PD interface automatic switching circuit supporting PCBA board front and back side test

Abstract

The invention discloses a PD interface automatic switching circuit supporting PCBA board front and back side testing. The PD interface automatic switching circuit comprises a main control module, a communication conversion module, a channel switching module, a PD interface module, a USB PD protocol module and a power supply adjusting module. Wherein the PD interface module is arranged between the circuit and a PCBA board to be tested, the channel switching module is electrically connected with a CC1 / CC2 channel of the PD interface module, and the main control module receives a PC end control signal converted by the communication conversion module and drives the channel switching module to conduct the CC1 or CC2 channel so as to realize test switching of the accessed PCBA board in different insertion directions; the USB PD protocol module is electrically connected with the PD interface module, and the power supply adjusting module provides voltage-stabilized power supply for the USB PD protocol module. According to the invention, by automatically switching the PD channels, manual repeated plugging is avoided, the test efficiency and reliability are improved, and the method is suitable for PD protocol communication and power management in a double-sided test scene.

Description

Technical Field

[0001] The present application relates to the field of electronic testing devices, and in particular to a PD interface automatic switching circuit that supports front and back side testing of PCBA boards. Background Art

[0002] With the widespread adoption of USB Type-C interfaces and the USB PD (Power Delivery) protocol in electronic devices, comprehensive testing of the PD protocol functionality of USB Type-C interfaces on PCBAs has become a critical step in production and R&D. The USB Type-C interface is reversible, requiring PD protocol communication, power supply voltage detection, and functional verification in both the CC1 and CC2 insertion orientations. Currently, PD interface testing on PCBAs typically utilizes a test fixture or manual insertion / unplugging methods, performing charging protocol negotiation, voltage and current detection, and communication stability testing on the board under test in both forward and reverse insertion positions.

[0003] However, the existing testing methods have the following shortcomings: (1) Since the Type-C interface has multiple pluggable directions, manual plugging and unplugging or mechanical flipping operations are cumbersome. Operators or test equipment need to repeatedly change the plugging and unplugging direction or flip the board to be tested, which is time-consuming and prone to poor contact or plugging damage. (2) When switching directions manually or with simple mechanical methods, the test speed may be slow, and the test conditions (such as contact status, response timing) may differ during the switching process in different directions, affecting the consistency and reliability of the test results. The test efficiency is low and the consistency is difficult to ensure. (3) At present, some automatic test systems have limited support for the direction switching of the PD interface, and mostly rely on external robotic arms or additional devices to flip the board. The system is complex and costly, and it is difficult to meet the needs of automated high-precision testing.

[0004] In view of the above problems, there is an urgent need for a test circuit that can realize automatic switching of CC1 / CC2 channels at the circuit level and realize automatic switching of PD protocol communication and voltage detection of PCBA boards in different insertion directions. Summary of the Invention

[0005] The present application provides a PD interface automatic switching circuit that supports testing the front and back sides of PCBA boards, so as to solve the problem that the existing technology relies on manual plugging and unplugging or mechanical flipping to switch the insertion direction, resulting in a complicated and inefficient testing process, and easily causing poor contact or plugging damage risks. It is impossible to achieve fast and reliable switching testing of PCBA boards with different insertion directions without the aid of an external mechanical flipping device.

[0006] In the first aspect, the present application provides a PD interface automatic switching circuit that supports front and back side testing of PCBA boards, the circuit comprising a main control module, a communication conversion module, a channel switching module, a PD interface module, a USB PD protocol module, and a power regulation module;

[0007] The PD interface module is arranged between the circuit and the PCBA board to be tested;

[0008] The channel switching module is electrically connected to the CC1 channel and CC2 channel of the PD interface module respectively;

[0009] The main control module is electrically connected to the communication conversion module and the channel switching module respectively;

[0010] The USB PD protocol module is electrically connected to the PD interface module;

[0011] The power regulation module is electrically connected to the USB PD protocol module and is used to provide a stabilized power supply;

[0012] The main control module is configured to receive the control signal from the PC end converted by the communication conversion module, and drive the channel switching module based on the control signal to turn on the CC1 channel or the CC2 channel to achieve test switching of the PCBA board to be tested connected through the PD interface module in different insertion directions.

[0013] Optionally, the channel switching module includes a first switch unit and a second switch unit;

[0014] The first switch unit is electrically connected to the CC1 channel of the PD interface module, and the second switch unit is electrically connected to the CC2 channel of the PD interface module;

[0015] The main control module is configured to turn on the first switch unit or the second switch unit based on the control signal to perform a switching test on the PCBA board to be tested in different insertion directions.

[0016] Optionally, the circuit further includes an indication module, and the indication module includes a first indication unit and a second indication unit;

[0017] The first indication unit corresponds to the CC1 channel and is electrically connected to the main control module, and the second indication unit corresponds to the CC2 channel and is electrically connected to the main control module;

[0018] The main control module is configured to control the first indicator unit to light up when the first switch unit is turned on, and to control the second indicator unit to light up when the second switch unit is turned on.

[0019] Optionally, the communication conversion module has a USB signal input terminal and a serial signal interface terminal;

[0020] The USB signal input terminal is electrically connected to the PC terminal, and the serial signal interface terminal is electrically connected to the main control module;

[0021] The communication conversion module is configured to perform bidirectional conversion between USB signals and serial signals to establish a communication connection between the main control module and the PC end.

[0022] Optionally, the USB PD protocol module includes a first USB PD protocol submodule and a second USB PD protocol submodule;

[0023] The PD signal end of the first USB PD protocol submodule and the PD signal end of the second USB PD protocol submodule are electrically connected to the PD circuits corresponding to the PD interface module respectively;

[0024] The communication interface end of the first USB PD protocol submodule and the communication interface end of the second USB PD protocol submodule are electrically connected to the main control module through corresponding I2 C communication buses respectively;

[0025] The main control module is configured to respectively obtain detection data of the first USB PD protocol submodule and the second USB PD protocol submodule, and drive the channel switching module based on the control signal to turn on the CC1 channel or the CC2 channel to implement PD protocol communication and voltage detection of the PCBA board to be tested in different insertion directions.

