Double-microphone input circuit

Abstract

The utility model relates to the technical field of microphones, in particular to a double-microphone input circuit, which comprises a system on chip (SOC) module, a detection module, a main circuit microphone module, a microphone switching module, an external microphone module and an auxiliary circuit microphone module, and is characterized in that the detection module is connected with the SOC module, the main circuit microphone module and the external microphone module; the microphone switching module is connected with the SOC module, the main circuit microphone module and the external microphone module, the microphone switching module is used for receiving a switching signal output by the SOC module to switch the main circuit microphone module or the external microphone module, and the auxiliary circuit microphone module is connected with the SOC module. According to the utility model, the dual-microphone input can be realized, and the main microphone module or the external microphone module is switched to be used as the first microphone input and the auxiliary microphone module is used as the second microphone input through the microphone switching module so as to realize the application scenarios requiring the dual-microphone input, such as double-person karaoke, real-time voice talkback and the like.

Description

TECHNICAL FIELD

[0001] The utility model relates to microphone technical field, especially a double microphone input circuit. BACKGROUND

[0002] With the rapid development of mobile terminal equipment, the tablet computer has become the multifunctional equipment of integrating entertainment, office. However, in recent years, in order to pursue more light and thin design and higher waterproof performance, the vast majority of tablet computers on the market have gradually cancelled the traditional 3.5mm analog earphone interface, or only reserved a 3.5mm four-section type (CTIA / OMTP standard) interface.

[0003] This trend although meets the demand of equipment miniaturization, but also brought many use restrictions, for example: audio input / output function is limited: single 3.5mm interface usually only supports audio output or single microphone input, cannot satisfy the application scene needing double microphone input such as double-person karaoke, real-time voice talkback. UTILITARY MODEL CONTENT

[0004] The main purpose of the utility model is to provide a double microphone input circuit, which aims to solve the problem that the application scene needing double microphone input such as double-person karaoke, real-time voice talkback cannot be satisfied.

[0005] In order to achieve the above purpose, the utility model provides a double microphone input circuit, which comprises a SOC module, a detection module, a main path microphone module, a microphone switching module, an external microphone module and an auxiliary path microphone module, the detection module is connected with the SOC module, the main path microphone module and the external microphone module respectively, the microphone switching module is connected with the SOC module, the main path microphone module and the external microphone module respectively, the microphone switching module is used for receiving the switching signal output by the SOC module so as to switch the main path microphone module or the external microphone module based on the switching signal, and the auxiliary path microphone module is connected with the SOC module.

[0006] In an embodiment, the microphone switching module comprises a single-pole double-throw switch, a first filter circuit and a second filter circuit, the first filter circuit is connected with the input end of the single-pole double-throw switch, the first output end of the single-pole double-throw switch is connected with the second filter circuit, the second output end of the single-pole double-throw switch is connected with the external microphone module, and the second filter circuit is connected with the main path microphone module.

[0007] In an embodiment, the first filter circuit comprises a first magnetic bead, a first capacitor, one end of the first magnetic bead is connected with a power supply, the other end of the first magnetic bead is connected with an input end of the single-pole double-throw switch, one end of the first capacitor is connected with the other end of the first magnetic bead and the input end of the single-pole double-throw switch respectively, and the other end of the first capacitor is grounded.

[0008] In an embodiment, the second filter circuit comprises a second magnetic bead, a third magnetic bead, a second capacitor, and a third capacitor, one end of the second magnetic bead and one end of the third magnetic bead are connected with the main path microphone module respectively, the other end of the second magnetic bead and the other end of the third magnetic bead are connected with a first output end of the single-pole double-throw switch respectively, one end of the second capacitor and one end of the third capacitor are connected with the first output end of the single-pole double-throw switch respectively, and the other end of the second capacitor and the other end of the third capacitor are both grounded.

[0009] In an embodiment, the external microphone module comprises a third filter circuit, and the third filter circuit is connected with the detection module.

[0010] In an embodiment, the third filter circuit comprises a fourth capacitor, a fifth capacitor, and a fourth magnetic bead, one end of the fourth magnetic bead and one end of the fifth capacitor are connected with the detection module respectively, the other end of the fourth magnetic bead is connected with one end of the fourth capacitor, and the other end of the fourth capacitor and the other end of the fifth capacitor are both grounded.

[0011] In an embodiment, the external microphone module further comprises a first TVS tube and a first microphone seat, one end of the first TVS tube and the first microphone seat are connected with the fourth magnetic bead respectively, and the other end of the first TVS tube is grounded.

