Dual-purpose XLR and USB circuit

Abstract

The utility model relates to microphone technical field discloses a kind of XLR and USB dual-purpose circuit, the circuit includes: input module, including the input unit of connection external audio signal;XLR module, including common mode inductance L1 and with the XLR interface of common mode inductance L1 output end connection;USB module, including codec, USB interface and amplifier U1, the amplifier U1 connects the codec, the codec is used for digital-analog conversion and connects the USB interface, the amplifier U1 is equipped with the power supply end connected with external power supply;Wherein, the output end of the input module is connected to the input end of the amplifier U1 and the input end of common mode inductance L1 respectively.This application realizes XLR and USB dual-purpose function, by shunt output to XLR interface and USB interface with input unit, XLR and USB dual-purpose function can be realized.

Description

Technical Field

[0001] This utility model belongs to the field of microphone technology, specifically relating to an XLR and USB dual-purpose circuit. Background Technology

[0002] In the field of audio equipment, XLR audio interfaces and USB interfaces are two common and important audio signal transmission interfaces, each playing a key role in different scenarios. XLR interfaces have balanced transmission characteristics, enabling high-quality long-distance audio signal transmission; USB interfaces, on the other hand, have advantages such as plug-and-play functionality and integrated data transmission and power supply. Currently, existing audio devices with XLR or USB interfaces typically only perform a single function when in normal working order: transmitting audio signals either via the XLR interface or the USB interface. This limitation restricts audio transmission to a single interface. This single-function limitation forces users to replace devices or make complex hardware adjustments to meet different application needs, reducing usability and limiting the application range of audio devices, making it difficult to meet users' demands for flexible and efficient audio equipment. Utility Model Content

[0003] This application provides a dual-purpose XLR and USB circuit, which can realize the dual-purpose XLR and USB functions by splitting the input unit output to the XLR interface and the USB interface.

[0004] This application discloses a dual-purpose XLR and USB circuit, the circuit comprising: The input module includes an input unit for connecting external audio signals; The XLR module includes a common-mode inductor L1 and an XLR interface connected to the output terminal of the common-mode inductor L1. The USB module includes a codec, a USB interface, and an amplifier U1. The amplifier U1 is connected to the codec. The codec is used for digital-to-analog conversion and is connected to the USB interface. The amplifier U1 is provided with a power supply terminal for connection to an external power source. The output terminal of the input module is connected to the input terminal of the amplifier U1 and the input terminal of the common-mode inductor L1, respectively.

[0005] In one embodiment, the input module further includes a controller U2 and an analog switch U3. The input unit is connected to the output terminal of the input module through the analog switch U3, and the controller U2 is used to control the on / off switching of the analog switch U3.

[0006] In one embodiment, the controller U2 includes a KEY terminal and a MIC_MUTE terminal. The KEY terminal is used to receive external trigger signals, and the controller U2 is connected to and controls the analog switch U3 through the MIC_MUTE terminal.

[0007] In one embodiment, the system further includes a filtering module, a first switch SW1, and a second switch SW2. The filtering module is connected in parallel with the input unit. The first switch SW1 controls the filtering module to switch to a high-pass filtering mode to attenuate the low-frequency signal output by the input unit. The second switch SW2 controls the filtering module to switch to a low-pass filtering mode to attenuate the high-frequency signal output by the input unit.

[0008] In one embodiment, the filtering module includes a transformer T1, a resistor R1, a resistor R2, and a capacitor C1. One end of the resistor R1 is connected to the MIC- terminal of the input unit, pin 2 of the second switch SW2, and pin 1 of the first switch SW1. The other end of the resistor R1 is connected to one end of the resistor R2 and pin 1 of the second switch SW2. The other end of the resistor R2 is connected to one end of the capacitor C1. Therefore, the other end of the capacitor C1 is connected to one end of the transformer T1 and the MIC+ terminal of the input unit. The other end of the transformer T1 is connected to pin 2 of the first switch SW1. Specifically, the first switch SW1 can be used to connect its pins 1 and 2, switching the filtering module to high-pass filtering mode; the second switch SW2 can be used to connect its pins 1 and 2, switching the filtering module to low-pass filtering mode.

