Communication circuit

Abstract

The utility model relates to the technical field of communication, and specifically provides a communication circuit. The communication circuit comprises a connector, a signal transmitting end, a signal receiving end, a signal receiving and transmitting circuit and a switching circuit, the connector comprises a grounding terminal pin, a power supply terminal pin and a signal terminal pin, the signal receiving and transmitting circuit comprises a signal transmitting circuit and a signal receiving circuit, the signal transmitting circuit is connected with the signal transmitting end, and the signal receiving circuit is connected with the signal receiving end. The signal receiving circuit is connected with a signal receiving end, the switching circuit is connected between the signal transmitting and receiving circuit and the signal terminal pins, the switching circuit has a first state and a second state, and when the switching circuit is in the first state, the signal transmitting circuit is connected with the first signal terminal pin and disconnected with the second signal terminal pin; when the switching circuit is in the first state, the signal receiving circuit is communicated with the second signal terminal pin and disconnected from the first signal terminal pin, and when the switching circuit is in the second state, the signal receiving circuit and the signal transmitting circuit are communicated with the same or two of the first signal terminal pin and the second signal terminal pin.

Description

Technical Field

[0001] This application relates to the field of communication technology, specifically providing a communication circuit. Background Technology

[0002] Existing technical solutions only allow for a single mode when the motherboard and display board are connected: either both use three-wire communication or both use four-wire communication. If the motherboard uses a three-wire communication circuit and the display board uses a four-wire communication circuit, or vice versa, the motherboard and display board are incompatible and cannot communicate with each other. Summary of the Invention

[0003] This application aims to solve the aforementioned technical problem, namely, to address the issue of relatively simple interoperability between circuit boards in the prior art.

[0004] This application provides a communication circuit, comprising: a connector including a ground terminal, a power terminal, and a signal terminal, wherein the signal terminal includes a first signal terminal and a second signal terminal; a signal transmitting end for transmitting a signal; a signal receiving end for receiving a signal; a signal transceiver circuit including a signal transmitting circuit and a signal receiving circuit, wherein the signal transmitting circuit is connected to the signal transmitting end; the signal receiving circuit is connected to the signal receiving end; and a switching circuit connected between the signal transceiver circuit and the signal terminal; the switching circuit has a first state and a second state. In the first state, the signal transmitting circuit is connected to the first signal terminal and disconnected from the second signal terminal, and the signal receiving circuit is connected to the second signal terminal and disconnected from the first signal terminal. In the second state, both the signal receiving circuit and the signal transmitting circuit are connected to the same or both of the first and second signal terminal.

[0005] In the optional technical solution of the above communication circuit, the signal transmitting circuit is connected to the first signal terminal pin, and the signal receiving circuit is connected to the second signal terminal pin; the switching circuit includes a first switching circuit and a second switching circuit, the first switching circuit is connected between the first signal terminal pin and the signal transmitting circuit, one end of the second switching circuit is connected between the first switching circuit and the signal transmitting circuit, and the other end of the second switching circuit is connected between the second signal terminal pin and the signal receiving circuit; when the switching circuit is in the first state, the first switching circuit is turned on and the second switching circuit is turned off; when the switching circuit is in the second state, the first switching circuit is turned on or off, and the second switching circuit is turned on.

[0006] In the optional technical solution of the above communication circuit, the first switching circuit includes a first switching resistor, and the second switching circuit includes a second switching resistor; when the switching circuit is in the first state, the first switching resistor is engaged, and the second switching resistor is not engaged; when the switching circuit is in the second state, the first switching resistor is engaged or not engaged, and the second switching resistor is engaged.

[0007] In the optional technical solutions of the above communication circuit, the first switching resistor and / or the second switching resistor includes a jumper resistor.

[0008] In the optional technical solution of the above communication circuit, the signal transmitting circuit is connected to the first signal terminal pin, and the signal receiving circuit is connected to the second signal terminal pin; one end of the switching circuit is connected between the first signal terminal pin and the signal transmitting circuit, and the other end of the switching circuit is connected between the second signal terminal pin and the signal receiving circuit; when the switching circuit is in the first state, the switching circuit is disconnected; when the switching circuit is in the second state, the switching circuit is turned on.

