Industrial personal computer USB interface anti-interference circuit and corresponding circuit board

Abstract

The utility model provides an industrial personal computer USB interface anti-interference circuit and a corresponding circuit board. The industrial personal computer USB interface anti-interference circuit is used for transmitting a group of differential data signals output by a CPU chip to post-stage equipment. The common-mode interference suppression module is used for suppressing common-mode interference of data signals, and the concentrator module comprises a group of input pins and a plurality of groups of output pins. The input pin is connected with the common-mode interference suppression module and is used for receiving a data signal. The hub module is used for amplifying data signals, and the data signals are used for being output from the multiple sets of output pins. The filtering module is used for filtering data signals, the surge suppression module is used for suppressing surge voltage of the data signals, and the electrostatic protection module is used for suppressing electrostatic interference of the data signals. The interface module is used for transmitting the data signal to a post-stage device, and the post-stage device can obtain the data of the CPU chip based on the data signal.

Description

Technical Field

[0001] The utility model relates to the technical field of circuits, and particularly relates to an anti-interference circuit for a USB interface of an industrial personal computer and a corresponding circuit board. Background Art

[0002] In modern society, the operating speed of the USB interface is relatively high, so the USB interface is widely used in the field of industrial control. The data signal output by the CPU chip can be transmitted to the subsequent device through the USB interface. However, the existing USB interface has weak anti-interference ability, so that the data signal is easily affected by instantaneous voltage impact and static electricity interference during the transmission process. Therefore, there is a technical problem that the data signal is prone to distortion or malfunction during the transmission process.

[0003] Therefore, it is necessary to provide an anti-interference circuit for a USB interface of an industrial personal computer and a corresponding circuit board to solve the above technical problems. Summary of the Utility Model

[0004] The utility model provides an anti-interference circuit for a USB interface of an industrial personal computer and a corresponding circuit board, effectively solving the technical problem that the data signal is prone to distortion or malfunction during the transmission process.

[0005] The utility model provides an anti-interference circuit for a USB interface of an industrial personal computer, which is used to transmit a group of differential data signals output by a CPU chip to a subsequent device. It includes:

[0006] A common-mode interference suppression module, connected to the CPU chip, for suppressing the common-mode interference of the data signal;

[0007] A hub module, which includes a group of input pins and multiple groups of output pins. The input pins are connected to the common-mode interference suppression module. The input pins are used to input the data signal. The hub module is used to amplify the data signal, and the data signal is used to output from any one of the groups of output pins;

[0008] A filtering module, connected in parallel with multiple groups of output pins, for filtering the data signal;

[0009] A surge suppression module, connected in parallel with multiple groups of output pins, for suppressing the surge voltage of the data signal;

[0010] An electrostatic protection module, connected in parallel with multiple groups of output pins, for suppressing the electrostatic interference of the data signal;

[0011] An interface module, one end of which is connected to multiple groups of output pins, and the other end is connected to a subsequent device, for transmitting the data signal to the subsequent device. The subsequent device is used to obtain the data of the CPU chip based on the data signal.

[0012] Further, the common-mode interference module includes a common-mode inductor, the hub module includes a hub chip, a set of the input pins and multiple sets of the output pins are all arranged on the hub chip, one end of the common-mode inductor is connected to the CPU chip, and the other end of the common-mode inductor is connected to the input pins.

[0013] Further, the filtering module includes a filtering capacitor, one end of the filtering capacitor is connected to the output pin, and the other end of the filtering capacitor is grounded.

[0014] Further, the surge suppression module includes a transient voltage suppression diode, one end of the transient voltage suppression diode is connected to the output pin, and the other end of the transient voltage suppression diode is grounded.

[0015] Further, the electrostatic protection module includes an electrostatic protector, and the electrostatic protector is connected to the output pin.

[0016] Further, the interface module includes a plurality of interfaces, and each interface is correspondingly connected to each set of the output pins one by one.

[0017] Further, the anti-interference circuit of the industrial computer USB interface further includes a debugging resistor, one end of the debugging resistor is connected to the output pin, and the other end of the debugging resistor is connected to the interface. The debugging resistor is used for performing debugging operations on the anti-interference circuit of the industrial computer USB interface.