[0009] In one embodiment, a voltage regulator and filter circuit is also included, which includes multiple grounding capacitors, all of which are connected between the external power supply and the power supply terminal of the amplifier U1.

[0010] In one embodiment, the voltage regulation and filtering circuit further includes resistors R3, R4, R5, and capacitor C2. One end of resistor R3 is connected to the positive input terminal of amplifier U1 and one end of capacitor C2. The other end of resistor R3 is connected to the other end of capacitor C2, one end of resistor R4, and one end of resistor R5. The other end of resistor R4 is connected between the external power supply and the power supply terminal of amplifier U1. The other end of resistor R5 is grounded.

[0011] In one embodiment, the USB module further includes a resistor R6 and a capacitor C3, one end of the resistor R6 being connected to the negative input terminal of the amplifier U1, and the other end of the resistor R6 being connected to the output terminal of the amplifier U1.

[0012] In some embodiments, the input module further includes capacitors C4 and C5, which are used to connect to the MIC+ and MIC- terminals of the input unit, respectively.

[0013] In some embodiments, the XLR module further includes a test point, wherein the XLR_OUT+, XLR_OUT-, and GND terminals of the test point are respectively connected to the positive terminal, negative terminal, and ground terminal of the XLR interface.

[0014] As can be seen from the above, the XLR / USB dual-purpose circuit in this application splits the output signal of the input module into two paths. One path sends the signal to the XLR module, which transmits it to the XLR interface through the common-mode inductor L1 for use by external audio devices. The other path sends the signal to the USB module, which transmits it to the codec for analog-to-digital conversion through the amplifier U1, converting it into a USB signal for transmission to the USB interface. This allows the circuit to meet the audio signal transmission needs of different scenarios without the need for additional adapters, improving the circuit's versatility and ease of use. An external power supply provides independent power control to the amplifier U1. When not powered on, the input module's signal is transmitted to the XLR module; when powered on, the input module's signal is transmitted to both the XLR and USB modules. This ensures both the balanced signal transmission advantage of the XLR interface and the digital transmission function of the USB interface, achieving a dual-purpose XLR and USB effect. Attached Figure Description

[0015] Figure 1 This is a schematic diagram of the principle structure of the XLR and USB dual-purpose circuit provided in the embodiments of this application.

[0016] Figure 2 This is a schematic diagram of the framework structure of the XLR and USB dual-purpose circuit provided in the embodiments of this application.

[0017] Figure 3 This is a schematic diagram of the structure of the input module provided in an embodiment of this application.

[0018] Figure 4 This is a schematic diagram of the structure of the XLR module provided in an embodiment of this application.

[0019] Figure 5 This is a schematic diagram of the structure of a USB module provided in an embodiment of this application.

[0020] Figure 6 This is a schematic diagram of the structure of the filtering module provided in an embodiment of this application.

[0021] Figure 7 This is a schematic diagram of the voltage stabilizing filter circuit provided in an embodiment of this application.

[0022] Figure 8This is a schematic diagram of the structure of the XLR and USB dual-purpose circuit provided in the embodiments of this application. Detailed Implementation

[0023] The preferred embodiments of this application will now be described in detail with reference to the accompanying drawings, so that the advantages and features of this application can be more easily understood by those skilled in the art, thereby providing a clearer definition of the scope of protection of this application.

[0024] Please refer to the diagrams, where the same component symbols represent the same components. The principles of this application are illustrated by way of example implementation in a suitable computing environment. The following description is based on the specific embodiments of this application exemplified, and should not be construed as limiting other specific embodiments not detailed herein.

[0025] Please see Figure 1 The figure shows the principle structure of the XLR and USB dual-purpose circuit provided in the embodiment of this application.

[0026] like Figure 1 As shown, the XLR and USB dual-use circuit includes an input module 1, an XLR module 2, and a USB module 3.

