Micro USB interface integrated multiplexing circuit and electronic equipment

Abstract

The present invention provides a Micro USB interface comprehensive multiplexing circuit and electronic device, which relates to the technical field of interface circuits. The circuit includes a Micro USB interface, a USB Switch chip, a USB Audio Codec chip, a USB A-type interface, a headphone interface, and an inductor; the ID pin of the Micro USB interface is respectively connected to the SEL pin of the USB Switch chip and the first left channel pin of the headphone interface; the second left channel pin of the headphone interface is connected to a ground signal after being connected in series with the inductor; the USB data pin of the USB Audio Codec chip and the USB data pin of the USB A-type interface are respectively connected to the first group of USB data pin pairs and the second group of USB data pin pairs of the USB Switch chip. The Micro USB interface comprehensive multiplexing circuit and electronic device provided by the embodiment of the present invention can realize the simultaneous use of voice function, charging function, and USB data transmission function through one Micro USB interface, which is more convenient to use and improves the user experience.

Description

Technical Field

[0001] The present invention relates to the technical field of interface circuits, and in particular to a Micro USB interface comprehensive multiplexing circuit and electronic equipment. Background Art

[0002] At present, the hardware design architecture of USB OTG headsets on the market is that the USB OTG function is connected to the USB AudioCodec chip, and the USB Audio Codec chip is then connected to the wired headset, and the USB Audio Codec chip is used as a USB slave device. At present, the USB OTG power supply circuit has been integrated into the charging chip on mobile phone chips. The USB OTG power supply circuit and the battery charging circuit follow the same path. To realize the OTG function, the mobile phone battery voltage is boosted to 5V through the Boost function circuit inside the charging chip, and then the 5V input pin of the charging chip outputs a 5V voltage to power the OTG peripheral. To realize the charging function, the input end of the charging chip must be used as a 5V input end, so it is contradictory to realize the OTG headset function and take into account charging at the same time. Summary of the invention

[0003] In view of this, the purpose of the present invention is to provide a Micro USB interface comprehensive multiplexing circuit and electronic device, which can realize the simultaneous use of Micro USB interface OTG headset function and charging function, and this electronic device can also be used as a USB data cable, which is more convenient to use and improves the user experience.

[0004] In the first aspect, an embodiment of the present invention provides a Micro USB interface integrated multiplexing circuit, including: a MicroUSB interface, a USB Switch chip, a USB Audio Codec chip, a USB Type A interface, a headphone interface and an inductor; the ID pin of the Micro USB interface is respectively connected to the SEL pin of the USB Switch chip and the first left channel pin of the headphone interface; the second left channel pin of the headphone interface is connected in series with the inductor and then connected to a ground signal; the USB data pin of the USB Audio Codec chip and the USB data pin of the USB Type A interface are respectively connected to the first group of USB data pin pairs and the second group of USB data pin pairs of the USB Switch chip.

[0005] In combination with the first aspect, an embodiment of the present invention provides a first possible implementation scheme of the first aspect, wherein the above-mentioned circuit also includes: an OTG power supply circuit, a USB charging circuit and a diode; the USB5V pin of the Micro USB interface is respectively connected to the IN pin of the USB charging circuit and the cathode of the diode, and the anode of the diode is connected to the OUT pin of the OTG power supply circuit.

[0006] In combination with the first possible implementation of the first aspect, the embodiment of the present invention provides a second possible implementation of the first aspect, wherein the OTG power supply circuit is a 5V boost converter chip.

[0007] In combination with the first possible implementation of the first aspect, the embodiment of the present invention provides a third possible implementation of the first aspect, wherein the forward voltage drop of the diode is less than 0.3V, and the reverse breakdown voltage of the diode is greater than 10V.

[0008] In combination with the first aspect, the embodiment of the present invention provides a fourth possible implementation of the first aspect, wherein the headphone jack is a 3.5 mm headphone jack.

[0009] In combination with the fourth possible implementation of the first aspect, the embodiment of the present invention provides a fifth possible implementation of the first aspect, wherein the headphone interface is a four-section headphone interface.

[0010] In combination with the first aspect, the embodiment of the present invention provides a sixth possible implementation of the first aspect, wherein the USB Switch chip is a double-pole double-throw chip.

[0011] In combination with the first aspect, the embodiment of the present invention provides a seventh possible implementation of the first aspect, wherein the USB Audio Codec chip is a PCM2912 series chip.

