CN210327962U

CN210327962U - Microphone plugging detection circuit and microphone system

Info

Publication number: CN210327962U
Application number: CN201921519318.5U
Authority: CN
Inventors: 何春宏
Original assignee: Guangzhou Shiyuan Electronics Thecnology Co Ltd
Current assignee: Guangzhou Shiyuan Electronics Thecnology Co Ltd
Priority date: 2019-09-12
Filing date: 2019-09-12
Publication date: 2020-04-14
Anticipated expiration: 2029-09-12

Abstract

The application provides a microphone unplugging and plugging detection circuit and a microphone system. The microphone plugging detection circuit comprises an indicator light power supply circuit and a detection sub-circuit. The indicator light power supply circuit includes an indicator light pin. The indicator light power supply circuit is used for supplying power to the indicator light in the microphone through the indicator light pin when the microphone is inserted. The detection sub-circuit is connected with the pin of the indicator light and is used for detecting the electric signal of the pin of the indicator light and determining the plugging and unplugging state of the microphone according to the electric signal. The microphone system includes a main board and a microphone. The mainboard comprises a microphone plugging detection circuit. The microphone comprises an indicator light, and when the microphone is inserted into the mainboard, the indicator light is connected with the microphone plugging detection circuit. The microphone plugging detection is simpler and more effective, and the application range is wide.

Description

Microphone plugging detection circuit and microphone system

Technical Field

The application relates to the field of microphones, in particular to a microphone plugging detection circuit and a microphone system.

Background

The existing microphone plugging detection is realized through a spring switch of an earphone jack or a microphone base, so that the microphone detection cannot be carried out when the earphone jack or the microphone base does not exist.

SUMMERY OF THE UTILITY MODEL

The application provides an improved microphone unplugging and plugging detection circuit and a microphone system.

The application provides a microphone is pulled out and is inserted detection circuitry includes:

the indicator light power supply circuit comprises an indicator light pin and is used for connecting an indicator light of the microphone through the indicator light pin to supply power to the indicator light when the microphone is inserted; and

the detection sub-circuit is connected with the indicating lamp pin of the indicating lamp power supply circuit and used for detecting an electric signal of the indicating lamp pin and determining the plugging and unplugging state of the microphone according to the electric signal.

Furthermore, the detection sub-circuit comprises a voltage comparison circuit and a control circuit, wherein the voltage comparison circuit is connected with the pin of the indicator light and is used for comparing the voltage of the pin of the indicator light with a reference voltage to generate a comparison result; the control circuit is connected with the voltage comparison circuit and used for determining the plugging and unplugging state of the microphone according to the comparison result.

Further, the voltage comparison circuit comprises a comparator and a reference voltage circuit, wherein the input end of the comparator is connected with the pin of the indicator light, the output end of the comparator is connected with the control circuit, and the reference voltage circuit is connected with the input end of the comparator and used for providing reference voltage for the comparator.

Furthermore, the indicator light power supply circuit comprises a first indicator light power supply circuit and a second indicator light power supply circuit, the first indicator light power supply circuit comprises a first indicator light pin, the second indicator light power supply circuit comprises a second indicator light pin, the first indicator light pin is connected with a first indicator light of the first microphone, and the second indicator light pin is connected with a second indicator light of the second microphone.

Further, the comparator comprises a first comparator and a second comparator;

the positive phase end of the first comparator is connected with the first indicator lamp pin, the inverting end of the first comparator is connected with the reference voltage circuit, and the output end of the first comparator is connected with the control circuit;

the positive phase end of the second comparator is connected with the second indicator lamp pin, the inverting end of the second comparator is connected with the reference voltage circuit, and the output end of the second comparator is connected with the control circuit.

Further, the output end of the first comparator and the output end of the second comparator are connected to the same port of the control circuit.

