USB interface power supply automatic test circuit and test method

Abstract

The invention relates to a USB interface power supply automatic test circuit and method. The test circuit comprises a control module; a simulation USB plugging module; a static load module; a dynamic load and analog overcurrent module; a simulation short circuit module; the USB female interface to be tested and the oscilloscope are respectively connected with the interface module. The invention discloses an automatic test circuit and method for a USB interface power supply, and aims to solve the problem of rapid automatic test of related test items of a single or full-function USB power supply for a single USB interface. The method and the circuit provide a test method for directly measuring a USB interface power supply, and provide functions of static load test, dynamic load test, simulation plugging test, simulation over-current test, simulation short-circuit test, full-function automatic test and the like. The objective of the invention is to solve the problems of insufficient test result precision, insufficient test, long test time consumption, welding in test and the like of the existing test means.

Description

Technical Field

[0001] The invention relates to the field of USB interface power supply testing, and in particular to a USB interface power supply automatic testing circuit and testing method. Background Art

[0002] The USB interface is one of the most commonly used interfaces in electronic devices. Unstable USB power supply can cause USB devices to hang and even affect the stability of the device system. Therefore, USB interface power supply related tests are very important. Currently, USB interface power supply related tests mainly refer to the 5V power supply test for the USB port.

[0003] At present, the USB power supply test mainly tests the 5V power supply on the motherboard that supplies power to the USB. It is rare to perform power supply-related tests on each USB port separately. Due to differences in PCB routing, the electrical performance of USB ports varies, so it is necessary to test each USB interface separately. In the USB port hardware reference circuit, the 5V power supply on the motherboard that supplies power to the USB port will be connected to the USB interface through a magnetic bead. The magnetic bead has a certain internal resistance, and the 5V power supply voltage will have a certain voltage drop when it reaches the USB interface, resulting in a voltage difference between the USB port voltage and the motherboard 5V, resulting in inaccurate test results. Due to design requirements, the current limiting chip of the USB interface is very close to the USB interface, making it difficult to weld the test fixture, and the USB interface overcurrent protection and short circuit protection tests are often ignored. Summary of the invention

[0004] The invention provides a USB interface power automatic test circuit and a test method, aiming to solve at least one of the technical problems existing in the prior art.

[0005] The technical solution of the present invention is a USB interface power automatic test circuit and a test method, wherein the USB interface power automatic test circuit at least comprises: Control module; A simulated USB plug-in module, the simulated USB plug-in module comprising a simulated plug-in on-off unit and a simulated plug-in display unit respectively connected to the control module; A static load module, the static load module comprising a USB2.0 static load unit, a USB3.0 static load unit and a static load display unit respectively connected to the control module; A dynamic load and simulated overcurrent module, the dynamic load and simulated overcurrent module comprising a dynamic load and simulated overcurrent load control unit, a dynamic load display unit and a simulated overcurrent display unit respectively connected to the control module; A simulated short circuit module, the simulated short circuit module comprising a simulated short circuit load unit and a simulated short circuit display unit respectively connected to the control module; The interface module also includes a USB female interface to be tested and an oscilloscope respectively connected to the interface module.

[0006] Furthermore, the present invention also provides a USB interface power supply automatic test method, the USB interface power supply automatic test method is applied to the USB interface power supply automatic test circuit, and the USB interface power supply automatic test method comprises the following steps: S100, connecting the output end of the USB interface power automation test circuit to the USB device to be tested through the USB interface, connecting the external trigger signal interface of the oscilloscope, and setting the maximum value range and trigger condition of the oscilloscope; S200, the control module identifies the type of the USB device to be tested, where the type of the USB device to be tested includes USB 2.0 and USB 3.0; S300, based on the selected test items, the control module controls the simulated USB plug-in module, the static load module, the simulated short circuit module and the dynamic load and simulated overcurrent module to perform the test; The step S300 includes the following steps: S310, the control module performs a simulated USB plug-in test through the simulated USB plug-in module; S320, the control module performs a static load test through the static load module; S330, the control module performs dynamic load and simulated overcurrent tests through the dynamic load and simulated overcurrent module; S340, the control module performs a simulated short circuit test through the simulated short circuit module; S350: If the full function test is selected, the control module sequentially performs a static load test, a dynamic load test, a simulated plug and unplug test, a simulated overcurrent test, and a simulated short circuit test; S400, the control module receives feedback signals from the simulated USB plug-in module, the static load module, the simulated short circuit module, the dynamic load module and the simulated overcurrent module, and determines and displays the test results.

[0007] Furthermore, the present invention also provides a computer-readable storage medium on which program instructions are stored. When the program instructions are executed by a processor, the USB interface power automatic testing method is implemented.

[0008] The beneficial effects of the present invention are: The USB interface power automation test circuit and method are intended to solve the problem of rapid automated testing of single or full-function USB power-related test items for a single USB interface. The method and circuit provide a test method for directly measuring the USB interface power, providing functions such as static load test, dynamic load test, simulated plug-in test, simulated overcurrent test, simulated short circuit test and full-function automated test. It is intended to solve the problems of existing test methods such as insufficient test result accuracy, insufficient test, long test time, and welding required for test.

[0009] The USB interface power supply automation test circuit and method integrate the USB interface power supply related test items, realize the automation test of USB interface power supply single test and full-function test, realize unattended test, and can quickly test single or multiple USB interfaces, greatly increasing the test efficiency. There is no need to weld the test fixture on the tested device to avoid damage to the tested device, and realize the USB interface access test method. The test method using USB interface access is closer to the actual use scenario than testing USB power supply on the mainboard of the tested device, and the test results are more accurate. The whole machine test can be directly carried out when the tested device system is running, and it can be carried out simultaneously with other whole machine test items, which is closer to the actual use scenario and the test results are more accurate. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] Figure 1 This is the block diagram of the USB interface power automation test circuit.

[0011] Figure 2 It is a circuit diagram of a control module in a USB interface power automation test circuit.

[0012] Figure 3 It is a circuit diagram of the interface module in the USB interface power automation test circuit.

[0013] Figure 4 It is a circuit diagram of simulating a USB plug-in module in a USB interface power automation test circuit.

[0014] Figure 5 It is a circuit diagram of a static load module in a USB interface power automation test circuit.

[0015] Figure 6 This is a schematic diagram of the dynamic load and simulated overcurrent module circuit in the USB interface power automation test circuit.

[0016] Figure 7 This is a schematic diagram of the circuit of the simulated short circuit module in the USB interface power automation test circuit.

[0017] Figure 8 It is a flow chart of the USB interface power automation test method.

[0018] Fig. 9 It is a flowchart of the USB interface power automation test method.

[0019] Fig.10 It is a flowchart of the full-function test in the USB interface power automation test method.

[0020] Fig.11 It is a flow chart of simulating USB plug-in and unplug test in the USB interface power automation test method.

[0021] Fig.12 It is a flow chart of static load test in the USB interface power automation test method.

[0022] Fig.13 It is a flow chart of dynamic load test in the USB interface power automation test method.

[0023] Fig.14 It is a flow chart of simulating overcurrent test in the USB interface power automation test method.

[0024] Fig.15 It is a flow chart of a simulated short circuit test in a USB interface power automation test method. DETAILED DESCRIPTION

[0025] The following will be combined with the embodiments and drawings to clearly and completely describe the concept, specific structure and technical effects of the present invention, so as to fully understand the purpose, scheme and effect of the present invention. It should be noted that the embodiments and features in the embodiments of this application can be combined with each other without conflict.

