USB communication circuit and display device

Abstract

The embodiment of the utility model discloses a USB communication circuit and a display device, the display device is provided with a main control chip, the USB communication circuit comprises a USB interface and a detection circuit, the USB interface is electrically connected with the main control chip, a connecting line between the USB interface and the main control chip comprises a power bus, the detection circuit comprises a detected module and a detection module, and the detected module is electrically connected with the main control chip. The detected module is arranged on the power bus, the detection module is electrically connected with the detected module, and the detected module and the detection module are both electrically connected with the main control chip. According to the embodiment of the invention, when the USB interface is connected to the USB external equipment and the main control chip cannot identify the USB external equipment, the detection module detects the detected module to generate the detection signal and sends the detection signal to the main control chip, and the main control chip identifies the USB external equipment again according to the detection signal, so that the problem that the main control chip cannot be identified probabilistically is solved.

Description

Technical Field

[0001] This application relates to the technical field of Universal Serial Bus, and in particular, to a USB communication circuit and a display device. Background Art

[0002] Display devices generally have USB interfaces. Among them, Universal Serial Bus (USB) is a serial bus standard for connecting computer systems and external devices, and is also a technical specification for input / output interfaces.

[0003] In the related art, because some USB communication circuits are relatively complex, after an external device is connected to the USB interface, the host device may malfunction. At this time, there may be a situation where the external device and the host device communicate only through the USB signal line, and the host device cannot normally recognize the external device, thus affecting the normal communication between the host device and the external device. Summary of the Utility Model

[0004] The embodiments of this application provide a USB communication circuit and a display device, aiming to solve the problem that the main control chip cannot be recognized probabilistically.

[0005] In the first aspect of the embodiments of this application, a USB communication circuit is provided. The USB communication circuit is applied to a display device. The display device is configured with a main control chip. The USB communication circuit includes a USB interface and a detection circuit. The USB interface is electrically connected to the main control chip. The connection line between the USB interface and the main control chip includes a power bus. The detection circuit includes a module to be measured and a detection module. The module to be measured is arranged on the power bus. The detection module is electrically connected to the module to be measured, and both the module to be measured and the detection module are electrically connected to the main control chip. Among them, the detection module is used to detect the module to be measured to generate a detection signal and send it to the main control chip, so that the main control chip re-identifies the USB external device according to the detection signal.

[0006] Further, the module to be measured includes a first resistor, and the detection module includes a voltage detection circuit. The voltage detection circuit is electrically connected to both ends of the first resistor to detect the voltage across the first resistor. The detection signal includes the voltage across the first resistor.

[0007] Further, the first electronic component is a shunt resistor.

[0008] Further, the voltage detection circuit includes a voltage division circuit and an amplification circuit. The voltage division circuit is electrically connected to both ends of the first resistor; the input end of the amplification circuit is electrically connected to the voltage division circuit, and the output end of the amplification circuit is electrically connected to the main control chip.

[0009] Further, the amplification circuit includes an operational amplifier, a second resistor, and a third resistor. The positive input end of the operational amplifier is grounded through the second resistor; the negative input end of the operational amplifier is electrically connected to one end of the third resistor; the output end of the operational amplifier is electrically connected to the other end of the third resistor.

[0010] Further, the voltage division circuit includes a fourth resistor and a fifth resistor. One end of the fourth resistor is electrically connected to one end of the first resistor, and the other end of the fourth resistor is electrically connected to the positive input end of the operational amplifier; one end of the fifth resistor is electrically connected to the other end of the first resistor, and the other end of the fifth resistor is electrically connected to the negative input end of the operational amplifier.

[0011] Further, both the fourth resistor and the fifth resistor are precision resistors.

[0012] Further, the USB communication circuit further includes a hub. One end of the hub is electrically connected to the USB interface, and the other end of the hub is electrically connected to the main control chip.

[0013] In a second aspect of the embodiments of the present application, a display device is provided. The display device includes the USB communication circuit, the main control chip, and a housing described in any one of the above. The main control chip is electrically connected to both the USB interface and the detection circuit. The main control chip and the detection circuit are both disposed inside the housing, and the USB interface is disposed on the housing and partially exposed outside the housing.