[0012] In an embodiment, the auxiliary path microphone module comprises a high-pass filter circuit, a low-pass filter circuit, and a second microphone seat, and the second microphone seat is connected with the high-pass filter circuit and the low-pass filter circuit respectively.

[0013] In an embodiment, the high-pass filter circuit comprises a first resistor, a second resistor, a sixth capacitor, and a seventh capacitor, one end of the first resistor is connected with a positive output end of the auxiliary path microphone module, the other end of the first resistor is connected with one end of the sixth capacitor, the other end of the sixth capacitor is connected with the second microphone seat, one end of the second resistor is connected with a negative output end of the auxiliary path microphone module, the other end of the second resistor is connected with one end of the seventh capacitor, and the other end of the seventh capacitor is connected with the second microphone seat.

[0014] In an embodiment, the low-pass filter circuit includes a third resistor, an eighth capacitor, one end of the eighth capacitor is connected with one end of the third resistor, the other end of the eighth capacitor is grounded, and the other end of the third resistor is connected with the second microphone seat.

[0015] The utility model discloses a SOC module, detection module, main road microphone module, microphone switching module, external microphone module, auxiliary road microphone module are used to realize double microphone input, and the main road microphone module or external microphone module is switched as the first road microphone input through the microphone switching module, and the auxiliary road microphone module is switched as the second road microphone input to realize the application scene such as double-person K song, real-time voice intercom that need double road microphone input. BRIEF DESCRIPTION OF DRAWINGS

[0016] In order to more clearly illustrate the technical scheme in the embodiment of the utility model or prior art, the following will be briefly introduced the drawing needed to be used in the embodiment or prior art description, obviously, the drawing in the following description only some embodiments of the utility model, for ordinary skilled person in the art, without creative labor, according to the structure shown in these drawings, other drawings can also be obtained.

[0017] Figure 1 It is double microphone input circuit module schematic diagram;

[0018] Figure 2 It is the circuit diagram of main road microphone module and microphone switching module;

[0019] Figure 3 It is the circuit diagram of external microphone module and detection module;

[0020] Figure 4 It is auxiliary road microphone module circuit diagram;

[0021] Figure 5 It is SOC module circuit diagram.

[0022] BRIEF DESCRIPTION OF DRAWINGS

[0023] 10, SOC module; 20, detection module; 30, main road microphone module; 40, microphone switching module; 50, external microphone module; 60, auxiliary road microphone module; U40, single-pole double-throw switch; 401, first filter circuit; 402, second filter circuit; B40, first magnetic bead; C40, first capacitor; B41, second magnetic bead; B42, third magnetic bead; C30, second capacitor; C31, third capacitor; 501, third filter circuit; C52, fourth capacitor; C53, fifth capacitor; B50, fourth magnetic bead; T51, first TVS tube; J50, first microphone seat; 601, high-pass filter circuit; 602, low-pass filter circuit; J60, second microphone seat; R63, first resistor; R64, second resistor; C61, sixth capacitor; C63, seventh capacitor; R62, third resistor; C60, eighth capacitor.

[0024] The realization, functional features and advantages of the utility model will be further described in combination with embodiments with reference to the drawings. DETAILED DESCRIPTION

[0025] The technical solutions in the embodiments of the utility model will be clearly and completely described below in combination with the drawings in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, rather than all the embodiments. Based on the embodiments in the utility model, all other embodiments obtained by those skilled in the art without creative labor fall within the protection scope of the utility model.

[0026] It should be noted that if the embodiments of the utility model involve directional indications (such as up, down, left, right, front, back, etc.), the directional indications are only used to explain the relative position relationship, movement condition, etc. between components in a certain specific posture (as shown in the drawings). If the specific posture changes, the directional indications also change accordingly.

[0027] In addition, if the embodiments of the utility model involve descriptions of "first", "second", etc., the descriptions of "first", "second", etc. are only for description purposes, and cannot be understood as indicating or implying the relative importance of the indicated technical features or implicitly indicating the number of the indicated technical features. Therefore, the features limited by "first" and "second" can explicitly or implicitly include at least one of the features. In addition, the meaning of "and / or" appearing throughout the text is that it includes three parallel schemes. Taking "A and / or B" as an example, it includes A scheme, or B scheme, or A and B schemes. In addition, the technical solutions of each embodiment can be combined with each other, but it must be based on the realization of those skilled in the art. When the combination of technical solutions appears contradictory or unachievable, it should be considered that the combination of technical solutions does not exist, and is not within the protection scope required by the utility model.

[0028] The utility model provides a double microphone input circuit.

