Audio interface circuit and electronic equipment

Abstract

The invention discloses an audio interface circuit and electronic equipment, and the audio interface circuit comprises an interface module, a first impedance matching module, a first isolation module, a digital signal decoding module and a plurality of power supply modules. The interface module is used for being connected with audio equipment. The first isolation module is used for unidirectionally transmitting a digital signal received by the first end of the first isolation module to the digital signal decoding module; the first isolation module is used for controlling one power supply voltage to be transmitted to the interface module through the first impedance matching module, and the first impedance matching module is used for adjusting the impedance of the first impedance matching module according to the power supply voltage. Multiple power supply voltages can be provided through the multiple power supply modules, the corresponding power supply voltage can be selected according to the power supply requirement of the audio equipment, the corresponding impedance can be configured through the first impedance matching module according to the power supply voltage, and therefore microphones of multiple models can be driven. The isolation between the digital signal and the analog signal can be realized through the first isolation module, so that the microphone can be compatible with microphones of various models.

Description

Technical Field

[0001] The present application belongs to the technical field of audio interface, and in particular, relates to an audio interface circuit and electronic equipment. Background Art

[0002] Currently, common microphones include microphones powered by digital voltage and microphones powered by analog voltage. If the microphones are to be compatible with the above-mentioned microphones, a more complex interface circuit is required, which increases the cost. Summary of the invention

[0003] The purpose of the present application is to provide an audio interface circuit and an electronic device, aiming to solve the problem that the traditional microphone interface circuit is difficult to be compatible with microphones powered by digital 10V and microphones powered by analog 48V / 5V.

[0004] A first aspect of an embodiment of the present application provides an audio interface circuit, comprising: an interface module, the interface module being used to connect to an audio device; a first impedance matching module, the first end of the first impedance matching module being connected to the interface module; a first isolation module, the first end of the first isolation module being connected to the second end of the first impedance matching module; a digital signal decoding module, the digital signal decoding module being connected to the second end of the first isolation module; the first isolation module being used to unidirectionally transmit a digital signal received by the first end of the first isolation module to the digital signal decoding module; a plurality of power supply modules, each of the power supply modules being connected to the third end of the first isolation module; each of the power supply modules being used to output different power supply voltages respectively, the first isolation module being used to control one of the power supply voltages to be transmitted to the interface module through the first impedance matching module, and the first impedance matching module being used to adjust its own impedance according to the power supply voltage.

[0005] In one embodiment, the first isolation module includes: a plurality of unidirectional conduction units and an isolation transformer; the unidirectional conduction units correspond to the power supply modules one by one, the input end of the unidirectional conduction unit is connected to the output end of the corresponding power supply module, the output end of the unidirectional conduction unit is connected to the middle tap of the primary winding of the isolation transformer, the two ends of the primary winding of the isolation transformer are connected to the second end of the first impedance matching module, and the two ends of the secondary winding of the isolation transformer T1 are connected to the digital signal decoding module.

[0006] In one embodiment, the audio interface circuit also includes a second impedance matching module, and at least one of the unidirectional conduction units includes: a photocoupler; the anode of the light-emitting device of the photocoupler is used to receive an enable signal, and the cathode of the light-emitting device of the photocoupler is grounded, and the first end of the optical receiver of the photocoupler is connected to the output end of the corresponding power supply module through at least one of the second impedance matching modules, and the second end of the optical receiver of the photocoupler is connected to the middle tap of the primary winding of the isolation transformer.

[0007] In one embodiment, the audio interface circuit also includes a second impedance matching module, and at least one of the unidirectional conduction units includes: a relay; a first end of the coil of the relay is used to receive an enable signal, and a second end of the coil of the relay is grounded, and a first end of the contact of the relay is connected to the output end of the corresponding power supply module through at least one of the second impedance matching modules, and a second end of the contact of the relay is connected to the middle tap of the primary winding of the isolation transformer.

[0008] In one embodiment, at least one of the one-way conductors includes: a one-way conductor; the anode of the one-way conductor is connected to the output end of the corresponding power supply module, and the cathode of the one-way conductor is connected to the middle tap of the primary winding of the isolation transformer.

[0009] In one embodiment, the power supply module includes a voltage regulating unit, and the voltage regulating unit is used to generate and output the power supply voltage based on an input voltage; the power supply voltage includes an analog voltage and a digital voltage.