[0012] In combination with the first aspect, the embodiment of the present invention provides an eighth possible implementation of the first aspect, wherein the inductance of the inductor is 10 mH.

[0013] In a second aspect, an embodiment of the present invention further provides an electronic device, which includes the Micro USB interface integrated multiplexing circuit provided by the first aspect and one of its possible implementations.

[0014] The embodiments of the present invention bring the following beneficial effects:

[0015] An embodiment of the present invention provides a Micro USB interface comprehensive multiplexing circuit and electronic device, the circuit comprising a Micro USB interface, a USB Switch chip, a USB Audio Codec chip, a USB A-type interface, a headphone interface and an inductor; the ID pin of the Micro USB interface is respectively connected to the SEL pin of the USB Switch chip and the first left channel pin of the headphone interface; the second left channel pin of the headphone interface is connected in series with the inductor and then connected to a ground signal; the USB data pin of the USB Audio Codec chip and the USB data pin of the USB A-type interface are respectively connected to the first group of USB data pin pairs and the second group of USB data pin pairs of the USB Switch chip. The Micro USB interface comprehensive multiplexing circuit provided by the embodiment of the present invention realizes the simultaneous use of charging function and headphone function, and the simultaneous use of USB data transmission and charging function by arranging a USB A-type interface and a headphone interface in the circuit; by connecting an inductor in series with the left channel pin of the headphone interface to ground, it can not only ensure that the left channel sound can be transmitted to the headphone, but also realize the headphone insertion detection function; by using a USB Switch chip to switch the USB signal channel in real time, the headphone function and the USB data function can be taken into account in a time-sharing manner; by separating the OTG power supply circuit and the USB charging circuit, and connecting a diode in series at the output end of the OTG power supply circuit, the current is prevented from flowing back to the OTG power supply circuit when the charger is charging; the circuit can realize the simultaneous use of the OTG headphone function and the charging function of the Micro USB interface, and can also realize the USB data transmission function, which is more convenient to use and improves the user experience.

[0016] Other features and advantages of the present disclosure will be set forth in the following description, or some features and advantages may be inferred or unambiguously determined from the description, or may be learned by implementing the above-mentioned technology of the present disclosure.

[0017] In order to make the above-mentioned objectives, features and advantages of the present disclosure more obvious and easy to understand, preferred embodiments are specifically cited below and described in detail with reference to the attached drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In order to more clearly illustrate the specific implementation methods of the present invention or the technical solutions in the prior art, the drawings required for use in the specific implementation methods or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some implementation methods of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0019] Figure 1 A USB OTG headset architecture diagram;

[0020] Figure 2 This is a schematic diagram of the internal structure of a headphone jack;

[0021] Figure 3 This is a schematic diagram of a 3.5mm American standard headphone plug;

[0022] Figure 4 A schematic diagram of a connection of a Micro USB interface integrated multiplexing circuit provided by an embodiment of the present invention;

[0023] Figure 5 A schematic diagram of an application scenario of a Micro USB interface integrated multiplexing circuit;

[0024] Figure 6 A block diagram of the circuit connection principle of a mobile phone provided by an embodiment of the present invention;

[0025] Figure 7 A schematic diagram of connection of a boost converter circuit provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0026] In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution of the present invention will be clearly and completely described below in conjunction with the accompanying drawings. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0027] At present, the smartphones on the market, including Android and IOS platforms, support the USB OTG function. USB OTG is mainly used for the connection between various devices or mobile devices for data exchange. The USB OTG standard is fully compatible with the USB2.0 standard and adds a power management (power saving) function, which allows the device to operate as both a host and a peripheral (dual-use OTG). OTG dual-use devices fully comply with the USB2.0 standard, determine the master and slave devices through the high and low levels of the USB ID pin, and support the host communication protocol (HNP) and the session request protocol (SRP).