[0009] In the optional technical solutions of the above communication circuit, the communication circuit further includes a power supply terminal and a ground terminal. The signal transmission circuit includes a first switching transistor, which includes a first terminal, a second terminal, and a first control terminal. The first terminal of the first switching transistor is connected to the power supply terminal, the second terminal of the first switching transistor is connected to the ground terminal, and the first control terminal is connected to the signal transmission terminal.

[0010] In the optional technical solution of the above communication circuit, the communication circuit further includes a power supply terminal and a ground terminal. The signal receiving circuit includes a second switching transistor, which includes a first terminal, a second terminal, and a second control terminal. The first terminal of the second switching transistor is connected to the power supply terminal and the signal receiving terminal, the second terminal of the second switching transistor is connected to the ground terminal, and the second control terminal is connected to the switching circuit.

[0011] In the optional technical solutions of the above communication circuit, the signal transceiver circuit further includes a filter circuit connected between the second control terminal and the ground terminal.

[0012] In the optional technical solution of the above communication circuit, the communication circuit further includes a power supply terminal, a ground terminal, and a protection circuit. The protection circuit is connected between the power supply terminal and the ground terminal. The protection circuit includes a first diode and a second diode connected in series, and the midpoint between the first diode and the second diode is connected to the switching circuit.

[0013] In the optional technical solutions of the above communication circuit, the communication circuit further includes a bidirectional transient voltage suppression diode connected between the ground terminal and the power supply terminal; and / or, the communication circuit further includes a capacitor connected between the ground terminal and the power supply terminal.

[0014] Taking the motherboard and display board as examples of the boards to be connected, and assuming that the motherboard circuit cannot be changed and the display board is equipped with the communication circuit of this application, when the motherboard uses four-wire communication, the switching circuit of the display board is switched to the first state. At this time, the signal transmitting end sends a signal to the first signal terminal pin through the signal transmitting circuit. The signal is transmitted to the signal receiving end through the second signal terminal pin and the signal receiving circuit. The signal transmitting end and the signal receiving end send and receive signals through different terminal pins of the connector, thereby realizing the four-wire communication connection between the display board and the motherboard. When the motherboard's communication line is three-wire communication, the switching circuit of the display board's communication circuit is switched to the second state. At this time, both the signal receiving circuit and the signal transmitting circuit can be connected to the same signal terminal pin. One of the first signal terminal pin or the second signal terminal pin is used as the signal terminal pin for the connector to send and receive signals, thereby realizing the three-wire communication connection between the display board and the motherboard. The communication circuit of this application can achieve three-wire and four-wire circuit compatibility between boards. Attached Figure Description

[0015] The preferred embodiments of this application are described below with reference to the accompanying drawings, in which:

[0016] Figure 1 This is a schematic diagram of a first embodiment of the communication circuit of this application;

[0017] Figure 2 This is a schematic diagram of a second embodiment of the communication circuit of this application;

[0018] Figure 3 yes Figure 2 A schematic diagram of the switching circuit in the communication circuit;

[0019] Figure 4 yes Figure 2 A schematic diagram of the signal transmission circuit in the communication circuit;

[0020] Figure 5 yes Figure 2 A schematic diagram of the signal receiving circuit in the communication circuit.

[0021] List of reference numerals in the attached diagram:

[0022] 1. Communication circuit; 10. Signal transceiver circuit; 11. Signal transmitting circuit; 110. First switching transistor; 111. First terminal of the first switching transistor; 112. Second terminal of the first switching transistor; 113. First control terminal; 12. Signal receiving circuit; 120. Second switching transistor; 121. First terminal of the second switching transistor; 122. Second terminal of the second switching transistor; 123. Second control terminal; 13. Switching circuit; 131. First switching circuit; R1. First switching resistor; 132. Second switching circuit; R2. Second switching resistor; 14. Connector; 141. Grounding terminal; 142. Power supply terminal; 143. Signal terminal; 1431. First signal terminal; 1432. Second signal terminal; 15. Filtering circuit; 16. Protection circuit; D2. First diode; D3. Second diode; D1. Bidirectional transient voltage suppressor diode; TXD1. Signal transmitting terminal; RXD1. Signal receiving terminal. Detailed Implementation

[0023] Exemplary embodiments will now be described in detail, examples of which are illustrated in the accompanying drawings. In the following description relating to the drawings, unless otherwise indicated, the same numbers in different drawings represent the same or similar elements. The terms “first,” “second,” and similar terms used in this specification and claims do not indicate any order, quantity, or importance, but are merely used to distinguish different components. “A plurality of” means two or more.