[0010] In one embodiment, the first impedance matching module includes a second resistor R2, a fourth resistor R4, a first switch device Q1 and a second switch device Q2; the first end of the first switch device Q1 is connected to the first end of the primary winding of the isolation transformer, the second end of the first switch device Q1 is connected to the first end of the interface module, the first end of the first switch device Q1 is connected to the second end of the first switch device Q1 through the second resistor R2, and the control end of the first switch device Q1 is used to receive a first control signal; the first end of the second switch device Q2 is connected to the second end of the primary winding of the isolation transformer, the second end of the second switch device Q2 is connected to the second end of the interface module, the first end of the second switch device Q2 is connected to the second end of the second switch device Q2 through the fourth resistor R4, and the control end of the second switch device Q2 is used to receive a second control signal.

[0011] In one embodiment, the first impedance matching module further includes a third switch device Q3, a first end of the third switch device Q3 is respectively connected to the control end of the first switch device Q1 and the control end of the second switch device Q2, a second end of the third switch device Q3 is grounded, and the control end of the third switch device Q3 is used to receive a third control signal.

[0012] In one embodiment, the interface module includes an interface unit and a filter unit; the interface unit is connected to the first impedance matching module through the filter unit.

[0013] In one embodiment, it further includes an analog signal decoding module and a second isolation module; the analog signal decoding module is connected to the interface module via the second isolation module, and the analog signal decoding module is used to obtain the analog signal via the second isolation module and decode the analog signal.

[0014] A second aspect of an embodiment of the present application provides an electronic device, comprising the audio interface circuit as described above.

[0015] Compared with the prior art, the embodiments of the present application have the following beneficial effects: multiple power supply voltages can be provided through multiple power supply modules, and the corresponding power supply voltage can be selected according to the power supply requirements of the audio device, and the corresponding impedance can be configured according to the power supply voltage through the first impedance matching module, so that the power supply of the audio device can be realized, thereby driving various types of microphones. The isolation between digital signals and analog signals can be realized through the first isolation module, so that various types of microphones can be compatible. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 A schematic diagram of an audio interface circuit provided by an embodiment of the present application;

[0017] Figure 2 A schematic diagram of a first isolation module provided in an embodiment of the present application;

[0018] Figure 3 A circuit diagram of a unidirectional conductive unit provided in one embodiment of the present application;

[0019] Figure 4 A circuit diagram of another unidirectional conductive unit provided in one embodiment of the present application;

[0020] Figure 5 A circuit diagram of another unidirectional conductive unit provided in an embodiment of the present application;

[0021] Figure 6 A circuit diagram of a first impedance matching module provided in an embodiment of the present application;

[0022] Figure 7A schematic diagram of an analog signal decoding module and a second isolation module provided in an embodiment of the present application;

[0023] Figure 8 A schematic diagram of an electronic device provided in accordance with an embodiment of the present application. DETAILED DESCRIPTION

[0024] In order to make the technical problems, technical solutions and beneficial effects to be solved by the present application more clearly understood, the present application is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and are not used to limit the present application.

[0025] It should be noted that when an element is referred to as being "fixed to" or "disposed on" another element, it can be directly on the other element or indirectly on the other element. When an element is referred to as being "connected to" another element, it can be directly connected to the other element or indirectly connected to the other element.

[0026] It should be understood that the orientation or position relationship indicated by terms such as "length", "width", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside" and "outside" are based on the orientation or position relationship shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present application.

[0027] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the features. In the description of this application, the meaning of "plurality" is two or more, unless otherwise clearly and specifically defined.

[0028] Figure 1 A schematic diagram of an audio interface circuit provided by an embodiment of the present application is shown. For ease of description, only the part related to the present embodiment is shown, which is described in detail as follows:

[0029] The audio interface circuit 10 includes: an interface module 100 , a first impedance matching module 200 , a first isolation module 300 , a digital signal decoding module 400 and a plurality of power supply modules 500 .

[0030] The interface module 100 can be used to connect to an audio device. The first end of the first impedance matching module 200 is connected to the interface module 100. The first end of the first isolation module 300 is connected to the second end of the first impedance matching module 200. The digital signal decoding module 400 is connected to the second end of the first isolation module 300. The first isolation module 300 is used to unidirectionally transmit the digital signal received by the first end of the first isolation module 300 to the digital signal decoding module 400. Each power supply module 500 is connected to the third end of the first isolation module 300. Each power supply module 500 is used to output different power supply voltages respectively, the first isolation module 300 is used to control one of the power supply voltages to be transmitted to the interface module 100 through the first impedance matching module 200, and the first impedance matching module 200 is used to adjust its own impedance according to the power supply voltage. Among them, the digital signal decoding module 400 may include a microprocessor such as an integrated circuit or a chip.