[0018] Further, the hub module includes a filtering unit, the hub chip includes a power supply pin, one end of the filtering unit is connected to an external power supply, the other end of the filtering unit is connected to the power supply pin, the external power supply is used for outputting a power supply voltage, the power supply voltage is used for powering the hub chip, and the filtering unit is used for filtering the power supply voltage.

[0019] Further, the number of the interfaces is 2 - 6.

[0020] A circuit board includes the anti-interference circuit of the industrial computer USB interface described in any one of the above.

[0021] Compared with the prior art, the beneficial effects of the present utility model are as follows: The present utility model provides an anti-interference circuit for the USB interface of an industrial control computer. The anti-interference circuit for the USB interface of the industrial control computer can transmit a group of differential data signals output by the CPU chip to the subsequent device. The anti-interference circuit for the USB interface of the industrial control computer includes a common-mode interference suppression module, a hub module, a filtering module, a surge suppression module, an electrostatic protection module, and an interface module. The common-mode interference suppression module can suppress the common-mode interference of the data signal, and the filtering module 13 can perform filtering operations on the data signal. The surge suppression module can suppress the surge voltage of the data signal, the electrostatic protection module suppresses the electrostatic interference of the data signal, and the interface module can transmit the data signal to the subsequent device. Therefore, the anti-interference circuit for the USB interface of the industrial control computer can improve the anti-interference ability of the data signal and enhance the reliability of the circuit. Moreover, the setting of the anti-interference circuit for the USB interface of the industrial control computer improves the stability and reliability of data signal transmission, can avoid the subsequent device connected to the USB interface from easily experiencing disconnection phenomena, and enhances the performance of the USB interface device. And, the anti-interference circuit for the USB interface of the industrial control computer effectively solves the technical problem that the data signal is prone to distortion or malfunction during the transmission process. The circuit structure of the anti-interference circuit for the USB interface of the industrial control computer is relatively simple, so the design and manufacturing costs of the corresponding circuit board are also relatively low. Description of the Drawings

[0022] In order to more clearly illustrate the technical solutions in the embodiments of the present utility model or the prior art, the following briefly introduces the drawings required to be used in the embodiments. The drawings in the following description are only the corresponding drawings of some embodiments of the present utility model.

[0023] Figure 1 It is a block diagram of an embodiment of the anti-interference circuit for the USB interface of the industrial control computer of the present utility model.

[0024] Figure 2 It is a circuit diagram of the common-mode interference suppression module of an embodiment of the anti-interference circuit for the USB interface of the industrial control computer of the present utility model.

[0025] Figure 3 It is a circuit diagram of the hub module of an embodiment of the anti-interference circuit for the USB interface of the industrial control computer of the present utility model.

[0026] Figure 4 It is one of the circuit diagrams of the interface module of an embodiment of the anti-interference circuit for the USB interface of the industrial control computer of the present utility model.

[0027] Figure 5 It is the second circuit diagram of the interface module of an embodiment of the anti-interference circuit for the USB interface of the industrial control computer of the present utility model.

[0028] Figure 6This is the circuit diagram of the filtering unit of an embodiment of the anti-interference circuit for the industrial control computer USB interface of the present utility model.

[0029] Figure 7 This is the circuit diagram of the interface power supply module of an embodiment of the anti-interference circuit for the industrial control computer USB interface of the present utility model.

[0030] Figure 8 This is the circuit diagram of the filtering module of an embodiment of the anti-interference circuit for the industrial control computer USB interface of the present utility model.

[0031] Figure 9 This is the circuit diagram of the surge suppression module of an embodiment of the anti-interference circuit for the industrial control computer USB interface of the present utility model.

[0032] Figure 10 This is one of the circuit diagrams of the electrostatic protection module of an embodiment of the anti-interference circuit for the industrial control computer USB interface of the present utility model.

[0033] Figure 11 This is the second circuit diagram of the electrostatic protection module of an embodiment of the anti-interference circuit for the industrial control computer USB interface of the present utility model.

[0034] Figure 12 This is the circuit diagram of the debugging resistor of an embodiment of the anti-interference circuit for the industrial control computer USB interface of the present utility model.