Further, the voltage comparison circuit comprises a current-limiting resistor, and the current-limiting resistor is connected between the positive phase end of the comparator and the pin of the indicator light; and/or

The comparator comprises a power supply end, the voltage comparison circuit comprises a filter capacitor, and the filter capacitor is connected between the power supply end of the comparator and the ground; and/or

The voltage comparison circuit comprises a pull-up resistor, and the pull-up resistor is connected with the output end of the comparator.

Further, the reference voltage circuit comprises a direct current power supply end, the reference voltage circuit comprises a voltage stabilizing diode and a diode current limiting resistor connected in series with the voltage stabilizing diode, the anode of the voltage stabilizing diode is grounded, the cathode of the voltage stabilizing diode is connected to the direct current power supply end through the diode current limiting resistor, and the input end of the comparator is connected between the voltage stabilizing diode and the diode current limiting resistor.

The present application provides a microphone system comprising:

a main board including the microphone plugging detection circuit; and

the microphone comprises an indicator light, and when the microphone is inserted into the mainboard, the indicator light is connected with the microphone plugging detection circuit.

Furthermore, the indicator light of the microphone comprises an LED light, when the microphone is inserted into the mainboard, the anode of the LED light is connected with the microphone plugging detection circuit, and the cathode of the LED light is grounded.

The utility model provides a microphone pulls out and inserts detection circuitry's pilot lamp supply circuit includes the pilot lamp pin of being connected with the pilot lamp of microphone when the microphone inserts, detects sub-circuit connection pilot lamp pin, detects the signal of telecommunication of pilot lamp pin, confirms the plug state of microphone, so, need not to dispose solitary microphone and pulls out to insert and explore foot and shell fragment switch etc. and it is more simple effective that the detection is pulled out to microphone, and application scope is wide.

Drawings

FIG. 1 is a schematic diagram of a microphone unplugging/plugging detection circuit;

FIG. 2 is a circuit block diagram of one embodiment of a microphone system of the present application;

FIG. 3 is a circuit diagram of one embodiment of a microphone of the microphone system shown in FIG. 2;

FIG. 4 is a circuit diagram of one embodiment of a microphone unplugging detection circuit of the microphone system shown in FIG. 2;

fig. 5 is a circuit diagram of another embodiment of a microphone unplugging detection circuit of the microphone system shown in fig. 2.

Detailed Description

Reference will now be made in detail to the exemplary embodiments, examples of which are illustrated in the accompanying drawings. When the following description refers to the accompanying drawings, like numbers in different drawings represent the same or similar elements unless otherwise indicated. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with the present application. Rather, they are merely examples of apparatus consistent with certain aspects of the present application, as detailed in the appended claims.

The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the application. Unless otherwise defined, technical or scientific terms used herein shall have the ordinary meaning as understood by one of ordinary skill in the art to which this application belongs. The use of the terms "a" or "an" and the like in the description and in the claims of this application do not denote a limitation of quantity, but rather denote the presence of at least one. "plurality" includes two, and is equivalent to at least two. The word "comprising" or "comprises", and the like, means that the element or item listed as preceding "comprising" or "includes" covers the element or item listed as following "comprising" or "includes" and its equivalents, and does not exclude other elements or items. The terms "connected" or "coupled" and the like are not restricted to physical or mechanical connections, but may include electrical connections, whether direct or indirect. As used in this specification and the appended claims, the singular forms "a", "an", and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise. It should also be understood that the term "and/or" as used herein refers to and encompasses any and all possible combinations of one or more of the associated listed items.

Fig. 1 is a schematic diagram of a microphone unplugging detection circuit 112. The microphone unplugging/plugging detection circuit 112 includes a dome switch 50 and a detection pin 60. The detection pin 60 is connected with one end of the dome switch 50, and when the dome switch 50 is turned on and off, the voltage of the detection pin 60 is different. The dome switch 50 and the detection pin 60 are located in the headphone jack or microphone base. When the microphone 70 is inserted, the dome switch 50 is closed, and when the microphone 70 is pulled out, the dome switch 50 is opened. By detecting the voltage of the detection pin 60, the unplugged state of the microphone 70 can be determined, and whether the microphone 70 is plugged into an earphone jack or a microphone base can be determined.