[0031] Multiple power supply modules 500 can provide multiple power supply voltages, and the corresponding power supply voltage can be selected according to the power supply requirements of the audio device, and the first impedance matching module 200 can configure the corresponding impedance according to the power supply voltage to realize the power supply of the audio device, so that multiple types of microphones can be driven. The first isolation module 300 can realize the isolation between digital signals and analog signals, so that multiple types of microphones can be compatible.

[0032] In one embodiment, if Figure 2 As shown, the first isolation module 300 includes: a plurality of unidirectional conduction units 310 and an isolation transformer T1. The unidirectional conduction units 310 correspond to the power supply modules 500 one by one, the input end of the unidirectional conduction unit 310 is connected to the output end of the corresponding power supply module 500, the output end of the unidirectional conduction unit 310 is connected to the middle tap of the primary winding of the isolation transformer T1, the two ends of the primary winding of the isolation transformer T1 are connected to the second end of the first impedance matching module 200, and the two ends of the secondary winding of the isolation transformer T1 are connected to the digital signal decoding module 400.

[0033] It is understandable that since the power supply modules 500 output different power supply voltages, the power supply modules 500 can be prevented from influencing each other through the unidirectional conduction units 310. Usually, only one unidirectional conduction unit 310 in the first isolation module 300 is turned on at the same time to output one power supply voltage.

[0034] By connecting the output end of the unidirectional conduction unit 310 to the middle tap of the primary winding of the isolation transformer T1 and connecting the two ends of the primary winding of the isolation transformer T1 to the second end of the first impedance matching module 200, two voltages can be generated based on one power supply voltage and provided to the audio device through the interface module 100.

[0035] At the same time, the isolation transformer T1 can also achieve isolation between the power supply voltage and the digital signal decoding module 400 , thereby preventing the power supply voltage from affecting the operation of the digital signal decoding module 400 .

[0036] In some embodiments, the turns ratio between the primary winding and the secondary winding of the isolation transformer T1 is 1:1.

[0037] In one embodiment, the audio interface circuit 10 further includes a second impedance matching module 600 , and the at least one unidirectional conduction unit 310 includes: a photoelectric coupler K1 .

[0038] like Figure 3 As shown, taking a unidirectional conduction unit 310 as an example, the anode of the light-emitting device of the photoelectric coupler K1 is used to receive an enable signal, the cathode of the light-emitting device of the photoelectric coupler K1 is grounded, the first end of the optical receiver of the photoelectric coupler K1 is connected to the output end of the corresponding power supply module 500 through at least one of the second impedance matching modules 600, and the second end of the optical receiver of the photoelectric coupler K1 is connected to the middle tap of the primary winding of the isolation transformer T1.

[0039] It is understandable that, when the anode of the light-emitting device of the photocoupler K1 does not receive the enable signal, the photocoupler K1 can realize mutual isolation between the power supply modules 500. After the anode of the light-emitting device of the photocoupler K1 receives the enable signal, the first end of the optical receiver of the photocoupler K1 and the second end of the optical receiver of the photocoupler K1 can be controlled to be turned on. When the power supply module 500 outputs an analog voltage, the unidirectional conduction unit 310 at the output end of the power supply module 500 can use the photocoupler K1.

[0040] The second impedance matching module 600 is used to coordinate the on-impedance between the power supply module 500 and the interface module 100 configured by the first impedance matching module 200 when the power supply module 500 outputs an analog voltage. It is understandable that the second impedance matching module 600 can be configured separately according to the power supply voltage of the power supply module 500, and when the power supply voltages of the power supply modules 500 are different, the on-impedances of the second impedance matching modules 600 are also different.

[0041] Specifically, Figure 3 In the illustrated embodiment, the second impedance matching module 600 includes a fifth resistor R5, a first end of the fifth resistor R5 is connected to the output end of the corresponding power supply module 500, and a second end of the fifth resistor R5 is connected to the first end of the optical receiver of the corresponding photocoupler K1.

[0042] In one embodiment, the at least one unidirectional conduction unit 310 includes: a relay K2.

