Expansion circuit and expansion device of USB Type-C interface

Abstract

The utility model discloses an expansion circuit and an expansion device of a USB Type-C interface, which realize audio expansion of the USB Type-C interface of terminal equipment through a circuit consisting of the USB Type-C interface, a signal switching chip, a digital audio coding and decoding chip and an earphone audio interface. According to the USB Type-C interface of the terminal equipment, the extension of the functions of the USB Type-C interface of the terminal equipment except for the audio is realized through a circuit consisting of one USB Type-C interface, the signal switching chip, the signal overturning chip and the other USB Type-C interface, and equivalently, after the audio of the USB Type-C interface of the terminal equipment is separated, the other functions are also kept. And the expansion requirements of a user on the USB Type-C interface of the terminal equipment in various application scenes can be met.

Description

TECHNICAL FIELD

[0001] The utility model relates to the field of USB interface peripheral equipment especially, a kind of extension circuit and extension device of USB Type-C interface. BACKGROUND

[0002] At present, most of the tablet computers even mobile phones on the market cancel 3.5mm audio interface, only keep a USB-C interface as the only physical interface of device and outside connection.This USB-C (Type-C) interface undertakes the data transmission and charging function of tablet computer, when using tablet computer, charging or transmitting data can only be two choices, cannot be carried out simultaneously.There is a kind of product of USB-C conversion USB-C charging+audio two interfaces on the market, can satisfy the demand of simultaneous charging+listening to songs, but the extended USB-C interface only supports charging function, and the other functions supported by the USB-C interface of tablet computer are discarded.

[0003] Therefore, the existing USB Type-C interface expansion function needs to be improved and improved. UTILITY MODEL CONTENTS

[0004] In view of the above technical problems, the utility model provides a kind of extension circuit and extension device of USB Type-C interface, not only can expand the charging function of terminal equipment USB Type-C interface, but also can expand other functions supported by terminal equipment USB Type-C interface.

[0005] An embodiment provides an extension circuit of USB Type-C interface, including: two USB Type-C interfaces, earphone audio interface, signal switching chip, digital audio codec chip and signal flip chip;

[0006] One of two USB Type-C interfaces is used to connect with terminal equipment needing to expand interface;

[0007] The first type data pin of one USB Type-C interface is connected with the first input and output end of the signal switching chip, the digital audio codec chip is connected with the second input and output end of the signal switching chip, and the first type data pin of another USB Type-C interface is connected with the third input and output end of the signal switching chip;

[0008] The second type data pin of one USB Type-C interface is connected with the second type data pin of another USB Type-C interface through the signal flip chip;

[0009] The digital audio codec chip is configured to receive a digital audio signal output by the signal switching chip through a USB Type-C interface, decode the digital audio signal into left and right channel audio, and output the left and right channel audio to the earphone audio interface; receive a microphone signal output by the earphone audio interface, encode the microphone signal into a digital audio signal, and output the digital audio signal to a USB Type-C interface through the signal switching chip;

[0010] The signal switching chip is configured to switch signals to connect two of the first input / output terminal, the second input / output terminal, and the third input / output terminal.

[0011] The signal flipping chip is configured to flip signals input / output between second type data pins of two USB Type-C interfaces to support normal and reverse insertion of the two USB Type-C interfaces.

[0012] An embodiment provides an extension circuit further comprising a charging chip supporting a PD charging protocol.

[0013] A VBUS pin of one USB Type-C interface is connected to a VBUS pin of another USB Type-C interface through the charging chip; and a CC pin of one USB Type-C interface is connected to a CC pin of another USB Type-C interface through the charging chip.

[0014] An embodiment provides an extension circuit, and the charging chip comprises:

[0015] A communication circuit is configured to communicate with a terminal device connected to the USB Type-C interface through a CC pin of the USB Type-C interface to determine whether the terminal device connected to the USB Type-C interface is a data type device or a charging type device.