When the microphone plugging detection circuit 112 detects that the microphone is plugged, an earphone jack or a microphone base of the dome switch 50 needs to be arranged, and an independent detection pin 60 needs to be arranged, so that the structure is complex, the microphone detection cannot be performed when the earphone jack or the microphone base does not exist, the applicability is limited, and the application range is small.

Fig. 2 is a circuit block diagram of one embodiment of a microphone system 200 of the present application. The microphone system 200 includes a main board 203 and a microphone 30. The main board 203 includes a microphone unplugging detection circuit 100 for detecting the unplugging state of the microphone 30 and detecting whether the microphone 30 is plugged into the main board 203. The main board 203 may be provided in a mobile phone, a computer, a platform, etc. into which the microphone 30 may be inserted. In some embodiments, the motherboard 203 may be provided with other circuitry. The microphone 30 includes an indicator lamp 31, and when the microphone 30 is inserted into the main board 203, the indicator lamp 31 is connected to the microphone unplugging detection circuit 100.

The microphone unplugging detection circuit 100 includes an indicator light supply circuit 10 and a detection sub-circuit 20. The indicator light power supply circuit 10 comprises an indicator light pin 109, and the indicator light power supply circuit 10 is used for supplying power to the indicator light 31 through the connection between the indicator light pin 109 and the indicator light 31 of the microphone 30 when the microphone 30 is inserted. The detection sub-circuit 20 is connected to the indicator pin 109 of the indicator power supply circuit 10, and is configured to detect an electrical signal of the indicator pin 109, determine a plugging/unplugging state of the microphone 30 according to the electrical signal, and determine whether the microphone 30 is plugged into the main board 203. When the microphone 30 is pulled out, the indicator light power supply circuit 10 and the indicator light 31 are disconnected, and the indicator light pin 109 is suspended. Since the electric signal of the indicator pin 109 is different when the microphone 30 is inserted into and removed from the main board 203, whether the microphone 30 is inserted into the main board 203 can be detected by detecting the electric signal of the indicator pin 109.

The microphone plugging detection circuit 100 supplies power to the indicator lamp 31 through the indicator lamp pin 109 and detects the plugging state of the microphone 30, the microphone plugging detection circuit 100 determines the plugging state of the microphone 30 according to an electric signal on the indicator lamp pin 109 without configuring an independent microphone plugging detection pin, a dome switch and the like, the circuit is simplified, the number of pins for connecting the mainboard 203 and the microphone 30 is reduced, the microphone plugging detection is simpler and more effective, the application range is wide, and the applicability and convenience of the microphone plugging detection are improved.

In some embodiments, the electrical signal comprises a voltage signal, and the unplugged state of the microphone 30 may be determined by detecting the voltage at the indicator pin 109. In other embodiments, the electrical signal comprises a current signal, and the unplugged or plugged-in state of the microphone 30 can be determined by detecting the current at the indicator pin 109.

In some embodiments, the detection sub-circuit 20 includes a voltage comparison circuit 201 and a control circuit 202, wherein the voltage comparison circuit 201 is connected to the indicator pin 109 and is configured to compare a voltage of the indicator pin 109 with a reference voltage to generate a comparison result. The control circuit 202 is connected to the voltage comparison circuit 201, and is configured to determine the plugging/unplugging state of the microphone 30 according to the comparison result. Thus, the voltage output by the voltage comparison circuit 201 can be applied to more types of control chips, the limitation on the control circuit 202 is small, and more types of control chips can be selected. In other embodiments, the control circuit 202 may be connected to the indicator pin 109, receive the voltage of the indicator pin 109, and determine the plugging status of the microphone 30 according to the voltage.

Fig. 3 is a circuit diagram of one embodiment of the microphone 30 shown in fig. 2. The microphone 30 comprises a microphone signal pin MIC, a microphone light pin LED and a microphone ground pin GND. The microphone grounding pin GND is grounded. The indicator light 31 of the microphone 30 is connected between the microphone light pin LED and ground. In some embodiments, the indicator light 31 of the microphone 30 comprises an LED light having an anode connected to the microphone light pin LED and a cathode connected to ground. In some embodiments, indicator light 31 is connected in series with resistor R1. The cathode of the LED lamp is connected to ground through a resistor R1.