[0027] Input module 1 includes an input unit 11, which receives audio signals from an external microphone. These audio signals are output through two channels: one to XLR module 2 and the other to USB module 3. XLR module 2 includes a common-mode inductor L1 and an XLR interface 21. The audio signal is transmitted through the common-mode inductor L1 to the XLR interface 21, which is used to connect to external devices. The common-mode inductor L1 presents high impedance to common-mode current, making it difficult for common-mode noise current to pass through, thus significantly attenuating or suppressing it. For differential-mode signals like audio signals, the common-mode inductor presents low impedance, allowing differential-mode signals to pass smoothly, thereby suppressing common-mode noise and reducing its impact on audio quality. USB module 3 includes an amplifier U1, a codec 32, and a USB interface 31. The amplifier U1 receives the audio signal from input module 1 and outputs it to the codec 32. The codec 32 performs analog-to-digital conversion on the audio signal, converting it into a USB signal for transmission to USB interface 31.

[0028] The amplifier U1 has an independent power supply, which controls the switching on and off of the USB module 3 via an external power source. When not powered, the USB module 3 is off, and the signal is output only from the XLR module 2. When powered on, the circuit functions as both USB and XLR modules. Users can flexibly choose to use the XLR interface 21 or both the XLR interface 21 and the USB interface 31 simultaneously, depending on the actual usage scenario. The independent power supply of amplifier U1 ensures stable operation of both modules in dual-use mode, and reduces the overall power consumption of the circuit when only the XLR module 2 is operating.

[0029] Understandably, the USB module 3 and XLR module 2 are connected via the output of the input module 1. Specifically, the output of the input module 1 is connected to the input of amplifier U1 and the input of common-mode inductor L1, allowing audio signals to enter the USB module 3 through amplifier U1 and the XLR module 2 through common-mode inductor L1. This common-mode inductor L1 prevents interference between different circuits, improves circuit safety, avoids problems caused by potential differences between preceding and following stages, and converts unbalanced signals into balanced signals to meet the signal transmission requirements of the XLR interface.

[0030] In addition, such as Figure 2 As shown, the input module 1 also includes an analog switch U3 and a controller U2. The audio signal output by the input unit 11 is transmitted to the USB module and the XLR module through the analog switch U3. The analog switch U3 is used to control the output of the audio signal of the input module 1. The controller U2 controls the analog switch U3 to realize the on / off control of the circuit in the input module 1, so that the XLR and USB dual-use circuit has a one-key mute function. The mute / non-mute function of XLR / USB is switched by opening or closing the analog switch U3.

[0031] Please see Figure 3 , Figure 3 The structure of the input module provided in an embodiment of this application is shown.

[0032] like Figure 3 As shown, the controller U2 is powered by an independent power supply system. An external power supply is connected to the power supply terminal through a current-limiting resistor. This power supply terminal is also connected to a grounding capacitor, which serves to filter and decouple the power supply. The controller U2 includes a KEY terminal and a MIC_MUTE terminal. The KEY terminal is connected to an external trigger button to provide a trigger signal to the controller U2. The controller U2 is connected to the analog switch U3 through the MIC_MUTE terminal. The analog switch U3 responds by opening or closing according to the level change of the MIC_MUTE terminal, thereby realizing the mute function of the dual-purpose circuit.

[0033] Input unit 11 includes a MIC+ terminal and a MIC- terminal for transmitting audio signals. Input module 1 also includes capacitors C4 and C5, which are respectively connected between the two signal lines, i.e., between the MIC+ terminal and the MIC- terminal of input unit 11. They exhibit low impedance characteristics to common-mode noise, effectively absorbing and filtering out common-mode interference, and reducing the impact of noise on differential signals. Capacitors C4 and C5 can be, but are not limited to, being located at the output terminal of analog switch U3.