[0035] In the figure, 10 is the anti-interference circuit for the industrial control computer USB interface; 11 is the common-mode interference suppression module; 12 is the hub module; 121 is the filtering unit; 122 is the power supply; 13 is the filtering module; 14 is the surge suppression module; 15 is the electrostatic protection module; 16 is the interface module; 161 is the first interface; 162 is the second interface; 163 is the third interface; 164 is the fourth interface; 17 is the interface power supply module; 171 is the voltage conversion unit; 172 is the filtering and surge protection unit; 173 is the first external power supply; 174 is the second external power supply; 18 is the CPU chip. Detailed implementation manners

[0036] Next, the technical solutions in the embodiments of the present utility model will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present utility model. Obviously, the described embodiments are only a part of the embodiments of the present utility model, rather than all of the embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those skilled in the art without creative efforts fall within the protection scope of the present utility model.

[0037] The directional terms mentioned in the present utility model, such as "upper", "lower", "front", "rear", "left", "right", "inner", "outer", "side", "top" and "bottom", etc., are only with reference to the orientation of the attached drawings. The directional terms used are for explaining and understanding the present utility model, rather than for limiting the present utility model.

[0038] In the terms of the present utility model, words such as "first" and "second" are only for descriptive purposes, and cannot be understood as indicating or implying relative importance, nor as a limitation on the sequence.

[0039] In the figures, units with similar structures are denoted by the same reference numerals.

[0040] Please refer to Figure 1 As shown in the figure, the present utility model provides an anti-interference circuit 10 for an industrial control computer USB interface. The anti-interference circuit 10 for an industrial control computer USB interface is applied to a circuit board. The anti-interference circuit 10 for an industrial control computer USB interface can transmit a group of differential data signals output by the CPU chip 18 to the subsequent device. The anti-interference circuit 10 for an industrial control computer USB interface includes a common-mode rejection module, a hub module 12, a filtering module 13, a surge suppression module 14, an electrostatic protection module 15 and an interface module 16. The common-mode interference rejection module 11 is connected to the CPU chip 18, and the common-mode interference rejection module 11 is used to suppress the common-mode interference of the data signal. The hub module 12 includes a group of input pins and multiple groups of output pins, and the input pins are connected to the common-mode interference rejection module 11. The input pins are used to input data signals, and the hub module 12 is used to amplify the data signals, and the data signals are output from any group of output pins.

[0041] Please refer to Figure 1 As shown in the figure, the filtering module 13 is connected in parallel with multiple groups of output pins, and the filtering module 13 is used to filter the data signals. The surge suppression module 14 is connected in parallel with multiple groups of output pins, and the surge suppression module 14 is used to suppress the surge voltage of the data signal. The electrostatic protection module 15 is connected in parallel with multiple groups of output pins, and the electrostatic protection module 15 is used to suppress the electrostatic interference of the data signal. One end of the interface module 16 is connected to multiple groups of output pins, and the other end of the interface module 16 is connected to the subsequent device. The interface module 16 is used to transmit the data signal to the subsequent device, and the subsequent device is used to obtain the data of the CPU chip 18 based on the data signal.

[0042] Please refer to Figures 2 to 12 As shown in the figure, the following is a detailed description of the specific structure of the anti-interference circuit 10 for an industrial control computer USB interface:

[0043] Please refer to Figure 2 and Figure 3, The common-mode interference module includes a common-mode inductor B12, and the hub module 12 includes a hub chip U25. A set of input pins and multiple sets of output pins are all arranged on the hub chip U25. The input pins are input pin DM_P4 and input pin DP_P4. The multiple sets of output pins can be four sets of output pins, and the output pins include output pin DM_P1, output pin DP_P1, output pin DM_P2, output pin DP_P2, output pin DM_P3, output pin DP_P3, output pin DM_P0, and output pin DP_P0. Among them, output pin DM_P1 and output pin DP_P1 are a set of output pins. Output pin DM_P2 and output pin DP_P2 are a set of output pins, output pin DM_P3 and output pin DP_P3 are a set of output pins, and output pin DM_P0 and output pin DP_P0 are a set of output pins. Moreover, the hub module 12 also includes a capacitor C227 and a resistor R212.