[0028] See also Figure 1, is a schematic diagram of the USB OTG headset architecture on the market, in which the Micro USB interface of the OTG headset is plugged into the Micro USB interface of the mobile phone, and the 4th pin (USB_ID) of the Micro USB interface is directly grounded. When the USB OTG headset is inserted into the Micro USB interface of the mobile phone, the CPU of the mobile phone will detect that the USB_ID signal is low level, and the CPU will control the OTG power supply circuit to output 5V voltage, which is output to the power supply pin of the USB Audio Codec chip through the 1st pin of the Micro USB interface. After the USB Audio Codec is powered on, it will communicate with the USB host device (the mobile phone CPU) through USB. The voice of the mobile phone is loaded into the USB signal and transmitted to the USB Audio Codec chip through USB. After receiving the digital voice signal, the USB Audio Codec chip performs PLL (Phase Locked Loop) demodulation. The demodulated digital voice signal is converted into an analog audio signal through a digital-to-analog converter, and then amplified by the power gain controller inside the USB Audio Codec chip, and then output to the left and right channels of the headset, thereby realizing the voice output function of the headset function.

[0029] In addition, the USB Audio Codec chip integrates a microphone bias voltage circuit, which is output to power the headphone microphone. After the headphone microphone receives the analog voice signal, it is transmitted to the power gain controller integrated in the USB Audio Codec chip for power gain amplification. The amplified analog voice signal is converted into a digital voice signal through an analog-to-digital converter. The converted digital voice signal is then modulated into a USB signal through PLL and sent to the CPU on the mobile phone through the USB channel, thereby realizing the microphone input function of the headset.

[0030] Currently, USB OTG headsets with Micro USB interfaces on the market only have the functions of listening to music and making calls, and cannot be used for USB communication with computers. The headset function cannot be used while charging. The headset cannot be charged while listening to music or making calls, and cannot be used while charging, which brings a lot of inconvenience to users.

[0031] Based on this, the embodiment of the present invention provides a Micro USB interface comprehensive multiplexing circuit and electronic device, which can realize the simultaneous use of the OTG headset function and charging function of the Micro USB interface, and the electronic device can also be used as a USB data cable, which is more convenient to use and improves the user experience.

[0032] To facilitate understanding of this embodiment, a Micro USB interface integrated multiplexing circuit disclosed in an embodiment of the present invention is first introduced in detail.

[0033] Embodiment 1:

[0034] An embodiment of the present invention provides a Micro USB interface comprehensive multiplexing circuit, which includes: a Micro USB interface, a USB Switch chip, a USB Audio Codec chip, a USB A-type interface, a headphone interface, and an inductor.

[0035] The ID pin of the Micro USB interface is respectively connected to the SEL pin of the USB Switch chip and the first left channel pin of the headphone interface, and the second left channel pin of the headphone interface is connected in series with the inductor and then connected to the ground signal. Here, the inductance of the inductor can be 10mH. In addition, the headphone interface can be a 3.5mm headphone interface, that is, a US standard headphone interface, and the interface is a four-section headphone interface, that is, a four-section US standard headphone interface.

[0036] like Figure 2-3 The following are schematic diagrams of the internal structure of a headphone jack and a schematic diagram of a 3.5mm American standard headphone plug. Figure 2 In the , pin 1 represents "ground", pins 2 and 5 are connected to the left channel, pin 3 is connected to the right channel, and pin 4 is the microphone input. Figure 3 In the definition of headphone plug, the definition of headphone interface corresponds to that of headphone jack. Figure 3 The definitions from right to left are: left channel, right channel, microphone input, and ground.

[0037] In addition, the USB data pins of the USB Audio Codec chip and the USB data pins of the USB A type interface in the circuit are respectively connected to the first group of USB data pin pairs and the second group of USB data pin pairs of the USB Switch chip. For example, the USB data pins D- and D+ of the USB Audio Codec chip are respectively connected to the USB data pins D1- and D1+ of the USB Switch chip, and the USB data pins D- and D+ of the USB A type interface are respectively connected to the USB data pins D2- and D2+ of the USB Switch chip.

[0038] In one embodiment, the USB Switch chip in the circuit is a double-pole double-throw chip, and the USB Audio Codec chip is a PCM2912 series chip. Here, the PCM2912 series chip is an audio codec with a USB interface, a mono microphone input and a stereo headphone output.

[0039] See also Figure 4 , is a connection diagram of a Micro USB interface integrated multiplexing circuit, consisting of Figure 4 It can be seen that the 2nd and 3rd pins of the MicroUSB interface are connected to the corresponding USB_D- and USB_D+ pins of the USB Switch chip, and the 1st pin of the Micro USB interface is connected to the 5V power supply pin of the USB Switch chip to power the USB Switch chip. The 4th pin (USB_ID) of the Micro USB interface is connected to the SEL pin of the USB Switch chip and the 5th pin of the 3.5MM headphone interface respectively. The two USB slave ends of the USBSwitch chip are D1-, D1+ and D2-, D2+ respectively, and these two USB slave ends are connected to the D-, D+ pins of the USB AudioCodec chip and the 2nd and 3rd pins of the USB A type interface respectively. Here, the USB Switch chip uses a DPDT (double-pole double-throw) type USB Switch. In addition, the USB Audio Codec chip can be a PCM2912 series chip of TI, and the USB A type interface can be a USB interface connected to the PC end.

