Audio processing circuit

Abstract

The utility model relates to an audio processing circuit, which comprises a plurality of audio input channels, a plurality of audio output channels and a controller, the DSP module is connected with the analog-to-digital conversion module, the digital-to-analog conversion module and the controller; wherein at least one audio input channel comprises a filter circuit, a phantom power supply circuit, a signal amplification circuit and a gain adjustment circuit; the phantom power circuit is connected with the filter circuit; the filter circuit is connected with the analog audio input and is used for filtering the analog audio input; the signal amplification circuit is connected with the filter circuit and is used for adjusting the signal amplitude of analog audio input; the gain adjusting circuit is connected with the signal amplifying circuit and the controller and used for adjusting the gain of the signal amplifying circuit. According to the utility model, audio processing effects in different application scenes can be ensured.

Description

Technical Field

[0001] The utility model relates to the technical field of audio processing, and more specifically to an audio processing circuit. Background Art

[0002] With the widespread use of audio equipment, the use scenarios of audio equipment are becoming more and more complex. Typical application scenarios include auditoriums, restaurants, hotels, conference rooms, lecture halls, banquet halls, multi-function halls, conference centers, etc. Using the same audio equipment design parameters for different application scenarios will cause defects in the effects of audio equipment in some application scenarios. Therefore, how to make audio equipment applicable to more application scenarios to ensure good audio effects in different application scenarios is an issue that needs to be considered more and more in audio equipment circuit design. Utility Model Content

[0003] The technical problem to be solved by the present invention is to provide an audio processing circuit to address the defect that the above-mentioned audio equipment in the prior art is difficult to meet the application requirements of multiple scenarios.

[0004] The technical solution adopted by the utility model to solve the technical problem is: constructing an audio processing circuit.

[0005] The audio processing circuit described in the utility model includes: a plurality of audio input channels, a plurality of audio output channels, a controller; an analog-to-digital conversion module connected to the audio input channels, a digital-to-analog conversion module connected to the audio output channels, and a DSP module connected to the analog-to-digital conversion module, the digital-to-analog conversion module and the controller;

[0006] Wherein, at least one audio input path includes a filter circuit, a phantom power circuit, a signal amplification circuit and a gain adjustment circuit;

[0007] The phantom power circuit is connected to the filter circuit;

[0008] The filtering circuit is connected to the analog audio input and is used to filter the analog audio input;

[0009] The signal amplification circuit is connected to the filter circuit and is used to adjust the signal amplitude of the analog audio input;

[0010] The gain adjustment circuit is connected to the signal amplifying circuit and the controller, and is used for receiving a control signal from the controller and adjusting the gain of the signal amplifying circuit.

[0011] Preferably, in the audio processing circuit of the utility model, the signal amplifying circuit includes a first amplifying circuit and a second amplifying circuit;

[0012] The first input terminal and the second input terminal of the first amplifier circuit are connected to the filter circuit respectively, the third input terminal of the first amplifier circuit is connected to the first terminal of the gain adjustment circuit, and the fourth input terminal of the first amplifier circuit is connected to the second terminal of the gain adjustment circuit;

[0013] The first input end of the second amplifier circuit is connected to the first output end of the first amplifier circuit, and the second input end of the second amplifier circuit is connected to the second output end of the first amplifier circuit; the third input end and the fourth input end of the second amplifier circuit are connected to the digital-to-analog conversion module to obtain the feedback signal of the audio output path; the first output end and the second output end of the second amplifier circuit are respectively connected to the analog-to-digital conversion module, and the first output end of the second amplifier circuit is connected to the second output end of the second amplifier circuit.

[0014] Preferably, in the audio processing circuit of the present utility model, the gain adjustment circuit comprises: a first register, at least one first switch and / or at least one second switch, and a first resistor corresponding to the first switch and a plurality of second resistors with different resistance values, a third resistor corresponding to the second switch and a plurality of fourth resistors with different resistance values;

[0015] The first end of the first resistor is connected to the third input end of the first amplifier circuit, the second end of the first resistor is connected to the common end of the first switch, the switching end of the first switch is connected to the first end of the corresponding second resistor, and the second ends of all the second resistors are connected to the fourth input end of the first amplifier circuit;

[0016] The first end of the third resistor is connected to the fourth input end of the first amplifier circuit, the second end of the third resistor is connected to the common end of the second switch, the switching end of the second switch is connected to the first end of the corresponding fourth resistor, and the second ends of all the fourth resistors are connected to the third input end of the first amplifier circuit;

[0017] The control end of the first register is connected to the controller, and the output end of the first register is respectively connected to the control end of the first switch and the control end of the second switch.