[0043] like Figure 4 As shown, taking a unidirectional conduction unit 310 as an example, the first end of the coil of the relay K2 is used to receive an enable signal, the second end of the coil of the relay K2 is grounded, the first end of the contact of the relay K2 is connected to the output end of the corresponding power supply module 500 through at least one of the second impedance matching modules 600, and the second end of the contact of the relay K2 is connected to the middle tap of the primary winding of the isolation transformer T1.

[0044] It is understandable that, when the coil of the relay K2 does not receive the enable signal, the relay K2 can realize mutual isolation between the power supply modules 500. After the coil of the relay K2 receives the enable signal, the first end of the contact of the relay K2 can be controlled to be connected with the second end of the contact of the relay K2. When the power supply module 500 outputs an analog voltage, the unidirectional conduction unit 310 at the output end of the power supply module 500 can use the relay K2.

[0045] Specifically, Figure 4 In the illustrated embodiment, the second impedance matching module 600 includes a sixth resistor R6, a first end of the sixth resistor R6 is connected to the output end of the corresponding power supply module 500, and a second end of the sixth resistor R6 is connected to the first end of the contact of the corresponding relay K2.

[0046] In one embodiment, the at least one unidirectional conductive unit 310 includes: a unidirectional conductive device D1.

[0047] like Figure 5 As shown, taking a unidirectional conducting unit 310 as an example, the anode of the unidirectional conducting device D1 is connected to the output end of the corresponding power supply module 500, and the cathode of the unidirectional conducting device D1 is connected to the middle tap of the primary winding of the isolation transformer T1.

[0048] Specifically, the unidirectional conductor D1 may include a diode. When the power supply module 500 outputs a digital voltage, the unidirectional conductor unit 310 at the output end of the power supply module 500 may use the unidirectional conductor D1.

[0049] In one embodiment, the power supply module 500 includes a voltage regulating unit, which is used to generate and output a supply voltage based on an input voltage, and the supply voltage includes an analog voltage and a digital voltage, for example, an analog 48V voltage, a digital 10V voltage, and an analog 5V voltage. The input voltage may be a voltage provided by a battery or an interface.

[0050] In some embodiments, the control terminal of the power supply module 500 may also be connected to a corresponding enable signal so as to output the power supply voltage after receiving the enable signal. Figure 5As shown, when the unidirectional conduction unit 310 corresponding to the power supply module 500 only includes the unidirectional conduction device D1, in order to control the output of the power supply module 500, the power supply module 500 can be connected to the enable signal EN3 to output the supply voltage when the enable signal EN3 is received, and stop outputting the supply voltage when the enable signal EN3 is not received.

[0051] In some embodiments, the audio interface circuit 10 includes three power supply modules 500 (i.e., a first power supply module, a second power supply module, and a third power supply module), and the first power supply module, the second power supply module, and the third power supply module respectively output different power supply voltages, so that the interface module 100 can respectively output a digital 10V voltage, an analog 48V voltage, and an analog 5V voltage. The digital 10V voltage, the analog 48V voltage, and the analog 5V voltage can meet the working conditions of most audio devices.

[0052] Specifically, the first power supply module may include a first DC / DC voltage regulating unit, the first DC / DC voltage regulating unit outputs a power supply voltage for generating a digital 10V voltage, the output end of the first DC / DC voltage regulating unit may be directly connected to the unidirectional conduction unit 310, wherein the unidirectional conduction unit 310 includes a unidirectional conduction device, and the first DC / DC voltage regulating unit may receive a first enable control signal, and the first enable control signal is used to control the first DC / DC voltage regulating unit to output or stop outputting the power supply voltage. The second power supply module may include a second DC / DC voltage regulating unit, the second DC / DC voltage regulating unit outputs a power supply voltage for generating an analog 48V voltage, and the output end of the second DC / DC voltage regulating unit may output the power supply voltage through the second impedance matching module 600 and the unidirectional conduction unit 310, wherein the unidirectional conduction unit 310 includes a photocoupler, and the photocoupler may control the output or stop outputting the power supply voltage according to the second enable signal. The third power supply module may include an LDO voltage regulating unit, which outputs a supply voltage for generating an analog 5V voltage. The output end of the LDO voltage regulating unit can output the supply voltage through the second impedance matching module 600 and the unidirectional conduction unit 310, through the unidirectional conduction unit 310, wherein the unidirectional conduction unit 310 includes a photocoupler, and the photocoupler can control the output or stop outputting the supply voltage according to the third enable signal.