[0024] Unless otherwise stated, the orientation or positional relationship indicated by "front" and "rear" is based on the orientation or positional relationship shown in the accompanying drawings and is only for the purpose of facilitating the description of this application and simplifying the description, and is not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this application.

[0025] It should be noted that when an element is referred to as being "fixed to" or "set on" another element, it can be directly on the other element or there may be an intervening element. When an element is considered to be "connected" to another element, it can be directly connected to the other element or there may be an intervening element. Furthermore, "connection" should be interpreted broadly; for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium; it can be a connection within two elements. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0026] It should also be noted that, Figures 1 to 5The power supply terminal is represented by +5, the ground terminal by DGND, and different capacitors are represented by C1, C2, C3, C4 and C5 respectively. Different diodes are represented by D1, D2 and D3, and different resistors are represented by R1 to R7.

[0027] This application provides a communication circuit 1, with reference to... Figure 1 and Figure 2 The following are two embodiments of the communication circuit 1 of this application. The communication circuit 1 includes a connector 14, a signal transmitting end TXD1, a signal receiving end RXD1, a signal transceiver circuit 10, and a switching circuit 13. The connector 14 includes a ground terminal 141, a power terminal 142, and a signal terminal 143. The signal terminal 143 includes a first signal terminal 1431 and a second signal terminal 1432. The signal transmitting end TXD1 is used to transmit signals, and the signal receiving end RXD1 is used to receive signals. The signal transceiver circuit 10 includes a signal transmitting circuit 11 and a signal receiving circuit 12. The signal transmitting circuit 11 is connected to the signal transmitting end TXD1, and the signal receiving circuit 12 is connected to the signal receiving end RXD1. The switching circuit 13 is connected between the signal transceiver circuit 10 and the signal terminal 143. The switching circuit 13 has a first state and a second state. In the first state, the signal transmitting circuit 11 is connected to the first signal terminal 1431 and disconnected from the second signal terminal 1432, while the signal receiving circuit 12 is connected to the second signal terminal 1432 and disconnected from the first signal terminal 1431. In the second state, both the signal receiving circuit 12 and the signal transmitting circuit 11 are connected to the same or both of the first and second signal terminals 1431 and 1432.

[0028] The communication circuit 1 of this application is compatible with both three-wire and four-wire communication. Taking a motherboard and a display board as examples, and assuming that the communication lines of the motherboard cannot be changed while the display board is equipped with the communication circuit 1 of this application, when the motherboard uses four-wire communication, the display board should also use four-wire communication. The switching circuit 13 of the display board is switched to the first state. At this time, the signal transmitting end TXD1 sends a signal to the first signal terminal 1431 through the signal transmitting circuit 11, and the signal from the connector 14 is transmitted to the signal receiving end RXD1 through the second signal terminal 1432 and the signal receiving circuit 12. The signal transmitting end TXD1 and the signal receiving end RXD1 send and receive signals through different terminals of the connector 14, thereby enabling the display board to use four-wire communication, and thus enabling the display board and the motherboard to communicate. When the communication lines of the motherboard use three-wire communication, the switching circuit 13 of the communication circuit 1 of the display board is switched to the second state. At this time, both the signal receiving circuit 12 and the signal transmitting circuit 11 can be connected to the same signal terminal 143. When both the signal receiving circuit 12 and the signal transmitting circuit 11 are connected to either the first signal terminal 1431 or the second signal terminal 1432, the display board achieves three-wire communication by sending and receiving signals to and from the signal terminal 143 of the connector 14, thereby enabling a three-wire communication connection between the display board and the motherboard. When both the signal receiving circuit 12 and the signal transmitting circuit 11 are connected to both the first signal terminal 1431 and the second signal terminal 1432, either the first signal terminal 1431 or the second signal terminal 1432 can be selected as the signal terminal 143 for the connector 14 to send and receive signals. In this case, the connector 14 sends and receives signals through the signal terminal 143 to achieve three-wire communication between the display board and the motherboard. Therefore, the communication circuit 1 of this application can achieve compatibility between three-wire and four-wire circuits of the board, thereby improving the diversity of board-to-board communication connections.