[0026] Optionally, the input end of the power regulation module is electrically connected to the power input circuit, and the output end is electrically connected to the power input ends of the first USB PD protocol submodule and the second USB PD protocol submodule respectively;

[0027] The power regulation module is configured to output a regulated power supply when the input voltage changes, to supply power to the first USB PD protocol submodule and the second USB PD protocol submodule.

[0028] Optionally, the PD interface module is a USB Type-C interface;

[0029] The CC1 channel and the CC2 channel are electrically connected to the PD interface of the PCBA board to be tested through the channel switching module, and are electrically connected to the USB PD protocol module and the power regulation module respectively through the VBUS line.

[0030] Optionally, the main control module further includes a feedback output terminal, and the feedback output terminal is electrically connected to the PC terminal through the communication conversion module;

[0031] The main control module is configured to output status information of the current CC channel conduction state and the insertion direction of the PCBA board to be tested.

[0032] Optionally, the main control module is configured to receive the output voltage value detected by the first USB PD protocol submodule and the second USB PD protocol submodule, compare the output voltage value with a preset threshold, and transmit the comparison result to the PC end through the communication conversion module.

[0033] Optionally, the main control module further includes a communication identification unit, and the communication identification unit is electrically connected to the communication conversion module;

[0034] The communication identification unit is configured to identify the established USB communication protocol type and transmit the identified communication protocol information to the PC end through the communication conversion module.

[0035] The technical solution provided by the embodiments of the present application offers the following advantages over existing technologies: The present invention provides an automatic PD interface switching circuit that supports front- and back-end testing of PCBA boards. By integrating a main control module, a communication conversion module, a channel switching module, a PD interface module, a USB PD protocol module, and a power regulation module, the circuit automatically switches between CC1 and CC2 channels in the USB Type-C interface. The main control module receives PC-side control signals converted by the communication conversion module and drives the channel switching module to conduct either CC1 or CC2. This enables PD protocol communication and voltage detection on the PCBA under test in different insertion orientations, avoiding the inefficiency and instability associated with traditional testing methods caused by repeated manual insertion and removal or mechanical flipping. The USB PD protocol module is electrically connected to the PD interface module, and a stable voltage is provided by the power regulation module, ensuring stable PD communication and reliable power supply during testing. This solution automatically identifies insertion orientation and switches channels at the circuit level, improving test efficiency, stability, and consistency. It is suitable for highly integrated automated PD protocol testing in production and R&D, offering significant advantages in simplified structure, reduced costs, and ease of system integration. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the invention and, together with the description, serve to explain the principles of the invention.

[0037] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, for ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative labor.

[0038] One or more embodiments are exemplarily illustrated by pictures in the corresponding drawings. These exemplifications do not constitute limitations on the embodiments. Elements with the same reference numerals in the drawings are represented as similar elements. Unless otherwise stated, the figures in the drawings do not constitute proportional limitations.

[0039] Figure 1 A schematic diagram of an automatic PD interface switching circuit that supports front and back side testing of PCBA boards provided in an embodiment of the present application. DETAILED DESCRIPTION

[0040] To make the purpose, technical solutions, and advantages of the embodiments of this application more clear, the technical solutions in the embodiments of this application will be clearly and completely described below in conjunction with the drawings in the embodiments of this application. Obviously, the described embodiments are part of the embodiments of this application, not all of the embodiments. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of this application.

[0041] The disclosure below provides many different embodiments or examples for implementing different configurations of the present invention. To simplify the disclosure of the present invention, the components and configurations of specific examples are described below. Of course, these are merely examples and are not intended to limit the present invention. In addition, the present invention may repeat reference numerals and / or letters in different examples. Such repetition is for the purpose of simplicity and clarity and does not in itself indicate the relationship between the various embodiments and / or configurations discussed.

[0042] Figure 1 A schematic diagram of an automatic PD interface switching circuit that supports front and back side testing of PCBA boards provided in an embodiment of the present application.

[0043] The circuit of this application includes a main control module, a communication conversion module, a channel switching module, a PD interface module, a USB PD protocol module, and a power regulation module;

[0044] The PD interface module is arranged between the circuit and the PCBA board to be tested;

[0045] The channel switching module is electrically connected to the CC1 channel and CC2 channel of the PD interface module respectively;

[0046] The main control module is electrically connected to the communication conversion module and the channel switching module respectively;

[0047] The USB PD protocol module is electrically connected to the PD interface module;

[0048] The power regulation module is electrically connected to the USB PD protocol module and is used to provide a stabilized power supply;

[0049] The main control module is configured to receive the control signal from the PC end converted by the communication conversion module, and drive the channel switching module based on the control signal to turn on the CC1 channel or the CC2 channel to achieve test switching of the PCBA board to be tested connected through the PD interface module in different insertion directions.

[0050] This embodiment provides a PD interface automatic switching circuit that supports testing the front and back sides of a PCBA board. Figure 1 As shown in the figure, the circuit includes a main control module, a communication conversion module, a channel switching module, a PD interface module, a USB PD protocol module and a power regulation module, which can realize automatic identification of PCBA boards in different insertion directions and PD protocol test switching.

[0051] The main control module can be implemented using an MCU chip, which controls the switching logic and data processing of the entire circuit. The communication conversion module converts the USB signal output from the PC into a serial communication signal and sends it to the main control module. In this embodiment, a CH340 series chip supporting USB-to-serial port conversion can be used. After receiving this control signal, the main control module controls the channel switching module according to the preset control logic.

[0052] The channel switching module includes two switch units, electrically connected to the CC1 and CC2 channels of the PD interface module. Under the control of the main control module, CC1 or CC2 can be selectively turned on, thereby simulating and testing the PD interface status under different insertion directions.

[0053] The PD interface module is placed between this circuit and the PCBA under test. It uses a USB Type-C connector and includes signal lines such as CC1, CC2, and VBUS for connecting to the PCBA's USB PD port. Users can insert the PCBA into the PD interface module in either the forward or reverse direction, and the main control module automatically identifies and switches based on the selected channel.

[0054] The USB PD protocol module includes two USB PD protocol chips (such as the SC2021), one for coordinating PD protocol communication detection on the CC1 and CC2 channels. Its PD signal end is connected to the PD interface module, and its communication interface end is connected to the main control module via the I2C bus. The main control module can obtain information such as the output voltage and protocol negotiation status of the two USB PD protocol chips.