[0040] for Figure 4 The Micro USB interface integrated multiplexing circuit shown can be used as a design of a headphone daughter board circuit, in which the USB Audio Codec chip obtains a digital audio signal from a USB channel, and then sends the digital audio signal to a PLL (Phase Locked Loop) inside the chip for demodulation. The demodulated digital audio signal is then converted into an analog signal through a digital-to-analog converter. A power gain controller is integrated inside the chip to amplify the analog signal and then play the audio through the left and right channels of the headphone.

[0041] In addition, the USB Audio Codec chip integrates a microphone bias voltage to power the headphone microphone. The USB Audio Codec chip receives analog audio signals through the microphone of the headphone, amplifies them through the power gain controller, and then sends them to the analog-to-digital converter inside the chip to convert the analog audio signals into digital signals. The digital signals are then debugged into the USB signal channel through the PLL and sent to the CPU through the Micro USB interface. In this way, the integrated multiplexing circuit realizes the processing of audio signals.

[0042] In another embodiment, the above-mentioned Micro USB interface integrated multiplexing circuit also includes: an OTG power supply circuit, a USB charging circuit and a diode, wherein the USB5V pin of the Micro USB interface is respectively connected to the IN pin of the USB charging circuit and the cathode of the diode, and the anode of the diode is connected to the OUT pin of the OTG power supply circuit.

[0043] In actual operation, the Micro USB interface integrated multiplexing circuit can be applied to mobile terminals, such as mobile phones, laptops, tablet computers, etc. In one implementation, see Figure 5 , is a schematic diagram of an application scenario of a Micro USB interface integrated multiplexing circuit, which includes a mobile phone motherboard circuit and an earphone sub-board circuit. Among them, the specific connection diagram of the mobile phone motherboard circuit can be found in Figure 6 .

[0044] Depend on Figure 5 and Figure 6 It can be seen that the CPU's D- and D+ signals are connected to the 2nd and 3rd pins of the Micro USB interface respectively, the CPU's ID signal is connected to the 4th pin of the Micro USB interface, and the 5th pin of the Micro USB interface is the ground pin. When the USB_ID pin is high, the CPU acts as a USB slave device; when the USB_ID pin is low, the CPU acts as a master device.

[0045] Depend on Figure 6 It can be seen that the IN end of the USB charging circuit is also connected to the 1 pin of the Micro USB interface, and the Battery pin is connected to the positive pole of the battery. When the charger is plugged in, the battery is charged through the Micro USB interface. Here, the USB charging circuit can use the charging circuit recommended by hardware platforms such as MTK (MediaTek. Inc) and Qualcomm.

[0046] In addition, according to Figure 6 As shown, the USB_ID pin of the mobile phone CPU is connected to the 4 pins of the Micro USB interface, the switch selection pin of the USBSwitch chip, and the detection pin of the headphone interface. Here, according to the provisions of the USB OTG protocol: when the USB_ID signal is at a high level, this terminal device is a slave device, and when the USB_ID pin is at a low level, this terminal device is a master device. The USB_ID pin of the terminal device is set to a high level by default, indicating that the terminal is a slave device in the default state (that is, when there is no other input signal input to the USB_ID pin). In this embodiment, the USB Audio Codec chip can only act as a USB slave device. If the mobile phone wants to communicate with the USB Audio Codec chip, the mobile phone is required to act as a USB master device.

[0047] In this embodiment, the OTG power supply circuit is a 5V boost converter chip, wherein the input end (IN) of the boost converter is connected to the positive pole of the mobile phone battery, and the boost converter is powered by the battery. The OUT pin of the boost converter needs to be connected in series with a diode and then connected to the 1 pin of the Micro USB interface to power the slave device. Here, the forward voltage drop of the diode is less than 0.3V, the reverse breakdown voltage is greater than 10V, and the USB OTG power supply voltage range is 4.75V to 5.25V. Therefore, in actual operation, the forward voltage drop of the diode should be as low as possible below 0.3V, and the output voltage of the voltage converter can be adjusted to about 5.2V, so that the cathode voltage of the diode is about 4.9V, which meets the USB OTG power supply voltage requirements.

