Audio interface expansion circuit and audio test system

Abstract

The invention discloses an audio interface expansion circuit and an audio test system. The audio interface expansion circuit comprises a protocol conversion module, a first multiplexing module, a second multiplexing module and an audio calibration channel module. The first multiplexing module provides a plurality of first input ends to be connected with a first audio input interface to realize interface expansion of a microphone, and the second multiplexing module provides a plurality of second output ends to be connected with a second audio output interface to realize interface expansion of a loudspeaker, so that synchronous testing of multiple products is facilitated, and the testing efficiency is improved. And the interface occupation of the audio data acquisition equipment is reduced, the remaining interface of the audio data acquisition equipment is connected with the audio calibration channel module, an audio calibration function is added, the audio test accuracy is improved, the first multiplexing module and the second multiplexing module are enabled and controlled by the protocol conversion module, and the audio test accuracy is improved. No complex logic processing device is needed, and the design cost is reduced, so that the test cost is reduced.

Description

Technical Field

[0001] The present invention relates to the technical field of automated testing, and in particular to an audio interface expansion circuit and an audio testing system. Background Art

[0002] The NI-4461 is a high-performance data acquisition device suitable for high-precision and high-bandwidth audio signal acquisition. However, it has a limited number of channels and can only connect to two microphones and speakers simultaneously. Therefore, the NI-4461's channel count cannot meet the needs of simultaneous testing of multiple products. The NI-4461 is expensive, and increasing the number of NI-4461s will lead to a significant increase in testing costs. Summary of the Invention

[0003] The present invention aims to solve at least one of the technical problems existing in the prior art. To this end, the present invention provides an audio interface expansion circuit and an audio test system, which can expand the number of audio interfaces and reduce test costs.

[0004] In one aspect, an embodiment of the present invention provides an audio interface expansion circuit, suitable for connecting to an audio data acquisition device, comprising: A protocol conversion module is connected to the USB interface and is used to convert USB protocol signals into serial protocol signals; A first multiplexing module comprises a first enabling terminal, a plurality of first channel control terminals, a first output terminal, and a plurality of first input terminals, wherein the first enabling terminal and the plurality of first channel control terminals are respectively connected to the protocol conversion module, the first output terminal is connected to a first audio output interface, the first audio output interface is adapted to be connected to a first target input interface of the audio data acquisition device, and the plurality of first input terminals are each connected to a corresponding first audio input interface; a second multiplexing module having a second enabling terminal, a plurality of second channel control terminals, a second input terminal, and a plurality of second output terminals, wherein the second enabling terminal and the plurality of second channel control terminals are respectively connected to the protocol conversion module, the second input terminal is connected to a second audio input interface, the second audio input interface is adapted to be connected to a first target output interface of the audio data acquisition device, and the plurality of second output terminals are each connected to a corresponding second audio output interface; The audio calibration channel module is connected to a third audio input interface and a third audio output interface, and the third audio input interface is suitable for connecting to the second target input interface of the audio data acquisition device.

[0005] According to some embodiments of the present invention, the first multiplexing module includes a single analog multiplexer, or the first multiplexing module includes a plurality of analog multiplexers connected in cascade.

[0006] According to some embodiments of the present invention, the model of the analog multiplexer is MAX14778.

[0007] According to some embodiments of the present invention, an audio signal amplifier is connected between the first output end and the first audio output interface.

[0008] According to some embodiments of the present invention, the audio signal amplifier is a MAX4061.

[0009] According to some embodiments of the present invention, the second multiplexing module includes a single analog multiplexer, or the second multiplexing module includes a plurality of analog multiplexers connected in cascade.

[0010] According to some embodiments of the present invention, the protocol conversion module uses an integrated circuit model FT232H.

[0011] According to some embodiments of the present invention, the audio calibration channel module uses an audio amplifier integrated circuit of model MAX4061.

[0012] On the other hand, an embodiment of the present invention provides an audio testing system, including a host computer, an acoustic calibrator, an audio data acquisition device and the above-mentioned audio interface expansion circuit, the host computer is connected to the USB interface, the acoustic calibrator is connected to the third audio input interface, and the audio data acquisition device is respectively connected to the first audio output interface, the second audio input interface and the third audio output interface, the first audio input interface is connected to a microphone, and the second audio output interface is connected to a speaker.

[0013] According to some embodiments of the present invention, the host computer includes a processor and a human-computer interaction module connected to each other, the human-computer interaction module is configured with a channel switching control interface, and the processor is used to respond to the user's channel switching operation on the channel switching control interface, send a channel switching instruction to the USB interface, so as to perform protocol conversion and analysis on the channel switching instruction through the protocol conversion module and control at least one of the first multiplexing module and the second multiplexing module to perform channel switching.