[0044] Please refer to Figure 2 and Figure 3 , One end of the common-mode inductor B12 is connected to the CPU chip 18, and the other end of the common-mode inductor B12 is connected to the input pin DM_P4 and the input pin DP_P4. The differential data signal output by the CPU passes through the common-mode inductor, and the common-mode interference generated by the asymmetry of the differential signal can be eliminated. The common-mode inductor B12 can be used to suppress the common-mode interference, thereby providing the stability and reliability of data transmission. Also, during the transmission of the data signal, the common-mode inductor B12 can also be used to suppress the electromagnetic interference from the external environment, thus ensuring that the subsequent devices can work properly for a long time. The data signal output by the CPU chip 18 can flow into the circuit through one end of the common-mode inductor B12, and then, the other end of the common-mode inductor B12 can output the data signal after suppressing the common-mode interference. The input pins of the hub chip U25 can input this data signal, and moreover, the hub chip U25 can output the amplified data signal. Signal amplification means increasing the amplitude of the signal, thereby increasing the signal strength, which is used to improve the signal transmission quality, coverage range, or system communication ability. Also, the hub chip can also play a role in suppressing external interference, effectively preventing the interference signal from directly damaging the CPU chip 18.

[0045] Please refer to Figure 3 , Figure 4 and Figure 5, the interface module 16 includes interface chips J26 and J27. Interface chip J26 includes D0- pin, D0+ pin, D1- pin, and D1+ pin. The D0- pin of interface chip J26 is connected to output pin DM_P3, and the D0+ pin of interface chip J26 is connected to output pin DP_P3. The D1- pin of interface chip J26 is connected to output pin DM_P0, and the D1+ pin of interface chip J26 is connected to output pin DP_P0. Interface chip J27 includes D0- pin, D0+ pin, D1- pin, and D1+ pin. The D0- pin of interface chip J27 is connected to output pin DM_P1, and the D0+ pin of interface chip J27 is connected to output pin DP_P1. The D1- pin of interface chip J27 is connected to output pin DM_P2, and the D1+ pin of interface chip J27 is connected to output pin DP_P2.

[0046] Please refer to Figure 3 , Figure 4 and Figure 5 , the interface module 16 includes multiple interfaces, and each interface is connected to a corresponding set of output pins one by one. The number of interfaces can be 2 - 6, preferably, the number of interfaces can be four, and the four interfaces are the first interface 161, the second interface 162, the third interface 163, and the fourth interface 164. Among them, the first interface 161 and the second interface 162 are connected to interface chip J26. Thus, the first interface 161 can be correspondingly connected to output pin DM_P1 and output pin DP_P1, and the second interface 162 can be correspondingly connected to output pin DM_P2 and output pin DP_P2. The third interface 163 and the fourth interface 164 are connected to interface chip J27. Thus, the third interface 163 can be correspondingly connected to output pin DM_P3 and output pin DP_P3, and the fourth interface 164 can be correspondingly connected to output pin DM_P0 and output pin DP_P0.

[0047] Please refer to Figure 3 , Figure 4 and Figure 5 , because each interface is connected to a corresponding set of output pins one by one, the industrial computer USB interface circuit can expand one input interface into 4 output interfaces. When one of the output interfaces is damaged, the other three output interfaces can still output data signals, which is beneficial to improving the stability and reliability of the transmitted data signals. The 4 output interfaces can be simultaneously connected to 4 subsequent devices. Thus, the data signals output by the CPU can be simultaneously transmitted to 4 subsequent devices, effectively improving the transmission efficiency of the data signals. The interface chip can be used to receive the data signals output by the output pins, and the interface chip transmits the data signals to the interface, and the interface transmits the data signals to the subsequent devices. And, the interface module 16 includes resistor R207, capacitor C247, resistor R254, and capacitor C301.

[0048] Please refer to Figure 2 and Figure 6 , the hub module 12 includes a filtering unit 121, and the hub chip includes a power supply pin VDDP / 5V. The power supply pin VDDP / 5V is connected to a power supply 122, and the power supply 122 is used to output a power supply voltage, and the power supply voltage is used to supply power to the hub chip U25. One end of the filtering unit 121 is connected to the power supply 122, and the other end of the filtering unit 121 is connected to the ground. Among them, the filtering module 13 includes a filtering capacitor C256 and a filtering capacitor C257. The filtering unit 121 can perform a filtering operation on the power supply voltage through the filtering capacitor C256 and the filtering capacitor C257. The filtering unit 121 can filter out interference components such as clutter and noise in the power supply voltage, so that the power supply 122 can output a stable power supply voltage, thereby ensuring the normal operation of the subsequent circuit. And, the hub module 12 further includes a resistor R233.