[0048] Here, see Figure 7 , is a schematic diagram of a boost converter circuit connection, consisting of Figure 7 It can be seen that the input voltage of the boost converter is 3.5V~4.2V, which is the battery voltage range. The input voltage is connected to the VIN pin of the boost converter; the EN pin is the enable pin of the boost converter, which is connected to the EN pin of the CPU; and the output end USB5V of the voltage converter is connected to the 1 pin of the Micro USB interface. Here, the output voltage range of the voltage converter is adjusted by the FB pin.

[0049] In this embodiment, by multiplexing the functions of pins 2 and 5 of the headphone interface, a 10mH inductor is connected in series to the ground signal of pin 2 of the headphone interface, and pin 5 of the headphone interface is used as the USB_ID pin function, thereby realizing headphone insertion detection. Here, because the audio signal is an AC signal, the inductor blocks the AC and passes the DC, so the audio signal will not be introduced into the ground signal.

[0050] In actual operation, when the headphone plug is inserted into the headphone jack, the tip of the headphone plug (left channel pin) will short-circuit with the 2nd and 5th pins of the headphone jack. Since the 2nd pin of the headphone jack is connected in series with a 10mH inductor to the ground signal (for the DC component, the inductor acts as a 0 ohm resistor), and since the 2nd and 5th pins of the headphone jack are short-circuited with the headphone plug, the 5th pin of the headphone jack (USB_ID) will be pulled down to the ground signal level (0V) by the 2nd pin. At this time, the ID pin of the mobile phone CPU is also 0V, and the mobile phone acts as a USB master. When the headphone plug is unplugged, the 2nd and 5th pins of the headphone jack return to the open circuit state, and the 5th pin (USB_ID) pin becomes high level without the pull-down effect of the 2nd pin. The ID pin of the mobile phone CPU also becomes high level, and the mobile phone acts as a USB slave.

[0051] In addition, for the USB channel switching of the USB Switch chip, here, the channel selection pin (SEL) of the USB Switch chip is also connected to the USB_ID pin. When the headphone plug is inserted into the headphone jack, the USB_ID pin is low, and the D1- and D1+ signal pins of the USBSwitch chip are connected to the D- and D+ signal pins on the USB Audio Codec chip side, so that the USB signal on the mobile phone side is connected to the USB signal on the USB Audio Codec chip; when the headphone plug is unplugged from the headphone jack, the USB_ID pin is high, and the D2- and D2+ signal pins of the USB Switch chip are connected to the 2 and 3 signal pins of the USB A type interface, so that the USB signal on the mobile phone side is connected to the USB signal on the PC side.

[0052] For the power supply circuit of the USB Audio Codec chip and the USB Switch chip, here, when the headphone plug is inserted into the headphone jack, the USB_ID pin will be pulled low, and the mobile phone CPU will detect that the ID signal pin is pulled low, then the mobile phone CPU will control the EN pin to output a high level, enabling the voltage converter of the USB OTG power supply circuit to output 5.1V voltage (USB5V), and the USB5V voltage is connected to the USB Audio Codec chip VCC power supply pin, the USBSwitch chip VCC power supply pin and the USB Type A interface 1 pin respectively through the Micro USB interface 1 pin.

[0053] When the headphone plug is unplugged, the USB_ID signal returns to a high level. The mobile phone CPU detects that the ID signal pin is at a high level, and then controls the EN pin to shut down the voltage converter of the USB OTG power supply circuit, so that it does not output the USB5V voltage and stops powering the USB Audio Codec chip and the USB Switch chip, thereby achieving battery power saving management on the mobile phone.

[0054] When the charger is inserted from the USB A type interface, the 5V voltage of the charger is connected to the 1 pin of the Micro USB interface on the mobile phone through the 1 pin of the Micro USB interface, the input end of the charging circuit, so as to charge the mobile phone battery. Because the output end of the USBOTG power supply circuit is connected in series with a diode, the charging current will not flow back into the USB OTG power supply circuit, thereby protecting the USB OTG power supply circuit.