[0029] In the embodiment of the utility model, Figure 1 As shown in the figure, the double microphone input circuit comprises an SOC module 10, a detection module 20, a main path microphone module 30, a microphone switching module 40, an external microphone module 50 and an auxiliary path microphone module 60, the detection module 20 is connected with the SOC module 10, the main path microphone module 30 and the external microphone module 50 respectively, the microphone switching module 40 is connected with the SOC module 10, the main path microphone module 30 and the external microphone module 50 respectively, the microphone switching module 40 is used for receiving the switching signal output by the SOC module 10 so as to switch the main path microphone module 30 or the external microphone module 50 based on the switching signal, and the auxiliary path microphone module 60 is connected with the SOC module 10.

[0030] The utility model discloses a double microphone input is realized through SOC module 10, detection module 20, main path microphone module 30, microphone switching module 40, external microphone module 50, auxiliary path microphone module 60, and the application scene such as double person K song, real-time voice intercom that needs double path microphone input is realized through the microphone switching module 40 switches the main path microphone module 30 or external microphone module 50 as the first path microphone input, and the auxiliary path microphone module 60 is as the second path microphone input.

[0031] The SOC module 10 is used for bias power supply for microphone, and the microphone input signal is input to the SOC module 10, the microphone input detection signal is connected to the SOC module 10, and the microphone switching signal is output by the SOC module 10. The microphone detection module 20 is used for detecting whether the external microphone is connected. The main path microphone module 30 provides a bias circuit, a first filter circuit 401 and a second filter circuit 402 for an electret microphone, and the external microphone module 50 can also provide a bias circuit and a filter circuit for the electret microphone. The auxiliary path microphone module 60 provides a bias circuit, a high-pass filter circuit 601 and a low-pass filter circuit 602 for the electret microphone. When there is no external microphone input, the microphone switching module switches the microphone input signal to the main path microphone module 30. When there is an external microphone input, the microphone switching module switches the microphone input signal to the external microphone. The auxiliary path microphone module 60 is used as the second path microphone input.

[0032] As shown in the figure, Figure 5 The model of the SOC module 10 is SC2720A, the MIC bias voltage filter capacitor C11 is connected to the E4 pin of the SOC module 10, and the HEADMIC bias voltage filter capacitor C10 is connected to the H5 pin of the SOC module 10.

[0033] AsFigure 3 As shown, the detection module 20 includes a pull-up resistor R20, a filter capacitor C20, a ninth capacitor C21, a second TVS tube T20, the pull-up resistor R20 is connected with the filter capacitor C20 and the ninth capacitor C21 respectively, and the second TVS tube T20 is connected with the ninth capacitor C21. When the external microphone is inserted, the fourth pin and the fifth pin of the first microphone seat J50 are disconnected, the level signal of EINT_SUB_MIC changes from low level to high level, and the level signal is input to the SOC module 10. The SOC module 10 judges that the external microphone has been inserted, and then outputs high level to GPIO_MIC_SWTCH, so that the single-pole double-throw switch U40 of the microphone switching module is switched from NC1 / NC2 to NO1 / NO2, so that the microphone input path is switched from the main road microphone module 30 to the external microphone module 50.

[0034] The main road microphone module 30 includes resistors R30 and R31 connected with the single-pole double-throw switch U40 respectively, for improving the ESD performance of the circuit. Resistors R30 and R31, capacitor C32 and capacitor C33 together constitute a HPF (High Pass Filter) high-pass filter circuit, and the cutoff frequency is about 10 Hz. Resistors R32, R33 and capacitor R34 together constitute a LPF (Low Pass Filter) low-pass filter circuit, and the cutoff frequency is about 71 Hz. Resistors R34 and R35 can reduce the high-frequency noise of MICBIAS crosstalk to MIC_P / MIC_N. The second capacitor C30 and the third capacitor C31 are used to filter out radio frequency interference in the circuit. The TVS tube T30 and the TVS tube T31 are used for electrostatic protection.

[0035] As shown in the figure, Figure 2 The microphone switching module 40 includes a single-pole double-throw switch U40, a first filter circuit 401 and a second filter circuit 402. The first filter circuit 401 is connected with the input end of the single-pole double-throw switch U40. The first output end of the single-pole double-throw switch U40 is connected with the second filter circuit 402. The second output end of the single-pole double-throw switch U40 is connected with the external microphone module 50. The second filter circuit 402 is connected with the main road microphone module 30.