[0029] It should be noted that when the communication circuit of the display board cannot be changed, the usage principle of the communication circuit 1 of this application set on the motherboard is the same as when the communication circuit of the motherboard cannot be changed and the communication circuit 1 of this application is set on the display board, and will not be described in detail here.

[0030] In one embodiment, reference Figure 1This is one embodiment of the communication circuit 1 of this application. A signal transmitting circuit 11 is connected to a first signal terminal 1431, and a signal receiving circuit 12 is connected to a second signal terminal 1432. One end of a switching circuit 13 is connected between the first signal terminal 1431 and the signal transmitting circuit 11, and the other end of the switching circuit 13 is connected between the second signal terminal 1432 and the signal receiving circuit 12. In the first state, the switching circuit 13 is disconnected; in the second state, the switching circuit 13 is connected. When the board needs to cooperate with other boards via four-wire communication, the switching circuit 13 is disconnected. The signal transmitting end TXD1 sends a signal to the first signal terminal 1431 through the signal transmitting circuit 11, and the signal on the connector 14 is transmitted from the signal receiving circuit 12 to the signal receiving end RXD1 through the second signal terminal 1432. When the board needs to cooperate with other boards via three-wire communication, the switching circuit 13 is turned on. At this time, the signal transmitter TXD1 can send a signal to the first signal terminal 1431 through the signal transmitting circuit 11, and can also send a signal to the second signal terminal 1432 sequentially through the signal transmitting circuit 11, the switching circuit 13, and the signal receiving circuit 12. The signal on the connector 14 can be transmitted to the signal receiver RXD1 sequentially through the second signal terminal 1432 and the signal receiving circuit 12, and can also be transmitted to the signal receiver RXD1 sequentially through the first signal terminal 1431, the signal transmitting circuit 11, the switching circuit 13, and the signal receiving circuit 12. At this time, both the signal transmitting circuit 11 and the signal receiving circuit 12 are connected to the first signal terminal 1431 and the second signal terminal 1432. The user can choose to use either the first signal terminal 1431 or the second signal terminal 1432 as the required signal terminal 143, thereby realizing three-wire communication.

[0031] In one embodiment, combined with Figures 2 to 5 , Figure 2 In another embodiment of the communication circuit 1 of this application, the signal transmitting circuit 11 is connected to the first signal terminal 1431, and the signal receiving circuit 12 is connected to the second signal terminal 1432. The switching circuit 13 includes a first switching circuit 131 and a second switching circuit 132. The first switching circuit 131 is connected between the first signal terminal 1431 and the signal transmitting circuit 11. One end of the second switching circuit 132 is connected between the first switching circuit 131 and the signal transmitting circuit 11, and the other end of the second switching circuit 132 is connected between the second signal terminal 1432 and the signal receiving circuit 12. In the first state, the first switching circuit 131 is on and the second switching circuit 132 is off. In the second state, the first switching circuit 131 is either on or off, and the second switching circuit 132 is on.

[0032] When the board needs to connect to other boards via four-wire communication, the first switching circuit 131 is turned on and the second switching circuit 132 is turned off. At this time, the signal transmitting end TXD1 sends a signal to the first signal terminal pin 1431 in sequence through the signal transmitting circuit 11 and the first switching circuit 131. The signal on the connector 14 is transmitted to the signal receiving end RXD1 in sequence through the second signal terminal pin 1432 and the signal receiving circuit 12.

[0033] When the board needs to connect to other boards via three-wire communication, both the first switching circuit 131 and the second switching circuit 132 can be turned on. In this case, the signal transmitter TXD1 can send a signal to the first signal terminal 1431 sequentially through the signal transmitter circuit 11 and the first switching circuit 131, and also send a signal to the second signal terminal 1432 sequentially through the signal transmitter circuit 11, the second switching circuit 132, and the signal receiver circuit 12. Similarly, the signal on the connector 14 can be transmitted to the signal receiver RXD1 via the second signal terminal 1432 and the signal receiver circuit 12, and can also be transmitted to the signal receiver RXD1 sequentially through the first signal terminal 1431, the first switching circuit 131, the second switching circuit 132, and the signal receiver circuit 12. At this time, both the signal transmitting circuit 11 and the signal receiving circuit 12 are connected to the first signal terminal 1431 and the second signal terminal 1432. The user can choose to use either the first signal terminal 1431 or the second signal terminal 1432 as the signal terminal 143 to be used, thereby realizing three-wire communication.