[0049] Please refer to Figure 4 、 Figure 5 and Figure 7 , the anti-interference circuit 10 of the industrial computer USB interface further includes an interface power supply module 17, and the interface power supply module 17 further includes a voltage conversion unit 171 and a filtering and surge protection unit 172. The voltage conversion unit 171 is used to connect a first external power supply 173 and a second external power supply 174. The first external power supply 173 is used to output a first voltage, and the second external power supply 174 is used to output a second voltage. The voltage conversion unit 171 is used to convert the first voltage and the second voltage into an interface power supply voltage, and the interface power supply voltage is used to supply power to the interface chip U25. The voltage conversion unit 171 further includes an output terminal USB_VCC, and the interface power supply voltage is output to the filtering and surge protection unit 172 through the output terminal USB_VCC. The voltage conversion unit 171 further includes a capacitor C273, a resistor 250, a resistor R251, a triode Q16. The voltage conversion unit 171 further includes a MOS transistor U40, a resistor 252, a resistor R253. The voltage conversion unit 171 further includes a capacitor TC6, a capacitor C132, a capacitor TC7, a capacitor C133, and an inductor B11.

[0050] Please refer to Figure 4 、 Figure 5 and Figure 7, the filtering and surge protection unit 172 receives the interface power supply voltage. The filtering and surge protection unit 172 can perform filtering operations on the interface power supply voltage, and the filtering and surge protection unit 172 can also suppress the surge voltage of the interface power supply voltage. The filtering and surge protection unit 172 includes an output terminal USB_VCC01, and the interface chip J27 includes VCC0 and VCC1 pins. The output terminal USB_VCC01 is connected to the VCC0 pin and the VCC1 pin of the interface chip J27. Therefore, the output terminal USB_VCC01 can output the filtered and surge-voltage-suppressed interface power supply voltage to the interface chip J27. The filtering and surge protection unit 172 includes an output terminal USB_VCC02, and the interface chip J26 includes VCC0 and VCC1 pins. The output terminal USB_VCC02 is connected to the VCC0 pin and the VCC1 pin of the interface chip J26. Therefore, the output terminal USB_VCC02 can output the filtered and surge-voltage-suppressed interface power supply voltage to the interface chip J26. The filtering and surge protection unit 172 further includes a capacitor TC10, a capacitor TC11, a capacitor C260, a capacitor C261, a capacitor C262, the filtering and surge protection unit 172 further includes a resistor R236, a resistor R237, and the filtering and surge protection unit 172 further includes a transient voltage suppression diode TVS27 and a transient voltage suppression diode TVS28.

[0051] Please refer to Figure 3 and Figure 8 , the filtering module 13 includes filtering capacitors. One end of the filtering capacitor is connected to the output pin, and the other end of the filtering capacitor is grounded. Among them, the filtering capacitors include a filtering capacitor C279, a filtering capacitor C280, a filtering capacitor C277, a filtering capacitor C278, a filtering capacitor C275, a filtering capacitor C276, a filtering capacitor C263, and a filtering capacitor C274. The filtering capacitor C279 is connected to the output pin DM_P1, and the filtering capacitor C280 is connected to the output pin DP_P1. The filtering capacitor C277 is connected to the output pin DM_P2, and the filtering capacitor C278 is connected to the output pin DP_P2. The filtering capacitor C275 is connected to the output pin DM_P3, and the filtering capacitor C276 is connected to the output pin DP_P3. The filtering capacitor C263 is connected to the output pin DM_P0, and the filtering capacitor C274 is connected to the output pin DP_P0. The output pin can output a data signal, and the filtering capacitor can perform filtering operations on the data signal. The filtering capacitor can filter out interference components such as clutter and noise in the data signal. Therefore, the data signal can be stably transmitted from the output pin to the interface chip.