[0026] It should be noted that, unless otherwise specified, when a feature is referred to as being "fixed" or "connected" to another feature, it may be directly fixed or connected to the other feature, or it may be indirectly fixed or connected to the other feature. In addition, the descriptions of up, down, left, right, top, bottom, etc. used in the present invention are only relative to the relative positional relationship of the components of the present invention in the drawings.

[0027] In addition, unless otherwise defined, all technical and scientific terms used herein have the same meaning as those generally understood by those skilled in the art. The terms used in this specification are only for describing specific embodiments, not for limiting the present invention. The term "and / or" used herein includes any combination of one or more related listed items.

[0028] It should be understood that, although the terms first, second, third, etc. may be used to describe various elements in the present disclosure, these elements should not be limited to these terms. These terms are only used to distinguish elements of the same type from each other. For example, without departing from the scope of the present disclosure, the first element may also be referred to as the second element, and similarly, the second element may also be referred to as the first element.

[0029] Reference Figures 1 to 15 In some embodiments, the technical solution of the present invention is a USB interface power automatic test circuit and test method, referring to Figure 1 , the USB interface power supply automatic test circuit at least includes: Control module; A simulated USB plug-in module, the simulated USB plug-in module comprising a simulated plug-in on-off unit and a simulated plug-in display unit respectively connected to the control module; A static load module, the static load module comprising a USB2.0 static load unit, a USB3.0 static load unit and a static load display unit respectively connected to the control module; A dynamic load and simulated overcurrent module, the dynamic load and simulated overcurrent module comprising a dynamic load and simulated overcurrent load control unit, a dynamic load display unit and a simulated overcurrent display unit respectively connected to the control module; A simulated short circuit module, the simulated short circuit module comprising a simulated short circuit load unit and a simulated short circuit display unit respectively connected to the control module; The interface module also includes a USB female interface to be tested and an oscilloscope respectively connected to the interface module.

[0030] The beneficial effects of the present invention are: The USB interface power automation test circuit and method are intended to solve the problem of rapid automated testing of single or full-function USB power-related test items for a single USB interface. The method and circuit provide a test method for directly measuring the USB interface power, providing functions such as static load test, dynamic load test, simulated plug-in test, simulated overcurrent test, simulated short circuit test and full-function automated test. It is intended to solve the problems of existing test methods such as insufficient test result accuracy, insufficient test, long test time, and welding required for test.

[0031] The USB interface power supply automation test circuit and method integrate the USB interface power supply related test items, realize the automation test of USB interface power supply single test and full-function test, realize unattended test, and can quickly test single or multiple USB interfaces, greatly increasing the test efficiency. There is no need to weld the test fixture on the tested device to avoid damage to the tested device, and realize the USB interface access test method. The test method using USB interface access is closer to the actual use scenario than testing USB power supply on the mainboard of the tested device, and the test results are more accurate. The whole machine test can be directly carried out when the tested device system is running, and it can be carried out simultaneously with other whole machine test items, which is closer to the actual use scenario and the test results are more accurate.

[0032] Specifically, refer to Figure 1 In some specific embodiments, the control module is an MCU module, and the USB interface power automation test circuit has five modules: a control module (MCU module), a simulated USB plug-in module, a dynamic load and simulated overcurrent module, a static load module, a simulated short circuit module and an interface module, wherein the interface module is externally connected to the USB female interface under test and to an oscilloscope.

[0033] Reference Figure 2 The main function of the control module (MCU module) is to select and control the test functions, including: test item selection function, USB type identification function, static load test control function, dynamic load test control function, simulated overcurrent test control function, simulated short circuit control function and test result and test progress display function.

[0034] Specifically, refer to Figure 2, where U0 is the MCU main control chip of the control module; Pin0 is the power supply pin, which can be battery powered or externally powered; Pin1 receives the USB identification signal, and the USB identification signal is high for USB2.0, and the signal is low for USB3.0; (how the signal is generated is analyzed in the interface module); Pin2 sends out an analog short-circuit control signal for controlling the analog short-circuit test; Pin3 sends out an analog plug-in control signal for controlling the analog plug-in test; Pin4 sends out a static load control signal for controlling the static load test; Pin5 receives an external trigger Aux out signal, which is sent by the oscilloscope. When a waveform trigger event occurs on the oscilloscope, the signal changes from high to low and locks the waveform; Pin6 sends out a dynamic load control signal or an analog overcurrent control signal for controlling the dynamic load test or the analog overcurrent control test; Pin7 receives a test function selection signal for selecting a test item. This signal is connected to the test function selection button. Whenever the button is pressed, the indicator LED corresponding to a test will light up to indicate the currently selected test item; VCC, R0 and SW0 constitute the function selection module. Whenever SW0 is pressed, the test function selection signal is connected to the ground, and a low pulse is generated for the MCU. The MCU selects the test items cyclically according to the number of low pulses. Pin 8 receives a 5V measurement signal, which is used to judge the test results of the simulated short circuit test and the simulated overcurrent protection. A low level is received for the test to pass, and a high level is received for the test to fail; (how to generate the judgment signal is analyzed in the corresponding test module). The 5V measurement power supply, the fifth resistor R5 and the sixth resistor R6 are used to divide the voltage to generate a 5V measurement signal connected to the ADC interface. When simulating the overcurrent test, if the USB current limiting chip of the device under test is working, the power supply of the USB interface is disconnected to make the 5V measurement signal low, that is, when the 5V measurement signal changes from high to low, it is judged that the simulated overcurrent test has passed. When the short circuit test is simulated, if the USB current limiting chip of the device under test works, the power supply of the USB interface is disconnected, so that the 5V measurement signal becomes low, that is, when the 5V measurement signal changes from high to low, it is judged that the simulated short circuit test has passed. Pin 9 sends a static load test signal, which is connected to a two-color LED light corresponding to the static load test and is used to control the two-color LED. When this test is selected, the signal is high and the LED lights up green. When the test passes, the signal is high and the LED lights up green. When the test fails, the signal is low and the LED lights up red. When control is not required, the signal is in high impedance state and the LED goes out; (How the LED works is analyzed in the corresponding module).Pin 10 sends a dynamic load test signal, which is connected to a bicolor LED lamp corresponding to the dynamic load test and is used to control the bicolor LED. When the test is selected, the signal is high and the LED lights up green. When the test passes, the signal is high and the LED lights up green. When the test fails, the signal is low and the LED lights up red. When control is not required, the signal is in a high impedance state and the LED turns off. (How the LED works is analyzed in the corresponding module). Pin 11 sends an analog plug-in test signal, which is connected to a bicolor LED lamp corresponding to the analog plug-in test and is used to control the bicolor LED. When the test is selected, the signal is high and the LED lights up green. When the test passes, the signal is high and the LED lights up green. When the test fails, the signal is low and the LED lights up red. When control is not required, the signal is in a high impedance state and the LED turns off. (How the LED works is analyzed in the corresponding module). Pin 12 sends out a simulated short-circuit test signal, which is connected to a bicolor LED lamp corresponding to the simulated short-circuit test and is used to control the bicolor LED. When the test is selected, the signal is high and the LED lights up green. When the test passes, the signal is high and the LED lights up green. When the test fails, the signal is low and the LED lights up red. When control is not required, the signal is in a high-impedance state and the LED turns off. (How the LED works is analyzed in the corresponding module). Pin 13 sends out a simulated overcurrent test signal, which is connected to a bicolor LED lamp corresponding to the simulated overcurrent test and is used to control the bicolor LED. When the test is selected, the signal is high and the LED lights up green. When the test passes, the signal is high and the LED lights up green. When the test fails, the signal is low and the LED lights up red. When control is not required, the signal is in a high-impedance state and the LED turns off. (How the LED works is analyzed in the corresponding module). Pin 14 sends out a full-function test signal, which is connected to a monochrome LED corresponding to the full-function test and is used to control the LED. When the test is selected, the signal is high and the LED lights up green. When the test passes, the signal is high and the LED lights up green. When the test fails, the signal is low and the LED turns off. When a test fails, the test failure result is displayed by the two-color LED of the test item. When control is not required, the signal is low and the LED turns off; (how the LED works is analyzed in the corresponding module). The power supply VCC, the third resistor R3, the fourth resistor R4, the second field effect tube Q2, the third field effect tube Q3 and LED1 form a full-function test display module. When the full-function test signal is high, the second field effect tube Q2 of the N tube is turned on, the third field effect tube Q3 of the P tube is turned on, and LED1 lights up, indicating that the full-function test item is selected.Pin 15 sends out a test process signal, which is connected to a monochrome LED light corresponding to the test process and is used to control the LED. When the test is in progress, the signal is high and the LED lights up green. When there is no test or the test is over, the signal is low and the LED turns off. When control is not required, the signal is low and the LED turns off; (how the LED works is analyzed in the corresponding module). The power supply VCC, the first resistor R1, the second resistor R2, the zeroth field effect transistor Q0, the first field effect transistor Q1 and LED0 form a test process display module. When the test process signal is high, the zeroth field effect transistor Q0 of the N tube is turned on, the first field effect transistor Q1 of the P tube is turned on, and LED0 lights up, indicating that the test is in progress. Pin 16 receives the current measurement signal and connects the dynamic load and the simulated overcurrent module.