[0016] A charging control circuit connected to the communication circuit is configured to, when the terminal device connected to one USB Type-C interface is a charging type device, output power transmitted by a VBUS pin of the USB Type-C interface to a VBUS pin of another USB Type-C interface to charge a terminal device connected to the other USB Type-C interface.

[0017] A first control circuit, an input terminal of the first control circuit is connected to the communication circuit, and an output terminal of the first control circuit is connected to the signal switching chip, the first control circuit is configured to, when neither of the terminal devices connected to the two USB Type-C interfaces is a charging type device, output a first control signal to the signal switching chip to make the signal switching chip connect the first input / output terminal and the third input / output terminal.

[0018] The second control circuit has an input end connected with the communication circuit, and has an output end connected with the signal flip chip. The second control circuit is configured to, when neither of the two USB Type-C interfaces is connected with a charging device, determine the positive and negative insertion of the two USB Type-C interfaces through signals of CC pins of the two USB Type-C interfaces, and output a second control signal to the signal flip chip according to a determination result, so that the signal input and output sequence of the signal flip chip is consistent with the determination result, to support the positive and negative insertion of the two USB Type-C interfaces.

[0019] The extension circuit further includes an auxiliary power supply. The auxiliary power supply is connected with the communication circuit, VBUS pins of the two USB Type-C interfaces, and at least one of the signal switching chip, the digital audio codec chip, the signal flip chip, and the charging chip.

[0020] The auxiliary power supply is configured to, when one of the two USB Type-C interfaces is not connected with a charging device, take power from a VBUS pin of the other USB Type-C interface, and provide the power to at least one of the signal switching chip, the digital audio codec chip, the signal flip chip, and the charging chip. When one of the two USB Type-C interfaces is connected with a charging device, the auxiliary power supply takes power from a VBUS pin of the USB Type-C interface, and provides the power to at least one of the signal switching chip, the digital audio codec chip, the signal flip chip, and the charging chip.

[0021] The first type of data pin supports data transmission of a low-version USB interface, and the second type of data pin supports data transmission of a high-version USB interface. The low-version USB interface includes a USB2.0 interface and a USB interface lower than the USB2.0 interface. The high-version USB interface includes a USB3.0 interface and a USB interface higher than the USB3.0 interface.

[0022] The first type of data pin includes a D+ pin and a D- pin, and the second type of data pin includes a TX pin and a RX pin.

[0023] The second type of data pin includes four groups of TX pins and RX pins. The charging chip is connected with one CC pin of one USB Type-C interface, and is further connected with two CC pins of the other USB Type-C interface. One of the two USB Type-C interfaces is a male head, and the other is a female head.

[0024] The extension circuit provided by an embodiment comprises a 3.5mm earphone audio interface.

[0025] An embodiment provides an extension device of a USB Type-C interface, comprising a shell and a circuit board arranged in the shell, and the circuit board is provided with the extension circuit as described above.

[0026] In the extension device provided by an embodiment, the two USB Type-C interfaces and the earphone audio interface are exposed to the shell.

[0027] The extension circuit and the extension device of the USB Type-C interface provided by the embodiments of the present application comprise a circuit composed of one USB Type-C interface, a signal switching chip, a digital audio codec chip and an earphone audio interface, and realize the audio extension of the USB Type-C interface of a terminal device. The extension circuit and the extension device of the USB Type-C interface provided by the embodiments of the present application comprise a circuit composed of one USB Type-C interface, a signal switching chip, a signal inverting chip and another USB Type-C interface, and realize the extension of the functions of the USB Type-C interface of a terminal device except audio, which is equivalent to dividing the audio of the USB Type-C interface of the terminal device and retaining other functions. The extension circuit and the extension device of the USB Type-C interface provided by the embodiments of the present application can meet the extension requirements of various application scenarios of the USB Type-C interface of a terminal device. BRIEF DESCRIPTION OF DRAWINGS

[0028] Figure 1 A structural block diagram of an embodiment of the extension circuit of the USB Type-C interface provided by the present application is provided.

[0029] Figure 2 A schematic diagram of an embodiment of the extension circuit of the USB Type-C interface provided by the present application is provided.