[0018] Preferably, in the audio processing circuit of the utility model, when the gain adjustment circuit includes the first switch, the first switch is an eight-channel switch;

[0019] When the gain adjustment circuit includes the second switch, the second switch is an eight-channel switch.

[0020] Preferably, in the audio processing circuit of the utility model, the first amplifying circuit includes a first operational amplifier chip, a first capacitor, a fifth resistor, a second capacitor, a sixth resistor, a third capacitor, a seventh resistor, a fourth capacitor and an eighth resistor;

[0021] The third pin of the first operational amplifier chip is the first input terminal of the first amplifier circuit, the fifth pin of the first operational amplifier chip is the second input terminal of the first amplifier circuit, the second pin of the first operational amplifier chip is the third input terminal of the first amplifier circuit, and the sixth pin of the first operational amplifier chip is the fourth input terminal of the first amplifier circuit;

[0022] The second pin of the first operational amplifier chip is connected to the first end of the first capacitor and the first end of the fifth resistor, the first pin of the first operational amplifier chip is connected to the second end of the first capacitor, the second end of the fifth resistor and the first end of the second capacitor, the second end of the second capacitor is connected to the first end of the sixth resistor, and the second end of the sixth resistor is the first output end of the first amplifier circuit;

[0023] The sixth pin of the first operational amplifier chip is connected to the first end of the third capacitor and the first end of the seventh resistor, the seventh pin of the first operational amplifier chip is connected to the second end of the third capacitor, the second end of the seventh resistor and the first end of the fourth capacitor, the second end of the fourth capacitor is connected to the first end of the eighth resistor, and the second end of the eighth resistor is the second output end of the first amplifier circuit.

[0024] Preferably, in the audio processing circuit of the present utility model, the second amplifying circuit includes a second operational amplifier chip, a fifth capacitor, a sixth capacitor, a ninth resistor, a tenth resistor, an eleventh resistor, a twelfth resistor and a thirteenth resistor;

[0025] The sixth pin of the second operational amplifier chip is the first input terminal of the second amplifier circuit, and the second pin of the second operational amplifier chip is the second input terminal of the second amplifier circuit; the fifth pin of the second operational amplifier chip is the third input terminal of the second amplifier circuit, and the third pin of the second operational amplifier chip is the fourth input terminal of the second amplifier circuit;

[0026] The sixth pin of the second operational amplifier chip is connected to the first end of the fifth capacitor and the first end of the ninth resistor, the seventh pin of the second operational amplifier chip is connected to the second end of the fifth capacitor and the first end of the tenth resistor, and the second end of the ninth resistor is connected to the second end of the tenth resistor, the first end of the eleventh resistor and the analog-to-digital conversion module;

[0027] The second pin of the second operational amplifier chip is connected to the first end of the sixth capacitor, the second end of the eleventh resistor and the first end of the twelfth resistor, the first pin of the second operational amplifier chip is connected to the second end of the sixth capacitor and the first end of the thirteenth resistor, and the second end of the twelfth resistor is connected to the second end of the thirteenth resistor and the analog-to-digital conversion module.

[0028] Preferably, in the audio processing circuit of the utility model, the filtering circuit includes a first inductor, a seventh capacitor, an eighth capacitor, a fourteenth resistor, a fifteenth resistor, a sixteenth resistor, a second inductor, a ninth capacitor, a tenth capacitor, a seventeenth resistor, an eighteenth resistor, a nineteenth resistor, a first TVS tube and a second TVS tube;

[0029] The first end of the first inductor and the first end of the second inductor are respectively used to receive the analog audio input;

[0030] The second end of the first inductor is connected to the first end of the seventh capacitor and the first end of the fourteenth resistor, the second end of the fourteenth resistor is connected to the first output end of the phantom power supply circuit and the first end of the eighth capacitor, the second end of the eighth capacitor is connected to the second end of the first TVS tube and the first end of the fifteenth resistor, and the second end of the fifteenth resistor is connected to the first end of the sixteenth resistor and the first input end of the first amplifier circuit;

[0031] The second end of the second inductor is connected to the first end of the ninth capacitor and the first end of the seventeenth resistor, the second end of the seventeenth resistor is connected to the second output end of the phantom power supply circuit and the first end of the tenth capacitor, the second end of the tenth capacitor is connected to the first end of the second TVS tube and the first end of the eighteenth resistor, and the second end of the eighteenth resistor is connected to the first end of the nineteenth resistor and the second input end of the first amplifier circuit;

[0032] The second end of the sixteenth resistor, the second end of the nineteenth resistor, the second end of the seventh capacitor, the second end of the ninth capacitor, the first end of the first TVS tube and the second end of the second TVS tube are grounded.