[0055] The power regulation module is connected between the PD power input line and the USB PD protocol module. It is used to provide stable voltage output under different input voltage conditions to ensure that the USB PD protocol module works normally when CC1 or CC2 is turned on. The power regulation module can be implemented using a buck-boost chip.

[0056] During the test, the PC sends a switching command through the communication conversion module. The main control module interprets the control signal and drives the channel switching module to connect the specified CC channel, allowing the USB PD protocol module to complete PD protocol negotiation and voltage detection with the PCBA under test. After completing the test in one direction, it automatically switches to the other channel to complete the PD protocol verification in both insertion directions (forward and reverse), achieving a fully automated testing process without manual board flipping or plugging.

[0057] The PD interface automatic switching circuit of this embodiment has the advantages of compact structure, fast switching response, and stable and consistent test results. It is suitable for batch forward and reverse insertion PD protocol testing scenarios of PCBA boards equipped with USB Type-C interfaces, effectively improving test efficiency and reducing manual operation costs.

[0058] Furthermore, the channel switching module includes a first switch unit and a second switch unit;

[0059] The first switch unit is electrically connected to the CC1 channel of the PD interface module, and the second switch unit is electrically connected to the CC2 channel of the PD interface module;

[0060] The main control module is configured to turn on the first switch unit or the second switch unit based on the control signal to perform a switching test on the PCBA board to be tested in different insertion directions.

[0061] In a preferred embodiment of the present invention, the channel switching module includes a first switch unit and a second switch unit, which are respectively connected to the CC1 channel and CC2 channel in the PD interface module, and are used to realize PD protocol test switching of the USB Type-C interface in different insertion directions.

[0062] Specifically, the input of the first switch unit is connected to the main control module, and the output is electrically connected to the CC1 channel of the PD interface module. The input of the second switch unit is also connected to the main control module, and the output is electrically connected to the CC2 channel of the PD interface module. In this embodiment, the first and second switch units can be implemented by N-channel MOS transistors, bidirectional analog switches (such as RS2227), or low-resistance electronically controlled switch chips, respectively, and their switch control terminals are respectively connected to the control pins of the main control module.

[0063] After receiving the PC-side control signal transmitted by the communication conversion module, the main control module determines the channel to be turned on in the current test phase based on preset logic and outputs the corresponding control level signal to drive the first or second switch unit to conduct. In this way, the CC1 or CC2 channel can be effectively connected to the subsequent PD protocol submodule, thereby completing the PD protocol test of the PCBA under test in the current insertion orientation.

[0064] For example, when the PCBA board is inserted in the forward direction, the main control module controls the first switch unit to turn on, the CC1 channel is connected, and the PD negotiation and voltage detection in the corresponding direction are completed; after the test is completed, the main control module controls the first switch unit to turn off, and controls the second switch unit to turn on, simulating the reverse insertion state, and driving the CC2 channel to participate in PD communication, thereby realizing automatic switching tests in the two insertion directions.

[0065] This embodiment dynamically controls the first and second switch units through the main control module to switch the CC1 and CC2 channels. This avoids the traditional test method of switching PD channels by mechanically flipping the board or repeatedly plugging and unplugging. This greatly improves the test automation level and test efficiency, and is suitable for batch and rapid Type-C PD interface test application scenarios.

[0066] Furthermore, the circuit further includes an indication module, and the indication module includes a first indication unit and a second indication unit;

[0067] The first indication unit corresponds to the CC1 channel and is electrically connected to the main control module, and the second indication unit corresponds to the CC2 channel and is electrically connected to the main control module;

[0068] The main control module is configured to control the first indicator unit to light up when the first switch unit is turned on, and to control the second indicator unit to light up when the second switch unit is turned on.

[0069] In this embodiment, the indicator module works closely with the main control module and channel switching module in the PD interface automatic switching circuit to provide intuitive status feedback. In terms of hardware, the main control module uses a CX32L003F8P6X MCU. Its GPIO pins are used to drive both the channel switching module (such as an RS2227 switch unit) and the LED indicator unit. The first indicator unit corresponds to channel CC1 and is connected to LED1 and a current-limiting resistor via a GPIO or driver circuit. The second indicator unit corresponds to channel CC2 and is connected to LED2 and its current-limiting resistor via another GPIO or driver circuit. Different LED colors can be used to distinguish channel status. The current-limiting resistor value is designed based on the LED forward voltage drop and the MCU output capability. If the MCU's direct drive capability is insufficient, a small-signal MOS transistor or transistor can be added between the GPIO and the LED as an open-drain driver. The PD interface module uses USB Type-C. The first and second switch units of the channel switching module are connected to channels CC1 and CC2, respectively. When the main control module drives the corresponding switch, the corresponding LED is simultaneously illuminated, achieving status linkage at the hardware level.

[0070] The software control process implements the synchronous switching of the main control and indicator modules in the firmware. When the system is powered on, the main control module sets all channel switches and LED indicators to the initial state, for example, all are closed and the LEDs are off, and then receives PC-side instructions through the CH340N communication conversion module. When the firmware parses the switch to CC1 test instruction, the main control first closes the second switch unit and turns off the second indicator unit, then drives the first switch unit to turn on the CC1 channel, and at the same time outputs the corresponding signal to light up the first indicator unit, indicating that the CC1 test state has entered; after the test is completed or when the switch to CC2 test instruction is received, the main control closes the first switch unit and turns off the first indicator unit, then drives the second switch unit to turn on the CC2 channel and lights up the second indicator unit, completing the CC2 test switch. If the PD protocol submodule (SC2021A) communication or voltage abnormality is detected during the switching or testing process, the firmware can indicate the abnormal state by flashing or lighting up two LEDs at the same time, and report to the PC side through the communication conversion module, and then reset the switch and indicator unit to wait for subsequent instructions.

