A USB function pin detection system

Abstract

The present invention discloses a USB function pin detection system, including a power adapter, a USB interface, a voltage detection unit, a CC control unit, a fast charging function unit, an MCU unit, an LDO power supply unit and a test indication unit, wherein the voltage detection unit, the CC control unit, the fast charging function unit, the LDO power supply unit and the test indication unit are all connected to the MCU unit, the voltage detection unit is also connected to the power adapter, the USB interface is connected to the MCU unit, and the power adapter is connected to the USB interface. The embodiment can determine whether the power management function and the fast charging function of the power adapter are normal, and can determine the connection status of the Type-C terminal in the USB. The power function of the power adapter can be determined by the indicator light. It can test the power management function while also testing the fast charging function. The circuit structure is simple and the implementation cost is low.

Description

Technical Field

[0001] The invention relates to the technical field of USB detection, and in particular to a USB function pin detection system. Background Art

[0002] USB Type-C power supply refers to a device that has an output using a USB Type-C terminal and supports the DFP function. The PD power adapter (DFP) is a typical USB Type-C power supply. It generally supports power management function and fast charging function, that is, PD function and QC function, see Figure 1 , the PD power adapter output port uses the Type-C interface. Figure 1 , the PIN pins actually used by the PD power adapter are A1, A12, B1, B12, A4, A9, B4, B9, A5, B5, A6, A7, B6, B7, that is, the PD power adapter uses GND, VBUS, CC1, CC2, D+, D- to transmit signals and energy, among which GND is the power and signal ground, VBUS is the POWER transmission pin, CC1 and CC2 are PD signal pins, and D+ and D- are QC signal pins. During the production process of the PD power adapter (Adapter), generally only the PD function and QC function are tested to see if they can be output. Some existing test methods may have the situation that the CC1 terminal is connected correctly, but CC2 is open, or CC2 is connected normally, but CC1 is open, and the phenomenon cannot be tested. It is also possible that the short circuit between CC1 and CC2 cannot be tested. In addition, there may be a situation where D+ and D- (such as A6 and A7) on one side are connected to the PCB correctly, but D+ and D- (such as B6 and B7) on the other side are not connected to the PCB. Although some testing solutions can test the above situations, they are relatively expensive. Summary of the invention

[0003] In order to overcome the deficiencies of the prior art, the present invention aims to provide a USB function pin detection system, which has a simple circuit structure, low cost and can comprehensively detect the functions of each USB pin.

[0004] The purpose of the present invention is achieved by the following technical solutions:

[0005] The present invention provides a USB function pin detection system, comprising a power adapter, a USB interface, a voltage detection unit, a CC control unit, a fast charging function unit, an MCU unit, a LDO power supply unit and a test indication unit, wherein the voltage detection unit, the CC control unit, the fast charging function unit, the LDO power supply unit and the test indication unit are all connected to the MCU unit, the voltage detection unit is also connected to the power adapter, the USB interface is connected to the MCU unit, the power adapter is connected to the USB interface, the LDO power supply unit is used to provide direct current to the MCU, the voltage detection unit is used to detect the output voltage of the power adapter, and set the CC1V1 pin and the CC2V2 pin to an input state, the CC control unit is used to control the EnCC1 pin and the EnCC2 pin to be enabled when the MCU is powered on, and the fast charging function unit is used to adjust the voltages of the DPV1 pin, the DPGND pin and the DMV1 pin when the power adapter outputs a set voltage, so that the MCU unit reads the VBUS voltage of the USB interface through the voltage detection unit after setting the voltage of the fast charging pin in the USB interface.

[0006] In the present invention, as an optional embodiment, the USB interface includes a power signal ground pin, an energy transmission pin, a power management signal pin, and a fast charging signal pin.

[0007] In the present invention, as an optional embodiment, the model of the MCU unit is CS32G02X.

