The frequency divider 3112 reduces the 10MHz signal to a 10kHz low-frequency clock signal, and its output is connected to the clock input of the counter 3111. The counter 3111 is a 4-bit asynchronous binary counter, composed of four cascaded D flip-flops. Its data input is grounded, its count enable is connected to a power-delay signal, and its output is connected to the first input of the comparator 312.

[0049] Comparator 312: A voltage comparator 312 is used, whose second input terminal is connected to the voltage signal corresponding to the reference count value; the reference count value is provided by the built-in register, and the value is converted into a voltage signal through digital-to-analog conversion, which serves as the comparison threshold; the output terminal of comparator 312 is connected to the input terminal of latch 32.

[0050] Latch 32: It is a rising-edge triggered D flip-flop. Its clock terminal is connected to the rising edge of the above-mentioned power-on delay signal, its reset terminal is connected to the system power-on reset signal, and its output terminal is connected to the selection terminal of the multiplexer 4. It is used to latch the output result of comparator 312 and keep it stable.

[0051] Control module 5: It adopts a level buffer, whose input is connected to the output of common port 1, to buffer and reduce noise of the logic level signal output by the switch microphone, so as to avoid signal attenuation or interference; the output of the level buffer is connected to the second input of the multiplexer 4.

[0052] Multiplexer 4: It adopts a 2-to-1 analog switch. Its first input terminal is connected to the output terminal of the oscillation module 2, the second input terminal is connected to the output terminal of the control module 5, the selection terminal is connected to the output terminal of the latch 32 of the identification logic module 3, and the output terminal is the signal output terminal of the entire circuit, which is used to output the frequency signal corresponding to the empty mic or the logic level signal corresponding to the switch mic.

[0053] Furthermore, in this embodiment, the aforementioned shared port 1, oscillation module 2, identification logic module 3, multiplexer 4, pull-up resistor, selection switch, and control module 5 are all integrated into the same CMOS chip, further reducing the circuit size and lowering the cost of peripheral components.

[0054] II. Circuit Working Process

[0055] Step 1: System power-on initialization

[0056] When the system is powered on by VCC, a power-on reset signal is first generated, which turns on the selector switch and connects the common port 1 to the input of the oscillation module 2. At the same time, the power-on reset signal resets the latch 32, and the output is low. The pull-up resistor provides a 3.3V bias voltage to the common port 1 to ensure that the connected empty microphone or switch microphone obtains the normal operating voltage.

[0057] Step 2: Oscillation module 2 outputs a signal according to the microphone type.

[0058] If a microphone is connected to the shared port 1: the core of the microphone is a variable capacitor, whose capacitance value changes with the vibration of external sound. The oscillation frequency of the oscillation module 2 is determined by "fixed resistor + variable capacitor of microphone", so the oscillation frequency will change synchronously with the capacitance value of microphone, and finally output a sinusoidal oscillation signal whose frequency changes with the sound; this oscillation signal is sent to the recognition logic module 3 on the one hand, and to the first input terminal of the multiplexer 4 on the other hand.

[0059] If a switch microphone is connected to port 1: The switch microphone has a push-button structure, outputting a high level when not pressed and a low level when pressed, and its output is a stable logic level signal. This logic level signal will suppress the RC oscillation of the oscillation module 2 (both high and low levels will prevent the RC circuit from meeting the oscillation conditions), so the oscillation module 2 only outputs a very low frequency noise signal, which is sent to the identification logic module 3. At the same time, the logic level signal of the switch microphone is directly sent to the control module 5, and after buffering, a stable logic level signal is output to the second input terminal of the multiplexer 4.

[0060] Step 3: Identification logic module 3 determines the microphone type and latches the result.

[0061] The counting component 311 operates as follows: After power-on, the power-on delay signal goes high, which on the one hand enables the counting enable pin of counter 3111, starting to count the clock signal output by frequency divider 3112; on the other hand, it triggers the clock pin of latch 32, preparing to latch the comparison result. The counting duration of counter 3111 is 1ms.

[0062] Comparator 312 determines: After the counting is complete, counter 3111 outputs the voltage signal corresponding to the count value to one end of comparator 312; comparator 312 compares this signal with the reference voltage (1.5V, corresponding to the count value "6") at the other end:

[0063] If an empty microphone is connected: the oscillation module 2 outputs a high frequency (1kHz to 10kHz), and the oscillation signal it generates will slightly interfere with the counting (the actual count value is slightly lower than 10, but higher than 6, such as "8", corresponding to a voltage of about 2.0V). Therefore, the comparator 312 outputs a high level (indicating that it is identified as an empty microphone).

[0064] If a switch microphone is connected: the output frequency of oscillation module 2 is extremely low (<100Hz), which has no obvious interference to the counting. The count value of counter 3111 is "10" (corresponding to a voltage of about 2.5V), which is greater than the reference count value "6". Therefore, comparator 312 outputs a low level (indicating that it is identified as a switch microphone).