[0035] Specifically, refer to Figure 3 In a specific embodiment of the interface module, J0 is a 50ohm oscilloscope coaxial interface, which is used to connect the external trigger Aux out signal interface of the oscilloscope, and is used to transmit the external trigger Aux out signal to the MCU; J1 is a 50ohm oscilloscope coaxial interface, which is used to connect the signal measurement interface of the oscilloscope, and is used to measure the USB5V signal; CONN0 is a USB3.0 male interface, which is used to connect the USB female connector of the device under test. Pin1 of the interface is the USB power supply pin USB5V; Pin4 is the power ground; shell is the shell ground; Pin7 is the signal ground, which is a USB3.0 pin, and there is no such pin in USB2.0. This pin is pulled up to the 5V measurement power supply through R7, and is used to generate a USB identification sending signal. Pin7 is the signal ground unique to USB3.0. When the connected USB port is USB2.0, this pin is in a floating state. Since the pin circuit is pulled up to 5V measurement power supply, the USB identification sending signal is high, and it is identified as a USB2.0 device; when the connected USB port is USB3.0, this pin is connected to the signal ground, the USB identification sending signal is low, and it is identified as a USB3.0 device. The signal is transmitted to the MCU control module; other pins are signal pins not related to power supply testing and are floating without connection.

[0036] Further, refer to Figure 4The analog plug-in on-off unit includes an eighth resistor R8, a fourth field effect transistor Q4, a fifth field effect transistor Q5 and a sixth field effect transistor Q6, the gate of the fourth field effect transistor Q4 is connected to the control module through the analog plug-in control signal terminal, the source of the fourth field effect transistor Q4 is grounded, the drain of the fourth field effect transistor Q4 and the gate of the fifth field effect transistor Q5 are connected to the USB5V power supply through the eighth resistor R8, the drain of the fifth field effect transistor Q5 is connected to the gate of the sixth field effect transistor Q6, the source of the fifth field effect transistor Q5 is connected to the USB5V power supply, and the source and drain of the sixth field effect transistor Q6 are both grounded; Reference Figure 4 The analog plug-in display unit includes a ninth resistor R9, a first zero resistor R10, a first first resistor R11, a first second resistor R12, a seventh field effect transistor Q7, an eighth field effect transistor Q8, a ninth field effect transistor Q9, a second red LED indicator and a second green LED indicator. The gate of the seventh field effect transistor Q7 and the gate of the ninth field effect transistor Q9 are connected to the control module through the analog plug-in test signal terminal, the drain of the seventh field effect transistor Q7 and the gate of the eighth field effect transistor Q8 are connected to the power supply VCC through the ninth resistor R9, the source of the eighth field effect transistor Q8 is connected to the power supply VCC through the first zero resistor R10, the drain of the eighth field effect transistor Q8 is connected to the positive electrode of the second green LED indicator, the source of the ninth field effect transistor Q9 is connected to the power supply VCC through the first first resistor R11, the drain of the ninth field effect transistor Q9 is connected to the positive electrode of the second red LED indicator, and the gate of the ninth field effect transistor Q9 is connected to the power supply VCC through the first second resistor R12.

[0037] Specifically, refer to Figure 4The main function of the analog USB plug-in module is to control the signal on and off of the USB3.0 male interface, which is used to perform USB analog plug-in tests and display the test results. A large voltage shock will be generated during the USB plug-in process, which may cause the USB device to fail to identify, so it is necessary to perform a simulated USB plug-in test. USB5V, the eighth resistor R8, the fourth field effect transistor Q4, the fifth field effect transistor Q5, the 5V measurement power supply, the sixth field effect transistor Q6, USB-PGND and the ground form a switch module. When the MCU control module outputs a simulated plug-in signal of a 1-second period PWM square wave, the fourth field effect transistor Q4 and the fifth field effect transistor Q5 are continuously switched on and off with a 1S period, and the USB5V and 5V measurement power supply are continuously connected and disconnected with a 1S period. Since the 5V measurement power supply changes in a 1S period, the sixth field effect transistor Q6 is continuously switched on and off with a 1S period, and the USB-PGND and the ground are continuously connected and disconnected with a 1S period. This simulates a USB plug-in operation with a 1S period. The power supply VCC, the ninth resistor R9, the first zero resistor R10, the first first resistor R11, the first second resistor R12, the seventh field effect transistor Q7, the eighth field effect transistor Q8, the ninth field effect transistor Q9 and LED2 form an analog plug-in display module. When the analog plug-in test signal is high, the N-tube seventh field effect transistor Q7 is turned on, the P-tube eighth field effect transistor Q8 is turned on, and the LED2 lights up green to display that the test item is selected; when the analog plug-in test signal is low, the P-tube ninth field effect transistor Q9 is turned on, and the LED2 lights up red to display that the test item fails; when no display is needed, the analog plug-in test signal is in a high impedance state, the seventh field effect transistor Q7 is turned off, the eighth field effect transistor Q8 is turned off, and the ninth field effect transistor Q9 is turned off, and the LED2 is turned off.