[0008] In the present invention, as an optional embodiment, the voltage detection unit includes a resistor R1 and a resistor R2, one end of the resistor R1 is connected to the VBUS pin of the USB interface, the other end of the resistor R1 is grounded through the resistor R2, one end of the resistor R1 is also connected to a power adapter, and the AINP8 pin of the MCU unit is connected between the resistor R1 and the resistor R2.

[0009] In the present invention, as an optional embodiment, the CC control unit includes a resistor R50, a resistor R51, a resistor R3, a resistor R8, a transistor Q4 and a transistor Q5, one end of the resistor R50 and one end of the resistor R51 are both connected to the MCU unit, the other end of the resistor R50 and the resistor R51 are connected to the CC1V1 pin of the USB interface, and the other ends are both connected to the USB interface and the CC2V2 pin of the USB interface, the other end of the resistor R50 is also connected to the collector of the transistor Q4, the collector of the transistor Q4 is also connected to the CC1_1 pin of the MCU unit, the emitter of Q4 is grounded, and the base of the transistor Q4 is connected to the EnCC1 pin of the MCU unit through the resistor R3, the other end of the resistor R51 is also connected to the collector of the transistor Q5, the collector of the transistor Q5 is also connected to the CC2_1 pin of the MCU unit, the emitter of Q5 is grounded, and the base of the transistor Q5 is connected to the EnCC2 pin of the MCU unit through the resistor R5.

[0010] In the present invention, as an optional embodiment, the LDO power supply unit includes a power chip, a resistor R27, a resistor R28, a resistor R29, a diode D1, a diode D2, a capacitor C32, a capacitor C33, a capacitor C34 and a capacitor C30, the positive end of the diode D1 is connected to the CVBUS pin of the USB interface, the positive end of the diode D2 is connected to the power input VIN1, the negative end of the diode D1 is connected to the input terminal Vin of the power chip through the resistor R27, the negative end of the diode D2 is connected to the input terminal Vin of the power chip through the resistor R29, one end of the capacitor C32 is connected to the input terminal Vin of the power chip, and the other end of the capacitor C32 is grounded; one end of the capacitor C33, one end of the capacitor C34 and one end of the resistor R28 are all connected to the output terminal Vout of the power chip, the other end of the capacitor C33 and the other end of the capacitor C34 are both grounded GND, the other end of the resistor R28 and one end of the capacitor C30 are connected to the MCU_VCC pin of the MCU unit, and the other end of the capacitor C30 is grounded.

[0011] In the present invention, as an optional embodiment, the model of the power chip is ME6203A33M3G.

[0012] In the present invention, as an optional embodiment, the test indication unit includes a light-emitting diode LED1, a light-emitting diode LED2, a light-emitting diode LED3, a resistor R47, a resistor R48, and a resistor R49. The positive terminal of the light-emitting diode LED1, the positive terminal of the light-emitting diode LED2, and the positive terminal of the light-emitting diode LED3 are all connected to the MCU unit, the negative terminal of the light-emitting diode LED1 is grounded through the resistor R49, the negative terminal of the light-emitting diode LED2 is grounded through the resistor R47, and the light-emitting diode LED3 is grounded through the resistor R48.

[0013] In the present invention, as an optional embodiment, the fast charging function unit includes a resistor R4, a resistor R5, a resistor R6, and a resistor R7. The resistor R4 and the resistor R6 are connected to form a first series branch, and the resistor R5 and the resistor R7 are connected to form a second series branch. One end of the first series branch and one end of the second series branch are both connected to the MCU unit, and the other end of the first series branch is also connected to the MCU unit. The other end of the second series branch is grounded, and the MCU unit is also respectively connected between the resistor R4 and the resistor R6 and between R5 and the resistor R7.