[0071] To ensure reliable coordination between the indicator module and the switching and PD protocol detection circuits, PCB layout considerations must be considered for interference mitigation and spatial layout. The LED indicator circuit should be properly isolated from the high-power circuitry of the PD interface and the surrounding USB PD protocol chip. Current-limiting resistors and driver components should be placed close to the MCU to avoid interference caused by long traces. The MCU driver circuit can be equipped with filtering or decoupling capacitors to ensure that power transients during channel switching or PD communication do not affect indicator stability. The LED should be positioned near the PD interface or in a prominent location on the test surface for easy identification by human observers or visual systems.

[0072] The setting of the indicator module realizes the function of lighting up the first indicator unit when the first switch unit is turned on and lighting up the second indicator unit when the second switch unit is turned on. It can intuitively reflect the status of the CC channel used in the current test, and cooperate with the switching logic of the channel switching module and the main control module to complete the automatic test of the PD interface under different insertion directions of the PCBA board, thereby improving the system's availability, maintainability and human-computer interaction experience.

[0073] Furthermore, the communication conversion module has a USB signal input terminal and a serial signal interface terminal;

[0074] The USB signal input terminal is electrically connected to the PC terminal, and the serial signal interface terminal is electrically connected to the main control module;

[0075] The communication conversion module is configured to perform bidirectional conversion between USB signals and serial signals to establish a communication connection between the main control module and the PC end.

[0076] In an embodiment of the present application, the communication conversion module adopts the CH340N chip, whose USB signal input terminal is electrically connected to the PC terminal via the USBType-C interface, and the CH340N is powered by a 3.3V power supply to realize the serial signal interface connection between the main control module (MCU). The serial signal interface terminal (TXD, RXD) of the CH340N is electrically connected to the UART interface of the main control module through level matching or directly, using a 3.3V TTL level so that the main control module can receive and send UART data. In terms of power supply, the CH340N obtains a 5V power supply from the USB interface and provides the required 3.3V or other voltages to the MCU and the CH340N itself through an onboard voltage regulator circuit (such as LDO) to ensure stable communication. Among them, the necessary crystal oscillator circuit and decoupling capacitor should be arranged near the CH340N to provide a stable time base for its USB clock. At the same time, when the IO port of the CH340N is connected to the MCU UART pin, the signal integrity and trace length should be considered to avoid signal distortion caused by excessive length.

[0077] The main control module initializes serial communication parameters via UART with a predetermined baud rate, no parity, and one stop bit to match the PC's serial port driver. The PC loads and uses the corresponding CH340N driver through the host test software, making it appear as a virtual serial port in the PC system. The host software sends control commands, such as channel switching and status query commands, through the serial port. The CH340N converts the USB signals into UART signals, which are then received and interpreted by the main control module. After the main control module completes the interpretation, it provides feedback on the execution results or status information and sends it to the CH340N via UART. The CH340N then converts the serial signals into USB signals and returns them to the PC, thus establishing bidirectional communication. During communication, the main control module can receive UART data using interrupts or DMA to ensure real-time performance. When parsing commands, command format checksums and timeout retransmission mechanisms can be configured to improve communication reliability.

[0078] When the system is powered on and the main control module starts, it initializes the UART interface and I 2 C, GPIO and other peripherals, and then detects UART data through queries or interrupts. When receiving a test task from the PC, the main control performs operations such as channel switching, PD protocol communication, and voltage detection according to the command content, and sends the processing results to the PC via UART. If a failure occurs during the communication process, such as a UART reception error or a PC disconnection or reconnection, the firmware can detect the UART bus status and restart the serial port reception process, or notify the upper software to restart the connection.

[0079] Furthermore, the USB PD protocol module includes a first USB PD protocol submodule and a second USB PD protocol submodule;

[0080] The PD signal end of the first USB PD protocol submodule and the PD signal end of the second USB PD protocol submodule are electrically connected to the PD circuits corresponding to the PD interface module respectively;

[0081] The communication interface end of the first USB PD protocol submodule and the communication interface end of the second USB PD protocol submodule are electrically connected to the main control module through corresponding I2 C communication buses respectively;

[0082] The main control module is configured to respectively obtain detection data of the first USB PD protocol submodule and the second USB PD protocol submodule, and drive the channel switching module based on the control signal to turn on the CC1 channel or the CC2 channel to implement PD protocol communication and voltage detection of the PCBA board to be tested in different insertion directions.

[0083] In terms of hardware implementation, the USB PD protocol module consists of two USB PD protocol submodules, each using an SC2021A chip. The PD signal terminals of the two SC2021As are electrically connected to the corresponding PD circuits of the PD interface module. In the actual circuit, the PD interface module uses a USB Type-C interface, including signal pins such as CC1, CC2, and VBUS. The CC and VBUS monitoring and control pins of the first USB PD protocol submodule are connected to the corresponding circuits of the PD interface module through a channel switching module. The corresponding pins of the second USB PD protocol submodule are connected in a similar way, and are switched to the PD interface only through the channel switching module under the control of the main control module.

[0084] The communication interface of the two SC2021A is connected through their respective I 2 C communication bus is electrically connected to the main control module (such as CX32L003F8P6X MCU). Usually, separate SDA and SCL lines can be arranged for each SC2021A on the PCB, or they can be connected on the same bus by address differentiation, depending on the chip address configuration capability and I 2 C-bus load requirements. The power inputs of the two SC2021As are provided with stable voltages by a power conditioning module (a buck-boost chip, such as the SC8723). This ensures proper operation and reliable voltage detection under varying input conditions. During PCB layout, ensure that the connection paths between the SC2021As and the PD interface circuits, channel selector (RS2227 or equivalent), and main control module are properly isolated to prevent electrical interference during switching or PD communication.

[0085] After the main control module receives the control signal from the PC via the communication conversion module (CH340N), it first determines the current test direction according to the test instruction: if the forward insertion test (corresponding to the CC1 channel) is required, the main control module closes the channel switching switch associated with the second USB PD protocol submodule and drives the first switch unit to connect the first USB PD protocol submodule to the PD interface module; if the reverse insertion test (corresponding to the CC2 channel) is required, the first switch unit is closed and the second switch unit is turned on to establish a connection between the second USB PD protocol submodule and the PD interface module. After the channel switching is completed, the main control module switches to the I 2 C communication bus sends a PD negotiation command to the corresponding SC2021A, triggering the SC2021A to negotiate with the PD protocol chip on the PCBA to be tested, and monitors the VBUS output voltage value through the ADC module inside the SC2021A. 2After reading back the voltage detection results, C compares the obtained voltage value with the preset threshold to determine whether the test results meet the requirements. In the event of an abnormality or exceeding the limit, the main control can record the error and feedback it to the PC-side test software through the communication conversion module. After completing the current direction test, the main control can automatically or sequentially switch to another channel according to the upper command or internal process, and repeat the above channel conduction, PD protocol negotiation and voltage detection operations. If the two SC2021As support parallel monitoring or redundant testing, the status of the two sub-modules can also be polled in parallel in the firmware, depending on the test requirements and the resource limitations of the SC2021A.