[0030] Figure 3 A structural block diagram of an embodiment of the charging chip of the present application is provided. DETAILED DESCRIPTION

[0031] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor fall within the protection scope of the present application.

[0032] The utility model discloses can extend the USB -C interface (USB Type -C interface) of terminal equipment such as tablet computer, and the USB -C interface of tablet computer is extended into a 3.5mm audio interface and a USB -C interface, wherein the extended USB -C interface supports charging to tablet computer, in addition, can also extend other functions supported by the USB -C interface of tablet computer, that is, the USB -C interface of tablet computer supports what function, and the extended USB -C interface also supports what function. For example, some tablet computers support native DisplayPort (using a USB3.0 data line can transmit picture) output through USB -C, so the application extended USB -C interface also supports native DisplayPort output. The following will be described in detail through some embodiments.

[0033] As Figure 1 And 2 The utility model discloses a USB Type -C interface's extension circuit, include: two USB Type -C interface, earphone audio interface 40, signal switching chip 20, digital audio codec chip 30 and signal flip chip 50. Two USB Type -C interface can be called USB -C (Type -C) uplink interface 10 and USB -C (Type -C) downlink interface 60, to distinguish.

[0034] One of two USB Type -C interfaces is used to connect with the terminal equipment needing to extend interface. That is, the extension circuit can support the positive and negative insertion of two USB Type -C interfaces. The terminal equipment can be tablet computer, mobile phone, smart wearable device, notebook computer, desktop computer and the like, as long as the device with USB Type -C interface. Whether the two USB Type -C interfaces adopt male head or female head is not limited, and the embodiment takes one of the two USB Type -C interfaces as male head and the other as female head as an example for description. Considering that the terminal equipment needing to extend interface is tablet computer, mobile phone and the like, the USB Type -C interface of which is usually female head, so the male head USB Type -C interface in the extension circuit is more commonly used, which can be called USB -C uplink interface 10, and the other female head USB Type -C interface can be called USB -C downlink interface 60.

[0035] After the USB -C uplink interface 10 is plugged with the USB Type -C interface of terminal equipment, Figure 1 The extension circuit shown in the drawing can extend the USB Type -C interface of terminal equipment into USB -C downlink interface 60 and earphone audio interface 40, which is very convenient. Of course, in other embodiments, the USB -C uplink interface 10 can also be female head, and the USB -C downlink interface 60 can also be male head.

[0036] One USB Type-C interface is connected with a terminal device which needs to expand interface, and the other USB Type-C interface can be connected with other terminal devices, chargers or display screens and the like.

[0037] The terminal device connected with the USB Type-C interface can be generally divided into two kinds, one is a data type device, such as the aforementioned various computers, mobile phones, display screens and the like, which can transmit data to the terminal device connected with the other USB Type-C interface of the expansion circuit and / or receive data transmitted by the terminal device connected with the other USB Type-C interface of the expansion circuit, and the other is a charging type device, such as a charger and the like, which can charge the terminal device connected with the other USB Type-C interface of the expansion circuit.

[0038] The earphone audio interface 40 can be used to connect earphones, microphones and the like. The present embodiment is described by taking a 3.5mm earphone audio interface as an example.

[0039] The first type data pin of one USB Type-C interface is connected with the first input / output end 1 of the signal switching chip 20, the digital audio codec chip 30 is connected with the second input / output end 2 of the signal switching chip 20, and the first type data pin of the other USB Type-C interface is connected with the third input / output end 3 of the signal switching chip 20.

[0040] The second type data pin of one USB Type-C interface is connected with the second type data pin of the other USB Type-C interface through the signal inverting chip 50. The first type data pin is different from the second type data pin.

[0041] The signal switching chip 20 is used to switch signals to turn on two of the first input / output end 1, the second input / output end 2 and the third input / output end 3, that is, two of the three can be selected to be turned on between one USB Type-C interface, the other USB Type-C interface and the digital audio codec chip 30. The signal switching chip 20 can be, for example, a signal switching chip with a model number of WAS7222Q, a signal switching chip with a model number of DIO3212 or a signal switching chip with a model number of MSUSB30 / N.