[0034] When the board needs to connect to other boards via three-wire communication, the first switching circuit 131 can be disconnected, and both the first and second switching circuits 132 can be turned on. In this case, the signal transmitter TXD1 sends a signal to the second signal terminal 1432 sequentially through the signal transmitter circuit 11 and the second switching circuit 132. The signal on the connector 14 is transmitted to the signal receiver RXD1 through the second signal terminal 1432 and the signal receiver circuit 12. At this time, both the signal transmitter circuit 11 and the signal receiver circuit 12 are connected to the second signal terminal 1432, thus achieving three-wire communication.

[0035] In one embodiment, combined with Figure 2 and Figure 3 The first switching circuit 131 includes a first switching resistor R1, and the second switching circuit 132 includes a second switching resistor R2. In the first state, the first switching resistor R1 is engaged, and the second switching resistor R2 is not engaged. In the second state, the first switching resistor R1 is engaged or not engaged, and the second switching resistor R2 is engaged. Figure 2 and Figure 3The example shown illustrates the situation where both the first switching resistor R1 and the second switching resistor R2 are engaged. When the first switching resistor R1 is engaged, the first switching circuit 131 is on; when the first switching resistor R1 is not engaged, the first switching circuit 131 is off. Similarly, when the second switching resistor R2 is engaged, the second switching circuit 132 is on; when the second switching resistor R2 is not engaged, the second switching circuit 132 is off. By controlling whether the first switching resistor R1 and the second switching resistor R2 are engaged or not, the on / off state of the first switching circuit 131 and the second switching circuit 132 can be flexibly controlled, thereby flexibly realizing three-wire or four-wire communication of the communication circuit 1 according to user needs.

[0036] In one embodiment, the first switching resistor R1 and / or the second switching resistor R2 include jumper resistors. Taking the example that both the first switching resistor R1 and the second switching resistor R2 are set as jumper resistors, the setting of jumper resistors can reduce the volume occupied by the first switching resistor R1 and the second switching resistor R2 in the circuit. Furthermore, the jumper resistors can be installed in the communication circuit 1 by a pick-and-place machine, thus improving production efficiency.

[0037] It should be noted that the above refers to... Figure 2 Taking the communication circuit 1 as an example, a first switching resistor R1 is set in the first switching circuit 131, and a second switching resistor R2 is set in the second switching circuit 132. The on / off state of the first switching circuit 131 and the second switching circuit 132 is controlled by whether the first switching resistor R1 and the second switching resistor R2 are engaged or disengaged. Of course, the on / off state of the first switching circuit 131 and the second switching circuit 132 can also be controlled by other methods. For example, switches can be directly set in the first switching circuit 131 and the second switching circuit 132, and the on / off state of the first switching circuit 131 and the second switching circuit 132 can be controlled by opening and closing the switches. The above is not limiting and can be set according to the needs of those skilled in the art. All of the above are within the protection scope of this application.

[0038] It should also be noted that, Figure 1 The communication circuit 1 shown is also implemented by setting a switching resistor in the switching circuit 13. Taking the setting of a second switching resistor R2 in the switching circuit 13 as an example, the on / off state of the switching circuit 13 can be controlled by checking or dispensing the second switching resistor R2. Of course, a switch can also be set on the switching circuit 13, and the on / off state of the switching circuit 13 can be controlled by opening or closing the switch. The above can also be configured according to the needs of those skilled in the art, and all of the above are still within the protection scope of this application.

[0039] For ease of explanation, the following communication circuit 1 will all be referred to as... Figure 2 The following will be introduced using communication circuit 1 as an example.