[0053] It should be noted that, by controlling the enable signal provided to the unidirectional conduction unit 310 corresponding to each power supply module 500, or controlling the enable signal provided to the voltage regulating unit, it is possible to make one power supply module 500 supply power to the interface module 100 at the same time, thereby avoiding mutual influence of the power supply modules 500. For example, at the same time, only one of the first enable control signal, the second enable control signal, and the third enable control signal may be provided, so that the interface module 100 outputs one of the digital 10V voltage, the analog 48V voltage, and the analog 5V voltage.

[0054] In one embodiment, if Figure 6 As shown, the first impedance matching module 200 includes a first resistor R1, a second resistor R2, a third resistor R3, a fourth resistor R4, a first switch device Q1, and a second switch device Q2. The first end of the first switch device Q1 is connected to the first end of the primary winding of the isolation transformer T1, the second end of the first switch device Q1 is connected to the first end IN+ of the interface module 100, the first end of the first switch device Q1 is connected to the control end of the first switch device Q1 through the first resistor R1, the first end of the first switch device Q1 is connected to the second end of the first switch device Q1 through the second resistor R2, and the control end of the first switch device Q1 is used to receive the first control signal. The first end of the second switch device Q2 is connected to the second end of the primary winding of the isolation transformer T1, the second end of the second switch device Q2 is connected to the second end IN- of the interface module 100, the first end of the second switch device Q2 is connected to the control end of the second switch device Q2 through the third resistor R3, the first end of the second switch device Q2 is connected to the second end of the second switch device Q2 through the fourth resistor R4, and the control end of the second switch device Q2 is used to receive the second control signal.

[0055] It should be noted that when the power supply voltage is an analog 48V voltage or an analog 5V voltage, the second resistor R2 and the fourth resistor R4 need to be connected to adjust the impedance between the power supply module 500 and the interface module 100. When the power supply voltage is a digital 10V voltage, the second resistor R2 and the fourth resistor R4 are not required to adjust the impedance, and the first switch device Q1 and the second switch device Q2 can be controlled to be turned on at the same time, and the second resistor R2 and the fourth resistor R4 are bypassed respectively.

[0056] It can be understood that the first control signal and the second control signal can be the same signal, and the first control signal and the second control signal can be provided by corresponding control devices.

[0057] In some embodiments, Figure 6As shown, the first impedance matching module 200 also includes a third switch device Q3, a first end of the third switch device Q3 is connected to the control end of the first switch device Q1 and the control end of the second switch device Q2, a second end of the third switch device Q3 is grounded, and the control end of the third switch device Q3 is used to receive a third control signal L_EN. When the third switch device Q3 is turned on, the first switch device Q1 and the second switch device Q2 are both turned off.

[0058] It should be noted that the third switching device Q3 is used to control the on and off of the first switching device Q1 and the second switching device Q2 according to the third control signal L_EN.

[0059] In some embodiments, Figure 6 As shown, the first impedance matching module 200 further includes a first capacitor C1 and a second capacitor C2. The first end of the first switch device Q1 is grounded through the first capacitor C1, and the first end of the second switch device Q2 is grounded through the second capacitor C2.

[0060] In some embodiments, the first switch device Q1, the second switch device Q2, and the third switch device Q3 can all be N+P type MOS tubes. It should be noted that the N+P type MOS tube has both an N channel and a P channel, and is provided with two base pins corresponding to the two channels. Which channel is used specifically can be selected to connect to a suitable base pin according to actual needs. It is understandable that the first switch device Q1, the second switch device Q2, and the third switch device Q3 can also select other types of switch devices according to actual needs, and this embodiment will not be repeated.

[0061] In some embodiments, the first switch device Q1 and the second switch device Q2 are both low-level conduction devices, and the third switch device Q3 is a high-level conduction device. When the control terminal of the third switch device Q3 receives the third control signal L_EN, the voltage of the control terminal of the third switch device Q3 is pulled up, so that the third switch device Q3 is turned on. When the third switch device Q3 is turned on, the control terminal of the first switch device Q1 and the control terminal of the second switch device Q2 are both grounded, and the first switch device Q1 and the second switch device Q2 are turned on, so that the second resistor R2 and the fourth resistor R4 are bypassed respectively.