[0052] Please refer to Figure 3 and Figure 9, the surge suppression module 14 includes transient voltage suppression diodes. One end of the transient voltage suppression diode is connected to the output pin, and the other end is grounded. Among them, the transient voltage suppression diodes include transient voltage suppression diode TVS31, transient voltage suppression diode TVS34, transient voltage suppression diode TVS30, transient voltage suppression diode TVS32, transient voltage suppression diode TVS33, transient voltage suppression diode TVS35, transient voltage suppression diode TVS39, and transient voltage suppression diode TVS42. The transient voltage suppression diode TVS31 is connected to the output pin DM_P1, and the transient voltage suppression diode TVS34 is connected to the output pin DP_P1. The transient voltage suppression diode TVS30 is connected to the output pin DM_P2, and the transient voltage suppression diode TVS32 is connected to the output pin DP_P2. The transient voltage suppression diode TVS33 is connected to the output pin DM_P3, and the transient voltage suppression diode TVS35 is connected to the output pin DP_P3. The transient voltage suppression diode TVS39 is connected to the output pin DM_P0, and the transient voltage suppression diode TVS42 is connected to the output pin DP_P0. The output pin can output a data signal, and the transient voltage suppression diode can suppress the surge voltage of the data signal. When a surge pulse voltage appears instantaneously in the protected circuit, the transient voltage suppression diode can quickly perform Zener breakdown. The transient voltage suppression diode can change from a high-impedance state to a low-impedance state, and the transient voltage suppression diode shunts and clamps the surge voltage, thereby protecting each component in the circuit from being damaged by the instantaneous surge pulse voltage. Moreover, the surge suppression module 14 further includes a transient voltage suppression diode TVS29 and a transient voltage suppression diode TVS41. The transient voltage suppression diode TVS29 is connected to the output terminal USB_VCC01, and the transient voltage suppression diode TVS41 is connected to the output terminal USB_VCC02.

[0053] Please refer to Figure 3 , Figure 10 and Figure 11, the electrostatic protection module 15 includes an electrostatic protector. The electrostatic protector is connected to the output pin and can be used to absorb and suppress static electricity or short pulse voltages. The electrostatic protector includes electrostatic protector U36 and electrostatic protector U38. Electrostatic protector U36 includes pin 1, pin 3, pin 4, and pin 6. Pin 1 of electrostatic protector U36 is connected to the DM_P1 pin, and pin 3 of electrostatic protector U36 is connected to the DP_P1 pin. Pin 4 of electrostatic protector U36 is connected to the DM_P2 pin, and pin 6 of electrostatic protector U36 is connected to the DP_P2 pin. Electrostatic protector U38 includes pin 1, pin 3, pin 4, and pin 6. Pin 1 of electrostatic protector U38 is connected to the DM_P3 pin, and pin 3 of electrostatic protector U38 is connected to the DP_P3 pin. Pin 4 of electrostatic protector U38 is connected to the DM_P0 pin, and pin 6 of electrostatic protector U38 is connected to the DP_P0 pin. The output pin can output a data signal, and the electrostatic protector can suppress the electrostatic interference of the data signal. The electrostatic protector can provide fast voltage protection when an electrostatic discharge event occurs, so that the electrostatic protector can protect electronic circuits, devices, and equipment from electrostatic damage.

[0054] Please refer to Figure 11 , the anti-interference circuit 10 of the industrial computer USB interface further includes a debugging resistor. One end of the debugging resistor is connected to the output pin, and the other end of the debugging resistor is connected to the interface. The debugging resistor is used to perform debugging operations on the anti-interference circuit 10 of the industrial computer USB interface. Among them, the debugging resistors include debugging resistor R243, debugging resistor R267, debugging resistor R245, debugging resistor R268, debugging resistor R242, debugging resistor R269, debugging resistor R244, debugging resistor R270, debugging resistor R238, debugging resistor R263, debugging resistor R239, debugging resistor R264, debugging resistor R240, debugging resistor R265, debugging resistor R241, and debugging resistor R266.