[0033] Preferably, in the audio processing circuit of the utility model, the phantom power supply circuit comprises a second register, a switch unit, a twentieth resistor and a twenty-first resistor;

[0034] The control end of the second register is connected to the controller, the output end of the second register is connected to the control end of the switch unit, the input end of the switch unit is connected to a power supply voltage, the output end of the switch unit is connected to the first end of the 20th resistor and the first end of the 21st resistor, the second end of the 20th resistor is the first output end of the phantom power circuit, and the second end of the 21st resistor is the second output end of the phantom power circuit.

[0035] Preferably, the audio processing circuit of the present invention further includes a USB sound card module and / or a Dante transmission module connected to the DSP module.

[0036] Preferably, in the audio processing circuit of the present invention, the controller includes one or more of an Ethernet module, a key trigger module, and a display module.

[0037] An audio processing circuit implementing the utility model has the following beneficial effects: it can be applied to a variety of application environments to ensure the audio processing effects in different application scenarios. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] The present invention will be further described below with reference to the accompanying drawings and embodiments, in which:

[0039] Figure 1 It is a structural schematic diagram of an embodiment of an audio processing circuit of the utility model;

[0040] Figure 2 The utility model is a partial circuit schematic diagram of an audio processing circuit embodiment. DETAILED DESCRIPTION

[0041] In order to have a clearer understanding of the technical features, purposes and effects of the present utility model, the specific implementation methods of the present utility model are now described in detail with reference to the accompanying drawings.

[0042] like Figure 1 As shown in FIG. 1 , an embodiment of the audio processing circuit of the utility model is shown. Figure 1As shown, in one embodiment of the audio processing circuit of the present utility model, the audio processing circuit includes: a plurality of audio input channels 110, a plurality of audio output channels 160, and a controller 140; and an analog-to-digital conversion module 120 connected to the audio input channel 110, a digital-to-analog conversion module 150 connected to the audio output channel 160, and a DSP module 130 connected to the analog-to-digital conversion module 120, the digital-to-analog conversion module 150 and the controller 140; wherein at least one audio input channel 110 includes a filter circuit 111, a phantom power supply circuit 113, a signal amplification circuit 112 and a gain adjustment circuit 114; the phantom power supply circuit 113 is connected to the filter circuit 111; the filter circuit 111 is connected to the analog audio input for filtering the analog audio input; the signal amplification circuit 112 is connected to the filter circuit 111 for adjusting the signal amplitude of the analog audio input; the gain adjustment circuit 114 is connected to the signal amplification circuit 112 and the controller 140 for receiving a control signal from the controller 140 and adjusting the gain of the signal amplification circuit 112.

[0043] Specifically, the audio input path 110 is used to receive an external analog audio signal. The audio input path 110 can be multi-channel, and each audio input path 110 can receive an external analog audio signal through a corresponding sound pickup device such as a microphone. In the following process, one of the audio input paths 110 is used as an example for explanation. In the audio input path 110, the analog audio signal is filtered and amplified by the filter circuit 111 and the signal amplification circuit 112. The gain matching resistance of the signal amplification circuit 112 is adjusted by the gain adjustment circuit 114 to achieve gain adjustment of the signal amplification circuit 112, so that the audio processing circuit can meet a variety of application scenarios. Among them, the gain adjustment circuit 114 is connected to the controller 140, and when receiving the control signal output by the controller 140, the gain matching resistance can be switched to achieve gain switching. The audio input path 110 outputs the conditioned analog audio signal to the analog-to-digital conversion module 120. The analog-to-digital conversion module 120 performs analog-to-digital conversion and inputs the signal to the DSP module 130. The DSP module 130 can use a general digital audio processing chip to process the signal input from the analog-to-digital conversion module 120 and obtain the final digital audio. The digital audio is converted by the digital-to-analog conversion module 150 and input to the audio output path 160 to be output to an audio playback device such as a speaker through the audio output path 160.

