A test circuit for Type-C interface audio channel

Abstract

This invention provides a test circuit for a Type-C interface audio channel, comprising a digital-to-analog signal switching circuit connected to a universal sound card interface circuit and a smartphone's Type-C interface; input terminals of an audio channel type identification circuit and an audio signal conditioning circuit connected to the smartphone's Type-C interface; an output terminal of the digital-to-analog signal switching circuit connected to an input terminal of a USB signal to IIS signal circuit; and output terminals of the digital-to-analog signal switching circuit, the audio channel type identification circuit, and the audio signal conditioning circuit all connected to an input terminal of the universal sound card interface circuit. The USB signal to IIS signal circuit is communicatively connected to the universal sound card interface circuit. The beneficial effect of this invention is that it enables the testing of both digital and analog audio channel functions of a smartphone's Type-C interface using only a single universal sound card.

Description

Technical Field

[0001] This utility model relates to the field of test circuit technology, specifically to a test circuit for a Type-C interface audio channel. Background Technology

[0002] The Type-C interface is a new interface developed by the USB standardization organization to address the long-standing shortcomings of USB interfaces, such as inconsistent physical interface specifications and unidirectional power transmission. It integrates charging, display, and data transfer functions. The Type-C interface is approximately 8.3mm × 2.5mm in size and, like other interfaces, supports USB standard functions such as charging, data transfer, and display output. The Type-C interface has the following characteristics:

[0003] Superior experience: Using Type-C allows direct connection to mobile phones and wired networks for internet access, providing a smoother experience than WiFi whether playing games or watching movies.

[0004] Fast charging: Type-C supports fast charging, which can shorten the charging time of devices by 2-4 times compared to the past.

[0005] Mutual recognition: The Type-C interface also makes it easier for the vehicle's infotainment system to recognize each other, and the data transfer speed is also faster.

[0006] Almost all current smartphones are equipped with a Type-C interface. During the manufacturing process, the Type-C interface needs to undergo various functional tests before it can leave the factory. One of the functional tests for the Type-C interface is the audio function test. The existing Type-C interface audio channels include both digital and analog audio channels. Since the testing methods for digital and analog audio channels are different, different sound cards are usually used to test the digital and analog audio channels of the Type-C interface separately. This not only requires two sound cards but also requires separate testing, which is time-consuming, labor-intensive, inefficient, and costly. Utility Model Content

[0007] To address the problems in the prior art, this utility model provides a test circuit for the audio channel of a Type-C interface. By incorporating a digital-to-analog signal switching circuit, an audio channel type identification circuit, a USB signal to IIS signal conversion circuit, and an audio signal conditioning circuit into the test circuit for the audio channel of a Type-C interface, it is possible to test whether the digital and analog audio channels of a smartphone's Type-C interface are functioning correctly using only a single general-purpose sound card. This method is simple to operate, significantly improves testing efficiency, and reduces testing costs. It solves the problem of low testing efficiency caused by the need to use different sound cards to test the digital and analog audio channels of the Type-C interface separately in the prior art.

[0008] This utility model provides a test circuit for a Type-C interface audio channel, positioned between the Type-C interface of a smartphone and a universal sound card interface circuit. It includes a digital-to-analog signal switching circuit, an audio channel type identification circuit, a USB signal to IIS signal conversion circuit, and an audio signal conditioning circuit. The input terminal of the digital-to-analog signal switching circuit is communicatively connected to the universal sound card interface circuit and the Type-C interface of the smartphone. The input terminals of the audio channel type identification circuit and the audio signal conditioning circuit are connected to the Type-C interface of the smartphone. The output terminal of the digital-to-analog signal switching circuit is connected to the input terminal of the USB signal to IIS signal conversion circuit. The output terminals of the digital-to-analog signal switching circuit, the audio channel type identification circuit, and the audio signal conditioning circuit are all connected to the input terminal of the universal sound card interface circuit. The USB signal to IIS signal conversion circuit is communicatively connected to the universal sound card interface circuit. The digital-to-analog signal switching circuit can directly output an analog signal to the universal sound card interface circuit according to the audio channel type identified by the audio channel type identification circuit, or control the USB signal to IIS signal conversion circuit to output a digital signal to the universal sound card interface circuit.