[0042] The signal flip chip 50 is used for input and output signal flip between the second type data pins of the two USB Type-C interfaces to support the positive and negative insertion of the two USB Type-C interfaces. For example, the USB-C uplink interface 10 is connected with a tablet computer, and the USB-C downlink interface 60 is connected with a display. The signal flip chip 50 does not flip, the tablet computer outputs data to the signal flip chip 50 through the second type data pins of the USB-C uplink interface 10, and the signal flip chip 50 outputs the data to the display connected with the USB-C downlink interface 60 through the second type data pins of the USB-C downlink interface 60, so that the display displays the content in the tablet computer. Conversely, if the USB-C uplink interface 10 is connected with a display, and the USB-C downlink interface 60 is connected with a tablet computer, the signal flip chip 50 flips the input and output (also called inversion), the tablet computer outputs data to the signal flip chip 50 through the second type data pins of the USB-C downlink interface 60, and the signal flip chip 50 outputs the data to the display connected with the USB-C uplink interface 10 through the second type data pins of the USB-C uplink interface 10, so that the display displays the content in the tablet computer. Since the data directions of the input and output of the signal flip chip 50 are opposite in the two cases, it is called signal flip. In this way, the positive and negative insertion of the two USB Type-C interfaces is realized. The signal flip chip 50 can be, for example, a signal flip chip with model number VL171 or a signal flip chip with model number VL170.

[0043] The digital audio codec chip 30 is used for receiving the digital audio signal (USB digital audio signal) output by the signal switching chip 20 of one USB Type-C interface 10, decoding the digital audio signal into left and right channel audio (left channel audio + right channel audio) and outputting to the earphone audio interface 40, so that the earphone connected with the earphone audio interface 40 can sound based on the audio. The digital audio codec chip 30 also receives the microphone signal output by the earphone audio interface 40, encodes the microphone signal into a digital audio signal (USB digital audio signal) and outputs to one USB Type-C interface 10 through the signal switching chip 20, that is, the audio collected by the microphone can be given to the terminal device such as a tablet computer through the expansion circuit. The digital audio codec chip can be, for example, a digital audio codec chip with model number AB229 or a digital audio codec chip with model number KT0210.

[0044] The utility model discloses an extension circuit, can also include the charging chip 70 of supporting PD charging agreement. One USBType -C interface's VBUS pin (also called power supply positive pole pin, power supply pin) is connected through the charging chip 70 another USBType -C interface's VBUS pin, in this embodiment, VBUS pin is USB Type -C interface's A4 pin, A9 pin, B4 pin and B9 pin. One USB Type -C interface's CC pin (configuration channel pin, also called CC agreement communication pin) is connected through the charging chip 70 another USB Type -C interface's CC pin. Figure 2 In the embodiment shown, the charging chip 70 connects one CC pin (CC1_1) of the USB-C uplink interface 10 and also connects two CC pins (CC2_1, CC2_2) of the USB-C downlink interface 60. The two CC pins can be A5 pin and B5 pin of the USB Type-C interface.

[0045] The charging chip 70 can be a three-port PD (Power Delivery) charging agreement control chip. The charging chip 70 is responsible for negotiation with the tablet computer connected to the USB-C uplink interface 10 and the charger connected to the USB-C downlink interface 60. After the negotiation is completed, the charger charges the tablet computer through the USB-C downlink interface 60 according to the agreed mode. When the USB-C downlink interface 60 is not connected to the charger but other devices, the charging chip 70 judges the positive and negative insertion through the CC2_1 and CC2_2 signals to control whether the signal inversion chip 50 inverts the signal. The charging chip 70 controls the signal switching chip 20 to switch the USB2.0 signal of the USB-C uplink interface 10 to the USB-C downlink interface 60. The charging chip 70 can be a USB PD protocol chip with model number LDR6020 or a charging control chip with model number CH226.

