An apparatus for implementing a dual-USB device in a single chip

Abstract

The utility model discloses a kind of device for realizing double USB equipment by single chip, belong to USB audio equipment technical field.The device includes main chip, double USB interface unit, audio input module, audio output module, control module and power module.Main chip is single integrated chip, built-in double USB data processing module, can simultaneously process two groups of USB data stream, respectively through first USB interface and second USB interface and external device connection;Audio input module is used to collect and amplify microphone signal;Audio output module is used to drive earphone monitoring;Control module includes sound mixing proportion adjustment, mute control and state indication function;Power module provides multiple voltage stabilizing and overvoltage protection.The utility model realizes the synchronous input, output and sound mixing monitoring of double equipment audio by highly integrated single chip architecture, with low cost, high integration, consistent tone quality, easy operation and the like Advantages, applicable to game live broadcast, network teaching and other multi-device audio application scenarios.

Description

Technical Field

[0001] This utility model relates to the field of USB audio device technology, and in particular to an audio input / output device based on a single chip to realize dual USB interfaces, which is suitable for devices such as microphones, headphones, and sound cards. Background Technology

[0002] With the rapid development of industries such as live streaming, esports, and online education, users' demands for the versatility, integration, and ease of use of audio devices have significantly increased. For example, game streamers often need to connect both a game console (such as a PS series) and a streaming computer simultaneously: the game console outputs game audio, while the streaming computer captures human voices and pushes the live stream, all while monitoring the mixed audio signals.

[0003] The existing technical solutions have the following core defects:

[0004] like Figure 1 The diagram shown is a circuit block diagram of a USB microphone currently on the market. The volume knob and mute control are physical buttons.

[0005] It requires two independent USB microphones and corresponding cantilever brackets, which not only results in high hardware costs (about twice that of a single device), but also makes the desktop space cluttered. Furthermore, the differences in the pickup angle and sensitivity of the two microphones can easily lead to inconsistent sound quality.

[0006] External mixer solution: It requires purchasing an additional mixer to connect the audio output of the two devices and then connecting headphones for monitoring, which increases the complexity of the device link. In addition, the mixer is not portable and is not suitable for desktop scenarios.

[0007] Dual-chip integrated solution: Some manufacturers use two USB audio chips in parallel design. Although this can achieve dual device connection, signal interference between chips can easily introduce noise, and the circuit complexity is high (requiring additional signal isolation circuit design). The production cost is more than 30% higher than that of the single-chip solution.

[0008] In summary, existing solutions cannot simultaneously meet users' needs for "low cost, high integration, low noise, and ease of operation," and there is an urgent need for a dual USB audio device solution based on a single-chip architecture. Utility Model Content

[0009] This invention provides a device for implementing dual USB devices on a single chip, particularly suitable for audio devices such as microphones, headphones, and USB sound cards. It enables simultaneous connection of two devices, audio mixing, independent volume adjustment, and status control. Through a highly integrated single-chip architecture, this device effectively solves problems such as device redundancy, inconsistent sound quality, complex operation, and high cost associated with traditional solutions.

[0010] This device includes a main chip, dual USB interface units, an audio input module, an audio output module, a control module, and a power supply module. The main chip is a single integrated chip with a built-in dual USB data processing module, capable of processing two sets of USB data streams simultaneously. These streams connect to external devices (such as game consoles and live streaming computers) via the first and second USB interfaces, respectively. Its principle lies in achieving signal splitting and protocol processing through a single chip, avoiding the signal interference and synchronization problems inherent in multi-chip solutions, and significantly improving system stability and integration.

[0011] Furthermore, the main chip also integrates an RGB ambient light driver module, a mute control unit, and a mixing control unit. The RGB ambient light driver module can directly control the color and brightness of external RGB light strips, enhancing the device's visual effects and user experience; the mute control unit quickly cuts off audio input via a hardware link, with a response time of less than 100 milliseconds, superior to software mute solutions; the mixing control unit, through potentiometer and ADC cooperation, achieves hardware-level mixing ratio adjustment of two downstream audio signals, allowing users to adjust the monitoring ratio of game and live streaming audio in real time.

[0012] Furthermore, the dual USB ports are preferably Type-C ports, both supporting the USB 2.0 full-speed transmission protocol. The first port is used to connect to the game console, and the second port is used to connect to the live streaming computer. This design ensures high-speed and stable data transmission while improving the device's versatility and ease of plugging and unplugging.