[0038] Further, refer to Figure 5 The USB2.0 static load unit includes a first zero field effect transistor Q10, a first field effect transistor Q11, a first second field effect transistor Q12, a first third resistor R13, a first fourth resistor R14, a first fifth resistor R15 and a 5V / 0.5A cement resistor. The gate of the first second field effect transistor Q12 is connected to the power supply VCC through the first fifth resistor R15, and the gate of the first second field effect transistor Q12 is also connected to the control module through the static load control signal terminal. The source of the first second field effect transistor Q12 is grounded, the drain of the first second field effect transistor Q12 and the gate of the first zero field effect transistor Q10 are connected to the 5V measurement power supply through the first fourth resistor R14, the source of the first zero field effect transistor Q10 is grounded, the drain of the first zero field effect transistor Q10 and the gate of the first field effect transistor Q11 are connected to the 5V measurement power supply through the first third resistor R13, and the drain of the first field effect transistor is connected to the ground through the 5V / 0.5A cement resistor; Reference Figure 5The USB3.0 static load unit includes a first four-field effect transistor Q14, a first three-field effect transistor Q13, a first six-resistor R16 and a 5V / 1A cement resistor, the gate of the first four-field effect transistor Q14 is connected to the control module through the static load control signal terminal, the source of the first four-field effect transistor Q14 is grounded, the drain of the first four-field effect transistor Q14 and the gate of the first three-field effect transistor Q13 are connected to the 5V measurement power supply through the first six-resistor R16, the source of the first three-field effect transistor Q13 is connected to the 5V measurement power supply, and the drain of the first three-field effect transistor Q13 is connected to the ground through the 5V / 1A cement resistor; Reference Figure 5 The static load display unit includes a first nine resistors R19, a second zero resistor R20, a first seven resistors R17, a first eight resistors R18, a first seven field effect transistors Q17, a first five field effect transistors Q15, a first six field effect transistors Q16, a third red LED indicator and a third green LED indicator, the gate of the first seven field effect transistors Q17 and the gate of the first six field effect transistors Q16 are connected to the control module through the static load signal terminal, the drain of the first seven field effect transistors Q17 and the gate of the first five field effect transistors Q15 are connected to the control module through the static load signal terminal, The first nine-resistor R19 is connected to the power supply VCC, the source of the first five-field effect transistor Q15 is connected to the power supply VCC through the second zero resistor R20, the drain of the first five-field effect transistor Q15 is connected to the positive electrode of the third green LED indicator, the source of the first six-field effect transistor Q16 is connected to the power supply VCC through the first seven-resistor R17, the drain of the first six-field effect transistor Q16 is connected to the positive electrode of the third red LED indicator, and the gate of the first six-field effect transistor Q16 is connected to the power supply VCC through the first eight-resistor R18.

[0039] Specifically, refer to Figure 5The main function of the static load module is to measure the stability of the power supply of the USB interface when the USB interface is loaded with the maximum load specified by the protocol, and to display the test results. For example, the USB2.0 protocol stipulates that the long-term stable power supply of the USB interface is 5V / 0.5A, and the USB3.0 protocol stipulates that the long-term stable power supply of the USB interface is 5V / 1A. After the USB interface has been working for a long time, due to the influence of temperature, device aging, etc., the power supply is unstable and the USB device works abnormally. Therefore, it is very necessary to perform a static load test to age the USB interface. Among them, the first zero field effect tube Q10, the first field effect tube Q11, the first second field effect tube Q12, the first third resistor R13, the first fourth resistor R14, the first fifth resistor R15, the 5V measurement power supply and the 5V / 0.5A cement resistor constitute the USB2.0 static load module. When the MCU recognizes that the access test interface is USB2.0, the static load control signal is low, the first second field effect tube Q12 is turned off, the first zero field effect tube Q10 is turned on, the first field effect tube Q11 is turned on, and the 5V measurement power supply pulls the 5V / 0.5A cement resistor load. When no test is required, the static load control signal is in high impedance state, the first second field effect tube Q12 is turned on, the first zero field effect tube Q10 is turned off, the first field effect tube Q11 is turned off, and the 5V measurement power supply is not loaded. Among them, the first six resistors R16, the first four field effect tubes Q14, the first three field effect tubes Q13, the 5V measurement power supply and the 5V / 1A cement resistor constitute the USB3.0 static load module. When the MCU recognizes that the access test interface is USB3.0, the static load control signal is high, the first four field effect tubes Q14 are turned on, the first three field effect tubes Q13 are turned on, and the 5V measurement power supply loads the 5V / 1A cement resistor load. When no test is required, the static load control signal is in high impedance state, the first four field effect tubes Q14 are turned off, the first three field effect tubes Q13 are turned off, and the 5V measurement power supply is not loaded. Among them, the first nine resistors R19, the second zero resistor R20, the first seven resistors R17, the first eight resistors R18, the first five field effect transistors Q15, the first six field effect transistors Q16, the first seven field effect transistors Q17 and LED3 form a static load display module. When the static load test signal is high, the first seven field effect transistors Q17 are turned on, the first eight field effect transistors Q18 are turned on, and the LED3 lights up green to display that the test item is selected; when the static test signal is low, the first six field effect transistors Q16 are turned on, and the LED3 lights up red to display that the test item fails; when no display is required, the static load test signal is in a high impedance state, the first seven field effect transistors Q17 are turned off, the first five field effect transistors Q15 are turned off, and the first six field effect transistors Q16 are turned off, and the LED3 is turned off.

[0040] Further, refer to Figure 6, the dynamic load and simulated overcurrent load control unit includes a first eight field effect transistor Q18, a first nine field effect transistor Q19, a second first resistor R21 and a 5V / 8A cement resistor, the gate of the first eight field effect transistor Q18 is connected to the control module through the dynamic load and simulated overcurrent control signal terminal, the drain of the first eight field effect transistor Q18 and the gate of the first nine field effect transistor Q19 are connected to the 5V measurement power supply through the second first resistor R21, the source of the first eight field effect transistor Q18 is connected to the ground, the source of the first nine field effect transistor Q19 is connected to the 5V measurement power supply, the drain of the first nine field effect transistor Q19 is connected to the ground through the 5V / 8A cement resistor, and the drain of the first nine field effect transistor Q19 is also connected to the control module through the current measurement signal terminal; Reference Figure 6 The dynamic load display unit includes a second second resistor R22, a second third resistor R23, a second fourth resistor R24, a second fifth resistor R25, a second zero field effect transistor Q20, a second field effect transistor Q21, a second second field effect transistor Q22, a fourth red LED indicator light and a fourth green LED indicator light, the gate of the second zero field effect transistor Q20 and the gate of the second second field effect transistor Q22 are connected to the control module through the dynamic load signal terminal, and the drain of the second zero field effect transistor Q20 and the gate of the second field effect transistor Q21 are connected to the control module through the dynamic load signal terminal. The second second field effect transistor Q21 is connected to the power supply VCC through the second third resistor R22, the source of the second field effect transistor Q21 is connected to the power supply VCC through the second third resistor R23, the drain of the second field effect transistor Q21 is connected to the positive electrode of the fourth green LED indicator, the source of the second second field effect transistor Q22 is connected to the power supply VCC through the second fourth resistor R24, the drain of the second second field effect transistor Q22 is connected to the positive electrode of the fourth red LED indicator, and the gate of the second second field effect transistor Q22 is connected to the power supply VCC through the second fifth resistor R25; Reference Figure 6The simulated overcurrent display unit includes a second sixth resistor R26, a second seventh resistor R27, a second eighth resistor R28, a second ninth resistor R29, a second third field effect transistor Q23, a second fourth field effect transistor Q24, a second fifth field effect transistor Q25, a fifth red LED indicator light and a fifth green LED indicator light, the gate of the second third field effect transistor Q23 and the gate of the second fifth field effect transistor Q25 are connected to the control module through the simulated overcurrent test signal terminal, and the drain of the second third field effect transistor Q23 and the gate of the second fourth field effect transistor Q24 are connected to the control module through the simulated overcurrent test signal terminal. The electrode of the second-fourth field effect transistor Q24 is connected to the power supply VCC through the second-sixth resistor R26, the source electrode of the second-fourth field effect transistor Q24 is connected to the power supply VCC through the second-seventh resistor R27, the drain electrode of the second-fourth field effect transistor Q24 is connected to the positive electrode of the fifth green LED indicator, the source electrode of the second-fifth field effect transistor Q25 is connected to the power supply VCC through the second-eighth resistor R28, the drain electrode of the second-fifth field effect transistor Q25 is connected to the positive electrode of the fifth red LED indicator, and the gate electrode of the second-fifth field effect transistor Q25 is connected to the power supply VCC through the second-nine resistor R29.