[0046] Specifically, as shown in Figure 3 The charging chip 70 includes a communication circuit 710, a charging control circuit 720 connected to the communication circuit 710, a first control circuit 730 and a second control circuit 740 in one embodiment.

[0047] The communication circuit 710 is used for communicating with the terminal device connected through the CC pin of the USB Type-C interface to determine whether the terminal device connected through the USB Type-C interface is a data class device or a charging class device. That is, the type of the terminal device connected through the two USB Type-C interfaces can be known through communication.

[0048] The charging control circuit 720 is configured to output the power transmitted by the VBUS pin of one USB Type-C interface to the VBUS pin of another USB Type-C interface to charge the terminal device connected to the other USB Type-C interface when the terminal devices connected to the two USB Type-C interfaces are both charging devices. For example, the USB-C uplink interface 10 is connected to a tablet computer, and the USB-C downlink interface 60 is connected to a charger. The power of the charger can be output to the tablet computer through the VBUS pin of the USB-C downlink interface 60, the charging control circuit 720, and the VBUS pin of the USB-C uplink interface 10. When the two USB Type-C interfaces are reversely connected, the power of the tablet computer can be output to the charger.

[0049] The input end of the first control circuit 730 is connected to the communication circuit 710, and the output end of the first control circuit 730 is connected to the signal switching chip 20. The first control circuit 730 is configured to output a first control signal to the signal switching chip 20 to make the signal switching chip 20 connect the first input / output terminal 1 and the third input / output terminal 3 when the terminal devices connected to the two USB Type-C interfaces are both non-charging devices. For example, the USB-C uplink interface 10 is connected to a tablet computer, and the USB-C downlink interface 60 is connected to a display. The first control circuit 730 outputs a first control signal to the signal switching chip 20 to make the signal switching chip 20 connect the first input / output terminal 1 and the third input / output terminal 3, so that the first type data pins (such as D+ / D- pins) of the USB-C uplink interface 10 and the USB-C downlink interface 60 are connected, and some data of the tablet computer can be transmitted to the display through the first type data pins.

[0050] The input end of the second control circuit 740 is connected to the communication circuit 710, and the output end of the second control circuit 740 is connected to the signal inversion chip 50. The second control circuit 740 is configured to determine the connection of the two USB Type-C interfaces according to the signals of the CC pins of the two USB Type-C interfaces when the terminal devices connected to the two USB Type-C interfaces are both non-charging devices, and output a second control signal to the signal inversion chip 50 according to the determination result to make the signal input / output order of the signal inversion chip 50 consistent with the determination result to support the connection of the two USB Type-C interfaces. For example, the USB-C uplink interface 10 is connected to a tablet computer, and the USB-C downlink interface 60 is connected to a display. This is a normal connection, and the signal inversion chip 50 does not invert the signal. If the USB-C uplink interface 10 is connected to a display, and the USB-C downlink interface 60 is connected to a tablet computer. This is a reverse connection, and the signal inversion chip 50 inverts the signal.

[0051] The first type data pin includes a D+ pin (data positive pin) and a D- pin (data negative pin); and the second type data pin includes a TX pin and a RX pin. Figure 2In the embodiment shown, the second type of data pin includes four groups of TX pin and RX pin.

[0052] In the embodiment, the first type of data pin supports data transmission of a low version USB interface, and the second type of data pin supports data transmission of a high version USB interface. The low version USB interface can include a USB2.0 interface and a USB interface lower than the USB2.0 interface, and the high version USB interface includes a USB3.0 interface and a USB interface higher than the USB3.0 interface. Taking the USB2.0 and the USB3.0 as examples, the first type of data pin can be A6 and A7 pins in a USB Type-C interface, which are a group of USB2.0 data pins, and the second type of data pin can be A2 / A3 pins, B10 / B11 pins, B2 / B3 pins and A10 / A11 pins, that is, four groups of USB3.0 data pins.