[0013] Furthermore, the power module includes an overvoltage protection unit and a multi-channel voltage regulator unit. The overvoltage protection uses an ETA7D14S2 chip, which automatically cuts off the power supply when the input voltage exceeds 5.5V, effectively preventing high-voltage surges from damaging the main chip and other units. The multi-channel voltage regulator unit uses an SGM2210-ADJ chip, which can output three voltages: 0.9V, 1.8V, and 3.3V, providing independent power supplies for the core circuit, ADC / DAC module, and interface unit, respectively. This improves power efficiency and reduces mutual interference between units.

[0014] Furthermore, the audio input module includes a microphone core, a first amplifier, a microphone volume adjustment potentiometer, and a second amplifier connected in sequence. The first amplifier is a weak signal amplifier with a gain of 20dB, used to improve the microphone's pickup sensitivity; the microphone volume adjustment potentiometer is a 10K linear potentiometer, allowing users to flexibly adjust the input volume; the second amplifier is an impedance matching amplifier with an output impedance not exceeding 100Ω, effectively suppressing noise and distortion during signal transmission.

[0015] Furthermore, the mixing control unit includes a 50K mixing ratio adjustment potentiometer, which is mechanically connected to the main knob. One end of the potentiometer is connected to a 3.3V power supply, and the other end is grounded. The middle tap is connected to the ADC_KE1 pin of the main chip. The main chip adjusts the mixing ratio of the two USB interface downstream audio channels within the range of 0-3.3V according to the voltage value of the ADC_KE1 pin.

[0016] Furthermore, the audio output module includes a headphone amplifier unit, a master headphone volume control potentiometer, and a 3.5mm stereo jack. The headphone amplifier unit supports independent amplification of the left and right channels, ensuring clear and balanced output sound quality; the master headphone volume control potentiometer is a 4.7K linear potentiometer, providing a smooth volume control experience; and the 3.5mm jack is a standard audio interface, compatible with most headphone devices.

[0017] Furthermore, the control module also includes a status indicator unit, equipped with a red mute indicator and a green recording indicator, which are connected to the GPIO_B1 and GPIO_B2 pins of the main chip, respectively. The red indicator lights up when the device is in mute mode, and the green indicator lights up when it is in recording mode, allowing the user to intuitively understand the device's operating status.

[0018] Furthermore, the device is equipped with mechanical structural units, including a metal pop filter and a detachable bracket. The pop filter is fixed to the front of the microphone core, effectively suppressing popping sounds and airflow noise; the bracket supports 360° rotation adjustment, allowing users to flexibly adjust the microphone position according to their usage habits, further enhancing ease of use and human-computer interaction experience.

[0019] Compared with the prior art, the present invention has the following beneficial effects:

[0020] Significantly reduced costs: A single chip enables dual USB processing, mixing control, and power management, reducing hardware costs by more than 30% compared to dual-chip solutions. Users do not need an external mixer, reducing procurement costs by 50%.

[0021] High integration and simple structure: A single device supports dual device connection, integrates volume adjustment, mixing control, status indication, ambient lighting and mechanical adjustment functions, and reduces desktop space occupation by 60%;

[0022] Good sound quality consistency: A single microphone core and a fixed amplification link ensure consistent sound quality for the two USB device inputs, avoiding differences in sound pickup between the two microphones;

[0023] Easy to operate and quick to respond: Hardware-level mixing ratio adjustment and independent mute button, with a response speed of <100ms, which is better than the 500ms latency of software adjustment, effectively improving the live streaming and gaming experience;

[0024] This invention is applicable to multi-device audio synchronous input and output scenarios such as game live streaming, online teaching, and voice communication, and has significant market competitiveness and user experience enhancement value. Attached Figure Description

[0025] To more clearly illustrate the technical solutions in the embodiments of this utility model, the drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0026] Figure 1 This is a circuit block diagram of the existing technology;

[0027] Figure 2 The circuit block diagram provided for the embodiments of this utility model;

[0028] Figure 3 This is a schematic diagram of the USB interface and power supply principle provided in the embodiment of this utility model;

[0029] Figure 4 A schematic diagram of the headphone amplifier circuit provided in an embodiment of this utility model;

[0030] Figure 5 A schematic diagram of the microphone preamplifier circuit provided in this embodiment of the utility model;

[0031] Figure 6 This is a schematic diagram of the main chip circuit provided in an embodiment of the present utility model;

[0032] Figure 7 , 8 A structural schematic diagram provided for an embodiment of this utility model;

[0033] Figure 9 This is a schematic diagram illustrating the use of this utility model according to an embodiment.