[0040] In one embodiment, combined with Figure 2 and Figure 4 The communication circuit 1 further includes a power supply terminal and a ground terminal DGND. The signal transmitting circuit 11 includes a first switching transistor 110, which has a first terminal 111, a second terminal 112, and a first control terminal 113. The first terminal 111 of the first switching transistor 110 is connected to the power supply terminal, the second terminal 112 of the first switching transistor 110 is connected to the ground terminal DGND, and the first control terminal 113 is connected to the signal transmitting terminal TXD1. The first switching transistor 110 is turned on or off according to the signal emitted by the signal transmitting terminal TXD1. When the signal transmitting circuit 11 of this application further includes a voltage divider circuit formed by resistors R3 and R4, the second terminal 112 of the first switching transistor 110 is connected to the midpoint of the voltage divider circuit, and resistor R4 is located between the second terminal 112 of the first switching transistor 110 and the ground terminal DGND. When the signal transmitting terminal TXD1 is at a high level, the first switching transistor 110 is turned off. At this time, the signal transmitted by the signal transmitting circuit 11 containing resistor R3 to the first switching circuit 131 or the second switching circuit 132 is a low-level signal. When the signal transmitting terminal TXD1 is at a low level, the first switching transistor 110 is turned on, and the signal transmitted by the signal transmitting circuit 11 containing resistor R3 to the first switching circuit 131 or the second switching circuit 132 is a high-level signal.

[0041] In one embodiment, combined with Figure 2 and Figure 5 The communication circuit 1 further includes a power supply terminal and a ground terminal DGND. The signal receiving circuit 12 includes a second switch 120, which has a first terminal 121, a second terminal 122, and a second control terminal 123. The first terminal 121 of the second switch 120 is connected to the power supply terminal and the signal receiving terminal RXD1, the second terminal 122 is connected to the ground terminal DGND, and the second control terminal 123 is connected to the switching circuit 13. The second switch 120 is turned on or off according to the signal from the second control terminal 123. When the signal receiving circuit 12 of this application further includes a voltage divider circuit formed by resistors R6 and R7, the first terminal 121 of the second switch 120 is connected to the midpoint of the voltage divider circuit, and resistor R7 is located between the first terminal 121 of the second switch 120 and the power supply terminal. When the second control terminal 123 is at a high level, the second switch 120 is turned on, and the signal transmitted from the signal receiving circuit 12 containing resistor R6 to the signal receiving terminal RXD1 is a low-level signal. When the second control terminal 123 is at a low level, the second switch 120 is turned off, and the signal transmitted from the signal receiving circuit 12 containing resistor R6 to the signal receiving terminal RXD1 is a high-level signal.

[0042] In one embodiment, combined with Figure 2 and Figure 5The signal transceiver circuit 10 also includes a filter circuit 15 connected between the second control terminal 123 and the ground terminal DGND. The filter circuit 15 can be an RC low-pass filter circuit 15 formed by capacitor C4 and resistor R5, used to filter out interference signals. Alternatively, the filter circuit 15 can also be an RC low-pass filter circuit 15 formed by capacitor C5 and resistor R6, which can also be used to filter out interference signals.

[0043] In one embodiment, combined with Figure 2 and Figure 3 The communication circuit 1 also includes a power supply terminal, a ground terminal DGND, and a protection circuit 16. The protection circuit 16 is connected between the power supply terminal and the ground terminal DGND. The protection circuit 16 includes a first diode D2 and a second diode D3 connected in series. The midpoint of the first diode D2 and the second diode D3 is connected to a switching circuit 13. When a surge occurs in the communication circuit 1, the protection circuit 16 can instantly dissipate the energy, thereby protecting the subsequent circuits and devices.

[0044] In one embodiment, reference is made to... Figure 2 The communication circuit 1 also includes a bidirectional transient voltage suppressor diode D1, connected between the ground terminal 141 and the power supply terminal 142. The bidirectional transient voltage suppressor diode D1 is used to protect the circuit 16 from damage caused by transient high voltages (such as ESD).

[0045] In one embodiment, reference continues... Figure 2 The communication circuit 1 also includes a capacitor connected between the ground terminal 141 and the power supply terminal 142. The capacitor can be... Figure 2 The capacitors C1, C2, and C3 are connected in parallel between the grounding terminal 141 and the power supply terminal 142. Capacitor C1 is an electrolytic capacitor used to store energy and filter low-frequency ripple. Capacitors C2 and C3 are used to filter high-frequency ripple. Of course, the capacitors can be any one or any two of capacitors C1, C2, and C3. This is not limiting; the capacitors can be configured according to the needs of those skilled in the art, and all of the above are within the scope of protection of this application.