[0086] The main control module turns off the channel switch corresponding to the previous SC2021A before each channel switching to avoid interference to the PD line from two channels at the same time. 2 The C communication logic must ensure normal communication with the current SC2021A during switching. If the same bus is used and the two SC2021As have the same address, isolation or timing must be implemented in hardware or firmware to avoid conflicts. If independent I 2 The C channel can be configured with different addresses, making switching easier. The power regulation module provides a stable operating voltage for the two SC2021As to avoid PD negotiation anomalies caused by VBUS or external power supply fluctuations. During the switching transient period, the power regulation module output remains stable to ensure continuous power supply to the SC2021A. The master controller should initialize I before each test. 2 C interface, clear the previous status, and reset the SC2021A working status after the test to ensure the accuracy of the next test.

[0087] Through the above hardware connection and firmware process, the system can automatically complete PD protocol communication and voltage detection with the corresponding SC2021A in different insertion directions, avoiding manual flipping or repeated plugging and unplugging operations, and improving the degree of test automation and consistency.

[0088] Furthermore, the input end of the power regulation module is electrically connected to the power input circuit, and the output end is electrically connected to the power input ends of the first USB PD protocol submodule and the second USB PD protocol submodule respectively;

[0089] The power regulation module is configured to output a regulated power supply when the input voltage changes, to supply power to the first USB PD protocol submodule and the second USB PD protocol submodule.

[0090] In this embodiment, the power regulation module uses a buck-boost chip such as the SC8723 to stabilize and regulate the voltage from the PD power input line and supply power to the USB PD protocol submodule. Specifically, when the PCBA board to be tested is inserted into the PD interface and connected to the PD adapter, the VBUS line of the PD interface module may provide a voltage of 5V or higher. The input end of the power regulation module is directly electrically connected to the PD power input line to accept this variable voltage input. The SC8723 chip automatically adjusts the voltage within the input range to the required stable operating voltage through its internal buck-boost topology and external feedback network, for example, providing 3.3V or other specified power supply voltage for two SC2021A USB PD protocol submodules. The regulated output is electrically connected to the power input ends of the first USB PD protocol submodule and the second USB PD protocol submodule through PCB traces. Regardless of whether the input voltage is higher, lower, or equal to the target output voltage, the SC8723 can maintain output stability, ensuring that the protocol submodule obtains reliable power support in any PD negotiation phase.

[0091] The power regulation module needs to be equipped with a feedback resistor network to set the regulated output voltage, and appropriate decoupling capacitors and input filter components should be placed at both the input and output ends to suppress transient interference that may occur during the PD interface and channel switching process. Because the channel switching module changes the connection status between the SC2021A and the PD interface in different test directions, the output of the power regulation module should continuously provide power to all USB PD protocol submodules without the need to disconnect the power during switching, to prevent the protocol chip from losing the negotiation state or requiring reinitialization due to power interruption. PCB layout should place the power regulation chip close to the SC2021A chip to shorten the output trace length and reduce parasitic inductance. A storage capacitor of appropriate capacity should also be added to the output end to cope with sudden current changes during channel switching or PD communication, thereby improving system stability. On the input side, a surge suppression or overvoltage protection circuit should also be added between the SC8723 and the PD interface to prevent sudden voltage changes in the PD adapter from damaging the power regulation module.

[0092] If the selected buck-boost chip supports dynamic output voltage adjustment via I2C or other interfaces, the main control module can configure the SC8723 during initialization or specific test scenarios to precisely match the power requirements of the USB PD protocol submodule. Otherwise, the output voltage can be fixed via a hardware feedback network. In this embodiment, the main control module (CX32L003F8P6X) performs basic checks on the power regulation module when the system is powered on. For example, it monitors the power chip status via I2C, checks whether the output voltage is within the expected range, and reports any abnormalities to the PC test software via the communication conversion module.

[0093] Furthermore, the PD interface module is a USB Type-C interface;

[0094] The CC1 channel and the CC2 channel are electrically connected to the PD interface of the PCBA board to be tested through the channel switching module, and are electrically connected to the USB PD protocol module and the power regulation module respectively through the VBUS line.

[0095] In this embodiment, the PD interface module utilizes a USB Type-C interface structure, with the CC1, CC2, and VBUS signal lines of the Type-C female connector arranged on the PCB in a rational manner to facilitate electrical connection with the channel switching module, USB PD protocol module, and power regulation module. Specifically, the USB Type-C female connector is connected to the first and second switch units of the channel switching module via PCB pads. The CC1 and CC2 lines, respectively, are routed through the channel switching module to the PD interface of the PCBA under test.

[0096] When the PCBA board to be tested is inserted into the Type-C interface, the main control module controls the channel switching module to conduct the corresponding CC line according to different directions, so that the PD protocol module can establish communication with the PD interface chip on the PCBA board. The VBUS line of the USB Type-C interface is directly connected to the input end of the power regulation module on the PCB, and at the same time provides a power input path to the USB PD protocol module to support the negotiation and detection functions of the PD chip. Since VBUS may generate different voltages after PD negotiation, the power regulation module in this embodiment adopts a buck-boost topology, which can accept 5V to high voltage input and output a stable voltage, providing a reliable working power supply for the USBPD protocol submodule. At the same time, the routing of the VBUS line needs to consider impedance matching and safety protection, and surge suppression and overcurrent protection components are arranged between VBUS and the Type-C female socket to ensure circuit stability during the insertion and removal of the PCBA board or PD adapter.