[0034] The following are the labeling elements in the figure:

[0035] 1. Main knob; 2. Indicator light; 3. Stand; 4. Headphone master volume adjustment potentiometer; 5. Microphone volume adjustment potentiometer; 6. Pop filter; 7. First USB port; 8. Second USB port.

[0036] The accompanying drawings have illustrated specific embodiments of the present invention, which will be described in more detail below. These drawings and descriptions are not intended to limit the scope of the present invention in any way, but rather to illustrate the concept of the present invention to those skilled in the art through reference to specific embodiments. Detailed Implementation

[0037] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of the present utility model.

[0038] To make the technical solution and advantages of this utility model clearer, the embodiments of this utility model will be described in further detail below with reference to the accompanying drawings.

[0039] Please see Figures 2-9 As shown, this utility model provides a device for implementing dual USB devices on a single chip, particularly suitable for audio devices such as microphones, headphones, and USB sound cards. It enables simultaneous connection of two devices, audio mixing, independent volume adjustment, and status control. Through a highly integrated single-chip architecture, this device effectively solves problems such as device redundancy, inconsistent sound quality, complex operation, and high cost in traditional solutions. The specific implementation methods of this utility model will be described in detail below with reference to the accompanying drawings.

[0040] like Figure 6 As shown, the main chip is the core of the device's control and signal processing. It is an integrated chip in a QFN40-5×5 package, supporting dual USB 2.0 full-speed interfaces, 16-bit ADC and 16-bit DAC modules. It also has built-in dual USB data processing modules, RGB ambient light PWM driver modules, mute control units and mixing control units. Its circuit design directly determines the device's functionality and performance. The main chip's power supply employs multiple independent voltage designs to adapt to the power requirements of different modules: The DVDD33 pin receives 3.3V, powering digital modules such as the USB interface and GPIO. A 10μF tantalum capacitor and a 0.1μF multilayer ceramic capacitor are connected in parallel next to this pin, forming a high-low frequency composite filter network to filter out low-frequency ripple and high-frequency noise in the power supply. The DVDD16 pin receives 1.8V, specifically powering the ADC / DAC module, and is connected in parallel with a 10μF MLCC capacitor to ensure power stability during analog signal processing. The DVDD11 pin receives 0.9V, powering the main chip's core CPU, and is connected in parallel with a 0.1μF MLCC capacitor to reduce power supply noise in the core circuitry. The main chip's AGND pin is analog ground, and the DGND pin is digital ground. Both are routed on the PCB through independent grounding networks, ultimately converging at a single-point ground pad to avoid ground loops and reduce interference between digital and analog signals.

[0041] The main chip's dual USB data processing module corresponds to two sets of USB 2.0 full-speed interfaces. Its HS_DP and HS_DM pins are connected to the DP and DM pins of the first USB interface via a 50Ω impedance-matched microstrip line. Similarly, the HS2_DP and HS2_DM pins are connected to the DP and DM pins of the second USB interface via a 50Ω impedance-matched microstrip line, ensuring a USB data transfer rate of 12Mbps with no signal reflection. To enhance the anti-interference capability of USB data transfer, a 600Ω@100MHz ferrite bead is connected in series on each DP / DM differential line to suppress high-frequency electromagnetic radiation.

[0042] The main chip's ADC module is responsible for acquiring external analog control signals. The ADC_KE1 pin is connected to the slider of the mixing ratio potentiometer via a 1kΩ current-limiting resistor, acquiring a voltage signal within the 0-3.3V range to determine the mixing ratio of the two USB downstream audio channels. The MIC_IN pin is connected to the output of the audio input module via a 1μF coupling capacitor, acquiring the amplified and volume-adjusted microphone analog signal. The ADC module's sampling rate is set to 48kHz, with a 16-bit sampling precision to ensure the quality of the digital conversion of the audio signal. The DAC module is responsible for converting the digital audio signal to an analog signal. Its DAC_LO and DAC_RO pins are each connected to the headphone amplifier unit of the audio output module via 1μF coupling capacitors, outputting analog audio signals for the left and right channels. The DAC module's output signal-to-noise ratio is ≥90dB, ensuring the clarity of the audio output.