[0014] In the embodiments of the present application, by providing a detection circuit on the USB communication circuit, and the detection circuit is electrically connected to the power bus and the main control chip; when a USB external device is plugged into the USB interface and the main control chip cannot recognize the USB external device, the detection circuit can detect that there is a USB external device inserted into the USB interface at this time, and send a detection signal to the main control chip; the main control chip controls the USB external device to be reset and enumerated again according to the received detection signal, so that the main control chip can re-recognize the USB external device, thereby solving the problem that the main control chip cannot recognize probabilistically. Description of the Drawings

[0015] To more clearly illustrate the technical solutions in the embodiments of the present application or the related art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the drawings in the following description are only some embodiments of the present application. For those skilled in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0016] Figure 1 It is a schematic diagram of the modules of a display device and a USB external device in an embodiment of the present application;

[0017] Figure 2 It is a schematic diagram of the modules of a USB communication circuit in an embodiment of the present application;

[0018] Figure 3 It is a schematic diagram of the modules of a display device in an embodiment of the present application;

[0019] Figure 4 It is a schematic diagram of the modules of a USB communication circuit in another embodiment of the present application;

[0020] Figure 5 It is a circuit schematic diagram of a detection circuit in an embodiment of the present application.

[0021] Explanation of the reference numerals in the drawings: 1 - display device; 10 - USB communication circuit; 11 - USB interface; 12 - detection circuit; 121 - module under test; 122 - detection module; R1 - first resistor; 1221 - voltage detection circuit; 1222 - voltage division circuit; 1223 - amplifier circuit; VBUS - power bus; VCC - power supply; U1 - operational amplifier; R5 - second resistor; R4 - third resistor; R3 - fourth resistor; R2 - fifth resistor; 13 - hub; 20 - main control chip; 30 - housing; 2 - USB external device. Detailed implementation manners

[0022] In order to make the objectives, technical solutions and advantages of the present application more clear and understandable, the following further details the present application in conjunction with the drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and are not used to limit the present application.

[0023] Please refer to Figure 1 - Figure 2, in the related art, a display device 1 usually performs insertion detection on a USB external device 2 inserted into a USB interface 11 through a signal line of USB2.0 or a signal line of USB3.0. It can be understood that the connection line between the USB interface 11 and the main control chip 20 includes a D- signal line, a D+ signal line, a StdA_SSTX- signal line, a StdA_SSRX+ signal line, a GND_DRAIN signal line, a StdA_SSTX+ signal line, and a StdA_SSTX- signal line; among them, the D- signal line is the negative of the USB2.0 differential signal, the D+ signal line is the positive of the USB2.0 differential signal, the StdA_SSTX- signal line is the negative of the high-speed data differential - transmission, the StdA_SSRX+ signal line is the positive of the high-speed data differential - reception, the StdA_SSTX+ signal line is the positive of the high-speed data differential - transmission, the StdA_SSTX- signal line is the negative of the high-speed data differential - reception, and the GND_DRAIN signal line is the signal line grounded.

[0024] Exemplarily, taking the signal line of USB2.0 as an example, when the USB external device 2 is not inserted into the USB interface 11, the D- signal line and the D+ signal line are pulled down through resistors so that the D- signal line and the D+ signal line are in a low level state; when the USB external device 2 is plugged into the USB interface 11, the USB external device 2 pulls up the D- signal line and the D+ signal line to a high level state according to the speed mode (low speed, full speed, high speed, or super high speed); that is, the main control chip 20 can determine whether a USB external device 2 is inserted by detecting the level states of the D- signal line and the D+ signal line.

[0025] However, in the complex USB communication circuit 10, the levels of the USB communication circuit 10 are numerous, and it is easy to occur that the USB communication circuit 10 cannot recognize the insertion of the USB external device 2 at one of the levels, resulting in the display device 1 being unable to recognize the USB external device 2.

[0026] Please refer to Figure 2 , therefore, in the embodiment of the present application, by setting a detection circuit 12 on the USB communication circuit 10, when the USB interface 11 plugs in the USB external device 2 and the main control chip 20 cannot recognize the USB external device 2, the detection circuit 12 can detect that there is a USB external device 2 inserted into the USB interface 11 at this time and send a detection signal to the main control chip 20; the main control chip 20 controls the USB external device 2 to perform a reset and enumeration again according to the received detection signal so that the main control chip 20 can recognize the USB external device 2 again, thereby solving the problem that the main control chip 20 cannot be recognized probabilistically.

[0027] Please refer to Figure 3, embodiments of the present application provide a display device 1, which may be one of existing displays or display screens such as a commercial display panel, a conference panel, an Interactive flat panel display (IFPD), etc. The display device 1 includes a USB communication circuit 10, a main control chip 20, and a housing 30.