[0034] like Figure 4 As shown, Figure 4 The structure of the XLR module provided in this embodiment is shown. The signal lines are connected to the negative and positive terminals of the XLR interface 21, respectively. Multiple grounding resistors and multiple grounding capacitors are connected to the input terminal of the common-mode inductor L1. A capacitor, resistor, and inductor are connected in series at the input terminal. Grounding diodes Z1 and Z2 are connected to the two signal lines, respectively. The diodes clamp excessive voltage within a safe range to prevent damage to subsequent circuits due to overvoltage. The synergistic effect of these components enables the audio signal input to the XLR interface 21 to achieve functions such as filtering, protection, isolation, and balanced transmission.

[0035] The XLR module 2 also includes test points, with the XLR_OUT+, XLR_OUT- and GND terminals of the test points connected to the positive, negative and ground terminals of the XLR interface 21, respectively, to facilitate rapid diagnostic testing of the circuit.

[0036] like Figure 5 As shown, Figure 5 The structure of the USB module provided in this embodiment is shown. The USB module 3 also includes a resistor R6 and a capacitor C3. One end of the resistor R6 is connected to the output terminal of the amplifier U1, and the other end is connected to the negative input terminal of the amplifier U1. The capacitor C3 is connected in parallel with the resistor R6. The capacitor C3 can suppress high-frequency noise and unwanted high-frequency components in the output signal of the amplifier U1. The combination of the capacitor C3 and the resistor R6 can adjust the frequency response characteristics of the amplifier U1, making the gain of the amplifier U1 more balanced at different frequencies. The output terminal of the amplifier U1 transmits the processed audio signal to the MIC terminal of the codec 32 through the series resistor and capacitor, and then the codec 32 transmits it to the USB interface 31.

[0037] Furthermore, a resistor R7 is connected in series at the positive input terminal of amplifier U1, and a resistor R8 is connected in series at the negative input terminal. Resistors R7 and R8 can adjust the input impedance of the amplifier to match the output impedance of the preceding circuit, thereby reducing signal reflection and loss during transmission and ensuring that the signal input to the amplifier is complete and undistorted. Additionally, they can be used in conjunction with resistor R6 and capacitor C3 to determine the voltage gain of amplifier U1.

[0038] like Figure 6 As shown, Figure 6 The structure of the filtering module provided in the embodiment of this application is shown. In the XLR and USB dual-use circuit, it also includes a filtering module 4, a first switch SW1 and a second switch SW2. The filtering module 4 is connected in parallel with the input unit 11. The first switch SW1 is used to control the filtering module 4 to switch to high-pass filtering mode, and the second switch SW2 is used to control the filtering module 4 to switch to low-pass filtering mode.

[0039] The filtering module 4 includes a transformer T1, resistors R1 and R2, and a capacitor C1. The input unit 11 includes a MIC+ terminal and a MIC- terminal. One end of the transformer T1 is connected between the analog switch U3 and the MIC- terminal of the input unit 11, and is also connected to one end of the capacitor C1. The other end of the transformer T1 is connected to pin 2 of the first switch SW1. The other end of the capacitor C1 is connected in series with the resistor R2. The other end of the resistor R2 is connected to pin 1 of the second switch SW2 and one end of the resistor R1. The other end of the resistor R1 is connected between pin 1 of the first switch SW1, pin 2 of the second switch SW2, the analog switch U3, and the MIC+ terminal of the input unit 11.

[0040] It is worth noting that both the first switch SW1 and the second switch SW2 have three pins. The switches have a first state and a second state, and switching between the two states enables communication between two of the pins. Specifically, in the first state, pins 1 and 2 of the first switch SW1 and the second switch SW2 are connected, while pin 3 is left unconnected. When switching from the first state to the second state, pins 2 and 3 are connected, while pin 1 is left unconnected, meaning pins 1 and 2 are disconnected.