The microphone 30 includes a microphone 32 and an amplifier U1 connected to the microphone 32. The microphone 32 is used for receiving sound and outputting electric current. The amplifier U1 is connected to the microphone signal pin MIC, amplifies the current, and outputs the current through the microphone signal pin MIC. A resistor R3 is connected between the microphone 32 and the amplifier U1, a resistor R2 is connected between the amplifier U1 and the microphone signal pin MIC, and the output end of the amplifier U1 is grounded through a capacitor C1.

Fig. 4 is a circuit diagram of one embodiment of the microphone unplugging detection circuit 100 shown in fig. 2. Referring collectively to fig. 3, the indicator lamp power supply circuit 10 includes a dc voltage source terminal VCC and voltage dividing resistors RD34, RD 5. The dc voltage source VCC may be connected to a power supply circuit (not shown) and connected to a power supply through the power supply circuit. The power circuit may convert alternating current (e.g., mains) output by the power supply to direct current, e.g., 12V direct current. The power supply circuit provides a stable dc voltage to the indicator lamp power supply circuit 10 via the dc voltage source VCC. The voltage dividing resistors RD34 and RD5 are connected in series between the dc voltage source terminal VCC and the ground terminal to divide the dc voltage. The indicator pin 109 is connected between the voltage dividing resistors RD34 and RD5, and the indicator pin 109 is connected to the microphone lamp pin LED in fig. 3, thereby being connected to the indicator 31. The voltage of the dc voltage source VCC is divided and supplied to the indicator lamp 31. The indicator pin 109 is connected to ground through a capacitor CD 61.

In some embodiments, the indicator light power supply circuit 10 includes a connector circuit 40, the connector circuit 40 includes a connector CN2, and a connector CN2 is provided on the main board 203 for plugging with the microphone 30. When the microphone 30 is inserted into the connector CN2, the microphone light pin LED is connected to the first pin 1 of the connector CN2 and further connected to the indicator light pin 109, so that the indicator light power supply circuit 10 is connected to the indicator light 31. The second pin 2 of the connector CN2 is connected to the microphone signal pin MIC of the microphone 30, and receives a current signal representing voice. The second pin 2 of the connector CN2 is connected to the output terminals MIC _ BIAS and MIC1_ IN, and is grounded through the capacitor C50. A resistor R143 is connected between the second pin 2 and the output terminal MIC _ BIAS, and a capacitor C18 is connected between the second pin 2 and the output terminal MIC1_ IN. The third pin 3 of the connector CN2 is connected to the microphone ground pin GND of the microphone 30 and is grounded.

When the microphone 30 is pulled out of the main board 203, the indicator light pin 109 is suspended, and the voltage on the indicator light pin 109 is the supply voltage output by the indicator light power supply circuit 10 and is the voltage divided by the dc voltage source terminal VCC; when the microphone 30 is plugged into the motherboard 203, the voltage at the indicator pin 109 is the voltage between the indicator 31 in the microphone 30 and ground, in the illustrated embodiment, the voltage drop across the indicator 31 and the voltage across the resistor R1. When the microphone 30 is inserted into the main board 203, the anode of the LED lamp is connected to the microphone unplugging/plugging detection circuit 100, and the cathode of the LED lamp is grounded. When the microphone 30 is inserted into the main board 203, the anode of the LED lamp is connected to the indicator pin 109, and the cathode of the LED lamp is grounded. After the LED lamp is turned on, the current flowing through the LED lamp is small, and the voltage across the resistor R1 is small, so that when the microphone 30 is plugged into the motherboard 203, the voltage at the pin 109 of the indicator lamp is substantially equal to the voltage drop across the LED lamp. The voltage drop on the LED lamp is a fixed voltage drop, and is less than 3V, so when the microphone 30 is inserted into the motherboard 203, the voltage on the indicator pin 109 is less than 3V, and after the microphone 30 is extracted from the motherboard 203, the voltage on the indicator pin 109 is the voltage after the voltage division of the dc voltage source VCC, and is greater than 3V. In this way, the unplugged and plugged state of the microphone 30 can be determined by detecting the voltage of the indicator pin 109.