[0055] Please refer to Figure 3 , Figure 5 and Figure 11, one end of the debugging resistor R243 is connected to the output pin DM_P1, the other end of the debugging resistor R243 is connected to the debugging resistor R267, and the debugging resistor R267 is connected to the D0- pin of the interface chip J27. One end of the debugging resistor R245 is connected to the output pin DP_P1, the other end of the debugging resistor R245 is connected to the debugging resistor R268, and the debugging resistor R268 is connected to the D0+ pin of the interface chip J27. One end of the debugging resistor R242 is connected to the output pin DM_P2, the other end of the debugging resistor R242 is connected to the debugging resistor R269, and the debugging resistor R269 is connected to the D1- pin of the interface chip J27. One end of the debugging resistor R244 is connected to the output pin DP_P2, the other end of the debugging resistor R244 is connected to the debugging resistor R270, and the debugging resistor R270 is connected to the D1+ pin of the interface chip J27.

[0056] Please refer to Figure 3 , Figure 4 and Figure 11 One end of the debugging resistor R238 is connected to the output pin DM_P3, the other end of the debugging resistor R238 is connected to the debugging resistor R263, and the debugging resistor R263 is connected to the D0- pin of the interface chip J26. One end of the debugging resistor R239 is connected to the output pin DP_P3, the other end of the debugging resistor R239 is connected to the debugging resistor R264, and the debugging resistor R264 is connected to the D0+ pin of the interface chip J26. One end of the debugging resistor R240 is connected to the output pin DM_P0, the other end of the debugging resistor R240 is connected to the debugging resistor R265, and the debugging resistor R265 is connected to the D1- pin of the interface chip J26. One end of the debugging resistor R241 is connected to the output pin DP_P0, the other end of the debugging resistor R241 is connected to the debugging resistor R266, and the debugging resistor R266 is connected to the D1+ pin of the interface chip J26. Before the circuit works normally, the user can install the debugging resistor between the output pin and the interface, so that the user can adjust and test the anti-interference circuit 10 of the industrial computer USB interface based on the debugging resistor.

[0057] The anti-interference circuit 10 of the industrial computer USB interface also has an anti-electromagnetic interference design. The grounding copper foil (i.e., GND copper foil) is segmented, and the grounding copper foil is segmented before and after the common mode inductor. The common mode interference suppression module 11 and the hub module 12 form the internal circuit of the hub chip, and the filtering module 13, the surge suppression module 14, the electrostatic protection module 15, and the interface module 16 form the interface circuit. The grounding copper foil is segmented into the internal circuit of the hub chip and the interface circuit, and the grounding copper foil at the bottom of the hub chip is segmented, and the grounding copper foil is connected by single-point grounding to prevent external interference from entering the internal circuit through the grounding copper foil. The grounding copper foil of the interface circuit adopts a flanging design, which can be in good contact with the shell, and is conducive to the external interference being discharged through the shell.

[0058] The working principle of the present utility model is as follows: When the anti-interference circuit 10 of the industrial control computer USB interface works, first, the CPU chip 18 outputs a data signal. This data signal flows through the common-mode interference suppression module 11, and the common-mode interference suppression module 11 can suppress the common-mode interference of the data signal. Then, the input pin of the hub module 12 inputs this data signal. The hub module 12 can amplify the data signal, and any set of output pins of the hub module 12 can output this data signal. In order to filter the data signal, a filter module 13 is connected in parallel to the output pin of the hub module 12. In order to suppress the surge voltage of the data signal, a surge suppression module 14 is connected in parallel to the output pin of the hub module 12. In order to suppress the electrostatic interference of the data signal, an electrostatic protection module 15 is connected in parallel to the output pin of the hub module 12. Then, the interface module 16 receives this data signal. Subsequently, the interface module 16 can transmit this data signal to the subsequent device, and the subsequent device can obtain the data of the CPU chip 18 based on this data signal.

[0059] The present utility model provides an anti-interference circuit for the USB interface of an industrial control computer. The anti-interference circuit of the USB interface of the industrial control computer can transmit a set of differential data signals output by the CPU chip to the subsequent device. The anti-interference circuit of the USB interface of the industrial control computer includes a common-mode interference suppression module, a hub module, a filter module, a surge suppression module, an electrostatic protection module, and an interface module. The common-mode interference suppression module can suppress the common-mode interference of the data signal, and the filter module 13 can filter the data signal. The surge suppression module can suppress the surge voltage of the data signal, the electrostatic protection module suppresses the electrostatic interference of the data signal, and the interface module can transmit the data signal to the subsequent device. Therefore, the anti-interference circuit of the USB interface of the industrial control computer can improve the anti-interference ability of the data signal and enhance the reliability of the circuit. Moreover, the setting of the anti-interference circuit of the USB interface of the industrial control computer improves the stability and reliability of the data signal transmission, can avoid the subsequent device connected to the USB interface from being prone to disconnection, and enhances the performance of the USB interface device. And, the anti-interference circuit of the USB interface of the industrial control computer effectively solves the technical problem that the data signal is prone to distortion or malfunction during the transmission process. The circuit structure of the anti-interference circuit of the USB interface of the industrial control computer is relatively simple, so the design and manufacturing cost of the corresponding circuit board of this circuit is also relatively low.