[0014] The embodiments of the present invention have at least the following beneficial effects: The first multiplexing module provides multiple first input terminals for connecting to the first audio input interface to realize the interface expansion of the microphone. The second multiplexing module provides multiple second output terminals for connecting to the second audio output interface to realize the interface expansion of the speaker, which is conducive to realizing synchronous testing of multiple products and reducing the interface occupancy of the audio data acquisition device. The remaining interfaces of the audio data acquisition device are connected to the audio calibration channel module to increase the audio calibration function and improve the accuracy of the audio test. The first multiplexing module and the second multiplexing module are enabled and channel switching is controlled by the protocol conversion module, without the need for complex logic processing devices, which is conducive to reducing design costs and thus reducing testing costs.

[0015] Additional aspects and advantages of the present invention will be set forth in part in the description which follows and, in part, will be obvious from the description which follows, or may be learned by practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] The above and / or additional aspects and advantages of the present invention will become apparent and readily understood from the following description of the embodiments with reference to the accompanying drawings, in which: Figure 1 This is a functional block diagram of an audio interface expansion circuit according to an embodiment of the present invention; Figure 2 for Figure 1 A functional block diagram of a first multiplexing module of the audio interface expansion circuit is shown; Figure 3 for Figure 1 A circuit schematic diagram of a first multiplexing module of an audio interface expansion circuit is shown; Figure 4 for Figure 1 A circuit schematic diagram of a second multiplexing module of the audio interface expansion circuit is shown; Figure 5 for Figure 1 A circuit schematic diagram of a protocol conversion module of an audio interface expansion circuit is shown; Figure 6 for Figure 1 The circuit schematic diagram of the audio calibration channel module of the audio interface expansion circuit is shown; Figure 7 is a functional block diagram of an audio test system according to an embodiment of the present invention; Figure 8 Schematic diagram of a channel switching control interface according to an embodiment of the present invention.

[0017] Reference numerals: Protocol conversion module 110, USB interface 111, first multiplexing module 120, second multiplexing module 130, audio calibration channel module 140, power module 150, audio signal amplifier 160, host computer 210, processor 211, human-computer interaction module 212, acoustic calibrator 220, audio data acquisition device 230, audio interface expansion circuit 100. DETAILED DESCRIPTION

[0018] The following describes embodiments of the present invention in detail. Examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are intended only to explain the present invention and are not to be construed as limiting the present invention.

[0019] In the description of the present invention, "several" means one or more, "multiple" means more than two, "greater than," "less than," and "exceed" are understood to exclude the number itself, and "above," "below," and "within" are understood to include the number itself. The use of terms such as "first" and "second" is solely for the purpose of distinguishing technical features and should not be construed as indicating or implying relative importance, or implicitly specifying the number of the indicated technical features, or implicitly specifying the order of the indicated technical features.

[0020] In the description of the present invention, unless otherwise clearly defined, words such as “setting”, “installation” and “connection” should be understood in a broad sense, and technicians in the relevant technical field can reasonably determine the specific meanings of the above words in the present invention based on the specific content of the technical solution.

[0021] Please refer to Figure 1 This embodiment discloses an audio interface expansion circuit 100, which is suitable for connecting to an audio data acquisition device 230, such as NI-4461. The audio interface expansion circuit 100 includes a protocol conversion module 110, a first multiplexing module 120, a second multiplexing module 130 and an audio calibration channel module 140.

[0022] The protocol conversion module 110 is connected to the USB interface 111, and is used to realize the conversion between the USB protocol signal and the serial protocol signal; the first multiplexing module 120 has a first enable terminal (as shown by the mark ENA in the figure), a plurality of first channel control terminals (as shown in the figure), and a plurality of first channel control terminals (as shown in the figure). Figure 1 SB0, SB1), a first output terminal and a plurality of first input terminals, a first enable terminal and a plurality of first channel control terminals are respectively connected to the protocol conversion module 110, and the first output terminal is connected to the first audio output interface (such as Figure 1 As shown by mark J3 in the figure, the first audio output interface is suitable for connecting to the first target input interface of the audio data acquisition device 230 (such as Figure 1 As shown in the mark NI_AI0 in the figure), the plurality of first input terminals are connected to the corresponding first audio input interface (such as Figure 1 The second multiplexing module 130 has a second enabling terminal, a plurality of second channel control terminals, a second input terminal and a plurality of second output terminals. The second enabling terminal and the plurality of second channel control terminals are respectively connected to the protocol conversion module 110. The second input terminal is connected to the second audio input interface (such as Figure 1 As shown by mark J1 in the figure, the second audio input interface is suitable for connecting to the first target output interface (such as Figure 1 As shown in the mark NI_AO0 in the figure), the plurality of second output terminals are connected to corresponding second audio output interfaces (such as Figure 1 The audio calibration channel module 140 is connected to a third audio input interface (such as Figure 1 J14) and the third audio output interface (as Figure 1 As shown in the mark J4, the third audio input interface is suitable for connecting to the second target input interface of the audio data acquisition device 230 (such as Figure 1 The audio interface expansion circuit 100 further includes a power supply module 150 , which is connected to the protocol conversion module 110 , the first multiplexing module 120 , the second multiplexing module 130 , and the audio calibration channel module 140 .