[0041] When the first switch SW1 is switched to the first state and the second switch SW2 is switched to the second state, the filtering module 4 switches to high-pass filtering mode. A high-pass filter network, consisting of transformer T1, resistors R1, R2, and C1, suppresses low-frequency signals while allowing high-frequency signals to pass, thus achieving high-pass filtering of the audio signal. When the second switch SW2 is switched to the first state and the first switch SW1 is switched to the second state, the filtering module 4 switches to low-pass filtering mode. A low-pass filter network, consisting of resistors R1, R2, and C1, suppresses high-frequency signals while allowing low-frequency signals to pass, thus achieving low-pass filtering of the audio signal. It is worth noting that resistor R1 is used to eliminate the popping sound from the audio device when the second switch SW2 is switched, i.e., the popping sound caused by the transient impact of the switch. The second switch SW2 is in a low-pass state when connected and can be considered as high-frequency boosting when disconnected.

[0042] like Figure 7 As shown, Figure 7 The structure of the voltage regulator and filter circuit provided in the embodiment of this application is shown. The voltage regulator and filter circuit 5 is connected to the power supply terminal of the amplifier U1. The voltage regulator and filter circuit 5 includes at least two grounding capacitors, so that high-frequency noise signals in the power supply will bypass to ground through these capacitors instead of entering the amplifier U1, thereby effectively suppressing high-frequency interference introduced by the power supply.

[0043] Furthermore, the voltage regulator and filter circuit 5 also includes resistors R3, R4, R5, and capacitor C2. Resistors R3 and R4 are connected in series to connect the power supply terminal of amplifier U1 and the positive input terminal of amplifier U1. Capacitor C2 is connected in parallel with resistor R3. Resistor R5 is a grounding resistor connected between resistors R3 and R4. Resistor R5 and resistor R3 form a voltage divider network to provide a reference bias voltage. The resistance value of resistor R4 can suppress the influence of the amplifier's input impedance change on the voltage divider network.

[0044] In addition, combined Figure 8 As shown, resistors R7 and R8 are connected in series at the positive and negative input terminals of amplifier U1, respectively. The gain of amplifier U1 can be controlled by adjusting the values ​​of resistors R3, R6, R7, and R8. Capacitor C2 can filter out high-frequency noise in the bias voltage of the non-inverting input terminal of amplifier U1, preventing high-frequency noise from entering amplifier U1 and being amplified. When transient changes occur in the circuit, capacitor C2 can maintain the stability of the bias voltage through charging and discharging.

[0045] like Figure 8 As shown, Figure 8 The structure of the XLR and USB dual-purpose circuit provided in the embodiments of this application is shown.

[0046] The audio signal enters the circuit through input unit 11 of input block 1. Based on the signal optimization requirements of different audio scenarios, the first switch SW1 and the second switch SW2 are adjusted to their first and second states, respectively, enabling switching between high-pass and low-pass filtering of the audio signal. The audio signal then enters analog switch U3, which is in the on state, allowing the audio signal to be transmitted to XLR module 2 and USB module 3. Through the same node branch, the signal is transmitted to XLR module 2 and USB module 3, achieving parallel signal processing and output control. Controller U2 controls analog switch U3, switching it to the off state to achieve a mute function. The amplifier U1 of USB module 3 is powered by an independent power supply. Disabling this independent power supply shuts down USB module 3, allowing the audio signal to be transmitted only to XLR module 2. By controlling the on / off state of the independent external power supply to amplifier U1, USB module 3 is switched on or off, thus achieving mode switching between XLR function and dual-use USB and XLR function.

[0047] As used herein, the term "module" can refer to a software or hardware object that executes on the computing system. Different components, modules, engines, and services described herein can be implementations on the computing system. The apparatus and methods described herein can be implemented in software or hardware, both of which are within the scope of this application.

[0048] In this document, the term "embodiment" means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this application. The appearance of this phrase in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment mutually exclusive with other embodiments. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.

[0049] In the description of this application, it should be noted that, unless otherwise expressly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection, an electrical connection, or a connection that allows communication between them; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication between two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0050] The embodiments of this application have been described in detail above with reference to the accompanying drawings. However, this application is not limited to the above embodiments. Within the scope of knowledge possessed by those skilled in the art, various changes can be made without departing from the spirit of this application.