[0044] Optional, such as Figure 2As shown, the signal amplifying circuit 112 includes a first amplifying circuit and a second amplifying circuit; the first input end and the second input end of the first amplifying circuit are respectively connected to the filtering circuit 111, the third input end of the first amplifying circuit is connected to the first end of the gain adjusting circuit 114, and the fourth input end of the first amplifying circuit is connected to the second end of the gain adjusting circuit 114; the first input end of the second amplifying circuit is connected to the first output end of the first amplifying circuit, and the second input end of the second amplifying circuit is connected to the second output end of the first amplifying circuit; the third input end and the fourth input end of the second amplifying circuit are connected to the digital-to-analog conversion module 150, which is used to obtain the feedback signal of the audio output path 160; the first output end and the second output end of the second amplifying circuit are respectively connected to the analog-to-digital conversion module 120, and the first output end of the second amplifying circuit is connected to the second output end of the second amplifying circuit. Specifically, in the audio processing circuit, the signal amplifying circuit 112 is composed of two-stage amplifying circuits, the first amplifying circuit is used to realize the primary amplification of the analog audio signal, and the second amplifying circuit is used to realize the further amplification of the analog audio signal. The gain adjustment circuit 114 is connected between the third input terminal and the fourth input terminal of the first amplifier circuit. By switching the resistance value of the gain adjustment circuit 114, the input impedance of the first amplifier circuit is adjusted to adjust the gain of the first amplifier circuit. The first amplifier circuit can be a common-phase differential amplifier, which is responsible for receiving and amplifying the input signal, eliminating common-mode noise, and improving the common-mode rejection ratio of the signal. The output signal of the first amplifier circuit is transmitted to the second amplifier circuit, and is further amplified and drives the load through the second amplifier circuit. At the same time, the output feedback signal is obtained according to the output of the digital-to-analog conversion unit, forming a feedback loop for realizing the second amplifier circuit, thereby controlling the gain and stability of the second amplifier circuit.

[0045] Optionally, the gain adjustment circuit 114 includes: a first register, at least one first switching switch and / or at least one second switching switch, and a first resistor corresponding to the first switching switch and a plurality of second resistors with different resistance values, a third resistor corresponding to the second switching switch and a plurality of fourth resistors with different resistance values; the first end of the first resistor is connected to the third input end of the first amplifier circuit, the second end of the first resistor is connected to the common end of the first switching switch, the switching end of the first switching switch is connected to the first end of the corresponding second resistor, and the second ends of all the second resistors are connected to the fourth input end of the first amplifier circuit; the first end of the third resistor is connected to the fourth input end of the first amplifier circuit, the second end of the third resistor is connected to the common end of the second switching switch, the switching end of the second switching switch is connected to the first end of the corresponding fourth resistor, and the second ends of all the fourth resistors are connected to the third input end of the first amplifier circuit; the control end of the first register is connected to the controller 140, and the output end of the first register is respectively connected to the control end of the first switching switch and the control end of the second switching switch. Specifically, in the gain adjustment circuit 114, the matching resistance setting of the gain adjustment circuit 114 is realized by switching the connected resistor by the switching switch. Among them, the switching switch can include one or more of the first switching switch and the second switching switch, and the number of the first switching switch and the second switching switch can also be set as needed. Take a first switch and a second switch as an example, the first switch and the second switch are both eight-channel switches. Figure 2As shown, the first register includes a register chip U5, the first switching switch includes a switching chip U1, the first resistor includes a resistor R10, and the second resistor includes resistors R2, R4, R6, R8, R11, R14, and R16 with different resistance values. The common end of the switching chip U1 is connected to the third input end of the first amplifier circuit via the resistor R10, and the switching end of the switching chip U1 is connected to the fourth input end of the first amplifier circuit via the second resistor. The control end of the switching chip U1 is connected to the first register, and the first register is switched according to the control signal of the controller 140 to achieve impedance matching by connecting different resistors between the third input end of the first amplifier circuit and the fourth input end of the first amplifier circuit. The second switching switch includes a switching chip U2, the third resistor includes a resistor R12, and the fourth resistor includes resistors R3, R5, R7, R9, R13, R15, and R17 with different resistance values. The common end of the switching chip U2 is connected to the fourth input end of the first amplifier circuit via the resistor R12, the switching end of the switching chip U2 is connected to the third input end of the first amplifier circuit via the fourth resistor, and the control end of the switching chip U2 is connected to the first register, which is switched by the first register according to the control signal of the controller 140, so that different resistors are connected between the third input end of the first amplifier circuit and the fourth input end of the first amplifier circuit for impedance matching. It can be understood that multiple matching resistors are realized by the switching chip U1 and the switching chip U2.