[0060] In summary, although the present utility model has been disclosed above with preferred embodiments, the above preferred embodiments are not intended to limit the present utility model. Those of ordinary skill in the art can make various changes and modifications without departing from the spirit and scope of the present utility model. Therefore, the protection scope of the present utility model is subject to the scope defined by the claims.

Claims

1. An industrial computer USB interface anti-interference circuit, used to transmit a set of differential data signals output by a CPU chip to a subsequent device, characterized in that: These include, A common mode interference suppression module, connected to the CPU chip, for suppressing common mode interference of the data signal; A hub module, comprising a group of input pins and a plurality of groups of output pins, wherein the input pins are connected to the common-mode interference suppression module, the input pins are used to input the data signal, the hub module is used to amplify the data signal, and the data signal is used to be output from any group of the output pins; A filtering module, connected in parallel with the plurality of groups of output pins, for performing a filtering operation on the data signal; A surge suppression module, connected in parallel with the plurality of groups of output pins, for suppressing a surge voltage of the data signal; An electrostatic protection module, connected in parallel with the plurality of groups of output pins, for suppressing electrostatic interference of the data signal; The interface module has one end connected to the plurality of output pins and the other end connected to a subsequent device, and is used to transmit the data signal to the subsequent device, and the subsequent device is used to obtain the data of the CPU chip based on the data signal.

2. The anti-interference circuit for USB interface of industrial computer according to claim 1, characterized in that: The common-mode interference module includes a common-mode inductor, the hub module includes a hub chip, a group of input pins and multiple groups of output pins are arranged on the hub chip, one end of the common-mode inductor is connected to the CPU chip, and the other end of the common-mode inductor is connected to the input pin.

3. The anti-interference circuit of the USB interface of the industrial computer according to claim 2, characterized in that: The filter module comprises a filter capacitor, one end of the filter capacitor is connected to the output pin, and the other end of the filter capacitor is grounded.

4. The anti-interference circuit for USB interface of industrial computer according to claim 2, characterized in that: The surge suppression module comprises a transient voltage suppression tube, one end of the transient voltage suppression tube is connected to the output pin, and the other end of the transient voltage suppression tube is grounded.

5. The anti-interference circuit for USB interface of industrial computer according to claim 2, characterized in that: The electrostatic protection module includes an electrostatic protector, and the electrostatic protector is connected to the output pin.

6. The anti-interference circuit for USB interface of industrial computer according to claim 1, characterized in that: The interface module includes a plurality of interfaces, and each of the interfaces is connected to each group of the output pins in a one-to-one correspondence.

7. The anti-interference circuit for USB interface of industrial computer according to claim 6, characterized in that: The industrial computer USB interface anti-interference circuit also includes a debugging resistor, one end of the debugging resistor is connected to the output pin, and the other end of the debugging resistor is connected to the interface. The debugging resistor is used to debug the industrial computer USB interface anti-interference circuit.

8. The anti-interference circuit for USB interface of industrial computer according to claim 2, characterized in that: The hub module includes a filtering unit, the hub chip includes a power supply pin, one end of the filtering unit is connected to an external power supply, and the other end of the filtering unit is connected to the power supply pin, the external power supply is used to output a power supply voltage, the power supply voltage is used to power the hub chip, and the filtering unit is used to filter the power supply voltage.

9. The anti-interference circuit for USB interface of industrial computer according to claim 6, characterized in that: The number of the interfaces is 2-6.

10. A circuit board, characterized in that: It includes the industrial computer USB interface anti-interference circuit described in any one of claims 1-9.

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