[0065] Result latching: After a certain period of time after power-on, the power-on delay signal becomes low level, the clock terminal of latch 32 receives the falling edge, and latches the output result of comparator 312: the latch 32 outputs a high level for an empty mic and a low level for a switched mic; the result remains unchanged after latching to avoid subsequent signal fluctuations affecting the recognition accuracy.

[0066] Step 4: Multiplexer 4 selects and outputs the corresponding signal.

[0067] Multiplexer 4 selects the corresponding input terminal based on the latch result of the selection terminal:

[0068] If SEL=1 (identified as empty microphone): Multiplexer 4 selects the first input terminal (IN1) and outputs the "oscillation signal whose frequency changes with the sound" output by oscillation module 2 from the OUT terminal.

[0069] If SEL=0 (identified as switch microphone): Multiplexer 4 selects the second input terminal (IN2) and outputs the "stable logic level signal" from the control module 5 from the OUT terminal.

[0070] The device embodiments described above are merely illustrative. The units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the modules can be selected to achieve the purpose of this embodiment according to actual needs. Those skilled in the art can understand and implement this without any creative effort.

[0071] Through the above description of the embodiments, those skilled in the art can clearly understand that each embodiment can be implemented by means of software plus necessary general-purpose hardware platforms, and of course, it can also be implemented by hardware. Based on this understanding, the above technical solutions, in essence or the part that contributes to the prior art, can be embodied in the form of a software product. This computer software product can be stored in a computer-readable storage medium, such as ROM / RAM, magnetic disk, optical disk, etc., and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute the methods described in the various embodiments or some parts of the embodiments.

[0072] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this utility model, and not to limit it. Although this utility model has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of this utility model.

Claims

1. A circuit with ports supporting both empty and switched microphones, characterized in that, include: Shared port, oscillation module, identification logic module and multiplexer; The input terminal of the common port is used to connect an empty microphone or a switch microphone, and the output terminal is connected to the input terminal of the oscillation module. The output terminal of the oscillation module is connected to the input terminal of the identification logic module, and the output terminal of the identification logic module is connected to the selection terminal of the multiplexer. The first input terminal of the multiplexer is connected to the output terminal of the oscillation module, and the second input terminal of the multiplexer is connected to the output terminal of the common port through the control module. The identification logic module is used to identify the output signal of the oscillation module to determine the microphone type. When the microphone type is an empty microphone, the multiplexer selects the first input terminal and outputs a frequency signal. When the microphone type is a switch microphone, the multiplexer selects the second input terminal and outputs a logic level signal.

2. The circuit according to claim 1, which supports both empty and switched microphones, is characterized in that... The identification logic module includes a frequency detection unit and a latch; The input terminal of the frequency detection unit is connected to the output terminal of the oscillation module, the output terminal of the frequency detection unit is connected to the input terminal of the latch, and the output terminal of the latch is connected to the selection terminal of the multiplexer. The frequency detection unit is used to detect the output frequency of the oscillation module and compare it with a preset threshold. The latch is used to latch the comparison result and output the microphone type.

3. The circuit according to claim 2 that supports both empty and switched microphones, characterized in that, The frequency detection unit includes: a counting component and a comparator; The input terminal of the counting component is connected to the output terminal of the oscillation module to count the oscillation pulses; The first input terminal of the comparator is connected to the output terminal of the counting component, and the second input terminal of the comparator is connected to a reference count value as the preset threshold.

4. The circuit according to claim 3 that supports both empty and switched microphones, characterized in that, The counting component includes: an oscillator, a frequency divider, and a counter; The oscillator is connected to the counter via the frequency divider; The oscillator is used to generate a high-frequency signal, the frequency divider is used to reduce the high-frequency signal to a low-frequency signal, and the counter is used to count the low-frequency signal.

5. The circuit according to claim 4 that supports both empty and switched microphones, characterized in that, The counter is an asynchronous binary counter, which is composed of multiple cascaded D flip-flops.

6. The circuit according to claim 3 that supports both empty and switched microphones, characterized in that, The reference count value is provided by a built-in register or generated by a fixed resistor voltage divider network connected to the power supply.

7. The circuit according to claim 3 that supports both empty and switched microphone ports, characterized in that, The latch is a D flip-flop, and the clock input of the D flip-flop is driven by a fixed-frequency clock signal or a power-on delay signal, which is used to latch the output result of the comparator at a specific time.

8. The circuit according to claim 4 that supports both empty and switched microphones, characterized in that, The circuit also includes a pull-up resistor; One end of the pull-up resistor is connected to the power supply, and the other end is connected between the common port and the input terminal of the oscillator.

9. The circuit according to claim 1, which supports both empty and switched microphones, is characterized in that... The shared port is also used to select whether to connect to the oscillation module or the control module.

10. The circuit according to any one of claims 1-9 that supports both empty and switched microphones, characterized in that, The shared port, the oscillation module, the identification logic module, and the multiplexer are integrated on the same chip.

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