[0062] In some embodiments, the power supply module 500 for outputting a digital voltage is configured to output the digital voltage when receiving an enable signal EN3, and stop outputting the digital voltage when not receiving the enable signal EN3. The enable signal EN3 and the third control signal L_EN can be the same signal or two signals output synchronously, so as to achieve synchronous control of the impedance switching of the first impedance matching module 200 and the output of the power supply module 500 for outputting a digital voltage, that is, when the power supply module 500 starts to output a digital voltage, the first switch device Q1, the second switch device Q2 and the third switch device Q3 are controlled to be turned on, and the impedance of the first impedance matching module 200 is changed.

[0063] In one embodiment, if Figure 7 As shown, the interface module 100 includes an interface unit J1 and two filter units 110. Two pins of the interface unit J1 are connected to the first impedance matching module 200 through the two filter units 110 respectively.

[0064] The filter unit 110 can filter the signal input by the interface unit J1 as required to reduce interference with signal decoding.

[0065] In one embodiment, if Figure 7 As shown, the audio interface circuit 10 further includes an analog signal decoding module 700 and a second isolation module 800. The analog signal decoding module 700 is connected to the interface module 100 through the second isolation module 800, and the analog signal decoding module 700 is used to obtain the analog signal through the second isolation module 800 and decode the analog signal. The analog signal decoding module 700 may include a microprocessor such as an integrated circuit, a chip, etc.

[0066] Specifically, the second isolation module 800 may include a third capacitor C3 and a fourth capacitor C4. The first end of the third capacitor C3 and the first end of the fourth capacitor C4 are respectively connected to the two filter units 110, specifically, the first end of the third capacitor C3 can be connected to the first end IN+ of the interface module 100, the first end of the fourth capacitor C4 can be connected to the second end IN- of the interface module 100, and the second end of the third capacitor C3 and the second end of the fourth capacitor C4 are connected to the analog signal decoding module 700.

[0067] The analog signal decoding module 700 can decode the received analog signal.

[0068] Figure 8 A schematic diagram of an electronic device provided by an embodiment of the present application is shown. For ease of description, only the parts related to the present embodiment are shown, which are described in detail as follows:

[0069] The electronic device 20 includes the audio interface circuit 10 according to any one of the above embodiments.

[0070] The electronic device 20 may specifically be a terminal device such as a computer, a tablet, or a video recorder.

[0071] The technicians in the relevant field can clearly understand that for the convenience and simplicity of description, only the division of the above-mentioned functional units and modules is used as an example for illustration. In practical applications, the above-mentioned function allocation can be completed by different functional units and modules as needed, that is, the internal structure of the device can be divided into different functional units or modules to complete all or part of the functions described above. The functional units and modules in the embodiment can be integrated in a processing unit, or each unit can exist physically separately, or two or more units can be integrated in one unit. The above-mentioned integrated unit can be implemented in the form of hardware or in the form of software functional units. In addition, the specific names of the functional units and modules are only for the convenience of distinguishing each other, and are not used to limit the scope of protection of this application. The specific working process of the units and modules in the above-mentioned system can refer to the corresponding process in the aforementioned method embodiment, which will not be repeated here.

[0072] In the above embodiments, the description of each embodiment has its own emphasis. For parts that are not described or recorded in detail in a certain embodiment, reference can be made to the relevant descriptions of other embodiments.

[0073] The embodiments described above are only used to illustrate the technical solutions of the present application, rather than to limit them. Although the present application has been described in detail with reference to the aforementioned embodiments, a person skilled in the art should understand that the technical solutions described in the aforementioned embodiments may still be modified, or some of the technical features may be replaced by equivalents. Such modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present application, and should all be included in the protection scope of the present application.

Claims

1. An audio interface circuit, characterized in that: include: An interface module (100), the interface module (100) being used to connect to an audio device; A first impedance matching module (200), wherein a first end of the first impedance matching module (200) is connected to the interface module (100); A first isolation module (300), wherein a first end of the first isolation module (300) is connected to a second end of the first impedance matching module (200); a digital signal decoding module (400), the digital signal decoding module (400) being connected to the second end of the first isolation module (300); the first isolation module (300) being used for unidirectionally transmitting the digital signal received by the first end of the first isolation module (300) to the digital signal decoding module (400); A plurality of power supply modules (500), each of the power supply modules (500) being connected to a third end of the first isolation module (300); each of the power supply modules (500) being used to output different power supply voltages respectively, the first isolation module (300) being used to control one of the power supply voltages to be transmitted to the interface module (100) through the first impedance matching module (200), and the first impedance matching module (200) being used to adjust its own impedance according to the power supply voltage.