[0009] This utility model is further improved by including a digital signal-to-analog signal switching chip U2 and an inductor L2 in the digital signal-to-analog signal switching circuit. The digital signal-to-analog signal switching chip U2 has 10 pins. Pins 6 and 7 of the digital signal-to-analog signal switching chip U2 are connected to the Type-C interface of the smartphone. Pins 2, 3, 5, and 8 of the digital signal-to-analog signal switching chip U2 are connected to the input terminal of the universal sound card interface circuit. Pins 1 and 10 of the digital signal-to-analog signal switching chip U2 are connected to the input terminal of the USB signal to IIS signal circuit. Pin 9 of the digital signal-to-analog signal switching chip U2 is connected to a 5V constant voltage power supply through the inductor L2. Pin 4 of the digital signal-to-analog signal switching chip U2 is grounded.

[0010] This utility model is further improved by including an audio channel type identification chip U1, resistors R1, R2, R3, and R4, and an inductor L1 within the audio channel type identification circuit. The audio channel type identification chip U1 has 10 pins. Pins 4 and 6 of the audio channel type identification chip U1 are connected to the Type-C interface of the smartphone. Pins 1 and 9 of the audio channel type identification chip U1 are connected to the input terminal of the universal sound card interface circuit. Pin 2 of the audio channel type identification chip U1 is connected to one end of resistor R1. The third pin of the audio channel type identification chip U1 is connected to one end of the resistor R2, the eighth pin of the audio channel type identification chip U1 is connected to one end of the resistor R3, the seventh pin of the audio channel type identification chip U1 is connected to one end of the resistor R4, the tenth pin of the audio channel type identification chip U1 is connected to a 5V constant voltage power supply through the inductor L1, and the other ends of the resistors R1, R2, R3, and R4, as well as the fifth pin of the audio channel type identification chip U1, are grounded.

[0011] This utility model is further improved by including resistors R9, R10, and R11, and capacitors C6 and C7 in the audio signal conditioning circuit. One end of resistor R9 is connected to the Type-C interface of the smartphone. One end of resistor R10 is connected to one end of capacitor C6, one end of capacitor C7, and the Type-C interface of the smartphone. The other end of capacitor C6 is connected to the other end of capacitor C7 and one end of resistor R11. The other end of resistor R11 is connected to the input terminal of the universal sound card interface circuit. The other ends of resistors R9 and R10 are grounded.

[0012] This utility model is further improved by including a signal conversion chip U3, a resistor R13 and a light-emitting diode LED1 in the USB signal to IIS signal circuit. The signal conversion chip U3 has 48 pins. The 4th and 5th pins of the signal conversion chip U3 are connected to the 1st and 10th pins of the digital signal to analog signal switching chip U2, respectively. The 20th, 27th, 28th, 29th and 30th pins of the signal conversion chip U3 are communicatively connected to the universal sound card interface circuit.

[0013] This utility model is further improved in that the universal sound card interface circuit is provided with a sound card interface CON1. ​​The input terminal of the sound card interface CON1 has 20 pins. The output terminal of the sound card interface CON1 is connected to a universal sound card. The first and second pins of the sound card interface CON1 are connected to the first and ninth pins of the audio channel type identification chip U1, respectively. The 18th, 17th, 3rd, and 4th pins of the sound card interface CON1 are connected to the second, third, 8th, and 5th pins of the digital signal-analog signal switching chip U2, respectively. The 20th pin of the sound card interface CON1 is connected to the other end of the resistor R11. The 8th, 6th, 12th, 9th, and 7th pins of the sound card interface CON1 are connected to the 20th, 27th, 28th, 29th, and 30th pins of the signal conversion chip U3, respectively.