[0043] The main chip's control pins handle device status control and indication: The GPIO_B1 pin is connected to the anode of the red mute indicator via a 1kΩ current-limiting resistor, with the LED cathode grounded. This pin is also grounded via a tactile button. When the button is pressed, the GPIO_B1 pin goes low, triggering the mute control unit to cut off the audio input link (response time <100ms). The red LED illuminates, indicating the device is in mute mode. The GPIO_B2 pin is connected to the anode of the green recording indicator via a 1kΩ current-limiting resistor, with the LED cathode grounded. When the device is recording, the main chip outputs a high level to the GPIO_B2 pin, illuminating the green LED and providing direct feedback on the device's operating status. The GPIO_A29 / B0 pins are connected to the DATA pin of the RGB ambient light via a 100Ω current-limiting resistor. The main chip controls the color and brightness of the RGB lights by outputting PWM signals, supporting various lighting effects such as breathing, gradient, and jump. The red channel PWM duty cycle is 100% when displaying pure red, while the green channel is 50% and the blue channel is 0%. It displays a light green color to meet the visual needs of different scenarios; the POWERKEY pin is connected to a 3.3V power supply through a 10kΩ pull-up resistor. When the power button is pressed, the level of this pin is pulled low, and the main chip starts the initialization program to complete the configuration and self-test of each module.

[0044] The main chip's clock circuit uses a 24MHz passive crystal oscillator. The two pins of the crystal oscillator are connected to the XO pin and XI pin of the main chip, respectively, and are grounded through a 22pF load capacitor to ensure stable oscillation of the crystal oscillator and provide a precise clock signal for the entire system. The clock deviation is ≤±50ppm, ensuring the timing consistency of USB data transmission and audio signal processing.

[0045] like Figure 3As shown, the dual USB interface unit uses two TYPE-C interfaces, serving as the first USB interface (for connecting the game console) and the second USB interface (for connecting the live streaming computer). The interface is reversible, improving user convenience. Each TYPE-C interface's VBUS pin is connected to the overvoltage protection unit input of the power module via a 1A resettable fuse to prevent overcurrent damage to the interface and internal circuitry. The DP and DM pins are connected to the corresponding USB differential data pins of the main chip, and an SMF05C TVS diode is connected in parallel at the interface. The anode of the TVS diode is grounded, and the cathode is connected to the DP and DM pins, respectively. When electrostatic discharge or transient overvoltage occurs, the TVS diode quickly breaks down and conducts, clamping the voltage below 5V to protect the main chip's USB module from damage. The GND pin is connected to system ground to ensure that the interface and internal circuitry have the same ground potential. The CC1 and CC2 pins are grounded via 5.1kΩ pull-down resistors to identify the connection status of USB devices. When an external device is plugged in, the change in the CC pin level is detected by the main chip, which then starts the USB enumeration program to establish a data communication link.

[0046] The power module is fundamental to the stable operation of the device. It mainly includes an overvoltage protection unit and a multi-channel voltage regulator unit, responsible for converting the 5V input voltage from the USB interface into the stable voltage required by each unit and providing overvoltage protection. The overvoltage protection unit uses an ETA7D14S2 overvoltage protection chip. The chip's IN pin is connected to the VBUS pin of the TYPE-C interface via a resettable fuse to receive the 5V input voltage; the OUT pin is connected to the input of the multi-channel voltage regulator unit; the EN pin is connected to the OUT pin via a 10kΩ pull-up resistor, keeping the chip enabled by default; the GND pin is grounded. The ETA7D14S2 chip's overvoltage protection threshold is set to 5.5V. When the input voltage exceeds 5.5V, the internal MOSFET of the chip quickly turns off, cutting off the output voltage and preventing high voltage damage to subsequent voltage regulator units and the main chip. When the input voltage returns to below 5V, the chip automatically turns back on, restoring power supply. The response time is <10μs, ensuring rapid and reliable protection.

[0047] The multi-channel voltage regulator unit uses the SGM2210-ADJ adjustable linear regulator, which achieves multiple voltage outputs through external resistor voltage division. A total of three voltage regulator circuits are designed to output 0.9V, 1.8V and 3.3V voltages respectively. The first voltage regulator circuit is used to power the core CPU of the main chip: the VIN pin of the SGM2210-ADJ is connected to the OUT pin of the overvoltage protection unit. The VOUT pin outputs a voltage of 0.9V after being filtered by a 10μF tantalum capacitor and a 0.1μF MLCC capacitor in parallel. The ADJ pin is connected to the VOUT pin through a resistor divider network. The divider resistors are precision resistors of 1kΩ and 2.2kΩ. According to the LDO output voltage formula VOUT = VREF × (1 + R2 / R1), where VREF is the internal reference voltage of the chip of 1.25V, we can calculate that VOUT = 1.25V × (1 + 2.2kΩ / 1kΩ) ≈ 0.9V, which meets the power supply requirements of the core CPU of the main chip.

