A test circuit for Type-C interface audio channel

Abstract

The application provides a test circuit for a Type-C interface audio channel, which comprises a digital signal analog signal switching circuit and a general sound card interface circuit, and is connected with a Type-C interface of a smart phone; an input end of an audio channel type identification circuit and an input end of an audio signal conditioning circuit are connected with the Type-C interface of the smart phone; an output end of the digital signal analog signal switching circuit is connected with an input end of a USB signal to IIS signal circuit; the output end of the digital signal analog signal switching circuit, the output end of the audio channel type identification circuit and the output end of the audio signal conditioning circuit are all connected with an input end of the general sound card interface circuit; and the USB signal to IIS signal circuit is in communication connection with the general sound card interface circuit. The application has the beneficial effect that only one general sound card can be used to test the digital signal audio channel and the analog signal audio channel functions of the Type-C interface of the smart phone.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of test circuit, in particular to a test circuit for Type-C interface audio channel. BACKGROUND

[0002] Type-C interface is a new interface formulated by USB standardization organization to solve the problems of long-term physical interface specification non-uniformity and one-way power transmission of USB interface, which integrates charging, display and data transmission functions. Type-C interface is about 8.3mm*2.5mm in size, and supports charging, data transmission, display output and other functions of USB standard like other interfaces. Type-C interface has the following characteristics:

[0003] Good experience: using Type-C can directly connect mobile phones and network cables for online, whether playing games or watching movies can bring more smooth use effect than WiFi.

[0004] Fast charging: Type-C can support fast charging, and the device charging time can be shortened by 2-4 times compared with the past.

[0005] Mutual recognition: Type-C interface can also facilitate the mutual recognition of car machines, and the transmission speed of data is faster.

[0006] The existing smart phones are almost equipped with Type-C interface, and the Type-C interface of smart phones needs to test various functions of Type-C interface in the production process, and only the products that pass the test can be put into the market. Among them, one of the function tests of Type-C interface is audio function test. The existing Type-C interface audio channel includes digital signal audio channel and analog signal audio channel. Since the test methods of digital signal audio channel and analog signal audio channel are different, different sound cards are usually used to test the digital signal audio channel and analog signal audio channel of Type-C interface respectively, which not only needs two test sound cards, but also needs to test separately, which is time-consuming and laborious, and the test efficiency is low, and the test cost is high. SUMMARY

[0007] In order to solve the problems in the prior art, the application provides a test circuit for a Type-C interface audio channel, which is capable of testing whether the digital signal audio channel and the analog signal audio channel of the Type-C interface of a smart phone are normally operated only by using one universal sound card, is simple to operate, greatly improves the test efficiency, reduces the test cost, and solves the problem of low test efficiency caused by the need to use different sound cards to test the digital signal audio channel and the analog signal audio channel of the Type-C interface respectively in the prior art.

[0008] The test circuit for the Type-C interface audio channel is arranged between the Type-C interface of the smart phone and a universal sound card interface circuit, comprises a digital signal analog signal switching circuit, an audio channel type identification circuit, a USB signal to IIS signal circuit and an audio signal conditioning circuit, the digital signal analog signal switching circuit is in communication connection with the universal sound card interface circuit and the Type-C interface of the smart phone, the input end of the audio channel type identification circuit and the input end of the audio signal conditioning circuit are connected with the Type-C interface of the smart phone, the output end of the digital signal analog signal switching circuit is connected with the input end of the USB signal to IIS signal circuit, the output end of the digital signal analog signal switching circuit, the output end of the audio channel type identification circuit and the output end of the audio signal conditioning circuit are all connected with the input end of the universal sound card interface circuit, the USB signal to IIS signal circuit is in communication connection with the universal sound card interface circuit, the Type-C interface of the smart phone can identify the audio channel type of the connected electronic device through the digital signal analog signal switching circuit and the audio channel type identification circuit, the digital signal analog signal switching circuit can directly output analog 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 signals to the universal sound card interface circuit.