The voltage comparison circuit 201 is connected to the indicator pin 109, compares the voltage of the indicator pin 109 with a reference voltage, and outputs a comparison result of a high level or a low level. In some embodiments, the reference voltage is greater than a voltage drop of the indicator 31 in the microphone 30 and is less than a supply voltage output after a dc voltage source terminal VCC of the indicator power supply circuit 10 is divided. The voltage comparison circuit 201 collects the voltage on the indicator light pin 109, compares the collected voltage with the reference voltage, and if the collected voltage is greater than the reference voltage, the voltage comparison circuit 201 outputs a high level to the control circuit 202, and the control circuit 202 determines that the microphone 30 is in the unplugged state according to the high level, and then executes actions related to the unplugged state of the microphone, such as turning off a loudspeaker and the like. If the collected voltage is smaller than the reference voltage, the voltage comparison circuit 201 outputs a low level to the control circuit 202, and the control circuit 202 determines that the microphone is in the insertion state according to the low level, and further performs an action related to the insertion state of the microphone, such as turning on a loudspeaker. In one example, the reference voltage may be set to 5V.

The voltage comparison circuit 201 includes a comparator UD8B and a reference voltage circuit 2013. The comparator UD8B comprises a first input I1 and a second input I2, the first input I1 of the comparator UD8B is connected to the indicator pin 109, and the output of the comparator UD8B is connected to the control circuit 202, and the reference voltage circuit 2013 is connected to the second input I2 of the comparator UD8B for providing a reference voltage to the comparator UD 8B. The reference voltage circuit 2013 is configured to provide a reference voltage to the comparator UD8B, and the comparator UD8B compares the reference voltage with the voltage at the indicator pin 109 and outputs a comparison result of high level or low level. The circuit is simple and the cost is low.

In this embodiment, the first input terminal I1 of the comparator UD8B is a non-inverting terminal of the comparator UD8B, and the second input terminal I2 of the comparator UD8B is an inverting terminal of the comparator UD 8B. In other embodiments, the first input I1 of the comparator UD8B is the inverting terminal of the comparator UD8B, and the second input I2 of the comparator UD8B is the non-inverting terminal of the comparator UD 8B.

The voltage comparison circuit 201 comprises a current limiting resistor RD22, the current limiting resistor RD22 is connected between the input end of the comparator UD8B and the indicator light pin 109, and the current limiting resistor RD22 can prevent the current between the input end of the comparator UD8B and the indicator light pin 109 from being too large. In some embodiments, current limiting resistor 2013 is connected to the non-inverting terminal of comparator UD 8B.

The comparator UD8B comprises a power supply terminal VDD, the voltage comparison circuit 201 comprises filter capacitors CD42 and CD43, and the filter capacitors CD42 and CD43 are connected between the power supply terminal VDD of the comparator UD8B and the ground. The voltage terminal VDD may be connected to the dc voltage source terminal VCC to receive the dc voltage. The filter capacitors CD42 and CD43 are used for eliminating the fluctuating voltage in the dc voltage source terminal VCC.

The voltage comparison circuit 201 comprises a pull-up resistor RD32, and the pull-up resistor RD32 is connected with the output end of the comparator UD 8B. In some embodiments, the comparator UD8B is an open collector output, and a pull-up resistor RD32 is disposed between the output terminal of the comparator UD8B and the control circuit 202, and is used for outputting a high level at the output terminal of the comparator UD 8B. In other embodiments, the comparator UD8B may be of a different type, and no pull-up resistor RD32 may be provided between the output of the comparator UD8B and the control circuit 202. In some embodiments, a current limiting resistor RD36 is connected in series between the output of the comparator UD8B and the control circuit 202 for limiting current. Port IO1 is shown connected to control circuit 202. The control circuit 202 may include a control chip.