[0097] The USB Type-C interface module should be placed in a position on the chassis or test fixture that is easy to plug and unplug, and ESD protection and filtering components should be reserved around it to prevent static electricity or interference from entering the internal circuit during plugging and unplugging; the CC1 / CC2 lines are led out from the Type-C socket and pass through the channel switching module (such as RS2227 or an equivalent dual-channel analog switch), and then respectively connected to the PD interface of the PCBA board to be tested, and the direction switching is achieved through firmware control. After the VBUS line is introduced from the Type-C female socket, necessary filtering and protection should be set before entering the power regulation module and the USB PD protocol module to prevent transient interference from affecting the protocol chip or the main control circuit. The output end of the power regulation module is electrically connected to the power input end of the USB PD protocol submodule to ensure that the USB PD protocol module is always stably powered during the switching process. The USB PD protocol module then passes through the I2 C communicates with the main control module to obtain the CC channel information and perform PD protocol negotiation and voltage detection.

[0098] Furthermore, the main control module further includes a feedback output terminal, and the feedback output terminal is electrically connected to the PC terminal through the communication conversion module;

[0099] The main control module is configured to output status information of the current CC channel conduction state and the insertion direction of the PCBA board to be tested.

[0100] In this embodiment, the main control module is based on the CX32L003F8P6X MCU platform, and is connected to the communication conversion module (such as CH340N) through its feedback output terminal to realize the feedback of status information to the PC side. In terms of hardware, the main control module reserves a set of UART or USART interface pins, which are connected to the TXD / RXD of CH340N. CH340N then establishes a two-way communication link with the virtual serial port on the PC side through USB. The feedback output terminal is the UART sending pin of the main control module, which is used to send the current CC channel conduction status and PCBA board insertion direction to the host computer in digital or character form. When laying out the PCB, ensure that the serial signal line between the MCU and CH340N is as short as possible and avoid high-frequency interference sources. At the same time, configure sufficient decoupling capacitors for the power supply and ground wires of CH340N and MCU to ensure that the feedback data transmission is stable and reliable during channel switching or PD protocol communication.

[0101] An appropriate serial port protection circuit, such as a TVS diode or current-limiting resistor, should be configured between the main control module's UART interface and the CH340N interface to prevent damage to the MCU during the plug-in / plug-out process or external interference. Furthermore, the ground layout should consider common ground interference with the PD interface and power regulation module to prevent backflow noise from affecting serial port data integrity. The serial port receive buffer should be properly configured during MCU design to prevent buffer overflows caused by high-frequency status output.

[0102] This embodiment integrates a feedback output terminal in the main control module and cooperates with the communication conversion module to achieve real-time feedback of the CC channel conduction status and the insertion direction of the PCBA board to be tested, accurately and promptly providing test progress and result information to the PC end, meeting the needs of automated testing and improving the system monitorability and stability.

[0103] Furthermore, the main control module is configured to receive the output voltage values ​​detected by the first USB PD protocol submodule and the second USB PD protocol submodule, compare the output voltage values ​​with a preset threshold, and transmit the comparison results to the PC end through the communication conversion module.

[0104] Based on the existing hardware architecture, this embodiment describes the specific implementation method of the main control module to obtain and compare the output voltage values ​​detected by the first USB PD protocol submodule and the second USB PD protocol submodule, and transmit the comparison results to the PC through the communication conversion module. In terms of hardware, the main control module still uses the CX32L003F8P6X MCU, and its I 2 The C bus is connected to two SC2021A USB PD protocol submodules. The internal ADC of SC2021A can sample the VBUS output voltage and output it to the I 2 The voltage value is returned in the C register. The firmware pre-sets a voltage threshold range in the main control module memory that is consistent with the technical briefing document. This threshold can be written during firmware compilation or dynamically written and saved in the MCU non-volatile storage area at runtime via host computer instructions to accommodate different testing requirements.

[0105] Specifically, two SC2021 USB PD protocol chips are connected to the PD port by the PD charger. The first SC2021 chip connects to the 31 / 32V UBS PWR / SNS P pin. The U28 MOS G gate is controlled by the 29-pin ISO NGATE. The S drain is fed to the SC8723 1 / 2 through the BUCK BOOST. BUS_5V is output from pins 15 / 16 and connected to the second SC2021 chip's 31 / 32V UBS PWR / SNS P pin. The U29 MOS G gate is controlled by the 29-pin ISO NGATE. The S drain is fed to the PD port of the docking station. The SC2021A integrates a high-performance 32-bit MCU core, 2.5KB of RAM, and 32KB of MTP storage, supporting proprietary fast charging protocols. It integrates VBUS discharge path, VCONN power supply, programmable feedback compensation, voltage and current detection, 10-bit ADC, dual 10-bit DACs, NMOS gate driver, I2C interface and protection circuit to minimize external components and enable effective PD protocol communication via I2C.

[0106] In the test process, the main control module first switches on the corresponding channel through the channel switching logic, so that the PCBA board to be tested establishes PD communication with the first or second USB PD protocol submodule and outputs VBUS voltage. 2C initiates a read operation on the ADC register of the corresponding SC2021A to obtain the digitized voltage value. If necessary, multiple readings can be performed and simple filtering or averaging can be performed to eliminate transient interference. The main control firmware converts the read digital value into an actual voltage value based on the ADC quantization and reference voltage parameters of the SC2021A. The firmware then compares the actual voltage value with the preset lower and upper thresholds. If the voltage value falls within the threshold range, it is considered qualified; if it exceeds the range, it is considered unqualified. The comparison result can be accompanied by the actual voltage value and channel identification information to form a result data packet.

[0107] When the whole machine is working, the USB-C communication port is connected to the PC via a USB2.0 data cable. The CH340N converts the command into a UART command to communicate with the CX32L003F8P6X to control the back-end circuit. In the communication link, the main control module sends the result data packet to the CH340N via the UART interface. The CH340N converts it into a USB virtual serial port signal and transmits it to the upper test software on the PC. After analysis, the upper software can display the test channel, actual voltage and pass / fail judgment in real time, and record the log or execute the next test instruction as needed. If an error occurs during the I2C reading or conversion process (such as no response from the SC2021A, data verification abnormality, etc.), the firmware will identify the error and can send a specific error code message and feedback to the PC through the communication conversion module so that the upper software can take retry or alarm measures in time.