[0046] Optionally, the first amplifier circuit includes a first operational amplifier chip, a first capacitor, a fifth resistor, a second capacitor, a sixth resistor, a third capacitor, a seventh resistor, a fourth capacitor and an eighth resistor; the third pin of the first operational amplifier chip is the first input end of the first amplifier circuit, the fifth pin of the first operational amplifier chip is the second input end of the first amplifier circuit, the second pin of the first operational amplifier chip is the third input end of the first amplifier circuit, and the sixth pin of the first operational amplifier chip is the fourth input end of the first amplifier circuit; the second pin of the first operational amplifier chip is connected to the first end of the first capacitor and the first end of the fifth resistor, the first pin of the first operational amplifier chip is connected to the second end of the first capacitor, the second end of the fifth resistor and the first end of the second capacitor, the second end of the second capacitor is connected to the first end of the sixth resistor, and the second end of the sixth resistor is the first output end of the first amplifier circuit; the sixth pin of the first operational amplifier chip is connected to the first end of the third capacitor and the first end of the seventh resistor, the seventh pin of the first operational amplifier chip is connected to the second end of the third capacitor, the second end of the seventh resistor and the first end of the fourth capacitor, the second end of the fourth capacitor is connected to the first end of the eighth resistor, and the second end of the eighth resistor is the second output end of the first amplifier circuit. Specifically, the first amplifier circuit can be composed of the first operational amplifier chip and its peripheral circuit. In a specific embodiment, the first operational amplifier chip includes an operational amplifier chip U7, the first capacitor may include a capacitor C7, the second capacitor includes a capacitor C8, the third capacitor includes a capacitor C11, and the fourth capacitor includes a capacitor C14. The fifth resistor includes a resistor R26, the sixth resistor includes a resistor R28, the seventh resistor includes a resistor R33, and the eighth resistor includes a resistor R37. The third pin of the operational amplifier chip U7 constitutes the first input end of the first amplifier circuit, the fifth pin of the operational amplifier chip U7 constitutes the second input end of the first amplifier circuit, the second pin of the operational amplifier chip U7 constitutes the third input end of the first amplifier circuit, and the sixth pin of the operational amplifier chip U7 constitutes the fourth input end of the first amplifier circuit.

[0047] Optionally, the second amplifier circuit includes a second operational amplifier chip, a fifth capacitor, a sixth capacitor, a ninth resistor, a tenth resistor, an eleventh resistor, a twelfth resistor and a thirteenth resistor; the sixth pin of the second operational amplifier chip is the first input end of the second amplifier circuit, and the second pin of the second operational amplifier chip is the second input end of the second amplifier circuit; the fifth pin of the second operational amplifier chip is the third input end of the second amplifier circuit, and the third pin of the second operational amplifier chip is the fourth input end of the second amplifier circuit; the sixth pin of the second operational amplifier chip is connected to the first end of the fifth capacitor and the first end of the ninth resistor, the seventh pin of the second operational amplifier chip is connected to the second end of the fifth capacitor and the first end of the tenth resistor, the second end of the ninth resistor is connected to the second end of the tenth resistor, the first end of the eleventh resistor and the analog-to-digital conversion module 120; the second pin of the second operational amplifier chip is connected to the first end of the sixth capacitor, the second end of the eleventh resistor and the first end of the twelfth resistor, the first pin of the second operational amplifier chip is connected to the second end of the sixth capacitor and the first end of the thirteenth resistor, and the second end of the twelfth resistor is connected to the second end of the thirteenth resistor and the analog-to-digital conversion module 120. Specifically, the second amplifier circuit can be composed of a second operational amplifier chip and its peripheral circuits. In a specific embodiment, the second operational amplifier chip includes an operational amplifier chip U10, the fifth capacitor includes a capacitor C5, the sixth capacitor includes a capacitor C12, the third capacitor includes a capacitor C11, and the fourth capacitor includes a capacitor C14. The ninth resistor includes a resistor R21, the tenth resistor includes a resistor R29, the eleventh resistor includes a resistor R32, the twelfth resistor includes a resistor R34, and the thirteenth resistor includes a resistor R38. The sixth pin of the operational amplifier chip U10 constitutes the first input terminal of the second amplifier circuit, the second pin of the operational amplifier chip U10 constitutes the second input terminal of the second amplifier circuit, the fifth pin of the operational amplifier chip U10 constitutes the third input terminal of the second amplifier circuit, and the third pin of the operational amplifier chip U10 constitutes the fourth input terminal of the second amplifier circuit.