The reference voltage circuit 2013 comprises a direct current power supply terminal VCC, the reference voltage circuit 2013 comprises a voltage stabilizing diode ZD6 and diode current limiting resistors RD47 and RD48 which are connected with the voltage stabilizing diode ZD6 in series, the anode of the voltage stabilizing diode ZD6 is grounded, the cathode of the voltage stabilizing diode ZD6 is connected to the direct current power supply terminal VCC through the diode current limiting resistors RD47 and RD48, and the input end of the comparator UD8B is connected between the voltage stabilizing diode ZD6 and the diode current limiting resistors RD47 and RD 48. The zener diode ZD6 operates in a reverse breakdown mode, and the diode current-limiting resistors RD47 and RD48 limit the current flowing through the zener diode ZD6, so that the operating current of the zener diode ZD6 is kept between a minimum stable current and a maximum stable current, wherein the minimum stable current is the minimum current required for stabilizing the voltage across the zener diode ZD6, and the maximum stable current is the maximum current allowed to pass when the zener diode ZD6 operates in a safe range. The voltage at the two ends of the zener diode ZD6 is the reference voltage output by the reference voltage circuit 2013. In some embodiments, the reference voltage output by the reference voltage circuit 2013 is 5V. The anode of the zener diode ZD6 is grounded, and the cathode is connected to the diode current limiting resistors RD47 and RD48 and the comparator UD 8B.

In some embodiments, the reference voltage circuit 2013 includes a zener filter capacitor C86 connected in parallel with a zener diode ZD 6. The voltage stabilizing filter capacitor C86 is used for improving the voltage stability of the output of the reference voltage circuit 2013.

The microphone unplugging detection circuit 100 shown in fig. 4 supports detecting a single microphone unplugging state. Fig. 5 is a circuit diagram of another embodiment of a microphone unplugging detection circuit 300. The microphone unplugging detection circuit 300 shown in fig. 5 is similar to the microphone unplugging detection circuit 100 shown in fig. 4. Compared with the microphone unplugging and plugging detection circuit 100 shown in fig. 4, the indicator light power supply circuit 10 of the microphone unplugging and plugging detection circuit 300 shown in fig. 5 comprises a first indicator light power supply circuit 101 and a second indicator light power supply circuit 102, the first indicator light power supply circuit 101 comprises a first indicator light pin MIC1_ LED, and when the first microphone is plugged into the main board 203 (shown in fig. 2) by the first indicator light power supply circuit 101, the first indicator light power supply circuit 101 supplies power to the first indicator light in the first microphone through a first indicator light pin MIC1_ LED; the second indicator light power supply circuit 102 comprises a second indicator light pin MIC2_ LED, and when the second microphone is inserted into the main board 203, the second indicator light power supply circuit 102 supplies power to a second indicator light in the second microphone through the second indicator light pin MIC2_ LED. The first indicator light power supply circuit 101 and the second indicator light power supply circuit 102 may be similar to the indicator light power supply circuit 10 shown in fig. 4, and are not described herein again.

In some embodiments, the motherboard 203 may plug in at least two microphones. The number of the indicator light power supply circuits 10 may be the same as the number of the microphones, and the indicator lights of the corresponding microphones are respectively supplied with power. In the illustrated embodiment, the main board 203 may be plugged with a first microphone and a second microphone, the first microphone and the second microphone may be the microphones 30 shown in fig. 2 and 3, and the indicator pin 109 includes a first indicator pin MIC1_ LED and a second indicator pin MIC2_ LED, and may be connected with a corresponding indicator. In other embodiments, the motherboard 203 may plug in three or more microphones.