[0009] The application is further improved, the digital signal analog signal switching circuit is internally provided with a digital signal analog signal switching chip U2 and an inductor L2, wherein the digital signal analog signal switching chip U2 is provided with ten pins, the sixth and seventh pins of the digital signal analog signal switching chip U2 are connected with the Type-C interface of the smart phone, the second, third, fifth and eighth pins of the digital signal analog signal switching chip U2 are connected with the input end of the general sound card interface circuit, the first and tenth pins of the digital signal analog signal switching chip U2 are connected with the input end of the USB signal to IIS signal circuit, the ninth pin of the digital signal analog signal switching chip U2 is connected with a 5V constant voltage power supply through the inductor L2, and the fourth pin of the digital signal analog signal switching chip U2 is grounded.

[0010] The application is further improved, the audio channel type identification circuit is internally provided with an audio channel type identification chip U1, resistors R1, R2, R3 and R4 and an inductor L1, wherein the audio channel type identification chip U1 is provided with ten pins, the fourth and sixth pins of the audio channel type identification chip U1 are connected with the Type-C interface of the smart phone, the first and ninth pins of the audio channel type identification chip U1 are connected with the input end of the general sound card interface circuit, the second pin of the audio channel type identification chip U1 is connected with one end of the resistor R1, the third pin of the audio channel type identification chip U1 is connected with one end of the resistor R2, the eighth pin of the audio channel type identification chip U1 is connected with one end of the resistor R3, the seventh pin of the audio channel type identification chip U1 is connected with one end of the resistor R4, the tenth pin of the audio channel type identification chip U1 is connected with a 5V constant voltage power supply through the inductor L1, and the other end of the resistor R1, the other end of the resistor R2, the other end of the resistor R3, the other end of the resistor R4 and the fifth pin of the audio channel type identification chip U1 are grounded.

[0011] The application is further improved, the audio signal conditioning circuit is internally provided with resistors R9, R10, R11, capacitors C6 and C7, wherein one end of the resistor R9 is connected with the Type-C interface of the smart phone, one end of the resistor R10 is connected with one end of the capacitor C6, one end of the capacitor C7 and the Type-C interface of the smart phone, the other end of the capacitor C6 is connected with the other end of the capacitor C7 and one end of the resistor R11, the other end of the resistor R11 is connected with the input end of the general sound card interface circuit, and the other end of the resistor R9 and the other end of the resistor R10 are grounded.

[0012] The USB signal to IIS signal circuit is internally provided with a signal conversion chip U3, a resistor R13 and a light emitting diode LED1, wherein the signal conversion chip U3 is provided with 48 pins, the 4th and 5th pins of the signal conversion chip U3 are connected with the 1st and 10th pins of the digital signal analog signal switching chip U2 respectively, and the 20th, 27th, 28th, 29th and 30th pins of the signal conversion chip U3 are in communication connection with the general sound card interface circuit.

[0013] The general sound card interface circuit is provided with a sound card interface CON1, the input end of the sound card interface CON1 is provided with 20 pins, the output end of the sound card interface CON1 is connected with a general sound card, the 1st and 2nd pins of the sound card interface CON1 are connected with the 1st and 9th 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 with the 2nd, 3rd, 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 with the other end of the resistor R11, and the 8th, 6th, 12th, 9th and 7th pins of the sound card interface CON1 are connected with the 20th, 27th, 28th, 29th and 30th pins of the signal conversion chip U3 respectively.

[0014] The digital signal analog signal switching chip U2 is of BCT4321N type.

[0015] The audio channel type identification chip U1 is of BL1530 type.

[0016] The signal conversion chip U3 is of CT7601 type.

[0017] The general sound card is of ITC-AU1307 type.

[0018] Compared with the prior art, the present application has the beneficial effect that a test circuit for a Type-C interface audio channel is provided, by setting a mutually coordinated digital signal-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 Type-C interface audio channel, the digital signal-analog signal switching circuit can directly output analog audio signals to a general 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 digital audio signals to the general sound card interface circuit, so that only one general sound card can be used to test whether the digital signal audio channel and the analog signal audio channel functions of the Type-C interface of a smart phone are normally running, the operation is simple, the test efficiency is greatly improved, the test cost is reduced, and the problem of low test efficiency caused by the need to use different sound cards to test the digital signal audio channel and the analog signal audio channel of the Type-C interface in the prior art is solved. BRIEF DESCRIPTION OF DRAWINGS

[0019] In order to more clearly illustrate the scheme in the present application or the prior art, the drawings needed to be used in the embodiments or the prior art description will be briefly introduced below. Obviously, the drawings in the following description are some embodiments of the present application, and other drawings can also be obtained by those skilled in the art without creative labor on the basis of these drawings.