[0028] Please refer to Figure 2 - Figure 3 , specifically, the main control chip 20 is electrically connected to the USB communication circuit 10. When a USB external device 2 is connected to the USB communication circuit 10, the main control chip 20 can call the USB external device 2 through the USB communication circuit 10 to implement communication between the main control chip 20 and the USB external device 2. The main control chip 20 is mainly responsible for executing programs, storing data, and communicating with the USB external device 2. At least part of the USB communication circuit 10 is installed inside the housing 30, so that the housing 30 protects the USB communication circuit 10, thereby preventing the USB communication circuit 10 from being exposed outside the display device 1.

[0029] The housing 30 of the display device 1 is usually made of plastic, metal, or other durable materials. Embodiments of the present application do not make specific limitations in this regard. Exemplarily, common plastic materials used to make the housing 30 include ABS material, PC material, and PVC material, etc. They are widely used in preparing the housing 30 of the display device 1 due to their good insulation, corrosion resistance, and low cost; the metal housing 30 may include aluminum alloy, stainless steel, etc., and the metal housing 30 has good heat dissipation performance, high mechanical strength, and good electromagnetic shielding effect.

[0030] Please refer to Figure 2 , the USB communication circuit 10 may include a USB interface 11. The USB interface 11 is provided on the housing 30 and partially exposed outside the housing 30. It can be understood that the USB interface 11 is an interface for connecting a standardized USB external device 2. When the USB external device 2 is plugged into the USB interface 11, communication between the display device 1 and the USB external device 2 can be achieved. Therefore, setting the USB interface 11 on the housing 30 and partially exposing it outside the housing 30 can, on the one hand, protect the USB interface 11 by the housing 30, and on the other hand, facilitate the USB external device 2 to be plugged into the USB interface 11.

[0031] It should be noted that the USB interface 11 has various interface types, and embodiments of the present application do not make specific limitations on the interface type of the USB interface 11. Exemplarily, common types of the USB interface 11 are Type-A, Type-C, and Type-B.

[0032] It should be noted that the USB external device 2 may include, but is not limited to, a user equipment (UE), such as a terminal device like a tablet computer, a laptop computer, a personal digital assistant, or a desktop computer. The embodiments of the present application do not make specific limitations thereto.

[0033] Please continue to refer to Figure 2 , further, the connection line between the USB interface 11 and the main control chip 20 further includes a power bus VBUS. It can be understood that when the USB external device 2 is inserted into the USB interface 11, the display device 1 supplies power to the USB external device 2 through the power bus VBUS. Herein, the embodiments of the present application do not make specific limitations on the voltage value for the power bus VBUS to supply power to the USB external device 2. Exemplarily, the voltage for the power bus VBUS to supply power to the USB external device 2 is generally 5V.

[0034] Please continue to refer to Figure 3 , the USB communication circuit 10 further includes a detection circuit 12. The detection circuit 12 is electrically connected to the power bus VBUS and the main control chip 20. Among them, when the USB external device 2 is plugged into the USB interface 11 and the main control chip 20 cannot recognize the USB external device 2, the main control chip 20 re-identifies the USB external device 2 according to the detection signal of the detection circuit 12. It can be understood that when the USB external device 2 is plugged into the USB interface 11 and the main control chip 20 cannot recognize the USB external device 2 through the above-mentioned USB2.0 signal line or USB3.0 signal line, the detection circuit 12 can detect the USB interface 11 to detect that the USB external device 2 is plugged into the USB interface 11 at this time. The detection circuit 12 sends the detection signal to the main control chip 20, and the main control chip 20 sends a control signal according to the detection signal to control the USB external device 2 to perform a re-reset and enumeration operation, thereby realizing the re-identification of the USB external device 2. In this way, the problem that the main control chip 20 cannot be recognized probabilistically can be solved.

[0035] It should be noted that enumeration means that after the USB external device 2 is plugged into the USB interface 11, the main control chip 20 recognizes and configures the USB external device 2 through a series of processes. During the enumeration process, the main control chip 20 first needs to send a request for reset to the USB external device 2; after the USB external device 2 receives the reset request, the USB external device 2 will perform a reset operation and prepare to enter the enumeration process; the enumeration process enables the main control chip 20 to correctly recognize and configure the USB external device 2, thereby ensuring normal communication between the USB external device 2 and the display device 1.