2. The audio interface circuit according to claim 1, characterized in that: The first isolation module (300) comprises: a plurality of unidirectional conduction units (310) and an isolation transformer T1; The one-way conducting unit (310) corresponds to the power supply module (500) in one-to-one correspondence; the input end of the one-way conducting unit (310) is connected to the output end of the corresponding power supply module (500); the output end of the one-way conducting unit (310) is connected to the middle tap of the primary winding of the isolation transformer T1; the two ends of the primary winding of the isolation transformer T1 are connected to the second end of the first impedance matching module (200); and the two ends of the secondary winding of the isolation transformer T1 are connected to the digital signal decoding module (400).

3. The audio interface circuit according to claim 2, characterized in that: The audio interface circuit further comprises a second impedance matching module (600), and at least one of the one-way conducting units (310) comprises: a photoelectric coupler K1; The anode of the light-emitting device of the photoelectric coupler K1 is used to receive an enable signal, the cathode of the light-emitting device of the photoelectric coupler K1 is grounded, the first end of the optical receiver of the photoelectric coupler K1 is connected to the output end of the corresponding power supply module (500) through at least one of the second impedance matching modules (600), and the second end of the optical receiver of the photoelectric coupler K1 is connected to the middle tap of the primary winding of the isolation transformer T1.

4. The audio interface circuit according to claim 2, characterized in that: The audio interface circuit further comprises a second impedance matching module (600), and at least one of the one-way conducting units (310) comprises: a relay K2; The first end of the coil of the relay K2 is used to receive an enable signal, the second end of the coil of the relay K2 is grounded, the first end of the contact of the relay K2 is connected to the output end of the corresponding power supply module (500) through at least one of the second impedance matching modules (600), and the second end of the contact of the relay K2 is connected to the middle tap of the primary winding of the isolation transformer T1.

5. The audio interface circuit according to claim 2, characterized in that: At least one of the one-way conducting units (310) comprises: a one-way conducting device D1; The anode of the one-way conductor D1 is connected to the output end of the corresponding power supply module (500), and the cathode of the one-way conductor D1 is connected to the middle tap of the primary winding of the isolation transformer T1.

6. The audio interface circuit according to any one of claims 1 to 5, characterized in that: The power supply module (500) comprises a voltage regulating unit, and the voltage regulating unit is used to generate and output the power supply voltage based on an input voltage; The supply voltage includes an analog voltage and a digital voltage.

7. The audio interface circuit according to any one of claims 2 to 5, characterized in that: The first impedance matching module (200) comprises a second resistor R2, a fourth resistor R4, a first switch device Q1 and a second switch device Q2; The first end of the first switch device Q1 is connected to the first end of the primary winding of the isolation transformer T1, the second end of the first switch device Q1 is connected to the first end of the interface module (100), the first end of the first switch device Q1 is connected to the second end of the first switch device Q1 via the second resistor R2, and the control end of the first switch device Q1 is used to receive a first control signal; The first end of the second switch device Q2 is connected to the second end of the primary winding of the isolation transformer T1, the second end of the second switch device Q2 is connected to the second end of the interface module (100), the first end of the second switch device Q2 is connected to the second end of the second switch device Q2 via the fourth resistor R4, and the control end of the second switch device Q2 is used to receive a second control signal.

8. The audio interface circuit according to claim 7, characterized in that: The first impedance matching module (200) further comprises a third switch device Q3, a first end of the third switch device Q3 being respectively connected to the control end of the first switch device Q1 and the control end of the second switch device Q2, a second end of the third switch device Q3 being grounded, and a control end of the third switch device Q3 being used to receive a third control signal.

9. The audio interface circuit according to any one of claims 1 to 5, characterized in that: The interface module (100) comprises an interface unit J1 and two filter units (110); The two pins of the interface unit J1 are respectively connected to the first impedance matching module (200) through the two filter units (110).

10. The audio interface circuit according to any one of claims 1 to 5, characterized in that: It also includes an analog signal decoding module (700) and a second isolation module (800); The analog signal decoding module (700) is connected to the interface module (100) via the second isolation module (800), and the analog signal decoding module (700) is used to acquire an analog signal via the second isolation module (800) and decode the analog signal.

11. An electronic device, characterized in that: The method comprises the audio interface circuit (10) as claimed in any one of claims 1 to 10.

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