[0048] The second voltage regulator circuit is used to power the ADC / DAC module of the main chip: the VIN pin of the SGM2210-ADJ is also connected to a 5V input, and the VOUT pin is filtered by a 10μF MLCC capacitor to output a voltage of 1.8V. The voltage divider resistors of the ADJ pin are 1kΩ (R3) and 0.47kΩ (R4). It can be calculated that VOUT = 1.25V × (1 + 0.47kΩ / 1kΩ) ≈1.8V. This voltage can ensure that the ADC / DAC module works in the best state and reduce the distortion of analog signals.

[0049] The third voltage regulator circuit is used to power the main chip's digital modules, USB interface, indicator lights, and RGB ambient lights: The VIN pin of the SGM2210-ADJ is connected to a 5V input, and the VOUT pin is filtered by a 22μF tantalum capacitor and a 0.1μF MLCC capacitor to output a 3.3V voltage. The voltage divider resistors for the ADJ pin are 1kΩ (R5) and 1.6kΩ (R6). Calculations show that VOUT = 1.25V × (1 + 1.6kΩ / 1kΩ) ≈ 3.3V. This voltage is the standard operating voltage for most digital devices and has strong compatibility.

[0050] The power module's PCB layout adopts a star topology. The output of the overvoltage protection unit serves as the power distribution center, supplying power to the three voltage regulator units respectively, thus preventing a failure in one voltage regulator circuit from affecting other circuits. The output line width of each voltage regulator unit is designed according to the current requirements. The filter capacitors are all placed close to the VOUT pin of the corresponding voltage regulator chip to reduce parasitic inductance and parasitic resistance and improve the filtering effect. Sufficient spacing is reserved between the power network and the ground network to prevent short circuits.

[0051] The audio input module is responsible for acquiring external sound signals and amplifying, adjusting volume, and matching impedance to ensure high-quality audio signal input to the main chip. It mainly includes a microphone core, a first amplifier, a microphone volume control potentiometer, and a second amplifier. The microphone core uses an ECM electret microphone (model WM-61A) with an operating voltage of 3.3V, a sensitivity of -42dB, and a frequency response of 20Hz-20kHz, suitable for capturing human voices and game sound effects. The positive terminal of the microphone core is connected to a 3.3V power supply through a 1kΩ current-limiting resistor, and the negative terminal is coupled to the input of the first amplifier through a 4.7μF electrolytic capacitor (model EEUFC0J470). This coupling capacitor blocks DC signals, transmitting only AC audio signals. The first amplifier uses an NJDM4580M dual operational amplifier with an operating voltage of 3.3V and an input offset voltage ≤5mV, suitable for weak signal amplification. The audio signal output from the microphone is input to the non-inverting input of the operational amplifier via a coupling capacitor. The inverting input is connected to the output via a 10kΩ feedback resistor (R42) and grounded via a 500Ω resistor R43, forming a non-inverting amplifier circuit. Its voltage gain Av = 1 + R42 / R43 = 1 + 10kΩ / 500Ω = 21dB, effectively amplifying the weak signal output from the microphone with a distortion ≤0.1% (at 1kHz). The output of the first amplifier is connected to the input of the second amplifier via a 10K linear potentiometer. This potentiometer acts as a microphone volume adjustment element; its sliding end adjusts the amplitude of the signal output to the second amplifier, enabling continuous adjustment of the microphone volume within a range of 0-20dB. Fixed terminal 1 of the potentiometer is connected to the output of the first amplifier, fixed terminal 3 is grounded, and sliding terminal 2 is coupled to the non-inverting input of the second amplifier via a 4.7μF electrolytic capacitor. The second amplifier also uses an NJDM4580M operational amplifier, primarily for impedance matching, reducing output impedance and preventing audio signal attenuation during transmission. The non-inverting input of the second amplifier is connected to a coupling capacitor, and the inverting input is connected to the output through a 1kΩ feedback resistor (R45), and grounded through a 10kΩ resistor (R46), forming a non-inverting amplifier circuit. The voltage gain Av = 1 + R45 / R46 = 1 + 1kΩ / 10kΩ = 1.1dB, close to 1, mainly serving a buffering function. The output impedance is ≤100Ω, meeting the input impedance requirements of the main chip's MIC_IN pin. The output of the second amplifier is connected to the main chip's MIC_IN pin through a 1μF coupling capacitor (model CL21A105KBNC) to complete the audio signal input transmission.