[0014] Compared with the prior art, the present invention has the following beneficial effects:

[0015] The USB function pin detection system provided by the present invention can determine whether the power management function and the fast charging function of the power adapter are normal by setting a voltage detection unit, a CC control unit, a fast charging function unit, an MCU unit, an LDO power supply unit and a test indication unit, and can determine the connection status of the Type-C terminal in the USB. Whether the power function of the power adapter is normal can be determined by the indicator light. It can test the power management function while also testing the fast charging function. The circuit structure is simple and the implementation cost is low. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 A schematic diagram of the module structure of a USB function pin detection system according to an embodiment of the present invention;

[0017] Figure 2 A circuit structure diagram of an MCU unit according to an embodiment of the present invention;

[0018] Figure 3 A circuit diagram of a USB interface according to an embodiment of the present invention;

[0019] Figure 4 is a circuit structure diagram of a voltage detection unit according to an embodiment of the present invention;

[0020] Figure 5 is a circuit structure diagram of a CC control unit according to an embodiment of the present invention;

[0021] Figure 6 1 is a circuit structure diagram of an LDO power supply unit according to an embodiment of the present invention;

[0022] Figure 7 is a circuit structure diagram of a test indication unit according to an embodiment of the present invention;

[0023] Figure 8 This is a circuit structure diagram of a fast charging function unit according to an embodiment of the present invention;

[0024] Fig. 9 This is a correspondence table of the voltages of D+ and D- in the QC2.0 handshake protocol used in the embodiment of the present invention. DETAILED DESCRIPTION

[0025] Below, in conjunction with the accompanying drawings and specific embodiments, the present invention is further described. It should be noted that, under the premise of no conflict, the various embodiments described below or the various technical features can be arbitrarily combined to form a new embodiment. Except for special instructions, the materials and equipment used in this embodiment can be purchased from the market. Examples of embodiments are shown in the accompanying drawings, in which the same or similar reference numerals throughout represent the same or similar elements or elements with the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present application, and the limitations of the present application cannot be understood.

[0026] In the description of the present application, it should be understood that the terms "upper", "lower", "front", "back", "vertical", "horizontal", "top", "bottom", "inside", "outside" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific position, be constructed and operated in a specific position, and therefore cannot be understood as a limitation on the present application. In the description of the present application, "plurality" means two or more, unless otherwise precisely and specifically specified.

[0027] In the description of this application, it should be noted that, unless otherwise clearly specified and limited, the terms "connected", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, or it can be connected through an intermediary medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0028] The terms "first", "second", etc. in the specification and claims of this application and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions. For example, a process, method, system, product or device that includes a series of steps or units is not necessarily limited to those steps or units clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0029] The embodiment of the present application provides a USB function pin detection system. By setting a voltage detection unit, a CC control unit, a fast charging function unit, an MCU unit, an LDO power supply unit and a test indication unit, it can be determined whether the power management function and the fast charging function of the power adapter are normal, and the connection status of the Type-C terminal in the USB can be determined. The indicator light can be used to determine whether the power function of the power adapter is normal. It can test the power management function while also testing the fast charging function. The circuit structure is simple and the implementation cost is low.

[0030] Figure 1 A schematic diagram of the module structure of a USB function pin detection system according to an embodiment of the present invention is shown. Figure 2 FIG. 1 shows a circuit structure diagram of an MCU unit according to an embodiment of the present invention. Figure 3 FIG. 1 shows a circuit structure diagram of a USB interface according to an embodiment of the present invention. Figure 4 FIG. 4 shows a circuit structure diagram of a voltage detection unit according to an embodiment of the present invention. Figure 5 FIG. 1 shows a circuit structure diagram of a CC control unit according to an embodiment of the present invention. Figure 6 FIG. 1 shows a circuit structure diagram of an LDO power supply unit according to an embodiment of the present invention. Figure 7 FIG. 1 shows a circuit structure diagram of a test indication unit according to an embodiment of the present invention. Figure 8 A circuit structure diagram of a fast charging functional unit according to an embodiment of the present invention is shown.