[0048] Optionally, the filtering circuit 111 includes a first inductor, a seventh capacitor, an eighth capacitor, a fourteenth resistor, a fifteenth resistor, a sixteenth resistor, a second inductor, a ninth capacitor, a tenth capacitor, a seventeenth resistor, an eighteenth resistor, a nineteenth resistor, a first TVS tube and a second TVS tube; the first end of the first inductor and the first end of the second inductor are respectively used to receive analog audio input; the second end of the first inductor is connected to the first end of the seventh capacitor and the first end of the fourteenth resistor, the second end of the fourteenth resistor is connected to the first output end of the phantom power circuit 113 and the first end of the eighth capacitor, the second end of the eighth capacitor is connected to the second end of the first TVS tube and the first end of the fifteenth resistor, and the fifteenth The second end of the resistor is connected to the first end of the sixteenth resistor and the first input end of the first amplifier circuit; the second end of the second inductor is connected to the first end of the ninth capacitor and the first end of the seventeenth resistor, the second end of the seventeenth resistor is connected to the second output end of the phantom power circuit 113 and the first end of the tenth capacitor, the second end of the tenth capacitor is connected to the first end of the second TVS tube and the first end of the eighteenth resistor, the second end of the eighteenth resistor is connected to the first end of the nineteenth resistor and the second input end of the first amplifier circuit; the second end of the sixteenth resistor, the second end of the nineteenth resistor, the second end of the seventh capacitor, the second end of the ninth capacitor, the first end of the first TVS tube and the second end of the second TVS tube are grounded. Specifically, in the filter circuit 111, an LC filter structure can be formed by inductance, capacitance and resistance, and surge protection is performed by the TVS tube to protect the subsequent circuit. In a specific embodiment, the first inductor includes the inductor L2, the seventh capacitor includes the capacitor C16, the eighth capacitor includes the capacitor C9, the fourteenth resistor includes the resistor R30, the fifteenth resistor includes the resistor R31, and the sixteenth resistor includes the resistor R27; the second inductor includes the inductor L3, the ninth capacitor includes the capacitor C15, the tenth capacitor includes the capacitor C13, the seventeenth resistor includes the resistor R35, the eighteenth resistor includes the resistor R36, the nineteenth resistor includes the resistor R39, the first TVS tube includes the TVS tube U8 and the second TVS tube includes the TVS tube U9.

[0049] Optionally, the phantom power circuit 113 includes a second register, a switch unit, a twentieth resistor and a twenty-first resistor; the control end of the second register is connected to the controller 140, the output end of the second register is connected to the control end of the switch unit, the input end of the switch unit is connected to a power supply voltage, the output end of the switch unit is connected to the first end of the twentieth resistor and the first end of the twenty-first resistor, the second end of the twentieth resistor is the first output end of the phantom power circuit 113, and the second end of the twenty-first resistor is the second output end of the phantom power circuit 113. Specifically, in the phantom power circuit 113, the switch unit is controlled to be turned on or off by the second register according to the control signal of the controller 140 to power on the analog audio input path 110. In a specific embodiment, the second register includes a serial shift register U6, and the switch unit is composed of a switch tube Q1 and a switch tube Q2 and their peripheral circuits. The base of the switch tube Q2 receives the output of the serial shift register U6 to control the on or off. The switch tube Q1 is controlled to be turned on or off by the state of the switch tube Q2, and finally provides an output voltage. The twentieth resistor includes the resistor R25, and the twenty-first resistor includes the resistor R24.

[0050] Optionally, the audio processing circuit of the utility model further includes a USB sound card module and / or a Dante transmission module connected to the DSP module 130. Specifically, the DSP module 130 can also transmit audio signals with external devices through the USB sound card module. The DSP module 130 can also transmit audio signals with external devices through the Dante transmission module. The Dante transmission module can transmit audio signals from 4-input and 4-output to 16-input and 16-output with other devices, which enables the system to process more audio channels and meet more complex application scenarios.