[0108] Furthermore, the main control module further includes a communication identification unit, and the communication identification unit is electrically connected to the communication conversion module;

[0109] The communication identification unit is configured to identify the established USB communication protocol type and transmit the identified communication protocol information to the PC end through the communication conversion module.

[0110] In this embodiment, the main control module is implemented based on the CX32L003F8P6X microcontroller, and is integrated with a communication identification unit for identifying the type of USB communication protocol established between the PC end and the test device, and transmitting the identification result to the PC end through the communication conversion module. The communication identification unit can judge the type of communication protocol currently used in the initialization phase or the initial stage of communication establishment by analyzing the baud rate, frame structure or communication handshake protocol of the received signal. For example, when the host computer and the test device establish a USB serial port connection through CH340N, the communication identification unit will parse the initialization signal received through UART to identify whether it conforms to the preset protocol format, such as whether it is a standard UART frame structure, whether the start bit / stop bit combination matches, whether it is a system-defined start identifier, etc., thereby confirming whether the currently established communication is the expected serial port communication protocol.

[0111] In a specific implementation, the communication identification unit can be composed of a receiving interrupt service routine and a protocol identification algorithm of the main control module. After receiving the communication initialization signal or command frame, the main control module compares the first frame data or specific fields with the predefined protocol template. For example, if it is recognized that the beginning contains a specific start character, a fixed-length command field, and an end check bit, it can be determined to be a custom serial port protocol. If it is found that the frame structure does not meet the standard or the baud rate is wrong, an unknown protocol or communication anomaly is returned. At the same time, the communication identification unit can also detect the response delay of the data frame, the ACK frame response rule, etc. during the handshake stage to assist in determining whether the communication protocol is a stable connection.

[0112] After identification is complete, the main control module encapsulates the identified communication protocol type information as status data and sends it via UART to the communication conversion module CH340N, which converts it into USB signals for transmission to the PC. The upper-level test software can accurately identify the current communication status. If the test software supports multi-protocol adaptation, this information can also be used to determine whether to automatically switch protocol processing modules.

[0113] Furthermore, the communication identification unit in this embodiment supports dynamic monitoring of connection status changes during communication. If it detects an abnormal baud rate change, a change in the data frame structure, or a communication interruption, the main control module immediately updates the communication protocol status and reports it to the PC via the communication conversion module. This feature facilitates rapid compatibility checks and automatic recovery from anomalies in multi-device testing platforms, improving system robustness and interoperability.

[0114] This application implements automatic switching of CC1 / CC2 channels at the circuit level, eliminating the need for a mechanical flip device or multiple manual plugging and unplugging, thereby eliminating the mechanical movements and human intervention in the traditional testing process. This can significantly shorten the test process time, reduce the risk of poor contact or interface damage due to improper plugging and unplugging, and improve test consistency and reliability.

[0115] By directly connecting the USB PD protocol module to the PD interface of the PCBA under test, PD protocol negotiation and voltage detection can be performed on the automatically switched channel. The power regulation module provides stable power to ensure the normal operation of the PD protocol module under different input conditions. This integrated approach eliminates the need for external independent measurements or additional bench equipment, ensures stable PD protocol communication during channel switching transients, and improves the accuracy of voltage measurement and protocol negotiation.

[0116] Through the communication conversion module, the main control module can receive test instructions issued by the PC and feed back information such as test results, channel status, and insertion direction to the PC. This solution is compatible with universal USB interfaces and does not require additional customized communication links. It is easy to integrate with upper-level test software or automated test platforms, realizing remote control and result collection, and improving the degree of automation of the test process.

[0117] By supporting the two-way PD protocol submodules to work in parallel or sequentially, the two-way PD interfaces can be independently or collaboratively tested under different test paths or insertion directions to meet the requirements of various test scenarios, thereby improving test flexibility and scalability, and facilitating the subsequent addition or replacement of PD protocol modules without affecting the scope of protection of the main claims.

[0118] The feedback output function enables the host system to monitor the test progress and switching status in real time. The communication identification unit can identify the USB protocol type, ensuring compatibility when testing in different protocol modes or performing specific mode verification, thereby improving the monitorability and adjustability of the test process and enhancing system stability.

[0119] The integrated design avoids external mechanical devices or additional instruments, reducing hardware investment costs. The modular circuit is easy to manufacture and maintain. When deploying the test platform, it only needs to be connected to the PC and the PCBA board to be tested, eliminating the need for complex configuration and simplifying the system architecture of the test equipment.

[0120] Those skilled in the art can clearly understand that, for the convenience and brevity of description, only the division of the above-mentioned functional units and modules is used as an example for illustration. In actual applications, the above-mentioned functions can be distributed and completed by different functional units and modules as needed, that is, the internal structure of the device can be divided into different functional units or modules to complete all or part of the functions described above. The functional units and modules in the embodiment can be integrated into one processing unit, or each unit can exist physically alone, or two or more units can be integrated into one unit. The above-mentioned integrated unit can be implemented in the form of hardware or in the form of software functional units. In addition, the specific names of the functional units and modules are only for the convenience of distinguishing each other, and are not used to limit the scope of protection of this application. The specific working process of the units and modules in the above-mentioned system can refer to the corresponding process in the aforementioned method embodiment, and will not be repeated here.

[0121] In the above embodiments, the description of each embodiment has its own focus. For parts that are not described or recorded in detail in a certain embodiment, reference can be made to the relevant description of other embodiments.

[0122] Those skilled in the art will appreciate that the units and algorithm steps of each example described in conjunction with the embodiments disclosed in this application can be implemented in electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are performed in hardware or software depends on the specific application and design constraints of the technical solution. Professional and technical personnel can use different methods to implement the described functions for each specific application, but such implementation should not be considered beyond the scope of this application.

[0123] In the embodiments provided in this application, it should be understood that the disclosed devices / terminal equipment and methods can be implemented in other ways. For example, the device / terminal equipment embodiments described above are merely illustrative. For example, the division of the modules or units is merely a logical function division. In actual implementation, there may be other division methods, such as multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be through some interfaces, indirect coupling or communication connection of devices or units, which can be electrical, mechanical or other forms.