[0031] Please refer to Figure 1As shown, the USB function pin detection system provided in this embodiment includes a power adapter, a USB interface, a voltage detection unit, a CC control unit, a fast charging function unit, an MCU unit, an LDO power supply unit and a test indication unit, wherein the voltage detection unit, the CC control unit, the fast charging function unit, the LDO power supply unit and the test indication unit are all connected to the MCU unit, the voltage detection unit is also connected to the power adapter, the USB interface is connected to the MCU unit, the power adapter is connected to the USB interface, the LDO power supply unit is used to provide direct current to the MCU, the voltage detection unit is used to detect the output voltage of the power adapter, and set the CC1V1 pin and the CC2V2 pin to an input state, the CC control unit is used to control the EnCC1 pin and the EnCC2 pin to be enabled when the MCU is powered on, and the fast charging function unit is used to adjust the voltages of the DPV1 pin, the DPGND pin and the DMV1 pin when the power adapter outputs a set voltage, so that the MCU unit reads the VBUS voltage of the USB interface through the voltage detection unit after setting the voltage of the fast charging pin in the USB interface. The power adapter is connected to the USB interface. The power adapter is a USB power adapter. The USB interface is equivalent to providing the power adapter with an interface to connect to the outside world. Figure 3 The USB interface includes PIN pins, signal transmission pins, power signal ground pins, energy transmission pins, power management signal pins, and fast charge signal pins. Specifically, the USB interface includes Figure 2 A1, A2, A3, A4, A5, A6, A7, A8, A9, A10, A11, A12, B12, B11, B10, B9, B8, B7, B6, B5, B4, B3, B2, and B1 correspond to the interface pins respectively. The PIN pins used by the power adapter include A1, A12, B1, B12, A4, A9, B4, B9, A5, B5, A6, A7, B6, and B7. That is, the power adapter uses GND, VBUS, CC1, CC2, D+, and D- to transmit signals and energy, where GND is the power signal ground pin, VBUS is the energy transmission pin, CC1 and CC2 are power management signal pins, and D+ and D- are fast charging signal pins. In the embodiment, by adjusting the voltages of the DPV1 pin, the DPGND pin and the DMV1 pin, the MCU unit reads the voltage difference of DP1, DM1, DP2 and DM2 to obtain the connection status of the two groups of D+ and D- of the power adapter.

[0032] See also Figures 2 to 4In the embodiment, the model of the MCU unit is CS32G02X. The voltage detection unit includes a resistor R1 and a resistor R2, one end of the resistor R1 is connected to the VBUS pin of the USB interface, the other end of the resistor R1 is grounded through the resistor R2, one end of the resistor R1 is also connected to a power adapter, and the MCU unit is connected between the resistor R1 and the resistor R2.

[0033] Combination Figure 5-Figure 8 The CC control unit of the embodiment includes a resistor R50, a resistor R51, a resistor R3, a resistor R8, a transistor Q4 and a transistor Q5, one end of the resistor R50 and one end of the resistor R51 are both connected to the MCU unit, the other end of the resistor R50 and the other end of the resistor R51 are both connected to the USB interface, the other end of the resistor R50 is also connected to the collector of the transistor Q4, the collector of the transistor Q4 is also connected to the MCU unit, the emitter of Q4 is grounded, the base of the transistor Q4 is connected to the MCU unit through the resistor R3, the other end of the resistor R51 is also connected to the collector of the transistor Q5, the collector of the transistor Q5 is also connected to the MCU unit, the emitter of Q5 is grounded, and the base of the transistor Q5 is connected to the MCU unit through the resistor R3.

[0034] Further, the LDO power supply unit includes a power chip, a resistor R27, a resistor R28, a resistor R29, a diode D1, a diode D2, a capacitor C32, a capacitor C33, a capacitor C34 and a capacitor C30, the positive end of the diode D1 is connected to the USB interface, the positive end of the diode D2 is connected to the power input, the negative end of the diode D1 is connected to the input end of the power chip through the resistor R27, the positive end of the diode D2 is connected to the input end of the power chip through the resistor R29, the negative end of the diode D2 is connected to the input end of the power chip through the resistor R29, one end of the capacitor C32 is connected to the input end of the power chip, and the other end of the capacitor C32 is grounded; one end of the capacitor C33, one end of the capacitor C34 and one end of the resistor R28 are all connected to the output end of the power chip, the other end of the capacitor C33 and the other end of the capacitor C34 are both grounded, the other end of the resistor R28 and one end of the capacitor C30 are connected to the MCU unit, and the other end of the capacitor C30 is grounded. In the embodiment, the model of the power chip is ME6203A33M3G. The LDO power supply unit provides a 3.3V voltage to the MCU unit for operation.