[0041] Specifically, refer to Figure 6 The main function of the dynamic load module is to measure the stability of the USB interface power supply when the load changes within the maximum load specified by the protocol, and to display the test results. For example, the USB2.0 protocol stipulates that the USB interface has a long-term stable power supply of 5V / 0.5A, that is, the load changes rapidly from 5V / 0A to 5V / 0.5A. The USB3.0 protocol stipulates that the USB interface has a long-term stable power supply of 5V / 1A, that is, the load changes rapidly from 5V / 0A to 5V / 0.5A. Fast dynamic loads can cause overshoot and back-hook of the power supply, causing abnormal operation of the USB device, so it is necessary to perform dynamic load tests. The main function of the simulated overcurrent module is to test the protection function of the USB current limiting protection chip when the USB interface pulls a load exceeding the specified current of the USB current limiting protection chip of the device under test, and to display the test results. The commonly used USB current limiting protection chip has a current limiting value of 4A. Loading the USB interface with a current exceeding the limit may cause negative effects such as high temperature, short circuit, and affect system stability, so it is necessary to perform simulated overcurrent tests.

[0042] Reference Figure 6, where the second resistor R21, the first eight field effect transistor Q18, the first nine field effect transistor Q19, the 5V measuring power supply and the 5V / 8A cement resistor form a dynamic load and simulated overcurrent load module. The principle is that the MCU sends a dynamic load and simulated overcurrent control signal in the form of PWM to control the first eight field effect transistor Q18 and the first nine field effect transistor Q19 to be continuously turned on and off, so that the 5V measuring power supply and the 5V / 8A cement resistor are continuously connected and disconnected. At the same time, the resistance of the 5V / 8A cement resistor is known to be 0.625 ohms. The voltage at both ends is detected to send a current measurement signal to the MCU. The current value is calculated by Ohm's law I=U / R. When the 5V measuring power supply and the 5V / 8A cement resistor are connected, the pull current gradually increases from 0A to 8A. When the 5V measuring power supply and the 5V / 8A cement resistor are disconnected, the pull current gradually decreases from 8A to 0A. Therefore, by adjusting the frequency and duty cycle of the PWM wave, dynamic load can be achieved. For example, connect the 5V measurement power supply and the 5V / 8A cement resistor. When the load current is detected to rise to 1A, disconnect the 5V measurement power supply and the 5V / 8A cement resistor, and the current drops to 0A. Repeat the above operation to achieve a dynamic load of 0A~1A. Similarly, by adjusting the frequency and duty cycle of the PWM wave, the simulated overcurrent current required for load can be achieved. Among them, the second second resistor R22, the second third resistor R23, the second fourth resistor R24, the second fifth resistor R25, the second zero field effect transistor Q20, the second first field effect transistor Q21, the second second field effect transistor Q22 and LED4 form a static load display module. When the dynamic load test signal is high, the second zero field effect tube Q20 is turned on, the second field effect tube Q21 is turned on, and LED4 lights up green to indicate that the test item is selected; when the dynamic test signal is low, the second second field effect tube Q22 is turned on, and LED4 lights up red to indicate that the test item fails; when no display is required, the static load test signal is in high impedance state, the second zero field effect tube Q20 is turned off, the second field effect tube Q21 is turned off, and the second second field effect tube Q22 is turned off, and LED4 is turned off. Among them, the second sixth resistor R26, the second seventh resistor R27, the second eighth resistor R28, the second ninth resistor R29, the second third field effect tube Q23, the second fourth field effect tube Q24, the second fifth field effect tube Q25 and LED5 form a simulated overcurrent display module. When the analog overcurrent test signal is high, the second and third field effect tube Q23 is turned on, the second and fourth field effect tube Q24 is turned on, and LED5 lights up green to indicate that the test item is selected; when the analog overcurrent signal is low, the second and fifth field effect tube Q25 is turned on, and LED5 lights up red to indicate that the test item fails; when no display is required, the analog overcurrent test signal is in a high-impedance state, the second and third field effect tube Q23 is turned off, the second and fourth field effect tube Q24 is turned off, and the second and fifth field effect tube Q25 is turned off, and LED5 is off.

[0043] Further, refer to Figure 7The simulated short-circuit load unit includes a second sixth field effect transistor Q26, a second seventh field effect transistor Q27 and a third zero resistor R30, the gate of the second sixth field effect transistor Q26 is connected to the control module through the simulated short-circuit control signal terminal, the source of the second sixth field effect transistor Q26 is grounded, the drain of the second sixth field effect transistor Q26 and the gate of the second seventh field effect transistor Q27 are connected to a 5V measurement power supply through the third zero resistor R30, the source of the second seventh field effect transistor Q27 is connected to the 5V measurement power supply, and the drain of the second seventh field effect transistor Q27 is grounded; Reference Figure 7 The simulated short circuit display unit includes a third first resistor R31, a third second resistor R32, a third third resistor R33, a third third resistor R34, a second eighth field effect transistor Q28, a second ninth field effect transistor Q29, a third zero field effect transistor Q30, a sixth red LED indicator light and a sixth green LED indicator light, the gate of the second eighth field effect transistor Q28 and the gate of the third zero field effect transistor Q30 are connected to the control module through the simulated short circuit test signal terminal, and the drain of the second eighth field effect transistor Q28 and the gate of the second ninth field effect transistor Q29 are connected to the control module through the simulated short circuit test signal terminal. The electrode of the second ninth field effect transistor Q29 is connected to the power supply VCC through the third first resistor R31, the source electrode of the second ninth field effect transistor Q29 is connected to the power supply VCC through the third second resistor R32, the drain electrode of the second ninth field effect transistor Q29 is connected to the positive electrode of the sixth green LED indicator, the source electrode of the third zero field effect transistor Q30 is connected to the power supply VCC through the third third resistor R33, the drain electrode of the third zero field effect transistor Q30 is connected to the positive electrode of the sixth red LED indicator, and the gate electrode of the third zero field effect transistor Q30 is connected to the power supply VCC through the third third resistor R34.