[0036] Please refer to Figure 4, in some embodiments, the USB communication circuit 10 further includes a hub 13, which is a device that can expand one USB interface 11 into multiple USB interfaces. And the hub 13 is disposed within the housing 30 so that the housing 30 can effectively protect the hub 13 from external impacts, dust, and moisture.

[0037] Further, one end of the hub 13 is electrically connected to the USB interface 11, and the other end of the hub 13 is electrically connected to the main control chip 20; that is, the hub 13 is disposed between the USB interface 11 and the main control chip 20, and when the USB external device 2 is plugged into the USB interface 11, the USB external device 2 can be electrically connected to the hub 13 through the USB interface 11. It can be understood that since the USB interface 11 is electrically connected to the hub 13 and the hub 13 is electrically connected to the main control chip 20, when the USB external device 2 is inserted into the USB interface 11, the USB external device 2 can communicate with the main control chip 20 through the USB interface 11 and the hub 13.

[0038] Furthermore, when the USB external device 2 is connected to the USB interface 11 and the main control chip 20 fails to recognize the USB external device 2, the main control chip 20 can receive the detection signal sent by the detection circuit 12. At this time, the main control chip 20 will send a control signal to the hub 13 according to the detection signal to control the hub 13 to re-recognize the USB external device 2.

[0039] Please continue to refer to Figure 4 , in some embodiments, the detection circuit 12 includes a module under test 121 and a detection module 122.

[0040] Specifically, the module under test 121 is disposed on the power bus VBUS, the detection module 122 is electrically connected to the module under test 121, and both the detection module 122 and the module under test 121 are electrically connected to the main control chip 20. It can be understood that the module under test 121 can be connected in series on the power bus VBUS; the detection module 122 generates a detection signal after detecting the module under test 121. Since the detection module 122 is electrically connected to the main control chip 20, the detection module 122 can send the detected detection signal to the main control chip 20, and the main control chip 20 controls the USB external device 2 to re-recognize according to the detection signal to solve the problem that the main control chip 20 cannot recognize probabilistically.

[0041] Please refer to Figure 4 - Figure 5, Further, in some embodiments, the module under test 121 includes a first resistor R1. One end of the first resistor R1 is electrically connected to the power supply VCC, and the other end of the first resistor R1 is electrically connected to the USB interface 11. And the power supply VCC is usually provided by the main control chip 20 to enable the main control chip 20 to supply voltage to the power bus VBUS. Wherein, the voltage of the power supply VCC is usually 5V; the detection module 122 includes a voltage detection circuit 1221. The voltage detection circuit 1221 is connected to both ends of the first resistor R1 to detect the voltage across the first resistor R1, and the detection signal includes the voltage across the first resistor R1. That is to say, the detection module 122 can detect the voltage drop across the first resistor R1, and the voltage drop across the first resistor R1 can be used to calculate the current consumed by the display device 1 at this time according to the calculation formula of Ohm's law. Among them, when the USB external device 2 can be normally recognized by the main control chip 20, the current consumed by the display device 1 ranges from 50 milliamps to 500 milliamps; when the USB external device 2 is not normally recognized by the main control chip 20, the current consumed by the display device 1 will be less than 100 milliamps; that is to say, if the detection module 122 detects that the current flowing through the first resistor R1 fluctuates or is greater than 100 milliamps, it means that the USB external device 2 is normally recognized by the main control chip 20 at this time, and the main control chip 20 will not send a control signal to the hub 13; if the detection module 122 detects that the current of the first resistor R1 remains below 100 milliamps for a long time, it means that the USB external device 2 is not normally recognized by the main control chip 20 at this time, and the detection module 122 will output a detection signal to the main control chip 20, so that the main control chip 20 sends a control signal to the hub 13 to control the hub 13 to reset and enumerate the USB external device 2, so as to realize the main control chip 20's re-identification of the USB external device 2.

[0042] In some embodiments, the first resistor R1 can be a shunt resistor. A shunt resistor is a resistor with a low resistance value and high precision. When current passes through the shunt resistor, a small voltage drop will be generated at both ends of the shunt resistor. This voltage drop is proportional to the current. At this time, by measuring this voltage drop, the voltage across the shunt resistor can be obtained, and the actual current flowing through the shunt resistor can be calculated through Ohm's law. Furthermore, usually the shunt resistor is connected in series in the circuit. That is to say, the first resistor R1 in the embodiment of the present application is arranged on the power bus VBUS, so that the detection module 122 can detect the voltage across the first resistor R1 and accurately obtain the current flowing through the first resistor R1, so as to facilitate the detection module 122 to detect whether the USB external device 2 is normally recognized by the main control chip 20 at this time.