In some embodiments, voltage comparison circuit 201 includes a first comparator UDBA, a second comparator UD8C, and a reference voltage circuit 2013. The reference voltage circuit 2013 is used for providing a reference voltage, and the first comparator UD8A is used for comparing the voltage on the first indicator light pin MIC1_ LED with the reference voltage and outputting a first comparison result; the second comparator UD8C is configured to compare a voltage at the second indicator light pin MIC2_ LED with a reference voltage, and output a second comparison result. The control circuit 202 (shown in fig. 2) determines the unplugging and plugging state of the first microphone according to the first comparison result and determines the unplugging and plugging state of the second microphone according to the second comparison result. The control circuit 202 may perform a control operation of the microphone insertion state, such as controlling a microphone (not shown) to be turned on, etc., when detecting that at least one of the microphones is inserted. The number of comparators may be the same as the number of pluggable microphones. Thus, a plurality of microphones can be plugged. The first comparator UDBA, the second comparator UD8C and the reference voltage circuit 2013 are substantially similar to the embodiment shown in fig. 4 and will not be described again here. The first comparator UDBA and the second comparator UD8C may be connected to the same reference voltage circuit 2013. The first comparator UDBA and the second comparator UD8C may share filter capacitors CD42, CD43, a pull-up resistor RD32, and a current limiting resistor RD 36.

In some embodiments, the output of the first comparator UD8B and the output of the second comparator 2012 may be connected to the same port of the control circuit 202, saving port resources. In other embodiments, the output of first comparator UD8B and the output of second comparator 2012 may be connected to different ports of control circuit 202.

The above description is only exemplary of the present application and should not be taken as limiting the present application, as any modification, equivalent replacement, or improvement made within the spirit and principle of the present application should be included in the scope of protection of the present application.

Claims

1. A microphone unplugging detection circuit, comprising:

2. The microphone unplugging detection circuit of claim 1 wherein the detection subcircuit comprises a voltage comparison circuit and a control circuit, the voltage comparison circuit being coupled to the indicator pin for comparing a voltage of the indicator pin to a reference voltage to produce a comparison result; the control circuit is connected with the voltage comparison circuit and used for determining the plugging and unplugging state of the microphone according to the comparison result.

3. The microphone unplugging detection circuit of claim 2 wherein the voltage comparison circuit comprises a comparator and a reference voltage circuit, an input of the comparator is coupled to the indicator pin and an output of the comparator is coupled to the control circuit, the reference voltage circuit is coupled to the input of the comparator for providing a reference voltage to the comparator.

4. The microphone unplugging detection circuit of claim 3 wherein the indicator light power supply circuit comprises a first indicator light power supply circuit and a second indicator light power supply circuit, the first indicator light power supply circuit comprising a first indicator light pin, the second indicator light power supply circuit comprising a second indicator light pin, the first indicator light pin coupled to a first indicator light of a first microphone, the second indicator light pin coupled to a second indicator light of a second microphone.

5. The microphone unplugging detection circuit of claim 4 wherein the comparator comprises a first comparator and a second comparator;

6. The microphone unplugging detection circuit of claim 5 wherein an output of the first comparator and an output of the second comparator are connected to a same port of the control circuit.

7. The microphone unplugging detection circuit of any of claims 3-6, wherein said voltage comparison circuit comprises a current limiting resistor connected between a positive terminal of said comparator and said indicator pin; and/or

8. A microphone unplugging detection circuit according to claim 3 wherein said reference voltage circuit comprises a dc supply terminal, said reference voltage circuit comprises a zener diode and a diode current limiting resistor in series with said zener diode, the anode of said zener diode is connected to ground, the cathode is connected to said dc supply terminal through said diode current limiting resistor, and the input terminal of said comparator is connected between said zener diode and said diode current limiting resistor.

9. A microphone system, characterized by: the method comprises the following steps:

a motherboard comprising a microphone unplugging detection circuit according to any of claims 1-8; and

10. The microphone system as defined by claim 9 wherein the indicator light of the microphone comprises an LED light, the anode of the LED light being connected to the microphone unplugging detection circuit when the microphone is plugged into the motherboard, the cathode of the LED light being connected to ground.