[0044] Specifically, refer to Figure 7, the third zero resistor R30, the second sixth field effect transistor Q26, the second seventh field effect transistor Q27 and the 5V measurement power supply form a simulated short-circuit load circuit. Because the current is very large during a short circuit, the simulated short-circuit control signal is set to a pulse signal at the millisecond level to protect the safety of the test equipment. When the simulated short-circuit control signal is high, the second sixth field effect transistor Q26 is turned on, the second seventh field effect transistor Q27 is turned on, the 5V measurement power supply is short-circuited to the ground, the USB current limiting chip of the device under test works, and the USB interface power supply is disconnected. The third first resistor R31, the third second resistor R32, the third third resistor R33, the third fourth resistor R34, the second eighth field effect transistor Q28, the second ninth field effect transistor Q29, the third zero field effect transistor Q30 and LED6 form a simulated short-circuit display module. When the analog short-circuit test signal is high, the second eighth field effect tube Q28 is turned on, the second ninth field effect tube Q29 is turned on, and LED6 lights up green to indicate that the test item is selected; when the analog short-circuit signal is low, the third zero field effect tube Q30 is turned on, and LED6 lights up red to indicate that the test item fails; when no display is required, the analog short-circuit test signal is in a high-impedance state, the second eighth field effect tube Q28 is turned off, the second ninth field effect tube Q29 is turned off, and the third zero field effect tube Q30 is turned off, and LED6 is off.

[0045] Further, refer to Figure 8 The present invention also provides a USB interface power supply automatic test method, the USB interface power supply automatic test method is applied to the USB interface power supply automatic test circuit, and the USB interface power supply automatic test method comprises the following steps: S100, connecting the output end of the USB interface power automation test circuit to the USB device to be tested through the USB interface, connecting the external trigger signal interface of the oscilloscope, and setting the maximum value range and trigger condition of the oscilloscope; S200, the control module identifies the type of the USB device to be tested, where the type of the USB device to be tested includes USB 2.0 and USB 3.0; S300, based on the selected test items, the control module controls the simulated USB plug-in module, the static load module, the simulated short circuit module and the dynamic load and simulated overcurrent module to perform the test; In a specific embodiment, referring to Figure 6 , the USB interface power automation test method includes the following steps: 1) Connect the USB test interface, connect the oscilloscope measurement interface, connect the oscilloscope external trigger Aux out signal interface, and set the trigger condition of the measurement signal on the oscilloscope.

[0046] For example, when measuring the 5V power supply of the USB interface, set the upper and lower 5% as the trigger condition. When the voltage deviation of 5V is greater than the upper and lower 5%, the oscilloscope generates a trigger event, locks the trigger waveform and sends the external trigger Aux out signal to the control module (MCU module).

[0047] 2) The control module (MCU module) identifies whether the USB type is 2.0 or 3.0, and then tests the function selection. It transmits the test function selection signal to the MCU module through the button to select dynamic load test, static load test, simulated plug and unplug test, simulated short circuit test, simulated overcurrent test or full function test.

[0048] 3) The control module (MCU module) controls each functional module to perform the selected power supply test items.

[0049] 4) The control module (MCU module) determines whether the test item passes based on the received signal and displays the corresponding result.

[0050] The step S300 includes the following steps: S310, the control module performs a simulated USB plug-in test through the simulated USB plug-in module; S320, the control module performs a static load test through the static load module; S330, the control module performs dynamic load and simulated overcurrent tests through the dynamic load and simulated overcurrent module; S340, the control module performs a simulated short circuit test through the simulated short circuit module; S350: If the full function test is selected, the control module sequentially performs a static load test, a dynamic load test, a simulated plug and unplug test, a simulated overcurrent test, and a simulated short circuit test; S400, the control module receives feedback signals from the simulated USB plug-in module, the static load module, the simulated short circuit module, the dynamic load module and the simulated overcurrent module, and determines and displays the test results.

[0051] Specifically, refer to Figure 8 In step S350, the full-function test process is as follows: when the full-function test item is selected, the test process LED is lit under the control of the control module (MCU module), indicating that the test is in progress, and then the static load test, dynamic load test, simulated plug-in test, simulated overcurrent test and simulated short circuit test are performed in sequence. When a test fails, the test process LED is turned off, indicating that the test is over.

[0052] Further, refer to Figure 8 , the step S310 comprises the following steps: S311, selecting a simulated USB plug-in test, the control module setting a test duration for executing the simulated USB plug-in test, and sending a simulated plug-in control signal of a preset frequency to a simulated plug-in on-off unit of the simulated USB plug-in module, wherein the simulated plug-in control signal is a PWM square wave of a preset frequency, and the simulated plug-in display unit of the simulated USB plug-in module displays the current test status in real time; S312, turn on the test progress LED indicator; S313, within the test duration of the simulated USB plug-in test, the control module detects the externally triggered Aux out signal through the interface module; S314, the control module determines the test result, if the test passes, the control module lights up the second green LED indicator light, if the test fails, the control module lights up the second red LED indicator light; S315, turn off the simulated plug-in control signal and turn off the test progress LED indicator.

[0053] Further, refer to Figure 8 , the step S320 comprises the following steps: S321, selecting a static load module, wherein the control module sets a static load control signal and a test duration based on the identified type of the USB device to be tested; S322, turn on the test progress LED indicator; S323, receiving an externally triggered Auxout signal; S324, wait for the test time to end, if the test passes, light up the third green LED indicator, if the test fails, light up the third red LED indicator; S325, turn off the static load control signal and turn off the test progress LED.

[0054] Further, refer to Figure 8 , the step S330 comprises the following steps: S331: If a dynamic load test is performed, the control module sets the frequency and duty cycle of the dynamic load control signal and the test duration based on the identified type of the USB device to be tested; S332, select dynamic load test, and light up the test progress LED indicator; S333, receiving an externally triggered Auxout signal; S334, wait for the test time to end, if the test passes, light up the fourth green LED indicator, if the test fails, light up the fourth red LED indicator; S335, turn off the dynamic load control signal and turn off the test progress LED; S336: If a simulated overcurrent test is performed, the control module sets the frequency and duty cycle of the dynamic load control signal and the test duration based on the identified type of the USB device to be tested; S337, select the simulated overcurrent test and light up the test progress LED indicator; S338, receiving a 5V measurement signal; S339, wait for the test time to end, if the 5V measurement signal is low, light up the fifth green LED indicator, if the 5V measurement signal is high, light up the fifth red LED indicator, turn off the simulated overcurrent control signal, and turn off the test progress LED.

[0055] Further, the step S340 includes the following steps: S341, if a simulated short circuit test is performed, the control module sets the pulse duration and the number of pulses of the simulated short circuit control signal and sets the test duration based on the identified type of the USB device to be tested; S342, turn on the test progress LED indicator; S343, receiving a 5V measurement signal; S344, wait for the test time to end, if the 5V measurement signal is low, light up the sixth green LED indicator, if the 5V measurement signal is high, light up the sixth red LED indicator, turn off the simulated overcurrent control signal, and turn off the test progress LED.

[0056] Furthermore, the present invention also proposes a computer-readable storage medium on which program instructions are stored, and when the program instructions are executed by a processor, the USB interface power automatic test method is implemented. The above is only a preferred embodiment of the present invention. The present invention is not limited to the above implementation. As long as the technical effect of the present invention is achieved by the same means, any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present disclosure should be included in the scope of protection of the present disclosure. They should all belong to the protection scope of the present invention. Within the protection scope of the present invention, its technical scheme and / or implementation method can have various modifications and changes.