[0014] This utility model is further improved, and the model number of the digital signal to analog signal switching chip U2 is BCT4321N.

[0015] This utility model is further improved, and the audio channel type identification chip U1 is model number BL1530.

[0016] This utility model is further improved, and the signal conversion chip U3 is model number CT7601.

[0017] This utility model is further improved, and the model of the universal sound card is ITC-AU1307.

[0018] Compared with the prior art, the beneficial effects of this utility model are as follows: It provides a test circuit for the audio channel of the Type-C interface. By setting up a digital-to-analog signal switching circuit, an audio channel type identification circuit, a USB signal to IIS signal conversion circuit, and an audio signal conditioning circuit in the test circuit for the audio channel of the Type-C interface, the digital-to-analog signal switching circuit can directly output an analog audio signal to the universal sound card interface circuit according to the audio channel type identified by the audio channel type identification circuit, or control the USB signal to IIS signal conversion circuit to output a digital audio signal to the universal sound card interface circuit. It can realize the testing of whether the digital signal audio channel and analog signal audio channel of the Type-C interface of a smartphone are working properly using only a universal sound card. It is simple to operate, greatly improves the testing efficiency, and reduces the testing cost. It solves the problem of low testing efficiency caused by the need to use different sound cards to test the digital signal audio channel and analog signal audio channel of the Type-C interface in the prior art. Attached Figure Description

[0019] To more clearly illustrate the solutions in this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this utility model. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0020] Figure 1 This is a schematic block diagram of a test circuit for a Type-C interface audio channel according to the present invention.

[0021] Figure 2 This is a circuit diagram of the digital signal to analog signal switching circuit of this utility model;

[0022] Figure 3 This is a circuit diagram of the audio channel type identification circuit and the audio signal conditioning circuit of this utility model;

[0023] Figure 4 This is a circuit diagram of the USB signal to IIS signal conversion circuit of this utility model;

[0024] Figure 5 This is a circuit diagram of the universal sound card interface circuit of this utility model. Detailed Implementation

[0025] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains; the terminology used herein in the specification is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention; the terms "comprising" and "having," and any variations thereof, in the specification, claims, and accompanying drawings of this invention are intended to cover non-exclusive inclusion. The terms "first," "second," etc., in the specification, claims, or accompanying drawings of this invention are used to distinguish different objects, not to describe a particular order.

[0026] 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 the present invention. 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.

[0027] To enable those skilled in the art to better understand the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings.

[0028] like Figures 1-5As shown, this utility model provides a test circuit for a Type-C interface audio channel, which is set between the Type-C interface of a smartphone and the universal sound card interface circuit. It includes a digital-to-analog signal switching circuit, an audio channel type identification circuit, a USB signal to IIS signal conversion circuit, and an audio signal conditioning circuit. The input terminal of the digital-to-analog signal switching circuit is communicatively connected to the universal sound card interface circuit and the Type-C interface of the smartphone. The input terminals of the audio channel type identification circuit and the audio signal conditioning circuit are connected to the Type-C interface of the smartphone. The output terminal of the digital-to-analog signal switching circuit is connected to the input terminal of the USB signal to IIS signal conversion circuit. The output terminals of the digital-to-analog signal switching circuit, the audio channel type identification circuit, and the audio signal conditioning circuit are all connected to the input terminal of the universal sound card interface circuit. The USB signal to IIS signal conversion circuit is communicatively connected to the universal sound card interface circuit. In this embodiment, the digital signal to analog signal switching circuit can directly output analog audio signals to the universal sound card interface circuit according to the audio channel type identified by the audio channel type identification circuit, or control the USB signal to IIS signal circuit to output digital audio signals to the universal sound card interface circuit. This enables the testing of whether the digital signal audio channel and analog signal audio channel of the smartphone's Type-C interface are functioning normally using only one universal sound card. The operation is simple, greatly improving testing efficiency and reducing testing costs.