[0053] The signal flipping chip 50 can be a USB3.0 signal flipping control chip, which is responsible for internally connecting the four groups of USB3.0 signals of the USB-C uplink interface 10 with the four groups of USB3.0 signals of the USB-C downlink interface 60, and the chip can internally select whether to flip the signals before linking them to the USB-C downlink interface 60 to support normal and reverse insertion. The signal switching chip 20 can be a USB2.0 signal switching chip, which is responsible for controlling the USB2.0 signal of the USB-C uplink interface 10 to be connected to the USB digital audio codec chip 30 or to the USB-C downlink interface 60. The USB3.0 can transmit video data, so as long as the tablet computer supports native DisplayPort output through USB-C (a USB3.0 data line can be used for picture transmission), the USB-C interface of the expansion circuit also supports native DisplayPort output.

[0054] The expansion circuit provided by the utility model can also include an auxiliary power supply 80. The auxiliary power supply 80 is connected with the communication circuit 710, the VBUS pins of the two USB Type-C interfaces, and is also connected with at least one of the signal switching chip 20, the digital audio codec chip 30, the signal flipping chip 50 and the charging chip 70. In the embodiment, the auxiliary power supply 80 is connected with the four components.

[0055] The auxiliary power supply 80 is used to take power from the VBUS pin of another USB Type-C interface when one USB Type-C interface is not connected with a charging type device (for example, when the USB-C downstream interface 60 is not connected with a charging type device), and provide power for at least one of the signal switching chip 20, the digital audio codec chip 30, the signal inversion chip 50 and the charging chip 70, and the embodiment is used to provide power for the four chips as an example. The auxiliary power supply 80 is also used to take power from the VBUS pin of one USB Type-C interface when the USB Type-C interface is connected with a charging type device (for example, when the USB-C downstream interface 60 is connected with a charging type device), and provide power for at least one of the signal switching chip 20, the digital audio codec chip 30, the signal inversion chip 50 and the charging chip 70, and the embodiment is used to provide power for the four chips as an example.

[0056] From the above, the utility model optimizes the shortcomings of various applications on the market, not only expands the function of charging and listening to songs, but also expands the full function. By restructuring the link of all signal lines in the USB-C interface of the tablet computer on the adapter board, the functions supported by the USB-C port of the tablet computer are all expanded. Then, the PD charging protocol control chip communicates through the protocol, and the expanded USB-C interface can also work normally when plugged in reversely (the USB-C interface design supports reverse insertion).

[0057] Based on the above-mentioned expansion circuit, the utility model also provides a kind of expansion device of USB Type-C interface, comprising: shell and circuit board being arranged in shell.There is expansion circuit as described above on circuit board.The expansion device is small and portable, and can be used with various mobile terminals.An embodiment, two USB Type-C interfaces, earphone audio interface are exposed to shell, facilitate plug and play.

[0058] The above embodiments are only used to illustrate the technical solutions of the utility model, but not limit them; although the utility model is described in detail with reference to the foregoing embodiments, those skilled in the art should understand that: it can still modify the technical solutions recorded in the foregoing embodiments, or make equivalent replacement to part of technical features; and these modifications or replacements do not make the essence of corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the utility model.