Claims

1. A USB interface power supply automatic test circuit, the USB interface power supply automatic test circuit at least comprising: Control module; A simulated USB plug-in module, the simulated USB plug-in module comprising a simulated plug-in on-off unit and a simulated plug-in display unit respectively connected to the control module; A static load module, the static load module comprising a USB2.0 static load unit, a USB3.0 static load unit and a static load display unit respectively connected to the control module; A dynamic load and simulated overcurrent module, the dynamic load and simulated overcurrent module comprising a dynamic load and simulated overcurrent load control unit, a dynamic load display unit and a simulated overcurrent display unit respectively connected to the control module; A simulated short circuit module, the simulated short circuit module comprising a simulated short circuit load unit and a simulated short circuit display unit respectively connected to the control module; The interface module also includes a USB female interface to be tested and an oscilloscope respectively connected to the interface module.

2. The USB interface power automatic test circuit according to claim 1, characterized in that: The analog plug-in on-off unit comprises an eighth resistor (R8), a fourth field effect tube (Q4), a fifth field effect tube (Q5) and a sixth field effect tube (Q6), the gate of the fourth field effect tube (Q4) is connected to the control module via the analog plug-in control signal terminal, the source of the fourth field effect tube (Q4) is grounded, the drain of the fourth field effect tube (Q4) and the gate of the fifth field effect tube (Q5) are connected to a USB5V power supply via an eighth resistor (R8), the drain of the fifth field effect tube (Q5) is connected to the gate of the sixth field effect tube (Q6), the source of the fifth field effect tube (Q5) is connected to the USB5V power supply, and the source and drain of the sixth field effect tube (Q6) are both grounded; The analog plug-in display unit comprises a ninth resistor (R9), a first zero resistor (R10), a first first resistor (R11), a first second resistor (R12), a seventh field effect tube (Q7), an eighth field effect tube (Q8), a ninth field effect tube (Q9), a second red LED indicator light and a second green LED indicator light, wherein the gate of the seventh field effect tube (Q7) and the gate of the ninth field effect tube (Q9) are connected to the control module via the analog plug-in test signal terminal, and the drain of the seventh field effect tube (Q7) and the gate of the eighth field effect tube (Q8) are connected to the control module via the analog plug-in test signal terminal. The electrode of the eighth field effect tube (Q8) is connected to the power supply VCC through a ninth resistor (R9), the source electrode of the eighth field effect tube (Q8) is connected to the power supply VCC through a first zero resistor (R10), the drain electrode of the eighth field effect tube (Q8) is connected to the positive electrode of the second green LED indicator light, the source electrode of the ninth field effect tube (Q9) is connected to the power supply VCC through a first resistor (R11), the drain electrode of the ninth field effect tube (Q9) is connected to the positive electrode of the second red LED indicator light, and the gate electrode of the ninth field effect tube (Q9) is connected to the power supply VCC through a first resistor (R12).

3. The USB interface power automatic test circuit according to claim 1, characterized in that: The USB2.0 static load unit comprises a first zero field effect transistor (Q10), a first field effect transistor (Q11), a first second field effect transistor (Q12), a first third resistor (R13), a first fourth resistor (R14), a first fifth resistor (R15) and a 5V / 0.5A cement resistor. The gate of the first second field effect transistor (Q12) is connected to the power supply VCC through the first fifth resistor (R15). The gate of the first second field effect transistor (Q12) is also connected to the control module through the static load control signal terminal. The source of the first second field effect transistor (Q12) is grounded, the drain of the first second field effect transistor (Q12) and the gate of the first zero field effect transistor (Q10) are connected to a 5V measurement power supply through a first four-resistor (R14), the source of the first zero field effect transistor (Q10) is grounded, the drain of the first zero field effect transistor (Q10) and the gate of the first field effect transistor (Q11) are connected to a 5V measurement power supply through a first three-resistor (R13), and the drain of the first field effect transistor is connected to the ground through a 5V / 0.5A cement resistor; The USB3.0 static load unit comprises a first four-field effect tube (Q14), a first three-field effect tube (Q13), a first six-resistor (R16) and a 5V / 1A cement resistor, the gate of the first four-field effect tube (Q14) is connected to the control module through a static load control signal terminal, the source of the first four-field effect tube (Q14) is grounded, the drain of the first four-field effect tube (Q14) and the gate of the first three-field effect tube (Q13) are connected to a 5V measurement power supply through a first six-resistor (R16), the source of the first three-field effect tube (Q13) is connected to a 5V measurement power supply, and the drain of the first three-field effect tube (Q13) is connected to the ground through a 5V / 1A cement resistor; The static load display unit comprises a first nine resistors (R19), a second zero resistor (R20), a first seven resistors (R17), a first eight resistors (R18), a first seven field effect transistor (Q17), a first five field effect transistor (Q15), a first six field effect transistor (Q16), a third red LED indicator and a third green LED indicator, the gate of the first seven field effect transistor (Q17) and the gate of the first six field effect transistor (Q16) being connected to the control module via a static load signal terminal, the drain of the first seven field effect transistor (Q17) and the drain of the first five field effect transistor (Q15) being connected to the control module via a static load signal terminal. The gate is connected to the power supply VCC through the first nine resistors (R19), the source of the first five field effect tubes (Q15) is connected to the power supply VCC through the second zero resistor (R20), the drain of the first five field effect tubes (Q15) is connected to the positive electrode of the third green LED indicator, the source of the first six field effect tubes (Q16) is connected to the power supply VCC through the first seven resistors (R17), the drain of the first six field effect tubes (Q16) is connected to the positive electrode of the third red LED indicator, and the gate of the first six field effect tubes (Q16) is connected to the power supply VCC through the first eight resistors (R18).

4. The USB interface power automatic test circuit according to claim 1, characterized in that: The dynamic load and simulated overcurrent load control unit comprises a first eight field effect transistor (Q18), a first nine field effect transistor (Q19), a second first resistor (R21) and a 5V / 8A cement resistor, the gate of the first eight field effect transistor (Q18) is connected to the control module through a dynamic load and simulated overcurrent control signal terminal, the drain of the first eight field effect transistor (Q18) and the gate of the first nine field effect transistor (Q19) are connected to a 5V measurement power supply through the second first resistor (R21), the source of the first eight field effect transistor (Q18) is connected to the ground, the source of the first nine field effect transistor (Q19) is connected to the 5V measurement power supply, the drain of the first nine field effect transistor (Q19) is connected to the ground through a 5V / 8A cement resistor, and the drain of the first nine field effect transistor (Q19) is also connected to the control module through a current measurement signal terminal; The dynamic load display unit comprises a second second resistor (R22), a second third resistor (R23), a second fourth resistor (R24), a second fifth resistor (R25), a second zero field effect transistor (Q20), a second field effect transistor (Q21), a second second field effect transistor (Q22), a fourth red LED indicator light and a fourth green LED indicator light, wherein the gate of the second zero field effect transistor (Q20) and the gate of the second second field effect transistor (Q22) are connected to the control module via a dynamic load signal terminal, and the drain of the second zero field effect transistor (Q20) and the drain of the second field effect transistor (Q21) are connected to the control module via a dynamic load signal terminal. The gate is connected to the power supply VCC through the second second resistor (R22), the source of the second field effect transistor (Q21) is connected to the power supply VCC through the second third resistor (R23), the drain of the second field effect transistor (Q21) is connected to the positive electrode of the fourth green LED indicator, the source of the second second field effect transistor (Q22) is connected to the power supply VCC through the second fourth resistor (R24), the drain of the second second field effect transistor (Q22) is connected to the positive electrode of the fourth red LED indicator, and the gate of the second second field effect transistor (Q22) is connected to the power supply VCC through the second fifth resistor (R25); The simulated overcurrent display unit comprises a second sixth resistor (R26), a second seventh resistor (R27), a second eighth resistor (R28), a second ninth resistor (R29), a second third field effect transistor (Q23), a second fourth field effect transistor (Q24), a second fifth field effect transistor (Q25), a fifth red LED indicator light and a fifth green LED indicator light, the gate of the second third field effect transistor (Q23) and the gate of the second fifth field effect transistor (Q25) being connected to the control module via the simulated overcurrent test signal terminal, the drain of the second third field effect transistor (Q23) and the drain of the second fourth field effect transistor (Q24) being connected to the control module via the simulated overcurrent test signal terminal, The gate of the second fourth field effect transistor (Q24) is connected to the power supply VCC through the second sixth resistor (R26), the source of the second fourth field effect transistor (Q24) is connected to the power supply VCC through the second seventh resistor (R27), the drain of the second fourth field effect transistor (Q24) is connected to the positive electrode of the fifth green LED indicator, the source of the second fifth field effect transistor (Q25) is connected to the power supply VCC through the second eighth resistor (R28), the drain of the second fifth field effect transistor (Q25) is connected to the positive electrode of the fifth red LED indicator, and the gate of the second fifth field effect transistor (Q25) is connected to the power supply VCC through the second ninth resistor (R29).