[0036] The single-pole double-throw switch U40 is a switch that can switch between two different paths, and is usually used to select different signal paths. The first filter circuit 401 functions to preliminarily filter the input signal, and is usually used to remove noise or unnecessary frequency components, so as to ensure that the signal entering the subsequent circuit is more pure. The second filter circuit 402 further cleans the signal, which may be to reduce high-frequency noise, or to perform band-pass filtering on the signal, so as to ensure that only the signal of the expected frequency range is passed and transmitted to the downstream microphone module.

[0037] The first filter circuit 401 includes a first magnetic bead B40, a first capacitor C40, one end of the first magnetic bead B40 is connected with a power supply, the other end of the first magnetic bead B40 is connected with an input end of the single-pole double-throw switch U40, one end of the first capacitor C40 is connected with the other end of the first magnetic bead B40 and the input end of the single-pole double-throw switch U40 respectively, and the other end of the first capacitor C40 is grounded. The first magnetic bead B40 and the first capacitor C40 constitute an LC filter circuit for suppressing the interference noise introduced from the power supply end. The single-pole double-throw switch U40 is of model RS2118H and is used for switching the main microphone and the external microphone.

[0038] The first magnetic bead B40 can effectively suppress the high-frequency interference signal in the power supply through its inductive characteristic, provide a low-impedance path for the interference signal, and show a high impedance to the working frequency (such as an audio signal), thereby preventing the interference signal from entering the subsequent circuit. The first capacitor C40 is used for smoothing voltage and filtering high-frequency noise, and guides the high-frequency noise in the power supply to the ground through a low-impedance path, thereby preventing the noise from interfering with the sensitive circuit.

[0039] The second filter circuit 402 includes a second magnetic bead B41, a third magnetic bead B42, a second capacitor C30, and a third capacitor C31. One end of the second magnetic bead B41 and one end of the third magnetic bead B42 are connected with the main microphone module 30 respectively, the other end of the second magnetic bead B41 and the other end of the third magnetic bead B42 are connected with a first output end of the single-pole double-throw switch U40 respectively, one end of the second capacitor C30 and one end of the third capacitor C31 are connected with the first output end of the single-pole double-throw switch U40 respectively, and the other end of the second capacitor C30 and the other end of the third capacitor C31 are both grounded. The second magnetic bead B41, the third magnetic bead B42, the second capacitor C30, and the third capacitor C31 constitute an LC filter circuit for filtering the radio frequency interference in the circuit.

[0040] The second magnetic bead B41 and the third magnetic bead B42 can effectively filter the high-frequency noise in the power supply or the signal path through their inductive characteristic. The magnetic beads show a low impedance to the high-frequency signal, so it can isolate the unwanted high-frequency interference signal from the main signal path.

[0041] The second capacitor C30 and the third capacitor C31 can effectively filter the high-frequency interference signal in the signal path. The capacitor helps to smooth the signal by guiding the high-frequency noise to the ground, thereby preventing the interference signal from entering the subsequent circuit. The capacitor functions to filter the high-frequency component in the circuit and maintain the stability of the low-frequency signal.

[0042] The external microphone module 50 includes a third filtering circuit 501, which is connected to the detection module 20. The third filtering circuit 501 includes a fourth capacitor C52, a fifth capacitor C53, and a fourth ferrite bead B50. One end of the fourth ferrite bead B50 and one end of the fifth capacitor C53 are respectively connected to the detection module 20. The other end of the fourth ferrite bead B50 is connected to one end of the fourth capacitor C52. The other ends of the fourth capacitor C52 and the fifth capacitor C53 are both grounded. The fourth capacitor C52, the fifth capacitor C53, and the fourth ferrite bead B50 form an LC filtering circuit used to filter out radio frequency interference in the circuit.

[0043] The external microphone module 50 also includes a first TVS diode T51 and a first microphone socket J50. One end of the first TVS diode T51 and the first microphone socket J50 are respectively connected to the fourth ferrite bead B50, and the other end of the first TVS diode T51 is grounded. The first TVS diode T51 is used for electrostatic protection. The first microphone socket J50 is a 3.5mm microphone socket with detection, model PJ35H006-4J2SX-01.

[0044] like Figure 4 As shown, the auxiliary microphone module 60 includes a high-pass filter circuit 601, a low-pass filter circuit 602, and a second microphone socket J60, which is connected to the high-pass filter circuit 601 and the low-pass filter circuit 602 respectively.