[0055] When the data cable is inserted from the USB Type A interface to connect to the PC, since the USB_ID signal is at a high level, the USB Switch chip will connect the USB pass-through to the USB signal of the USB Type A interface. The mobile phone acts as a USB slave device and is connected to the USB signal on the PC, thereby realizing USB communication.

[0056] In this way, the Micro USB interface integrated multiplexing circuit provided in this embodiment realizes both the charging function and the headphone function by setting a USB A type interface and a headphone interface in the circuit; by connecting an inductor in series with the left channel pin of the headphone interface to ground, it can not only ensure that the left channel sound can be transmitted to the headphone, but also realize the headphone insertion detection function; by using the USB Switch chip to switch the USB signal channel in real time, the headphone function and the USB data function can be taken into account in a time-sharing manner; by separating the OTG power supply circuit and the USB charging circuit, and connecting a diode in series at the output end of the OTG power supply circuit, the current of the charger is effectively prevented from flowing back to the OTG power supply circuit when charging, so that the function of charging while listening to music or charging while making a call can be realized.

[0057] In addition, the Micro USB interface comprehensive multiplexing circuit provided in the embodiment of the present invention multiplexes the Micro USB interface with the headphone interface function and maintains the original function of the Micro USB interface, so that the headphone interface can be omitted when the circuit is used in electronic equipment. For example, when used in mobile phone design, the overall structural design of the mobile phone can better control the thickness of the mobile phone, so that the mobile phone as a whole has only one interface to the outside, which helps to make the mobile phone design lighter and more beautiful.

[0058] The embodiment of the present invention provides a Micro USB interface comprehensive multiplexing circuit, which includes a Micro USB interface, a USB Switch chip, a USB Audio Codec chip, a USB A-type interface, a headphone interface and an inductor; the ID pin of the MicroUSB interface is respectively connected to the SEL pin of the USB Switch chip and the first left channel pin of the headphone interface; the second left channel pin of the headphone interface is connected to the ground signal after being connected in series with the inductor; the USB data pin of the USB Audio Codec chip and the USB data pin of the USB A-type interface are respectively connected to the first group of USB data pin pairs and the second group of USB data pin pairs of the USB Switch chip; the USB5V pin of the Micro USB interface is connected to the USB5V pin of the USB A-type interface. The circuit can realize the simultaneous use of the OTG function and the charging function of the Micro USB interface, and can also realize the USB data transmission function, which is more convenient to use and improves the user experience.

[0059] Embodiment 2:

[0060] The embodiment of the present invention further provides an electronic device, which includes the Micro USB interface integrated multiplexing circuit provided by the above-mentioned embodiment 1 and one of its possible implementation modes. The electronic device provided by the embodiment of the present invention has the same technical features as the Micro USB interface integrated multiplexing circuit provided by the above-mentioned embodiment, so it can also solve the same technical problems and achieve the same technical effects.

[0061] Those skilled in the art can clearly understand that, for the convenience and brevity of description, the specific working process of the electronic device described above can refer to the corresponding process in the aforementioned Micro USB interface integrated multiplexing circuit embodiment, which will not be repeated here.

[0062] Unless otherwise specifically stated, the relative steps, numerical expressions and values ​​of the components and steps set forth in these embodiments do not limit the scope of the present invention.

[0063] In all examples shown and described herein, any specific values ​​should be interpreted as merely exemplary and not as limiting, and thus other examples of the exemplary embodiments may have different values.

[0064] The flow charts and block diagrams in the accompanying drawings show the possible architecture, functions and operations of the system, method and computer program product according to multiple embodiments of the present invention. In this regard, each box in the flow chart or block diagram can represent a module, a program segment or a part of a code, and the module, a program segment or a part of a code contains one or more executable instructions for realizing the specified logical function. It should also be noted that in some alternative implementations, the functions marked in the box can also occur in a different order from the order marked in the accompanying drawings. For example, two consecutive boxes can actually be executed substantially in parallel, and they can sometimes be executed in the opposite order, depending on the functions involved. It should also be noted that each box in the block diagram and / or flow chart, and the combination of the boxes in the block diagram and / or flow chart can be implemented with a dedicated hardware-based system that performs a specified function or action, or can be implemented with a combination of dedicated hardware and computer instructions.

[0065] In addition, in the description of the embodiments of the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0066] In the description of the present invention, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first", "second", and "third" are used for descriptive purposes only, and cannot be understood as indicating or implying relative importance.