[0051] Optionally, the controller 140 includes one or more of an Ethernet module, a key trigger module, and a display module. Specifically, the controller 140 can communicate with the host device through the Ethernet module, receive user operation instructions through the key trigger module, and display device information through the display module.

[0052] It can be understood that the above embodiments only express the preferred implementation methods of the utility model, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the patent scope of the utility model. It should be pointed out that, for ordinary technicians in this field, without departing from the concept of the utility model, the above-mentioned technical features can be freely combined, and several deformations and improvements can be made, which all belong to the protection scope of the utility model. Therefore, all equivalent changes and modifications made to the scope of the claims of the utility model should belong to the scope covered by the claims of the utility model.

Claims

1. An audio processing circuit, characterized in that: include: A plurality of audio input channels, a plurality of audio output channels, and a controller; and an analog-to-digital conversion module connected to the audio input path, a digital-to-analog conversion module connected to the audio output path, and a DSP module connecting the analog-to-digital conversion module, the digital-to-analog conversion module and the controller; Wherein, at least one audio input path includes a filter circuit, a phantom power circuit, a signal amplification circuit and a gain adjustment circuit; The phantom power circuit is connected to the filter circuit; The filtering circuit is connected to the analog audio input and is used to filter the analog audio input; The signal amplification circuit is connected to the filter circuit and is used to adjust the signal amplitude of the analog audio input; The gain adjustment circuit is connected to the signal amplifying circuit and the controller, and is used for receiving a control signal from the controller and adjusting the gain of the signal amplifying circuit.

2. The audio processing circuit according to claim 1, characterized in that: The signal amplifying circuit comprises a first amplifying circuit and a second amplifying circuit; The first input terminal and the second input terminal of the first amplifier circuit are connected to the filter circuit respectively, the third input terminal of the first amplifier circuit is connected to the first terminal of the gain adjustment circuit, and the fourth input terminal of the first amplifier circuit is connected to the second terminal of the gain adjustment circuit; The first input end of the second amplifier circuit is connected to the first output end of the first amplifier circuit, and the second input end of the second amplifier circuit is connected to the second output end of the first amplifier circuit; the third input end and the fourth input end of the second amplifier circuit are connected to the digital-to-analog conversion module to obtain the feedback signal of the audio output path; the first output end and the second output end of the second amplifier circuit are respectively connected to the analog-to-digital conversion module, and the first output end of the second amplifier circuit is connected to the second output end of the second amplifier circuit.

3. The audio processing circuit according to claim 2, characterized in that: The gain adjustment circuit comprises: a first register, at least one first switch and / or at least one second switch, and a first resistor corresponding to the first switch and a plurality of second resistors with different resistance values, a third resistor corresponding to the second switch and a plurality of fourth resistors with different resistance values; The first end of the first resistor is connected to the third input end of the first amplifier circuit, the second end of the first resistor is connected to the common end of the first switch, the switch end of the first switch is connected to the first end of the corresponding second resistor, and the second ends of all the second resistors are connected to the fourth input end of the first amplifier circuit; The first end of the third resistor is connected to the fourth input end of the first amplifier circuit, the second end of the third resistor is connected to the common end of the second switch, the switching end of the second switch is connected to the first end of the corresponding fourth resistor, and the second ends of all the fourth resistors are connected to the third input end of the first amplifier circuit; The control end of the first register is connected to the controller, and the output end of the first register is respectively connected to the control end of the first switch and the control end of the second switch.

4. The audio processing circuit according to claim 3, characterized in that: When the gain adjustment circuit includes the first switch, the first switch is an eight-channel switch; When the gain adjustment circuit includes the second switch, the second switch is an eight-channel switch.

5. The audio processing circuit according to claim 2, characterized in that: The first amplifier circuit includes a first operational amplifier chip, a first capacitor, a fifth resistor, a second capacitor, a sixth resistor, a third capacitor, a seventh resistor, a fourth capacitor and an eighth resistor; The third pin of the first operational amplifier chip is the first input terminal of the first amplifier circuit, the fifth pin of the first operational amplifier chip is the second input terminal of the first amplifier circuit, the second pin of the first operational amplifier chip is the third input terminal of the first amplifier circuit, and the sixth pin of the first operational amplifier chip is the fourth input terminal of the first amplifier circuit; The second pin of the first operational amplifier chip is connected to the first end of the first capacitor and the first end of the fifth resistor, the first pin of the first operational amplifier chip is connected to the second end of the first capacitor, the second end of the fifth resistor and the first end of the second capacitor, the second end of the second capacitor is connected to the first end of the sixth resistor, and the second end of the sixth resistor is the first output end of the first amplifier circuit; The sixth pin of the first operational amplifier chip is connected to the first end of the third capacitor and the first end of the seventh resistor, the seventh pin of the first operational amplifier chip is connected to the second end of the third capacitor, the second end of the seventh resistor and the first end of the fourth capacitor, the second end of the fourth capacitor is connected to the first end of the eighth resistor, and the second end of the eighth resistor is the second output end of the first amplifier circuit.