[0029] like Figure 2 As shown, the digital-to-analog signal switching circuit includes a digital-to-analog signal switching chip U2 and an inductor L2. The digital-to-analog signal switching chip U2 is model BCT4321N and has 10 pins. Pins 6 and 7 of the chip are connected to the Type-C interface of the smartphone. Pins 2, 3, 5, and 8 are connected to the input of the universal sound card interface circuit. Pins 1 and 10 are connected to the input of the USB signal to IIS signal circuit. Pin 9 of the chip is connected to a 5V constant voltage power supply through inductor L2, and pin 4 is grounded. Figure 4As shown, the USB signal to IIS signal conversion circuit includes a signal conversion chip U3, a resistor R13, and a light-emitting diode LED1. The signal conversion chip U3 is a CT7601 model with 48 pins. Pins 4 and 5 of the signal conversion chip U3 are connected to pins 1 and 10 of the digital-to-analog signal switching chip U2, respectively. Pins 20, 27, 28, 29, and 30 of the signal conversion chip U3 are communicatively connected to the general-purpose sound card interface circuit. This embodiment describes the USB signal to IIS signal conversion circuit. In this embodiment, the digital-to-analog signal switching circuit is controlled by analog switch control 3 and analog switch control 4. In digital signal audio channel mode, the D+(R) and D-(L) signals of the smartphone's Type-C interface are digital audio signals. These signals pass through the digital-to-analog signal switching circuit and enter the USB signal to IIS signal circuit, where they are converted into IIS audio signals and connected to the digital audio port of the general-purpose sound card. In analog signal audio channel mode, the D+(R) and D-(L) signals of the smartphone's Type-C interface are analog audio signals. These signals pass through the digital-to-analog signal switching circuit and are connected to the analog audio port of the general-purpose sound card. Here, IIS signal refers to the Inter-IC Sound bus, also known as I2S, a serial digital audio bus protocol proposed by Philips. IIS uses three serial buses to transmit data; other signals (such as control signals) must be transmitted separately. To minimize the number of pins on the chip, IIS uses only three serial buses.

[0030] like Figure 3As shown, the audio channel type identification circuit includes an audio channel type identification chip U1, resistors R1, R2, R3, R4, and inductor L1. The audio channel type identification chip U1 is a BL1530 with 10 pins. Pins 4 and 6 of U1 are connected to the Type-C interface of the smartphone. Pins 1 and 9 are connected to the input of the universal sound card interface circuit. Pin 2 is connected to one end of resistor R1. Pin 3 is connected to one end of resistor R2. Pin 8 is connected to one end of resistor R3. Pin 7 is connected to one end of resistor R4. Pin 10 is connected to a 5V constant voltage power supply through inductor L1. The other ends of resistors R1, R2, R3, and R4, and pin 5 of U1 are grounded. In this embodiment, the audio channel type identification circuit determines the resistors connected to CC1 and CC2 by the high and low levels of analog switch control 1 and analog switch control 2, thereby enabling the smartphone to identify whether the device connected to the smartphone's Type-C interface is a digital signal audio channel type or an analog signal audio channel type, and thus determine whether to output an analog audio signal or a digital audio signal.

[0031] like Figure 3 As shown, the audio signal conditioning circuit includes resistors R9, R10, and R11, and capacitors C6 and C7. One end of resistor R9 is connected to the Type-C interface of the smartphone. One end of resistor R10 is connected to one end of capacitor C6, one end of capacitor C7, and the Type-C interface of the smartphone. The other end of capacitor C6 is connected to the other end of capacitor C7 and one end of resistor R11. The other end of resistor R11 is connected to the input terminal of the universal sound card interface circuit. The other ends of resistors R9 and R10 are grounded. In this embodiment, the audio signal conditioning circuit is used to adjust the analog or digital audio signal output to the universal sound card interface circuit. Here, a simple resistor and capacitor are used to build the signal conditioning circuit connected to the analog audio port of the universal sound card.