[0023] First multiplexing module 120 provides multiple first input terminals for connecting to first audio input interfaces, enabling microphone interface expansion. Second multiplexing module 130 provides multiple second output terminals for connecting to second audio output interfaces, enabling speaker interface expansion. This facilitates simultaneous testing of multiple products and reduces the interface usage of audio data acquisition device 230. For example, audio data acquisition device 230 NI-4461 has four native interfaces, two of which are microphone interfaces and two are speaker interfaces. In this embodiment, first multiplexing module 120 and second multiplexing module 130 only need to occupy one microphone interface and one speaker interface to connect multiple microphones and multiple speakers. The remaining interfaces of audio data acquisition device 230 can be connected to audio calibration channel module 140, adding audio calibration functionality and improving audio test accuracy. First multiplexing module 120 and second multiplexing module 130 are enabled and channel switching controlled by protocol conversion module 110, eliminating the need for complex logic processor 211, thus reducing design costs and thus testing costs.

[0024] In some application examples, the first multiplexing module 120 includes a single analog multiplexer, or, in other application examples, refer to Figure 2The first multiplexing module 120 includes a plurality of cascade-connected analog multiplexers. The plurality of cascade-connected analog multiplexers can be used to expand more audio interfaces, thereby meeting the synchronous testing requirements of more products.

[0025] Please refer to Figure 3 The analog multiplexer model is MAX14778, which is a highly integrated analog multiplexer that implements flexible signal routing through independent control pins, especially in application scenarios that require a simplified circuit structure. Please refer to the figure, the circuit schematic diagram of the analog multiplexer used as the first multiplexing module 120 is shown as U2 in the figure. The analog multiplexer MAX14778 has channel A, where the pins of channel A are marked A0~A3 respectively. Channel A is configured with a multiplexed output pin ACOM and an enable pin ENA. In some application examples, the multiplexed output pin ACOM is connected to the first audio output interface, such as Figure 3 As shown by NI_AI0 in FIG. 1 , or in other application examples, an intermediate processing module, such as audio signal amplifier 160, may be connected between multiplexed output pin ACOM and the first audio output interface. Each pin of channel A serves as a first input terminal of first multiplexing module 120, making analog multiplexer MAX14778 suitable for connecting to a microphone.

[0026] Please continue to refer to Figure 3 An audio signal amplifier 160 is connected between the first output end and the first audio output interface. The audio signal amplifier 160 is used to amplify the signal output from the first output end and output it to the first audio output interface. It can increase the signal collection range of the microphone at the input end of the first multiplexing module 120, so that even the tiny sound signal collected by the microphone can be effectively output, which is conducive to improving the reliability of the test.

[0027] Please refer to Figure 3 The model of audio signal amplifier 160 is MAX4061. MAX4061 is a highly integrated, low-power differential microphone preamplifier designed specifically for processing differential microphone signals. It can effectively suppress common-mode noise and has high electrical characteristics, such as a high power supply rejection ratio, which can effectively reduce the impact of power supply noise. It also has a high common-mode rejection ratio, which can enhance anti-interference capabilities and help improve audio quality. The circuit schematic of audio signal amplifier 160 is shown in the figure below. Figure 3 As shown by the mark U5 in the middle, the non-inverting input pin IN+ of the audio signal amplifier 160 is connected to the multiplexed output pin ACOM of the analog multiplexer. The non-inverting input pin IN+ of the audio signal amplifier 160 is also connected to a pull-up branch (such as a circuit composed of resistors R11 and R12), and is connected to the reference voltage through the pull-up branch. Figure 3As shown in the MIC_BIAS mark, this ensures the signal stability of the non-inverting input pin IN+, thereby improving audio quality.