[0052] The PCB routing of the audio input module follows analog signal routing rules. All audio signal lines are 0.3mm wide and as short and straight as possible to avoid detours. A 0.1μF MLCC capacitor is connected in parallel next to the power supply pins of both the first and second amplifiers to filter out power supply noise. The wiring between the microphone and the first amplifier is kept away from the digital signal link and uses a shielded design with the shielding layer grounded to reduce electromagnetic interference. The potentiometer is placed close to the operation panel on the device casing for easy user adjustment, and the wiring between its pins and the amplifier uses short wire connections to avoid signal loss.

[0053] The audio output module is responsible for amplifying and adjusting the volume of the analog audio signal output from the main DAC chip, and then outputting it through the headphone jack for user monitoring. It mainly includes a headphone amplifier unit, a headphone master volume control potentiometer, and a 3.5mm stereo headphone jack. The headphone amplifier unit uses the HT920L stereo headphone amplifier, which operates at 3.3V, has an output power of 100mW@32Ω load, distortion ≤0.5% (at 1kHz), and a signal-to-noise ratio ≥85dB, making it suitable for driving mainstream 32Ω-150Ω impedance headphones.

[0054] The left channel analog signal (DAC_LO pin) output from the main chip's DAC module is input to the left channel input of the headphone amplifier via a 1μF coupling capacitor, and the right channel analog signal (DAC_RO pin) is input to the right channel input (RIN pin) via a 1μF coupling capacitor. The headphone amplifier's enable pin (EN pin) is connected to a 3.3V power supply via a 10kΩ pull-up resistor, ensuring the chip is in default working state. The power supply pin is connected to a 3.3V power supply, and the ground pin is connected to system ground. The left channel feedback resistor (RFL pin) is connected to the left channel output (LOUT pin) via a 1kΩ resistor (R70), and the right channel feedback resistor (RFR pin) is connected to the right channel output (ROUT pin) via a 1kΩ resistor (R75). The feedback resistors are used to adjust the headphone amplifier's gain. According to the chip datasheet, the gain calculation formula is Av = 20×lg (1 + Rf / Rg), where Rg is the input resistance (fixed at 20kΩ internally), and Rf... With a feedback resistor (1kΩ), the calculated value is Av ≈ 26dB, ensuring that the power of the audio signal meets the headphone monitoring requirements.

[0055] The left channel output LOUT pin and the right channel output ROUT pin of the headphone amplifier are respectively connected to the two fixed terminals of a 4.7K linear potentiometer (model RV2, B4.7K). This potentiometer serves as the master volume control element for the headphones. Its sliding terminal is connected to the corresponding channel pin of the 3.5mm stereo headphone jack. By rotating the potentiometer, the signal amplitude output to the headphones can be adjusted. The volume adjustment range is 0-25dB, which can meet the monitoring volume needs of different users.

[0056] The 3.5mm stereo headphone jack uses the PJ-327A model. This jack features a design to prevent mis-insertion and supports stereo output. Its left channel pin (L) is connected to the left channel output of the potentiometer slider, and the right channel pin (R) is connected to the right channel output of the slider. The ground pin (GND) is connected to the system ground, and the detection pin (DET) is connected to the 3.3V power supply through a 10kΩ pull-up resistor. When headphones are plugged in, the DET pin level is pulled low. The main chip detects this level change through GPIO and can trigger automatic switching of audio output mode (such as switching from external speaker to headphone output; this device does not currently support external speaker and is mainly used for status recognition).

[0057] The PCB layout of the audio output module also follows analog signal routing rules. The coupling capacitor between the headphone amplifier chip and the main chip DAC pin is placed close to the input terminal of the headphone amplifier to reduce signal transmission paths. A 0.1μF MLCC capacitor is connected in parallel next to the power supply pin of the headphone amplifier to filter out power supply noise. The headphone jack and potentiometer are located close to the side of the device casing for easy plugging and unplugging of headphones and adjustment of volume. Audio signal lines and digital signal lines (such as USB lines and GPIO lines) are separated by grounding isolation strips to avoid interference. The metal casing of the headphone jack is connected to the system ground through a grounding via to enhance the electromagnetic shielding effect.