Claims

1. A dual-purpose XLR and USB circuit, characterized in that, The circuit includes: The input module includes an input unit for connecting external audio signals; The XLR module includes a common-mode inductor L1 and an XLR interface connected to the output terminal of the common-mode inductor L1. The USB module includes a codec, a USB interface, and an amplifier U1. The amplifier U1 is connected to the codec. The codec is used for digital-to-analog conversion and is connected to the USB interface. The amplifier U1 is provided with a power supply terminal for connection to an external power source. The output terminal of the input module is connected to the input terminal of the amplifier U1 and the input terminal of the common-mode inductor L1, respectively.

2. The XLR and USB dual-purpose circuit as described in claim 1, characterized in that, The input module also includes a controller U2 and an analog switch U3. The input unit is connected to the output terminal of the input module through the analog switch U3. The controller U2 is used to control the on / off switching of the analog switch U3.

3. The XLR and USB dual-purpose circuit as described in claim 2, characterized in that, The controller U2 includes a KEY terminal and a MIC_MUTE terminal. The KEY terminal is used to receive external trigger signals, and the controller U2 is connected to and controls the analog switch U3 through the MIC_MUTE terminal.

4. The XLR and USB dual-purpose circuit as described in claim 1, characterized in that, It also includes a filtering module, a first switch SW1, and a second switch SW2. The filtering module is connected in parallel with the input unit. The first switch SW1 controls the filtering module to switch to a high-pass filtering mode to attenuate the low-frequency signal output by the input unit. The second switch SW2 controls the filtering module to switch to a low-pass filtering mode to attenuate the high-frequency signal output by the input unit.

5. The XLR and USB dual-purpose circuit as described in claim 4, characterized in that, The filtering module includes a transformer T1, resistors R1 and R2, and a capacitor C1. One end of resistor R1 is connected to the MIC- terminal of the input unit, pin 2 of the second switch SW2, and pin 1 of the first switch SW1. The other end of resistor R1 is connected to one end of resistor R2 and pin 1 of the second switch SW2. The other end of resistor R2 is connected to one end of capacitor C1. Therefore, the other end of capacitor C1 is connected to one end of transformer T1 and the MIC+ terminal of the input unit. The other end of transformer T1 is connected to pin 2 of the first switch SW1. Specifically, the first switch SW1 can be used to connect its pins 1 and 2, switching the filtering module to high-pass filtering mode; the second switch SW2 can be used to connect its pins 1 and 2, switching the filtering module to low-pass filtering mode.

6. The XLR and USB dual-purpose circuit as described in claim 1, characterized in that, It also includes a voltage regulator and filter circuit, which includes multiple grounding capacitors, all of which are connected between the external power supply and the power supply terminal of the amplifier U1.

7. The XLR and USB dual-purpose circuit as described in claim 6, characterized in that, The voltage regulation and filtering circuit also includes resistors R3, R4, R5 and capacitor C2. One end of resistor R3 is connected to the positive input terminal of amplifier U1 and one end of capacitor C2. The other end of resistor R3 is connected to the other end of capacitor C2, one end of resistor R4 and one end of resistor R5. The other end of resistor R4 is connected between the external power supply and the power supply terminal of amplifier U1. The other end of resistor R5 is grounded.

8. The XLR and USB dual-purpose circuit as described in claim 1, characterized in that, The USB module also includes a resistor R6 and a capacitor C3. One end of the resistor R6 is connected to the negative input terminal of the amplifier U1, and the other end of the resistor R6 is connected to the output terminal of the amplifier U1.

9. The XLR and USB dual-purpose circuit as described in claim 1, characterized in that, The input module also includes capacitors C4 and C5, which are used to connect to the MIC+ and MIC- terminals of the input unit, respectively.

10. The XLR and USB dual-purpose circuit as described in claim 1, characterized in that, The XLR module also includes a test point, wherein the XLR_OUT+, XLR_OUT- and GND terminals of the test point are respectively connected to the positive terminal, negative terminal and ground terminal of the XLR interface.

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