[0028] In some application examples, the second multiplexing module 130 includes a single analog multiplexer, or, in other application examples, refer to Figure 2 The second multiplexing module 130 includes multiple cascade-connected analog multiplexers. The second multiplexing module 130 includes multiple cascade-connected analog multiplexers. The multiple cascade-connected analog multiplexers can be used to expand more audio interfaces, thereby meeting the synchronous testing requirements of more products.

[0029] Please refer to Figure 4 The MAX14778 analog multiplexer has channels A and B. Channel A's pins are labeled A0 through A3, and channel B's pins are labeled B0 through B3. Channel A is equipped with a multiplexed output pin ACOM and an enable pin ENA, while channel B is equipped with a multiplexed output pin BCOM and an enable pin ENB. When the analog multiplexer is used in the second multiplexer module 130, the multiplexed output pins ACOM and BCOM serve as positive and negative output terminals (denoted by the labels AO1+ and AO1- in the figure), respectively, connected to the first audio output interface, as indicated by the label NI_AO0 in the figure. Channels A and B are divided into four groups: (A0, B0), (A1, B1), (A2, B2), and (A3, B3). Each group of channels serves as the first input terminal of the first multiplexer module 120, with channel A serving as the positive input terminal and channel B serving as the negative input terminal. This makes the MAX14778 analog multiplexer suitable for connecting to microphones. In addition, the enable pin ENA and the enable pin ENB are connected to the protocol conversion module 110, such as Figure 4 As shown by the mark U1_EN in the figure, the synchronous switching control of channel A and channel B is realized, that is, the switching of microphones of different channels is realized. Among them, channel A and channel B are both connected with TVS diodes, for example Figure 4 As shown by the marks D27 and D28, the spike signal can be effectively suppressed to ensure the stability of the input signal.

[0030] Please refer to Figure 5 The protocol conversion module 110 uses an integrated circuit model FT232H. The circuit schematic is as follows: Figure 5As shown in the figure marked U3, the integrated circuit model FT232H is a high-speed, single-channel USB-to-multiprotocol interface chip that supports multiple common protocols, including UART, FIFO, SPI, I2C, and JTAG. Its integrated low-dropout linear regulator reduces the need for external components and simplifies the circuit structure. This embodiment receives control signals from an external host computer 210 via a USB interface 111 and converts USB protocol-based signals into serial signals via a protocol conversion module. This allows control of the first multiplexing module 120 and the second multiplexing module 130, eliminating the need for a complex logic processor 211, such as a CPU or FPGA. This simplifies the circuit, reduces circuit costs, and thus reduces testing costs.

[0031] Please refer to Figure 6 Audio calibration channel module 140 utilizes the MAX4061 audio amplifier integrated circuit. The MAX4061 boasts superior electrical characteristics, such as high power supply rejection ratio and common-mode rejection ratio, which improve signal quality. Using the MAX4061 as the audio amplifier integrated circuit for audio calibration channel module 140 ensures signal quality while simplifying the circuit structure and reducing design costs. Furthermore, using the same integrated circuit for audio calibration channel module 140 and audio signal amplifier 160 reduces the number of required integrated circuits and the complexity of production and preparation, thereby lowering design and production costs, and ultimately, testing costs.

[0032] Please refer to Figure 7 An embodiment of the present invention provides an audio testing system, including a host computer 210, an acoustic calibrator 220, an audio data acquisition device 230, and the above-mentioned audio interface expansion circuit 100, wherein the host computer 210 is connected to the USB interface 111, the acoustic calibrator 220 is connected to the third audio input interface, and the audio data acquisition device 230 is connected to the first audio output interface, the second audio input interface, and the third audio output interface respectively. The first audio input interface is connected to a microphone, and the second audio output interface is connected to a speaker.

[0033] The first multiplexing module 120 provides multiple first input terminals for connecting to the first audio input interface to realize the interface expansion of the microphone. The second multiplexing module 130 provides multiple second output terminals for connecting to the second audio output interface to realize the interface expansion of the speaker, which is conducive to realizing the synchronous testing of multiple products and reducing the interface occupancy of the audio data acquisition device 230. The remaining interfaces of the audio data acquisition device 230 are connected to the audio calibration channel module 140 to add the audio calibration function and improve the accuracy of the audio test. The first multiplexing module 120 and the second multiplexing module 130 are enabled and channel switching controlled by the protocol conversion module 110, without the need for a complex logic processor 211, which is conducive to reducing design costs and thus reducing testing costs.