[0020] Figure 1 A principle block diagram of a test circuit for a Type-C interface audio channel of the present application;

[0021] Figure 2 A circuit diagram of a digital signal-analog signal switching circuit of the present application;

[0022] Figure 3 A circuit diagram of an audio channel type identification circuit and an audio signal conditioning circuit of the present application;

[0023] Figure 4 A circuit diagram of a USB signal to IIS signal conversion circuit of the present application;

[0024] Figure 5 A circuit diagram of a general sound card interface circuit of the present application. DETAILED DESCRIPTION

[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 application belongs; the terminology used in the description herein is for describing particular embodiments only and is not intended to be limiting upon the scope of the application; the description herein and the claims of the application and the above description of the drawings herein use the term "comprising" and "including" and variations thereof, which are intended to cover not exclusive inclusion; the description herein and the claims of the application or the above description of the drawings herein use the terms "first", "second", etc. to distinguish different objects, not to describe a particular order.

[0026] Reference herein to "an embodiment" means that a particular feature, structure, or characteristic described in connection with the embodiment can be included in at least one embodiment of the application. The appearances of the phrase in various places in the specification are not necessarily all referring to the same embodiment, nor are they necessarily mutually exclusive or alternative embodiments. It is expressly understood that the embodiments described herein can be combined with each other.

[0027] In order to make the technical personnel in the art better understand the application scheme, the technical solutions in the embodiments of the application will be clearly and completely described below in conjunction with the drawings.

[0028] As Figures 1-5As shown, the application provides a test circuit for Type-C interface audio channel, which is arranged between the Type-C interface of a smart phone and a general sound card interface circuit, and includes a digital signal analog signal switching circuit, an audio channel type identification circuit, a USB signal to IIS signal circuit and an audio signal conditioning circuit. The digital signal analog signal switching circuit is in communication connection with the general sound card interface circuit and the Type-C interface of the smart phone. The input end of the audio channel type identification circuit and the input end of the audio signal conditioning circuit are connected with the Type-C interface of the smart phone. The output end of the digital signal analog signal switching circuit is connected with the input end of the USB signal to IIS signal circuit. The output end of the digital signal analog signal switching circuit, the output end of the audio channel type identification circuit and the output end of the audio signal conditioning circuit are all connected with the input end of the general sound card interface circuit. The USB signal to IIS signal circuit is in communication connection with the general sound card interface circuit. The Type-C interface of the smart phone can identify the audio channel type of the connected electronic device through the digital signal analog signal switching circuit and the audio channel type identification circuit. In this embodiment, the digital signal analog signal switching circuit can directly output analog audio signals to the general 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 general sound card interface circuit, so that the digital signal audio channel and the analog signal audio channel functions of the Type-C interface of the smart phone can be tested with only one general sound card, which is simple in operation, greatly improves the test efficiency and reduces the test cost.