[0032] like Figure 5As shown, the universal sound card interface circuit includes a sound card interface CON1. ​​The input terminal of the sound card interface CON1 has 20 pins. The output terminal of the sound card interface CON1 is connected to a universal sound card, model ITC-AU1307. Pins 1 and 2 of the sound card interface CON1 are connected to pins 1 and 9 of the audio channel type identification chip U1, respectively. Pins 18, 17, 3, and 4 of the sound card interface CON1 are connected to pins 2, 3, 8, and 5 of the digital signal-analog signal switching chip U2, respectively. Pin 20 of the sound card interface CON1 is connected to the other end of resistor R11. Pins 8, 6, 12, 9, and 7 of the sound card interface CON1 are connected to pins 20, 27, 28, 29, and 30 of the signal conversion chip U3, respectively. In this embodiment, the general-purpose sound card has a digital audio port, an analog audio port, a general-purpose I / O port, and a USB port. In this embodiment, the digital audio port is used to connect to the digital audio signal of the digital signal audio channel, the analog audio port is used to connect to the analog audio signal of the analog signal audio channel, and the general-purpose I / O port is used to control the analog switch switching. The configuration of the sound card and the audio data input and output are completed through USB.

[0033] As can be seen from the above, this utility model provides a test circuit for the audio channel of a Type-C interface. By setting up a digital-to-analog signal switching circuit, an audio channel type identification circuit, a USB signal to IIS signal conversion circuit, and an audio signal conditioning circuit in the test circuit for the audio channel of the Type-C interface, the digital-to-analog signal switching circuit can directly output an analog audio signal to the universal sound card interface circuit according to the audio channel type identified by the audio channel type identification circuit, or control the USB signal to IIS signal conversion circuit to output a digital audio signal to the universal sound card interface circuit. This enables the testing of whether the digital signal audio channel and analog signal audio channel of the Type-C interface of a smartphone are functioning normally using only a universal sound card. The operation is simple, greatly improving the testing efficiency and reducing the testing cost. It solves the problem of low testing efficiency caused by the need to use different sound cards to test the digital signal audio channel and analog signal audio channel of the Type-C interface in the prior art.

[0034] The specific embodiments described above are preferred embodiments of this utility model, and are not intended to limit the specific scope of this utility model. The scope of this utility model includes but is not limited to the specific embodiments described above. All equivalent changes made in accordance with this utility model are within the protection scope of this utility model.

Claims

1. A test circuit for a Type-C interface audio channel, disposed between the Type-C interface of a smartphone and a universal sound card interface circuit, characterized in that: The system includes a digital-to-analog signal switching circuit, an audio channel type recognition circuit, a USB signal to IIS signal conversion circuit, and an audio signal conditioning circuit. The input terminal of the digital-to-analog signal switching circuit is communicatively connected to the universal sound card interface circuit and the Type-C interface of the smartphone. The input terminals of the audio channel type recognition circuit and the audio signal conditioning circuit are connected to the Type-C interface of the smartphone. The output terminal of the digital-to-analog signal switching circuit is connected to the input terminal of the USB signal to IIS signal conversion circuit. The output terminals of the digital-to-analog signal switching circuit, the audio channel type recognition circuit, and the audio signal conditioning circuit are all connected to the input terminal of the universal sound card interface circuit. The USB signal to IIS signal conversion circuit is communicatively connected to the universal sound card interface circuit. The digital-to-analog signal switching circuit can directly output an analog signal to the universal sound card interface circuit according to the audio channel type recognized by the audio channel type recognition circuit, or control the USB signal to IIS signal conversion circuit to output a digital signal to the universal sound card interface circuit.