[0035] The test indication unit includes a light-emitting diode LED1, a light-emitting diode LED2, a light-emitting diode LED3, a resistor R47, a resistor R48, and a resistor R49. The positive terminal of the light-emitting diode LED1, the positive terminal of the light-emitting diode LED2, and the positive terminal of the light-emitting diode LED3 are all connected to the MCU unit, the negative terminal of the light-emitting diode LED1 is grounded through the resistor R49, the negative terminal of the light-emitting diode LED2 is grounded through the resistor R47, and the light-emitting diode LED3 is grounded through the resistor R48.

[0036] The fast charging function unit of the present application includes resistor R4, resistor R5, resistor R6, and resistor R7. The resistor R4 and resistor R6 are connected to form a first series branch, and the resistor R5 and the resistor R7 are connected to form a second series branch. One end of the first series branch and one end of the second series branch are both connected to the MCU unit, and the other end of the first series branch is also connected to the MCU unit. The other end of the second series branch is grounded, and the MCU unit is also respectively connected between resistor R4 and resistor R6 and between R5 and resistor R7.

[0037] Based on the above, in order to overcome the problems existing in the prior art, in the embodiment, CC1 and CC2 are used to test the power management function of the power adapter respectively. When testing one of CC1 or CC2, the other is pulled to the GND ground terminal. If CC1 and CC2 are short-circuited, there is no output in the test. When the CC1 (or CC2) channel is tested, the voltage of the CC1 (or CC2) port is controlled according to whether the UPF (power receiving end) is connected to the CC port voltage, so that the power adapter thinks that the UPF (power receiving end) has been removed, thereby stopping the output voltage. When testing the QC function, according to the QC2.0 protocol, D+ and D- are set to different voltages through voltage divider resistors to induce the power adapter to output the corresponding voltage; when D+ is set to 3.3V and D- is set to 0.6V, the MCU unit collects the voltages of all DP and DP to determine the connection status of the Type-C terminals D+ and D- of the power adapter. This application can determine whether the power management function and fast charging function of the power adapter are normal, and can determine the connection status of CC1, CC2, D+ and D- of the Type-C terminal of the USB interface of the power adapter. The test steps are encapsulated in the test program. After the tester puts the test product into the test switch, presses the test switch, and uses the indicator light to determine whether the power function of the adapter and the Type-C power function pin are normal. The test device uses an MCU, resistors, transistors, etc., which are all low-cost devices, which can not only improve the quality of the produced products, but also take into account the production benefits.

[0038] In the embodiment, a separate 5V power supply is used to power the power board. When the MCU unit is powered on and initialized, it is necessary to enable EnCC1 and EnCC2 of the CC control unit first, and set CC1V1 and CC2V2 to input state, so that CC1 and CC2 are pulled low. The power adapter to be tested is connected to the AC socket, and the power adapter is connected to the test circuit of this test system with a TYPE-C full-function line. When the button is pressed, the MCU unit first shields its own PD function, and enables CC1 by setting EnCC1 low. When the power adapter detects that a UFP is inserted through the CC line, it will output a 5V voltage. However, if CC1 and CC2 are short-circuited, since CC2 is set to a low level at this time, CC1 will also be set to a low level, and the power adapter cannot detect the connection of this test circuit, and will not output 5V. The MCU unit determines whether the power adapter has a 5V output through the voltage detection unit. If there is an output, the CC1 terminal of the power adapter is connected OK, and is not connected to CC2 or other terminals that cause CC1 to be pulled low.