6. The audio processing circuit according to claim 2, characterized in that: The second amplifier circuit includes a second operational amplifier chip, a fifth capacitor, a sixth capacitor, a ninth resistor, a tenth resistor, an eleventh resistor, a twelfth resistor and a thirteenth resistor; The sixth pin of the second operational amplifier chip is the first input terminal of the second amplifier circuit, and the second pin of the second operational amplifier chip is the second input terminal of the second amplifier circuit; the fifth pin of the second operational amplifier chip is the third input terminal of the second amplifier circuit, and the third pin of the second operational amplifier chip is the fourth input terminal of the second amplifier circuit; The sixth pin of the second operational amplifier chip is connected to the first end of the fifth capacitor and the first end of the ninth resistor, the seventh pin of the second operational amplifier chip is connected to the second end of the fifth capacitor and the first end of the tenth resistor, and the second end of the ninth resistor is connected to the second end of the tenth resistor, the first end of the eleventh resistor and the analog-to-digital conversion module; The second pin of the second operational amplifier chip is connected to the first end of the sixth capacitor, the second end of the eleventh resistor and the first end of the twelfth resistor, the first pin of the second operational amplifier chip is connected to the second end of the sixth capacitor and the first end of the thirteenth resistor, and the second end of the twelfth resistor is connected to the second end of the thirteenth resistor and the analog-to-digital conversion module.

7. The audio processing circuit according to claim 2, characterized in that: The filtering circuit includes a first inductor, a seventh capacitor, an eighth capacitor, a fourteenth resistor, a fifteenth resistor, a sixteenth resistor, a second inductor, a ninth capacitor, a tenth capacitor, a seventeenth resistor, an eighteenth resistor, a nineteenth resistor, a first TVS tube and a second TVS tube; The first end of the first inductor and the first end of the second inductor are respectively used to receive the analog audio input; The second end of the first inductor is connected to the first end of the seventh capacitor and the first end of the fourteenth resistor, the second end of the fourteenth resistor is connected to the first output end of the phantom power supply circuit and the first end of the eighth capacitor, the second end of the eighth capacitor is connected to the second end of the first TVS tube and the first end of the fifteenth resistor, and the second end of the fifteenth resistor is connected to the first end of the sixteenth resistor and the first input end of the first amplifier circuit; The second end of the second inductor is connected to the first end of the ninth capacitor and the first end of the seventeenth resistor, the second end of the seventeenth resistor is connected to the second output end of the phantom power supply circuit and the first end of the tenth capacitor, the second end of the tenth capacitor is connected to the first end of the second TVS tube and the first end of the eighteenth resistor, and the second end of the eighteenth resistor is connected to the first end of the nineteenth resistor and the second input end of the first amplifier circuit; The second end of the sixteenth resistor, the second end of the nineteenth resistor, the second end of the seventh capacitor, the second end of the ninth capacitor, the first end of the first TVS tube and the second end of the second TVS tube are grounded.

8. The audio processing circuit according to claim 1, characterized in that: The phantom power circuit includes a second register, a switch unit, a twentieth resistor and a twenty-first resistor; The control end of the second register is connected to the controller, the output end of the second register is connected to the control end of the switch unit, the input end of the switch unit is connected to a power supply voltage, the output end of the switch unit is connected to the first end of the 20th resistor and the first end of the 21st resistor, the second end of the 20th resistor is the first output end of the phantom power circuit, and the second end of the 21st resistor is the second output end of the phantom power circuit.

9. The audio processing circuit according to claim 1, characterized in that: It also includes a USB sound card module and / or a Dante transmission module connected to the DSP module.

10. The audio processing circuit according to claim 1, characterized in that: The controller includes one or more of an Ethernet module, a key trigger module, and a display module.

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