[0124] In addition, the functional units in the various embodiments of the present application may be integrated into a single processing unit, or each unit may exist physically separately, or two or more units may be integrated into a single unit. The aforementioned integrated units may be implemented in the form of hardware or software functional units.

[0125] If the integrated module / unit is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the present application implements all or part of the process in the above-mentioned embodiment method, and can also be completed by instructing the relevant hardware through a computer program. The computer program can be stored in a computer-readable storage medium, and when the computer program is executed by the processor, it can implement the steps of the above-mentioned various method embodiments. Among them, the computer program includes computer program code, and the computer program code can be in source code form, object code form, executable file or some intermediate form. The computer-readable medium may include: any entity or device capable of carrying the computer program code, recording medium, USB flash drive, mobile hard disk, magnetic disk, optical disk, computer memory, read-only memory (ROM), random access memory (RAM), electric carrier signal, telecommunication signal and software distribution medium. It should be noted that the content contained in the computer-readable medium can be appropriately increased or decreased according to the requirements of legislation and patent practice in the jurisdiction. For example, in some jurisdictions, according to legislation and patent practice, computer-readable media do not include electric carrier signals and telecommunication signals.

[0126] The present application implements all or part of the processes in the above-mentioned embodiment method, and can also be completed through a computer program product. When the computer program product is run on a terminal device, the terminal device can implement the steps in the above-mentioned method embodiments when executing.

[0127] The above embodiments are intended only to illustrate the technical solutions of the present application and are not intended to limit them. Although the present application has been described in detail with reference to the above embodiments, those skilled in the art should understand that they may still modify the technical solutions described in the above embodiments or replace some of the technical features therein with equivalents; and such modifications or replacements do not deviate from the spirit and scope of the technical solutions of the embodiments of the present application and should be included within the scope of protection of the present application.

Claims

1. A PD interface automatic switching circuit that supports PCBA board front and back side testing, characterized in that: The circuit includes a main control module, a communication conversion module, a channel switching module, a PD interface module, a USB PD protocol module, and a power regulation module; The PD interface module is arranged between the circuit and the PCBA board to be tested; The channel switching module is electrically connected to the CC1 channel and CC2 channel of the PD interface module respectively; The main control module is electrically connected to the communication conversion module and the channel switching module respectively; The USB PD protocol module is electrically connected to the PD interface module; The power regulation module is electrically connected to the USB PD protocol module and is used to provide a stabilized power supply; The main control module is configured to receive the control signal from the PC end converted by the communication conversion module, and drive the channel switching module based on the control signal to turn on the CC1 channel or the CC2 channel to achieve test switching of the PCBA board to be tested connected through the PD interface module in different insertion directions.

2. The PD interface automatic switching circuit according to claim 1, characterized in that: The channel switching module includes a first switch unit and a second switch unit; The first switch unit is electrically connected to the CC1 channel of the PD interface module, and the second switch unit is electrically connected to the CC2 channel of the PD interface module; The main control module is configured to turn on the first switch unit or the second switch unit based on the control signal to perform a switching test on the PCBA board to be tested in different insertion directions.

3. The PD interface automatic switching circuit according to claim 2, characterized in that: The circuit further includes an indication module, wherein the indication module includes a first indication unit and a second indication unit; The first indication unit corresponds to the CC1 channel and is electrically connected to the main control module, and the second indication unit corresponds to the CC2 channel and is electrically connected to the main control module; The main control module is configured to control the first indicator unit to light up when the first switch unit is turned on, and to control the second indicator unit to light up when the second switch unit is turned on.

4. The PD interface automatic switching circuit according to claim 1, characterized in that: The communication conversion module has a USB signal input terminal and a serial signal interface terminal; The USB signal input terminal is electrically connected to the PC terminal, and the serial signal interface terminal is electrically connected to the main control module; The communication conversion module is configured to perform bidirectional conversion between USB signals and serial signals to establish a communication connection between the main control module and the PC end.

5. The PD interface automatic switching circuit according to claim 1, characterized in that: The USB PD protocol module includes a first USB PD protocol submodule and a second USB PD protocol submodule; The PD signal end of the first USB PD protocol submodule and the PD signal end of the second USB PD protocol submodule are electrically connected to the PD circuits corresponding to the PD interface module respectively; The communication interface end of the first USB PD protocol submodule and the communication interface end of the second USB PD protocol submodule are electrically connected to the main control module through corresponding I2 C communication buses respectively; The main control module is configured to respectively obtain detection data of the first USB PD protocol submodule and the second USB PD protocol submodule, and drive the channel switching module based on the control signal to turn on the CC1 channel or the CC2 channel to implement PD protocol communication and voltage detection of the PCBA board to be tested in different insertion directions.

6. The PD interface automatic switching circuit according to claim 5, characterized in that: The input end of the power regulation module is electrically connected to the power input circuit, and the output end is electrically connected to the power input ends of the first USB PD protocol submodule and the second USB PD protocol submodule respectively; The power regulation module is configured to output a regulated power supply when the input voltage changes, to supply power to the first USB PD protocol submodule and the second USB PD protocol submodule.

7. The PD interface automatic switching circuit according to claim 1, characterized in that: The PD interface module is a USB Type-C interface; The CC1 channel and the CC2 channel are electrically connected to the PD interface of the PCBA board to be tested through the channel switching module, and are electrically connected to the USB PD protocol module and the power regulation module respectively through the VBUS line.

8. The PD interface automatic switching circuit according to claim 1, characterized in that: The main control module further includes a feedback output terminal, which is electrically connected to the PC terminal through the communication conversion module; The main control module is configured to output status information of the current CC channel conduction state and the insertion direction of the PCBA board to be tested.

9. The PD interface automatic switching circuit according to claim 5, characterized in that: The main control module is configured to receive the output voltage values ​​detected by the first USB PD protocol submodule and the second USB PD protocol submodule, compare the output voltage values ​​with a preset threshold, and transmit the comparison results to the PC end through the communication conversion module.

10. The PD interface automatic switching circuit according to claim 1, characterized in that: The main control module further includes a communication identification unit, which is electrically connected to the communication conversion module; The communication identification unit is configured to identify the established USB communication protocol type and transmit the identified communication protocol information to the PC end through the communication conversion module.

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