[0039] Combination Fig. 9The corresponding table of the voltages of D+ and D- in the QC2.0 handshake protocol is shown. Since the power adapter has output 5V, the D+ voltage needs to be set to 0.6V and D- to 0V. The MCU unit sets the fast charging function unit to set DPV1 to high (3.3V) and DPGND to low (0V). According to Ohm's law, the voltage of DP1 (D+) is V=3.3V / (4.2KΩ+1 KΩ)*1 KΩ≈0.6V; the MCU unit sets the DM1 pin to low, then D- is 0V. After a certain delay, D+ is set to 3.3V and D- is set to 0.6V, that is, DPV1 outputs high, DPGND is set to input, DP1 is set to ADC mode, DMV1 outputs high, DM1 is set to ADC mode, and DP2 and DM2 are also set to ADC mode. The MCU unit uses the internal ADC module to first read whether the voltages of DP1 and DP2 are greater than 3V and close to each other, and then read whether the voltages of DM1 and DM2 are greater than 0.5V and less than 0.7V. If the above two conditions are not met, it is possible that the D+ and D- connections of the output terminals of the power adapter are abnormal, or D+ and D- are short-circuited; if the above two conditions are met, the MCU unit reads whether the VBUS voltage is 9V through the voltage detection unit. If so, the QC9V gear test passes. Similarly, D+ can be set to 0.6V and D- to 0.6V to see if the VBUS voltage is 12V. After 5V, 9V, and 12V are tested OK, the QC2.0 function is basically tested OK, which also proves that the D+ and D- functions of the power adapter are normal. It can be indirectly confirmed that if the power adapter protocol chip supports the QC3.0 function, the QC3.0 of the power adapter can work normally. The MCU unit turns on its own PD protocol and negotiates with the power adapter to allow the power adapter to output different voltages of 5V, 9V, 12V, 15V, and 20V (different output voltages need to be requested according to different adapter protocol chips). After sending the application, the MCU unit confirms whether the output voltage is normal through the voltage detection unit. If everything is normal, it confirms that the CC1 channel is normal.

[0040] To test CC2, you need to disconnect CC1 first, and the voltage of CC line needs to be greater than Figure 6The MCU unit outputs CC1V1 high, thereby pulling up the CC line level, making the power adapter think that the device has been disconnected from it, and the power adapter has no output. Then, CC2 is enabled by setting EnCC2 low. The MCU unit negotiates with the power adapter to allow the power adapter to output different voltages of 5V, 9V, 12V, 15V, and 20V (different output voltages need to be requested according to different adapter protocol chips). If the MCU unit detects that the corresponding voltage is output, it is considered that the CC2 channel is normal and the PD function of the adapter is normal, and then CC2V2 is set to output high to stop the power adapter from outputting. After the above tests are normal, the MCU unit sets the green indicator light to on, otherwise the red indicator light is set to on.

[0041] Although only certain components and embodiments of the present application have been illustrated and described, many modifications and changes may be conceived by those skilled in the art without actually departing from the scope and spirit of the claims, such as changes in the size, dimensions, structure, shape and proportion of the various elements, mounting arrangements, material usage, color, orientation, etc.

[0042] The above implementation modes are only preferred implementation modes of the embodiments of the present invention and cannot be used to limit the protection scope of the embodiments of the present invention. Any non-substantial changes and replacements made by technicians in this field on the basis of the embodiments of the present invention shall fall within the scope of protection required by the embodiments of the present invention.