[0029] As shown, Figure 2 The digital signal analog signal switching circuit is provided with a digital signal analog signal switching chip U2 and an inductor L2. The model of the digital signal analog signal switching chip U2 is BCT4321N. The digital signal analog signal switching chip U2 is provided with 10 pins. The 6th and 7th pins of the digital signal analog signal switching chip U2 are connected with the Type-C interface of the smart phone. The 2nd, 3rd, 5th and 8th pins of the digital signal analog signal switching chip U2 are connected with the input end of the general sound card interface circuit. The 1st and 10th pins of the digital signal analog signal switching chip U2 are connected with the input end of the USB signal to IIS signal circuit. The 9th pin of the digital signal analog signal switching chip U2 is connected with a 5V constant voltage power supply through the inductor L2. The 4th pin of the digital signal analog signal switching chip U2 is grounded. Figure 4As shown, the USB signal to IIS signal circuit is provided with a signal conversion chip U3, a resistor R13 and a light emitting diode LED1, wherein the model of the signal conversion chip U3 is CT7601, the signal conversion chip U3 is provided with 48 pins, the 4th and 5th pins of the signal conversion chip U3 are connected with the 1st and 10th pins of the digital signal analog signal switching chip U2 respectively, and the 20th, 27th, 28th, 29th and 30th pins of the signal conversion chip U3 are in communication connection with the general sound card interface circuit. In the embodiment, the USB signal to IIS signal circuit is used. In the embodiment, the digital signal analog signal switching circuit is controlled to switch by the analog switch control 3 and the analog switch control 4. In the digital signal audio channel mode, the D+ (R) and D- (L) of the Type-C interface of the smart phone are digital audio signals, the signals enter the USB signal to IIS signal circuit to be converted into IIS audio signals and are connected to the digital audio port of the general sound card; in the analog signal audio channel mode, the D+ (R) and D- (L) of the Type-C interface of the smart phone are analog audio signals, the signals enter the general sound card through the digital signal analog signal switching circuit and are connected to the analog audio port of the general sound card. Wherein, the IIS signal refers to Inter-IC Sound bus, also known as I2S, which is a serial digital audio bus protocol proposed by Philips company, IIS uses three serial buses to transmit data, and other signals (such as control signals) must be transmitted separately, in order to make the lead-out pins of the chip as few as possible, IIS only uses three serial buses.

[0030] As 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 general sound card interface circuit is provided with a sound card interface CON1, the input end of the sound card interface CON1 is provided with 20 pins, the output end of the sound card interface CON1 is connected with a general sound card, the model of the general sound card is ITC-AU1307, the 1st and 2nd pins of the sound card interface CON1 are connected with the 1st and 9th pins of an audio channel type identification chip U1 respectively, the 18th, 17th, 3rd and 4th pins of the sound card interface CON1 are connected with the 2nd, 3rd, 8th and 5th pins of a digital signal-analog signal switching chip U2 respectively, the 20th pin of the sound card interface CON1 is connected with the other end of a resistor R11, and the 8th, 6th, 12th, 9th and 7th pins of the sound card interface CON1 are connected with the 20th, 27th, 28th, 29th and 30th pins of a signal conversion chip U3 respectively. In the embodiment, the general sound card has a digital audio port, an analog audio port, a general IO port and a USB port, in the embodiment, the digital audio port is used for connecting the digital audio signal of the digital signal audio channel, the analog audio port is used for connecting the analog audio signal of the analog signal audio channel, the general IO port is used for controlling the analog switch switching, and the configuration of the sound card and the input and output of the audio data are completed through the USB.

[0033] As known from the above, the application provides a test circuit for a Type-C interface audio channel, by setting a digital signal-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 cooperation with each other in the test circuit for the Type-C interface audio channel, the digital signal-analog signal switching circuit can directly output the analog audio signal to the general 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 the digital audio signal to the general sound card interface circuit, so that only one general sound card can be used to test whether the digital signal audio channel and the analog signal audio channel of the Type-C interface of the smart phone are normally operated, the operation is simple, the test efficiency is greatly improved, the test cost is reduced, and the problem of low test efficiency caused by the need of using different sound cards to test the digital signal audio channel and the analog signal audio channel of the Type-C interface in the prior art is solved.

[0034] The above specific embodiments are the preferred embodiments of the application, and the specific implementation range of the application is not limited by the above specific embodiments, the range of the application includes but is not limited to the above specific embodiments, and any equivalent changes made according to the application are within the protection scope of the application.

Claims

1. A test circuit for a Type-C interface audio channel, arranged between a Type-C interface of a smart phone and a general sound card interface circuit, characterized in that: The digital signal analog signal switching circuit, the audio channel type identification circuit, the USB signal to IIS signal circuit and the audio signal conditioning circuit, the digital signal analog signal switching circuit and the general sound card interface circuit, the Type-C interface of the smart phone are connected in communication, the input end of the audio channel type identification circuit, the input end of the audio signal conditioning circuit and the Type-C interface of the smart phone are connected, the output end of the digital signal analog signal switching circuit and the input end of the USB signal to IIS signal circuit are connected, the output end of the digital signal analog signal switching circuit, the output end of the audio channel type identification circuit, the output end of the audio signal conditioning circuit are connected with the input end of the general sound card interface circuit, the USB signal to IIS signal circuit and the general sound card interface circuit are connected in communication, the Type-C interface of the smart phone can identify the audio channel type of the electronic equipment accessed through the digital signal analog signal switching circuit and the audio channel type identification circuit, the digital signal analog signal switching circuit can directly output analog signal to the general 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 signal to the general sound card interface circuit.