[0067] Finally, it should be noted that the above-described embodiments are only specific implementations of the present invention, which are used to illustrate the technical solutions of the present invention, rather than to limit them. The protection scope of the present invention is not limited thereto. Although the present invention is described in detail with reference to the above-described embodiments, ordinary technicians in the field should understand that any technician familiar with the technical field can still modify the technical solutions recorded in the above-described embodiments within the technical scope disclosed by the present invention, or can easily think of changes, or make equivalent replacements for some of the technical features therein; and these modifications, changes or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present invention, and should be included in the protection scope of the present invention. Therefore, the protection scope of the present invention shall be based on the protection scope of the claims.

Claims

1. A Micro USB interface integrated multiplexing circuit, characterized in that: include: Micro USB port, USB Switch chip, USB Audio Codec chip, USB Type A port, headphone port and inductor; The ID pin of the Micro USB interface is connected to the SEL pin of the USB Switch chip and the first left channel pin of the headphone interface respectively; The second left channel pin of the headphone interface is connected in series with the inductor and then connected to the ground signal; The USB data pins of the USB Audio Codec chip and the USB data pins of the USB Type A interface are respectively connected to the first group of USB data pin pairs and the second group of USB data pin pairs of the USB Switch chip; The USB Audio Codec chip obtains a digital audio signal from a USB channel; sends the digital audio signal to a PLL disposed inside the USB Audio Codec chip for demodulation; The demodulated digital audio signal is converted into an analog signal by a digital-to-analog converter arranged inside the USB Audio Codec chip; a power gain controller arranged inside the USB Audio Codec chip amplifies the analog signal to play audio through the left and right channels of the earphone connected to the earphone interface; The USB Audio Codec chip has an internal integrated microphone bias voltage to power the microphone of the headset; the USB Audio Codec chip receives an analog audio signal through the microphone; amplifies the analog audio signal through the power gain controller, and sends the amplified analog audio signal to an analog-to-digital converter to convert the amplified analog audio signal into a digital signal; and debugs the digital signal into the USB channel through the PLL; Sending to the CPU of the mobile phone via the Micro USB interface; The headphone interface multiplexes the functions of the second left channel pin and the 5th pin, connects the second left channel pin to the ground signal through the series connection of the inductor, the 5th pin is used to implement headphone detection insertion, the inductor is used to prevent the AC signal from conducting the DC signal, and the AC signal will not be introduced into the ground signal; When an earphone plug is inserted into the earphone interface, the left channel pin of the earphone plug is short-circuited with the second left channel pin and the 5th pin of the earphone interface, the inductor acts as a 0 ohm resistor, the 5th pin is pulled down to the ground signal level by the second left channel pin, and the mobile phone acts as a USB host device; When the headphone plug is unplugged, the second left channel pin and the 5th pin are in an open circuit state, the 5th pin becomes a high level, and the mobile phone acts as a USB slave device.

2. The Micro USB interface integrated multiplexing circuit according to claim 1, characterized in that: Also includes: OTG power supply circuit, USB charging circuit and diode; The USB5V pin of the Micro USB interface is connected to the IN pin of the USB charging circuit and the cathode of the diode respectively, and the anode of the diode is connected to the OUT pin of the OTG power supply circuit.

3. The Micro USB interface integrated multiplexing circuit according to claim 2, characterized in that: The OTG power supply circuit is a 5V boost converter chip.

4. The Micro USB interface integrated multiplexing circuit according to claim 2, characterized in that: The forward voltage drop of the diode is less than 0.3V, and the reverse breakdown voltage of the diode is greater than 10V.

5. The Micro USB interface integrated multiplexing circuit according to claim 1, characterized in that: The headphone jack is a 3.5mm headphone jack.

6. The Micro USB interface integrated multiplexing circuit according to claim 5, characterized in that: The headphone interface is a four-section headphone interface.

7. The Micro USB interface integrated multiplexing circuit according to claim 1, characterized in that: The USB Switch chip is a double-pole double-throw chip.

8. The Micro USB interface integrated multiplexing circuit according to claim 1, characterized in that: The USB AudioCodec chip is a PCM2912 series chip.

9. The Micro USB interface integrated multiplexing circuit according to claim 1, characterized in that: The inductance of the inductor is 10 mH.

10. An electronic device, characterized in that: The invention comprises the Micro USB interface integrated multiplexing circuit as described in any one of claims 1 to 9.

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