[0034] Please refer to Figure 7 and Figure 8 The host computer 210 includes a processor 211 and a human-computer interaction module 212 connected to each other. The human-computer interaction module 212 is configured with a channel switching control interface (such as Figure 8 As shown, the processor 211 is configured to respond to a user's channel switching operation on the channel switching control interface by sending a channel switching instruction to the USB interface 111, so that the protocol conversion module 110 performs protocol conversion and analysis on the channel switching instruction and controls at least one of the first multiplexing module 120 and the second multiplexing module 130 to switch channels. The human-computer interaction module 212 may be an integrated module of a touch screen display, or a combination module of a keyboard, a mouse, and a conventional display. The human-computer interaction module 212 facilitates user operation of the channel switching control interface and issues a channel switching instruction based on the interface operation. The USB interface 111 transmits the instruction to the protocol conversion module 110, which then performs protocol conversion and analysis, thereby controlling the first multiplexing module 120 and the second multiplexing module 130 to switch channels. This eliminates the need to design a complex logic processor 211 in the audio interface expansion circuit 100, thereby simplifying circuit design and reducing testing costs while achieving audio signal interface expansion.

[0035] The embodiments of the present invention are described in detail above with reference to the accompanying drawings. However, the present invention is not limited to the above embodiments. Various changes can be made within the knowledge of ordinary technicians in the relevant technical field without departing from the scope of the present invention.

Claims

1. An audio interface expansion circuit, suitable for connecting an audio data acquisition device (230), characterized in that: include: A protocol conversion module (110) is connected to the USB interface (111), and the protocol conversion module (110) is used to realize conversion between USB protocol signals and serial protocol signals; a first multiplexing module (120) having a first enabling terminal, a plurality of first channel control terminals, a first output terminal, and a plurality of first input terminals, wherein the first enabling terminal and the plurality of first channel control terminals are respectively connected to the protocol conversion module (110), the first output terminal is connected to a first audio output interface, the first audio output interface is suitable for connecting to a first target input interface of the audio data acquisition device (230), and the plurality of first input terminals are each connected to a corresponding first audio input interface; A second multiplexing module (130) has a second enabling terminal, a plurality of second channel control terminals, a second input terminal, and a plurality of second output terminals, wherein the second enabling terminal and the plurality of second channel control terminals are respectively connected to the protocol conversion module (110), the second input terminal is connected to a second audio input interface, the second audio input interface is suitable for connecting to a first target output interface of the audio data acquisition device (230), and the plurality of second output terminals are each connected to a corresponding second audio output interface; The audio calibration channel module (140) is connected to a third audio input interface and a third audio output interface, wherein the third audio input interface is suitable for connecting to the second target input interface of the audio data acquisition device (230).

2. The audio interface expansion circuit according to claim 1, characterized in that: The first multiplexing module (120) includes a single analog multiplexer, or the first multiplexing module (120) includes a plurality of analog multiplexers connected in cascade.

3. The audio interface expansion circuit according to claim 2, characterized in that: The model of the analog multiplexer is MAX14778.

4. The audio interface expansion circuit according to claim 1, 2 or 3, characterized in that: An audio signal amplifier (160) is connected between the first output end and the first audio output interface.

5. The audio interface expansion circuit according to claim 4, characterized in that: The model of the audio signal amplifier (160) is MAX4061.

6. The audio interface expansion circuit according to any one of claims 1 to 3 and 5, characterized in that: The second multiplexing module (130) includes a single analog multiplexer, or the second multiplexing module (130) includes a plurality of analog multiplexers connected in cascade.

7. The audio interface expansion circuit according to claim 1, characterized in that: The protocol conversion module (110) uses an integrated circuit of model FT232H.

8. The audio interface expansion circuit according to claim 1, characterized in that: The audio calibration channel module (140) adopts an audio amplifier integrated circuit of model MAX4061.

9. An audio testing system, characterized in that: The invention comprises a host computer (210), an acoustic calibrator (220), an audio data acquisition device (230), and an audio interface expansion circuit (100) as claimed in any one of claims 1 to 8, wherein the host computer (210) is connected to the USB interface (111), the acoustic calibrator (220) is connected to the third audio input interface, and the audio data acquisition device (230) is respectively connected to the first audio output interface, the second audio input interface, and the third audio output interface, the first audio input interface is connected to a microphone, and the second audio output interface is connected to a speaker.

10. The audio test system according to claim 9, characterized in that: The host computer (210) includes a processor (211) and a human-computer interaction module (212) connected to each other, the human-computer interaction module (212) is configured with a channel switching control interface, and the processor (211) is used to respond to a channel switching operation of the user on the channel switching control interface, send a channel switching instruction to the USB interface (111), so that the protocol conversion module (110) performs protocol conversion and analysis on the channel switching instruction and controls at least one of the first multiplexing module (120) and the second multiplexing module (130) to perform channel switching.

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