[0058] In addition to the mute control, status indicator, and RGB ambient light control directly associated with the main chip, the control module also includes a mixing ratio adjustment circuit. This circuit works with the main chip's ADC module via a hardware potentiometer to adjust the mixing ratio of the two USB downstream audio streams. The mixing ratio adjustment potentiometer is a 50K linear potentiometer (model RV3, B50K). One end is connected to a 3.3V power supply through a 1kΩ current-limiting resistor, and the other end is grounded. The sliding end is connected to the ADC_KE1 pin of the main chip through a 1kΩ current-limiting resistor, forming a voltage acquisition circuit. When the potentiometer is rotated, the voltage at the sliding end changes linearly within the range of 0-3.3V. The main chip's ADC module acquires this voltage signal at a sampling rate of 48kHz and maps the voltage value to the mixing ratio of the two USB downstream audio streams through an internal program: when the voltage is 0V, the audio from USB1 (game console) accounts for 100% and the audio from USB2 (live streaming computer) accounts for 0%; when the voltage is 1.65V, each audio stream accounts for 50%; when the voltage is 3.3V, the audio from USB2 accounts for 100% and the audio from USB1 accounts for 0%, achieving continuous adjustment of the mixing ratio of the two audio streams to meet the user's needs for monitoring the intensity of different audio sources during game live streaming. The PCB layout of the mixing ratio adjustment potentiometer is close to the front operating area of ​​the device casing, arranged in a line with the microphone volume adjustment potentiometer and the headphone master volume adjustment potentiometer, making it convenient for users to quickly identify and operate. The wiring between the potentiometer and the main chip ADC pin uses a 0.2mm line width and is connected in series with a 100Ω current-limiting resistor to prevent damage to the main chip ADC module from electrostatic discharge or overvoltage. The wiring is kept away from high-frequency digital signal links to reduce interference and ensure the accuracy of voltage acquisition.

[0059] like Figure 7 , 8 As shown, to ensure the practicality and stability of the device, it also includes mechanical structures such as a metal pop filter and a detachable stand. The metal pop filter is made of 0.5mm thick stainless steel with a 0.5mm aperture. It is fixed to the front of the microphone core with a snap-fit ​​mechanism, 5mm away from the microphone core. This effectively suppresses popping sounds and airflow noise during user speech, improving the microphone's pickup quality. The pop filter surface is sandblasted, providing both aesthetics and a non-slip surface. The detachable stand is made of ABS engineering plastic and is connected to the PCB mounting base of the main unit using M3 screws. The bottom of the stand has a 2mm thick silicone anti-slip pad, preventing it from sliding when placed on a table. The stand supports 360° rotation and ±45° tilt adjustment, allowing users to adjust the microphone's pickup angle according to the usage scenario, improving ease of use.

[0060] In actual use, this device, such as Figure 9As shown, the user connects the game console to the first USB port via a USB data cable, and the live streaming computer to the second USB port via a USB data cable. Headphones are plugged into the 3.5mm headphone jack. After powering on the device, the main chip automatically initializes. The sound signal collected by the microphone is amplified and volume-adjusted by the audio input module before being input to the main chip's ADC module. This converted signal is then transmitted to the game console and live streaming computer via two USB ports. The downstream audio signals from the game console and live streaming computer are transmitted to the main chip via USB ports. After being converted to analog signals by the DAC module, they are mixed by the mixing control unit according to the mixing potentiometer adjustment ratio. The signals are then amplified by the headphone amplifier unit, adjusted by the headphone volume potentiometer, and output to the headphones for user monitoring. The user can quickly mute the microphone input using the mute button, understand the device's operating status through indicator lights, and enhance the ambiance of the usage scenario through RGB ambient lighting. The entire device achieves the functionality of dual-device audio input / output and monitoring with a single device, and is low-cost, highly integrated, and provides stable sound quality, fully meeting the needs of scenarios such as game live streaming and online teaching. Figure 7 As shown, the mixing control unit includes a 50K mixing ratio adjustment potentiometer, which is mechanically connected to the main knob 1. One end of the potentiometer is connected to a 3.3V power supply, the other end is grounded, and the middle tap is connected to the ADC_KE1 pin of the main chip. The main chip adjusts the mixing ratio of the two USB interface downstream audio in the range of 0-3.3V according to the voltage value of the ADC_KE1 pin.

[0061] Other embodiments of the present invention will readily occur to those skilled in the art upon consideration of the specification and practice of the invention. This application is intended to cover any variations, uses, or adaptations of the invention that follow the general principles of the invention and include common knowledge or customary techniques in the art not disclosed herein. The specification and embodiments are to be considered exemplary only, and the true scope and spirit of the invention are indicated by the foregoing claims.

[0062] It should be understood that this invention is not limited to the precise structure described above and shown in the accompanying drawings, and various modifications and changes can be made without departing from its scope. The scope of this invention is limited only by the appended claims.