[0043] It should be noted that the resistance value of the shunt resistor should be as low as possible to reduce the impact on the power supply bus VBUS, and the embodiments of the present application do not specifically limit the resistance value of the shunt resistor. Exemplarily, the resistance value of the shunt resistor can be 0.1 ohm.

[0044] Please continue to refer to Figure 4 - Figure 5 , further, in some embodiments, the voltage detection circuit 1221 includes a voltage division circuit 1222 and an amplification circuit 1223.

[0045] The voltage division circuit 1222 is electrically connected to both ends of the first resistor R1; the input end of the amplification circuit 1223 is electrically connected to the voltage division circuit 1222, and the output end of the amplification circuit 1223 is electrically connected to the main control chip 20. It can be understood that the voltage division circuit 1222 divides the voltage detected at both ends of the first resistor R1, and then inputs the divided voltage to the input end of the amplification circuit 1223; the amplification circuit 1223 amplifies the voltage and outputs a voltage signal to the main control chip 20, so that the main control chip 20 analyzes the voltage signal, and the current consumed at this time is calculated according to Ohm's law based on this voltage. That is, the main control chip 20 determines whether the USB external device 2 is normally recognized by the main control chip 20 according to the amount of current consumed by flowing through the first resistor R1. If the current consumed by the first resistor R1 remains below 100 milliamps for a long time, it means that the USB external device 2 is not normally recognized by the main control chip 20, and at this time, the voltage signal is set as the detection signal. At this time, the main control chip 20 sends a control signal to the hub 13 to control the hub 13 to reset and enumerate the USB external device 2 to achieve the re-identification of the USB external device 2 by the main control chip 20. If the current consumed by the first resistor R1 fluctuates or is greater than 100 milliamps, it means that the USB external device 2 is normally recognized by the main control chip 20. Since the hub 13 will not control other USB external devices 2 that have been normally recognized by the main control chip 20 to be reset, the main control chip 20 will not send a control signal to the hub 13 at this time.

[0046] It should be noted that the voltage at which the USB external device 2 is not normally recognized by the main control chip 20 is less than the voltage at which the USB external device 2 can be normally recognized by the main control chip 20. Exemplarily, the voltage at which the USB external device 2 is normally recognized by the main control chip 20 is 0.01V, while the voltage at which the USB external device 2 is not normally recognized by the main control chip 20 is less than 0.01V.

[0047] Please continue to refer to Figure 4 - Figure 5, in some embodiments, the amplifier circuit 1223 includes an operational amplifier U1, a second resistor R5, and a third resistor R4. Among them, the positive input terminal of the operational amplifier U1 is grounded through the second resistor R5; the negative input terminal of the operational amplifier U1 is electrically connected to one end of the third resistor R4; the output terminal of the operational amplifier U1 is electrically connected to the other end of the third resistor R4. It can be understood that the operational amplifier U1 is an electronic device that can increase the signal amplitude (voltage, current, or power). It utilizes the non-linear characteristics of electronic devices to amplify the input signal by controlling the amplitude, phase, or frequency of the input signal. That is, after the operational amplifier U1 adjusts and amplifies the voltage input by the voltage division circuit 1222, the operational amplifier U1 outputs the amplified voltage signal to the main control chip 20, so that the main control chip 20 can determine whether the USB external device 2 is normally recognized according to the voltage signal.

[0048] It should be noted that the second resistor R5 can pull up the operational amplifier U1 to provide a stable reference voltage; the third resistor R4 is the feedback voltage of the operational amplifier U1, and the third resistor R4 can determine the gain value of the operational amplifier U1.

[0049] Please refer to Figure 5 , further, the voltage division circuit 1222 includes a fourth resistor R3 and a fifth resistor R2. Among them, one end of the fourth resistor R3 is electrically connected to one end of the first resistor R1, and the other end of the fourth resistor R3 is electrically connected to the positive input terminal of the operational amplifier U1; one end of the fifth resistor R2 is electrically connected to the other end of the first resistor R1, and the other end of the fifth resistor R2 is electrically connected to the negative input terminal of the operational amplifier U1. It can be understood that the fourth resistor R3 and the fifth resistor R2 can form a voltage division network. Among them, the voltage division is based on Ohm's law and the characteristics of series resistors. By connecting resistors with different resistance values, the voltage of the resistor is distributed to different voltage division points in a certain proportion. That is, after the voltage division network detects the voltage value of the first resistor R1, the resistance values of the fourth resistor R3 and the fifth resistor R2 are used to control the magnitude of the divided voltage, so as to realize the distribution and adjustment of the input voltage of the operational amplifier U1.