2. The test circuit for a Type-C interface audio channel according to claim 1, characterized in that: The digital-to-analog signal switching circuit includes a digital-to-analog signal switching chip U2 and an inductor L2. The digital-to-analog signal switching chip U2 has 10 pins. Pins 6 and 7 of the digital-to-analog signal switching chip U2 are connected to the Type-C interface of the smartphone. Pins 2, 3, 5, and 8 of the digital-to-analog signal switching chip U2 are connected to the input terminal of the universal sound card interface circuit. Pins 1 and 10 of the digital-to-analog signal switching chip U2 are connected to the input terminal of the USB signal to IIS signal circuit. Pin 9 of the digital-to-analog signal switching chip U2 is connected to a 5V constant voltage power supply through the inductor L2. Pin 4 of the digital-to-analog signal switching chip U2 is grounded.

3. The test circuit for the audio channel of the Type-C interface according to claim 2, characterized in that: The audio channel type recognition circuit includes an audio channel type recognition chip U1, resistors R1, R2, R3, and R4, and an inductor L1. The audio channel type recognition chip U1 has 10 pins. Pins 4 and 6 of the audio channel type recognition chip U1 are connected to the Type-C interface of the smartphone. Pins 1 and 9 of the audio channel type recognition chip U1 are connected to the input terminal of the universal sound card interface circuit. Pin 2 of the audio channel type recognition chip U1 is connected to one end of resistor R1. Pin 3 of the audio channel type identification chip U1 is connected to one end of resistor R2. Pin 8 of the audio channel type identification chip U1 is connected to one end of resistor R3. Pin 7 of the audio channel type identification chip U1 is connected to one end of resistor R4. Pin 10 of the audio channel type identification chip U1 is connected to a 5V constant voltage power supply through inductor L1. The other ends of resistor R1, resistor R2, resistor R3, and resistor R4, and pin 5 of the audio channel type identification chip U1 are grounded.

4. The test circuit for a Type-C interface audio channel according to claim 3, characterized in that: The audio signal conditioning circuit includes resistors R9, R10, and R11, and capacitors C6 and C7. One end of resistor R9 is connected to the Type-C interface of the smartphone. One end of resistor R10 is connected to one end of capacitor C6, one end of capacitor C7, and the Type-C interface of the smartphone. The other end of capacitor C6 is connected to the other end of capacitor C7 and one end of resistor R11. The other end of resistor R11 is connected to the input terminal of the universal sound card interface circuit. The other ends of resistors R9 and R10 are grounded.

5. The test circuit for a Type-C interface audio channel according to claim 4, characterized in that: The USB signal to IIS signal conversion circuit includes a signal conversion chip U3, a resistor R13, and a light-emitting diode LED1. The signal conversion chip U3 has 48 pins. Pins 4 and 5 of the signal conversion chip U3 are connected to pins 1 and 10 of the digital signal to analog signal switching chip U2, respectively. Pins 20, 27, 28, 29, and 30 of the signal conversion chip U3 are communicatively connected to the universal sound card interface circuit.

6. The test circuit for a Type-C interface audio channel according to claim 5, characterized in that: The universal sound card interface circuit includes a sound card interface CON1, which has 20 input pins. The output of the sound card interface CON1 is connected to a universal sound card. Pins 1 and 2 of the sound card interface CON1 are connected to pins 1 and 9 of the audio channel type identification chip U1, respectively. Pins 18, 17, 3, and 4 of the sound card interface CON1 are connected to pins 2, 3, 8, and 5 of the digital signal-analog signal switching chip U2, respectively. Pin 20 of the sound card interface CON1 is connected to the other end of the resistor R11. Pins 8, 6, 12, 9, and 7 of the sound card interface CON1 are connected to pins 20, 27, 28, 29, and 30 of the signal conversion chip U3, respectively.

7. The test circuit for a Type-C interface audio channel according to claim 6, characterized in that: The digital-to-analog signal switching chip U2 is model BCT4321N.

8. The test circuit for a Type-C interface audio channel according to claim 7, characterized in that: The audio channel type identification chip U1 is model BL1530.

9. The test circuit for a Type-C interface audio channel according to claim 8, characterized in that: The signal conversion chip U3 is model CT7601.

10. The test circuit for a Type-C interface audio channel according to claim 9, characterized in that: The model of the general-purpose sound card is ITC-AU1307.

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