Claims

1. A device for implementing dual USB devices on a single chip, characterized in that, include: Main chip, dual USB interface unit, audio input module, audio output module, control module and power supply module; The main chip is a single integrated chip with a built-in dual USB data processing module, used to process two sets of USB data streams simultaneously. The dual USB interface unit includes a first USB interface (7) and a second USB interface (8), which are electrically connected to the dual USB data processing module respectively, and are used to connect to external devices; The audio input module is electrically connected to the ADC module of the main chip and is used to acquire external audio signals and convert them into digital signals; The audio output module is electrically connected to the DAC module of the main chip and is used to convert digital audio signals into analog signals and output them. The control module is connected to the GPIO pins of the main chip and is used to adjust audio parameters and control the device status. The power module supplies power to each unit of the device.

2. The apparatus for implementing dual USB devices on a single chip according to claim 1, characterized in that, The main chip also has a built-in RGB ambient light driver module, a mute control unit and a mixing control unit; the RGB ambient light driver module is electrically connected to an external RGB light strip and is used to control the color and brightness of the light strip; the mute control unit is electrically connected to the mute button of the control module and is used to cut off the audio input link; the mixing control unit is used to adjust the mixing ratio of the downstream audio of the first USB interface (7) and the second USB interface (8).

3. The apparatus for implementing dual USB devices on a single chip according to claim 1, characterized in that, Both the first USB interface (7) and the second USB interface (8) are TYPE-C interfaces and both support the USB 2.0 full-speed data transmission protocol; the first USB interface (7) is used to connect to the game console and the second USB interface (8) is used to connect to the live streaming computer.

4. The apparatus for implementing dual USB devices on a single chip according to claim 1, characterized in that, The power supply module includes an overvoltage protection unit and a multi-channel voltage regulator unit. The overvoltage protection unit uses an ETA7D14S2 chip and disconnects the output when the input voltage exceeds 5.5V. The multi-channel voltage regulator unit uses an SGM2210-ADJ chip and outputs three voltages: 0.9V, 1.8V, and 3.3V, which power the main chip core circuit, ADC / DAC module, and interface unit, respectively.

5. The apparatus for implementing dual USB devices on a single chip according to claim 1, characterized in that, The audio input module includes a microphone core, a first amplifier, a microphone volume adjustment potentiometer (5) and a second amplifier connected in sequence; the first amplifier is a weak signal amplifier with a gain of 20dB; the microphone volume adjustment potentiometer (5) is a 10K linear potentiometer; the second amplifier is an impedance matching amplifier with an output impedance ≤100Ω.

6. The apparatus for implementing dual USB devices on a single chip according to claim 2, characterized in that, The mixing control unit includes a 50K mixing ratio adjustment potentiometer, which is mechanically connected to the main knob (1). One end of the potentiometer is connected to a 3.3V power supply, and the other end is grounded. The middle tap is connected to the ADC_KE1 pin of the main chip. The main chip adjusts the mixing ratio of the two USB interface downlink audio in the range of 0-3.3V according to the voltage value of the ADC_KE1 pin.

7. The apparatus for implementing dual USB devices on a single chip according to claim 1, characterized in that, The audio output module includes a headphone amplifier unit, a headphone master volume adjustment potentiometer (4), and a headphone jack connected in sequence; the headphone amplifier unit supports independent amplification of the left and right channels; the headphone master volume adjustment potentiometer (4) is a 4.7K linear potentiometer; and the headphone jack is a 3.5mm stereo jack.

8. The apparatus for implementing dual USB devices on a single chip according to claim 1, characterized in that, The control module also includes a status indicator unit, including a red mute indicator and a green recording indicator; the red mute indicator is connected to the GPIO_B1 pin of the main chip, and the green recording indicator is connected to the GPIO_B2 pin; when the device is in mute mode, the red indicator is lit, and when the device is in recording mode, the green indicator is lit.

9. The apparatus for implementing dual USB devices on a single chip according to claim 1, characterized in that, It also includes mechanical structural units, including a blowout preventer (6) and a bracket (3); the blowout preventer (6) is made of metal and is fixed in front of the microphone core; the bracket (3) is detachably connected to the main body of the device and supports 360° rotation adjustment.

10. An apparatus for implementing dual USB devices on a single chip according to any one of claims 1-9, characterized in that, The device can be used as a microphone, USB sound card, or headphone device, and supports simultaneous connection to a game console and a live streaming computer to achieve synchronous input and output of game audio and live streaming audio, as well as mixing and monitoring.

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