[0050] It should be noted that the fourth resistor R3 and the fifth resistor R2 are both precision resistors. It can be understood that a precision resistor is a resistor device with characteristics such as high stability, high accuracy, and low temperature drift. And by setting the fourth resistor R3 and the fifth resistor R2 as precision resistors, the accuracy of voltage division for the voltage of the first resistor R1 can be improved; that is, compared with ordinary resistors, the resistance value error of precision resistors can be controlled within the range of one ten-thousandth to one thousandth, so that the fourth resistor R3 and the fifth resistor R2 can more accurately distribute voltage according to a predetermined ratio. Moreover, because precision resistors have strict technical requirements in terms of materials and processes, the reliability and lifespan of precision resistors are generally better than those of ordinary resistors. Therefore, in the embodiment of the present application, since the fourth resistor R3 and the fifth resistor R2 are both precision resistors, the costs of maintenance and replacement caused by the damage of the fourth resistor R3 and the fifth resistor R2 are reduced.

[0051] In the drawings of this embodiment, the same or similar reference numerals correspond to the same or similar components; in the description of the present application, it should be understood that if there are terms such as "upper", "lower", "left", "right", etc. indicating the orientation or positional relationship, it is based on the orientation or positional relationship shown in the drawings. It is 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 orientation, be constructed and operated in a specific orientation. Therefore, the terms describing the positional relationship in the drawings are only for illustrative purposes and cannot be understood as a limitation to the present application. For those of ordinary skill in the art, the specific meanings of the above terms can be understood according to specific circumstances.

[0052] The above are only the preferred embodiments of the present application and are not used to limit the present application. Any modifications, equivalent replacements, and improvements made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A USB communication circuit, characterized in that, Applied to a display device, the display device is configured with a main control chip, and the USB communication circuit includes: A USB interface electrically connected to the main control chip, and the connection line between the USB interface and the main control chip includes a power bus; and, A detection circuit including a module to be detected and a detection module, the module to be detected is disposed on the power bus, the detection module is electrically connected to the module to be detected, and both the module to be detected and the detection module are electrically connected to the main control chip; Wherein, the detection module is used to detect the module to be detected to generate a detection signal and send it to the main control chip, so that the main control chip re-identifies the USB external device according to the detection signal.

2. The USB communication circuit according to claim 1, wherein The module to be detected includes a first resistor, the detection module includes a voltage detection circuit, the voltage detection circuit is electrically connected to both ends of the first resistor to detect the voltage across the first resistor, and the detection signal includes the voltage across the first resistor.

3. The USB communication circuit according to claim 2, wherein The first resistor is a shunt resistor.

4. The USB communication circuit according to claim 2, characterized in that, The voltage detection circuit includes: A voltage division circuit electrically connected to both ends of the first resistor; and, An amplification circuit, the input end of which is electrically connected to the voltage division circuit, and the output end of which is electrically connected to the main control chip.

5. The USB communication circuit according to claim 4, wherein The amplification circuit includes an operational amplifier, a second resistor, and a third resistor; The positive input end of the operational amplifier is grounded through the second resistor; The negative input end of the operational amplifier is electrically connected to one end of the third resistor; The output end of the operational amplifier is electrically connected to the other end of the third resistor.

6. The USB communication circuit according to claim 5, characterized in that, The voltage division circuit includes a fourth resistor and a fifth resistor; One end of the fourth resistor is electrically connected to one end of the first resistor, and the other end is electrically connected to the positive input end of the operational amplifier; One end of the fifth resistor is electrically connected to the other end of the first resistor, and the other end is electrically connected to the negative input end of the operational amplifier.

7. The USB communication circuit according to claim 6, wherein, Both the fourth resistor and the fifth resistor are precision resistors.

8. The USB communication circuit according to any one of claims 1-7, characterized in that, The USB communication circuit further includes: A hub, one end of which is electrically connected to the USB interface, and the other end of which is electrically connected to the main control chip.

9. A display device, characterized in that, The display device includes: The USB communication circuit according to any one of claims 1-8; A main control chip electrically connected to both the USB interface and the detection circuit; and, A housing, both the main control chip and the detection circuit are disposed in the housing, and the USB interface is disposed on the housing and partially exposed from the housing.

Images