Claims

1. A USB function pin detection system, characterized in that: It includes a power adapter, a USB interface, a voltage detection unit, a CC control unit, a fast charging function unit, an MCU unit, an LDO power supply unit and a test indication unit. The voltage detection unit, the CC control unit, the fast charging function unit, the LDO power supply unit and the test indication unit are all connected to the MCU unit. The voltage detection unit is also connected to the power adapter. The USB interface is connected to the MCU unit. The power adapter is connected to the USB interface. The LDO power supply unit is used to provide direct current to the MCU. The voltage detection unit is used to detect the output voltage of the power adapter and set the CC1V1 pin and CC2V2 pin to the input state. The control unit is used to control the enabling of the EnCC1 pin and the EnCC2 pin when the MCU is powered on. The fast charging function unit is used to adjust the voltages of the DPV1 pin, the DPGND pin and the DMV1 pin when the power adapter outputs a set voltage, so that the MCU unit reads the VBUS voltage of the USB interface through the voltage detection unit after setting the voltage of the fast charging pin in the USB interface; the voltage detection unit includes a resistor R1 and a resistor R2, one end of the resistor R1 is connected to the VBUS pin of the USB interface, the other end of the resistor R1 is grounded through the resistor R2, one end of the resistor R1 is also connected to the power adapter, and the MCU unit is connected to the resistor R1 and The CC control unit includes a resistor R50, a resistor R51, a resistor R3, a resistor R8, a transistor Q4 and a transistor Q5, one end of the resistor R50 and one end of the resistor R51 are both connected to the MCU unit, the other end of the resistor R50 and the other end of the resistor R51 are both connected to the USB interface, the other end of the resistor R50 is also connected to the collector of the transistor Q4, the collector of the transistor Q4 is also connected to the MCU unit, the emitter of Q4 is grounded, the base of the transistor Q4 is connected to the MCU unit through the resistor R3, the other end of the resistor R51 is also connected to the collector of the transistor Q5, the collector of the transistor Q5 is also connected to the MCU unit, the The emitter of Q5 is grounded, and the base of the transistor Q5 is connected to the MCU unit through a resistor R3; the LDO power supply unit includes a power chip, a resistor R27, a resistor R28, a resistor R29, a diode D1, a diode D2, a capacitor C32, a capacitor C33, a capacitor C34 and a capacitor C30, the positive end of the diode D1 is connected to the USB interface, the positive end of the diode D2 is connected to the power input, the negative end of the diode D1 is connected to the input end of the power chip through a resistor R27, the negative end of the diode D2 is connected to the input end of the power chip through a resistor R29, one end of the capacitor C32 is connected to the input end of the power chip, and the other end of the capacitor C32 is grounded;One end of the capacitor C33, one end of the capacitor C34 and one end of the resistor R28 are all connected to the output end of the power chip, the other end of the capacitor C33 and the other end of the capacitor C34 are grounded, the other end of the resistor R28 and one end of the capacitor C30 are connected to the MCU unit, and the other end of the capacitor C30 is grounded; the test indication unit includes a light-emitting diode LED1, a light-emitting diode LED2, a light-emitting diode LED3, a resistor R47, a resistor R48, and a resistor R49, the positive end of the light-emitting diode LED1, the positive end of the light-emitting diode LED2, and the positive end of the light-emitting diode LED3 are all connected to the MCU unit, and the negative end of the light-emitting diode LED1 is connected to the MCU unit through The resistor R49 is grounded, the negative terminal of the light emitting diode LED2 is grounded through the resistor R47, and the light emitting diode LED3 is grounded through the resistor R48; the fast charging function unit includes resistors R4, R5, R6, and R7, the resistors R4 and R6 are connected to form a first series branch, the resistors R5 and R7 are connected to form a second series branch, one end of the first series branch and one end of the second series branch are both connected to the MCU unit, the other end of the first series branch is also connected to the MCU unit, the other end of the second series branch is grounded, and the MCU unit is also connected between the resistors R4 and R6 and between R5 and R7. ; 2. The USB function pin detection system according to claim 1, characterized in that: The USB interface includes a power signal ground pin, an energy transmission pin, a power management signal pin, and a fast charging signal pin.

3. The USB function pin detection system according to claim 1, characterized in that: The model of the MCU unit is CS32G02X.

4. The USB function pin detection system according to claim 1, characterized in that: The model of the power chip is ME6203A33M3G.

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