Claims

1. An extension circuit of a USB Type-C interface, characterized in that, The application relates to a USB Type-C interface expansion device. The device comprises: two USB Type-C interfaces, an earphone audio interface, a signal switching chip, a digital audio codec chip and a signal inversion chip; one of the two USB Type-C interfaces is used for connecting with a terminal device requiring an expanded interface; a first type data pin of one USB Type-C interface is connected with a first input / output end of the signal switching chip, the digital audio codec chip is connected with a second input / output end of the signal switching chip, and a first type data pin of the other USB Type-C interface is connected with a third input / output end of the signal switching chip; a second type data pin of one USB Type-C interface is connected with a second type data pin of the other USB Type-C interface through the signal inversion chip; the digital audio codec chip is used for receiving digital audio signals output by one USB Type-C interface through the signal switching chip, decoding the digital audio signals into left and right channel audio and outputting the left and right channel audio to the earphone audio interface, receiving microphone signals output by the earphone audio interface and encoding the microphone signals into digital audio signals and outputting the digital audio signals to one USB Type-C interface through the signal switching chip; the signal switching chip is used for switching signals to turn on two of the first input / output end, the second input / output end and the third input / output end; 2. The extension circuit of claim 1, wherein, the signal inversion chip is used for inverting input / output signals between the second type data pins of the two USB Type-C interfaces to support the positive and negative insertion of the two USB Type-C interfaces. The device further comprises a charging chip supporting a PD charging protocol; 3. The extension circuit of claim 2, wherein, a VBUS pin of one USB Type-C interface is connected with a VBUS pin of the other USB Type-C interface through the charging chip, and a CC pin of one USB Type-C interface is connected with a CC pin of the other USB Type-C interface through the charging chip. The charging chip comprises: a communication circuit used for communicating with a terminal device connected with the USB Type-C interface through the CC pin of the USB Type-C interface to determine whether the terminal device connected with the USB Type-C interface is a data type device or a charging type device; a charging control circuit connected with the communication circuit and used for outputting electric energy transmitted by the VBUS pin of one USB Type-C interface to the VBUS pin of the other USB Type-C interface to charge a terminal device connected with the other USB Type-C interface when the terminal device connected with one USB Type-C interface is a charging type device. A first control circuit, an input end of the first control circuit is connected with the communication circuit, and an output end of the first control circuit is connected with the signal switching chip, and the first control circuit is configured to output a first control signal to the signal switching chip to make the signal switching chip connect the first input / output end and the third input / output end when neither of the two USB Type-C interfaces is connected with a charging device. A second control circuit, an input end of the second control circuit is connected with the communication circuit, and an output end of the second control circuit is connected with the signal flip chip, and the second control circuit is configured to determine the positive and negative insertion of the two USB Type-C interfaces through the signals of the CC pins of the two USB Type-C interfaces, and then output a second control signal to the signal flip chip according to the determination result to make the signal input / output sequence of the signal flip chip consistent with the determination result to support the positive and negative insertion of the two USB Type-C interfaces.

4. The extension circuit of claim 3, wherein, The auxiliary power supply is connected with the communication circuit, the VBUS pins of the two USB Type-C interfaces, and at least one of the signal switching chip, the digital audio codec chip, the signal flip chip, and the charging chip. The auxiliary power supply is configured to take power from the VBUS pin of one of the two USB Type-C interfaces when the other USB Type-C interface is not connected with a charging device, and provide the power to at least one of the signal switching chip, the digital audio codec chip, the signal flip chip, and the charging chip, and take power from the VBUS pin of the USB Type-C interface connected with the charging device, and provide the power to at least one of the signal switching chip, the digital audio codec chip, the signal flip chip, and the charging chip.

5. The extension circuit of claim 1, wherein, The first type of data pin supports data transmission of a low version USB interface, and the second type of data pin supports data transmission of a high version USB interface; the low version USB interface includes a USB2.0 interface and a USB interface lower than the USB2.0 interface; and the high version USB interface includes a USB3.0 interface and a USB interface higher than the USB3.0 interface.

6. The extension circuit of claim 2, wherein, The first type of data pin includes a D+ pin and a D- pin; and the second type of data pin includes a TX pin and a RX pin.

7. The extension circuit of claim 6, wherein, The second type of data pin includes four groups of TX pins and RX pins; the charging chip is connected with one CC pin of one of the two USB Type-C interfaces and two CC pins of the other USB Type-C interface; one of the two USB Type-C interfaces is a male head, and the other is a female head.

8. The extension circuit of claim 1, wherein, The earphone audio interface is a 3.5mm earphone audio interface.

9. An extension device for a USB Type-C interface, comprising: A shell and a circuit board arranged in the shell, characterized in that the circuit board is provided with the expansion circuit according to any one of claims 1-8.

10. The extension device of claim 9, wherein, The two USB Type-C interfaces and the earphone audio interface are exposed outside the shell.

Images