[0045] The high-pass filter circuit 601 includes a first resistor R63, a second resistor R64, a sixth capacitor C61, and a seventh capacitor C63. One end of the first resistor R63 is connected to the positive output terminal of the auxiliary microphone module 60, and the other end of the first resistor R63 is connected to one end of the sixth capacitor C61. The other end of the sixth capacitor C61 is connected to the second microphone socket J60. One end of the second resistor R64 is connected to the negative output terminal of the auxiliary microphone module 60, and the other end of the second resistor R64 is connected to one end of the seventh capacitor C63. The other end of the seventh capacitor C63 is connected to the second microphone socket J60. The first resistor R63 and the second resistor R64 are used to improve the ESD performance of the circuit. The first resistor R63, the second resistor R64, the sixth capacitor C61, and the seventh capacitor C63 together form an HPF (High Pass Filter) high-pass filter circuit with a cutoff frequency of approximately 10Hz.

[0046] The low-pass filter circuit 602 comprises a third resistor R62, an eighth capacitor C60, one end of the eighth capacitor C60 is connected with one end of the third resistor R62, the other end of the eighth capacitor C60 is grounded, and the other end of the third resistor R62 is connected with the second microphone seat J60.

[0047] The auxiliary road microphone module 60 further comprises a resistor R61 and a resistor R66, the resistor R61 is connected with the resistor R66 in series, the resistor R61 is connected with the sixth capacitor C61, and the resistor R60 is connected with the seventh capacitor C63. The resistor R61 and the resistor R66 can reduce the high-frequency noise of MICBIAS crosstalk to MIC_P / MIC_N. The auxiliary road microphone module 60 further comprises a capacitor C64, a capacitor C65, a TVS tube T60, a TVS tube T61, a capacitor C66 and a TVS tube T62, one end of the capacitor C64 and the TVS tube T60 are connected with the sixth capacitor C61 respectively, one end of the capacitor C65 and the TVS tube T61 are connected with the seventh capacitor C63 respectively, and the capacitor C64 and the capacitor C65 are used for filtering radio frequency interference in the circuit. The TVS tube T60 and the TVS tube T61 are used for electrostatic protection. The third resistor R62 provides a pull-up level for EINT_SUB_MIC. The eighth capacitor C60 is used for filtering, the third resistor R62 is connected with the capacitor C66 and the TVS tube T62, the capacitor C66 is used for debouncing, and the TVS tube T62 is used for electrostatic protection.

[0048] The preferred embodiments of the utility model are described above only, and are not used for limiting the utility model, for the person skilled in the art, the utility model can have various changes, combinations and changes. Any modification, equivalent replacement, improvement etc. that is made in the spirit and principle of the utility model should be contained in the claim range of the utility model.

Claims

1. A dual microphone input circuit, characterized by, The application relates to a microphone switching module, which comprises an SOC module, a detection module, a main-path microphone module, a microphone switching module, an external microphone module and an auxiliary-path microphone module.

2. The dual microphone input circuit of claim 1, wherein, The microphone switching module comprises a single-pole double-throw switch, a first filter circuit and a second filter circuit.

3. The dual microphone input circuit of claim 2, wherein, The first filter circuit comprises a first magnetic bead and a first capacitor.

4. The dual microphone input circuit of claim 2, wherein, The second filter circuit comprises a second magnetic bead, a third magnetic bead, a second capacitor and a third capacitor.

5. The dual microphone input circuit of claim 1, wherein, The external microphone module comprises a third filter circuit.

6. The dual microphone input circuit of claim 5, wherein, The third filter circuit comprises a fourth capacitor, a fifth capacitor and a fourth magnetic bead.

7. The dual microphone input circuit of claim 6, wherein, The external microphone module further comprises a first TVS tube and a first microphone seat.

8. The dual microphone input circuit of claim 1, wherein, The auxiliary-path microphone module comprises a high-pass filter circuit, a low-pass filter circuit and a second microphone seat.

9. The dual microphone input circuit of claim 8, wherein, The high-pass filter circuit comprises a first resistor, a second resistor, a sixth capacitor and a seventh capacitor, one end of the first resistor is connected with a positive output end of the auxiliary path microphone module, the other end of the first resistor is connected with one end of the sixth capacitor, the other end of the sixth capacitor is connected with the second microphone seat, one end of the second resistor is connected with a negative output end of the auxiliary path microphone module, the other end of the second resistor is connected with one end of the seventh capacitor, the other end of the seventh capacitor is connected with the second microphone seat.

10. The dual microphone input circuit of claim 8, wherein, The low-pass filter circuit comprises a third resistor and an eighth capacitor, one end of the eighth capacitor is connected with one end of the third resistor, the other end of the eighth capacitor is grounded, and the other end of the third resistor is connected with the second microphone seat.

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