2. The test circuit for Type-C interface audio channel according to claim 1, characterized in that: The digital signal analog signal switching circuit is provided with a digital signal analog signal switching chip U2 and an inductor L2, wherein the digital signal analog signal switching chip U2 is provided with 10 pins, the 6th and 7th pins of the digital signal analog signal switching chip U2 are connected with the Type-C interface of the smart phone, the 2nd, 3rd, 5th and 8th pins of the digital signal analog signal switching chip U2 are connected with the input end of the general sound card interface circuit, the 1st and 10th pins of the digital signal analog signal switching chip U2 are connected with the input end of the USB signal to IIS signal circuit, the 9th pin of the digital signal analog signal switching chip U2 is connected with a 5V constant voltage power supply through the inductor L2, and the 4th pin of the digital signal analog signal switching chip U2 is grounded.

3. The test circuit for Type-C interface audio channels according to claim 2, characterized in that: The audio channel type identification circuit is internally provided with an audio channel type identification chip U1, resistors R1, R2, R3, R4, and an inductor L1, wherein the audio channel type identification chip U1 is provided with 10 pins, the 4th and 6th pins of the audio channel type identification chip U1 are connected with the Type-C interface of the smartphone, the 1st and 9th pins of the audio channel type identification chip U1 are connected with the input end of the general sound card interface circuit, the 2nd pin of the audio channel type identification chip U1 is connected with one end of the resistor R1, the 3rd pin of the audio channel type identification chip U1 is connected with one end of the resistor R2, the 8th pin of the audio channel type identification chip U1 is connected with one end of the resistor R3, the 7th pin of the audio channel type identification chip U1 is connected with one end of the resistor R4, the 10th pin of the audio channel type identification chip U1 is connected with a 5V constant voltage power supply through the inductor L1, and the other end of the resistor R1, the other end of the resistor R2, the other end of the resistor R3, the other end of the resistor R4, and the 5th pin of the audio channel type identification chip U1 are grounded.

4. The test circuit for Type-C interface audio channels according to claim 3, characterized in that: The audio signal conditioning circuit is internally provided with resistors R9, R10, R11, capacitors C6 and C7, wherein one end of the resistor R9 is connected with the Type-C interface of the smartphone, one end of the resistor R10 is connected with one end of the capacitor C6, one end of the capacitor C7, and the Type-C interface of the smartphone, the other end of the capacitor C6 is connected with the other end of the capacitor C7 and one end of the resistor R11, the other end of the resistor R11 is connected with the input end of the general sound card interface circuit, and the other end of the resistor R9 and the other end of the resistor R10 are grounded.

5. The test circuit for Type-C interface audio channels according to claim 4, characterized in that: The USB signal to IIS signal circuit is internally provided with a signal conversion chip U3, a resistor R13, and a light emitting diode LED1, wherein the signal conversion chip U3 is provided with 48 pins, the 4th and 5th pins of the signal conversion chip U3 are respectively connected with the 1st and 10th pins of the digital signal analog signal switching chip U2, and the 20th, 27th, 28th, 29th, and 30th pins of the signal conversion chip U3 are in communication connection with the general sound card interface circuit.

6. The test circuit for Type-C interface audio channels according to claim 5, characterized in that: The general sound card interface circuit is provided with a sound card interface CON1, the input end of the sound card interface CON1 is provided with 20 pins, the output end of the sound card interface CON1 is connected with a general sound card, the 1st and 2nd pins of the sound card interface CON1 are connected with the 1st and 9th 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 with the 2nd, 3rd, 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 with the other end of the resistor R11, the 8th, 6th, 12th, 9th and 7th pins of the sound card interface CON1 are connected with the 20th, 27th, 28th, 29th and 30th pins of the signal conversion chip U3 respectively.

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

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

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

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

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