5. The USB interface power automatic test circuit according to claim 1, characterized in that: The simulated short-circuit load unit comprises a second sixth field effect tube (Q26), a second seventh field effect tube (Q27) and a third zero resistor (R30), the gate of the second sixth field effect tube (Q26) is connected to the control module via the simulated short-circuit control signal terminal, the source of the second sixth field effect tube (Q26) is grounded, the drain of the second sixth field effect tube (Q26) and the gate of the second seventh field effect tube (Q27) are connected to a 5V measurement power supply via the third zero resistor (R30), the source of the second seventh field effect tube (Q27) is connected to the 5V measurement power supply, and the drain of the second seventh field effect tube (Q27) is grounded; The simulated short circuit display unit comprises a third first resistor (R31), a third second resistor (R32), a third third resistor (R33), a third third resistor (R34), a second eighth field effect transistor (Q28), a second ninth field effect transistor (Q29), a third zero field effect transistor (Q30), a sixth red LED indicator light and a sixth green LED indicator light, the gate of the second eighth field effect transistor (Q28) and the gate of the third zero field effect transistor (Q30) being connected to the control module via the simulated short circuit test signal terminal, the drain of the second eighth field effect transistor (Q28) and the drain of the second ninth field effect transistor (Q29) being connected to the control module via the simulated short circuit test signal terminal. The gate of the second ninth field effect transistor (Q29) is connected to the power supply VCC through a third first resistor (R31), the source of the second ninth field effect transistor (Q29) is connected to the power supply VCC through a third second resistor (R32), the drain of the second ninth field effect transistor (Q29) is connected to the positive electrode of the sixth green LED indicator, the source of the third zero field effect transistor (Q30) is connected to the power supply VCC through a third third resistor (R33), the drain of the third zero field effect transistor (Q30) is connected to the positive electrode of the sixth red LED indicator, and the gate of the third zero field effect transistor (Q30) is connected to the power supply VCC through a third third resistor (R34).

6. A USB interface power automatic testing method, characterized in that: The USB interface power supply automation test method is applied to the USB interface power supply automation test circuit described in any one of claims 1 to 5, and the USB interface power supply automation test method comprises the following steps: S100, connecting the output end of the USB interface power automation test circuit to the USB device to be tested through the USB interface, connecting the external trigger signal interface of the oscilloscope, and setting the maximum value range and trigger condition of the oscilloscope; S200, the control module identifies the type of the USB device to be tested, where the type of the USB device to be tested includes USB 2.0 and USB 3.0; S300, based on the selected test items, the control module controls the simulated USB plug-in module, the static load module, the simulated short circuit module and the dynamic load and simulated overcurrent module to perform the test; The step S300 includes the following steps: S310, the control module performs a simulated USB plug-in test through the simulated USB plug-in module; S320, the control module performs a static load test through the static load module; S330, the control module performs dynamic load and simulated overcurrent tests through the dynamic load and simulated overcurrent module; S340, the control module performs a simulated short circuit test through the simulated short circuit module; S350: If the full function test is selected, the control module sequentially performs a static load test, a dynamic load test, a simulated plug and unplug test, a simulated overcurrent test, and a simulated short circuit test; S400, the control module receives feedback signals from the simulated USB plug-in module, the static load module, the simulated short circuit module, the dynamic load module and the simulated overcurrent module, and determines and displays the test results.

7. The USB interface power automatic testing method according to claim 6, characterized in that: The step S310 includes the following steps: S311, selecting a simulated USB plug-in test, the control module setting a test duration for executing the simulated USB plug-in test, and sending a simulated plug-in control signal of a preset frequency to a simulated plug-in on-off unit of the simulated USB plug-in module, wherein the simulated plug-in control signal is a PWM square wave of a preset frequency, and the simulated plug-in display unit of the simulated USB plug-in module displays the current test status in real time; S312, light up the test progress LED indicator; S313, within the test duration of the simulated USB plug-in test, the control module detects the externally triggered Aux out signal through the interface module; S314, the control module determines the test result, if the test passes, the control module lights up the second green LED indicator light, if the test fails, the control module lights up the second red LED indicator light; S315, turn off the simulated plug-in control signal and turn off the test progress LED indicator.

8. The USB interface power automatic testing method according to claim 6, characterized in that: The step S320 includes the following steps: S321, selecting a static load module, wherein the control module sets a static load control signal and a test duration based on the identified type of the USB device to be tested; S322, light up the test progress LED indicator; S323, receiving an Auxout signal triggered externally; S324, wait for the test time to end, if the test passes, light up the third green LED indicator, if the test fails, light up the third red LED indicator; S325, turn off the static load control signal and turn off the test progress LED.

9. The USB interface power automatic testing method according to claim 6, characterized in that: The step S330 includes the following steps: S331: If a dynamic load test is performed, the control module sets the frequency and duty cycle of the dynamic load control signal and the test duration based on the identified type of the USB device to be tested; S332, select dynamic load test, and light up the test progress LED indicator; S333, receiving an Auxout signal triggered externally; S334, wait for the test time to end, if the test passes, light up the fourth green LED indicator, if the test fails, light up the fourth red LED indicator; S335, turn off the dynamic load control signal and turn off the test progress LED; S336: If a simulated overcurrent test is performed, the control module sets the frequency and duty cycle of the dynamic load control signal and the test duration based on the identified type of the USB device to be tested; S337, select the simulated overcurrent test and light up the test progress LED indicator; S338, receiving a 5V measurement signal; S339, wait for the test time to end, if the 5V measurement signal is low, light up the fifth green LED indicator, if the 5V measurement signal is high, light up the fifth red LED indicator, turn off the simulated overcurrent control signal, and turn off the test progress LED.

10. The USB interface power automatic testing method according to claim 6, characterized in that: The step S340 includes the following steps: S341, if a simulated short circuit test is performed, the control module sets the pulse duration and the number of pulses of the simulated short circuit control signal and sets the test duration based on the identified type of the USB device to be tested; S342, turn on the test progress LED indicator; S343, receiving a 5V measurement signal; S344, wait for the test time to end, if the 5V measurement signal is low, light up the sixth green LED indicator, if the 5V measurement signal is high, light up the sixth red LED indicator, turn off the simulated overcurrent control signal, and turn off the test progress LED.

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