[0046] It should be noted that since capacitor C2 and capacitor C3 have the same function, one of them can be installed in communication circuit 1. When the application environment of communication circuit 1 is relatively harsh, capacitor C2 and capacitor C3 can be installed in communication circuit 1 at the same time.

[0047] The above description is merely a preferred embodiment of this application and is not intended to limit this application. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the scope of protection of this application.

Claims

1. A communication circuit, characterized in that, include: The connector includes a ground terminal pin, a power terminal pin, and a signal terminal pin, wherein the signal terminal pin includes a first signal terminal pin and a second signal terminal pin. Signal transmitting end, used to send signals; Signal receiver, used to receive signals; A signal transceiver circuit includes a signal transmitting circuit and a signal receiving circuit, wherein the signal transmitting circuit is connected to the signal transmitting end; and the signal receiving circuit is connected to the signal receiving end. A switching circuit is connected between the signal transceiver circuit and the signal terminal pin; the switching circuit has a first state and a second state. When the switching circuit is in the first state, the signal transmitting circuit is connected to the first signal terminal pin and disconnected from the second signal terminal pin, and the signal receiving circuit is connected to the second signal terminal pin and disconnected from the first signal terminal pin. When the switching circuit is in the second state, both the signal receiving circuit and the signal transmitting circuit are connected to the same or both of the first signal terminal pin and the second signal terminal pin.

2. The communication circuit according to claim 1, characterized in that, The signal transmitting circuit is connected to the first signal terminal pin, and the signal receiving circuit is connected to the second signal terminal pin; the switching circuit includes a first switching circuit and a second switching circuit, the first switching circuit is connected between the first signal terminal pin and the signal transmitting circuit, one end of the second switching circuit is connected between the first switching circuit and the signal transmitting circuit, and the other end of the second switching circuit is connected between the second signal terminal pin and the signal receiving circuit; When the switching circuit is in the first state, the first switching circuit is turned on and the second switching circuit is turned off. When the switching circuit is in the second state, the first switching circuit is turned on or off, and the second switching circuit is turned on.

3. The communication circuit according to claim 2, characterized in that, The first switching circuit includes a first switching resistor, and the second switching circuit includes a second switching resistor; when the switching circuit is in the first state, the first switching resistor is engaged, and the second switching resistor is not engaged. When the switching circuit is in the second state, the first switching resistor is either active or not active, and the second switching resistor is active.

4. The communication circuit according to claim 3, characterized in that, The first switching resistor and / or the second switching resistor include jumper resistors.

5. The communication circuit according to claim 1, characterized in that, The signal transmitting circuit is connected to the first signal terminal pin, and the signal receiving circuit is connected to the second signal terminal pin; one end of the switching circuit is connected between the first signal terminal pin and the signal transmitting circuit, and the other end of the switching circuit is connected between the second signal terminal pin and the signal receiving circuit. When the switching circuit is in the first state, the switching circuit is disconnected; When the switching circuit is in the second state, the switching circuit is turned on.

6. The communication circuit according to claim 1, characterized in that, The communication circuit further includes a power supply terminal and a ground terminal. The signal transmission circuit includes a first switching transistor, which includes a first terminal, a second terminal, and a first control terminal. The first terminal of the first switching transistor is connected to the power supply terminal, the second terminal of the first switching transistor is connected to the ground terminal, and the first control terminal is connected to the signal transmission terminal.

7. The communication circuit according to claim 1, characterized in that, The communication circuit further includes a power supply terminal and a ground terminal. The signal receiving circuit includes a second switching transistor, which includes a first terminal, a second terminal, and a second control terminal. The first terminal of the second switching transistor is connected to the power supply terminal and the signal receiving terminal, the second terminal of the second switching transistor is connected to the ground terminal, and the second control terminal is connected to the switching circuit.

8. The communication circuit according to claim 7, characterized in that, The signal transceiver circuit also includes a filter circuit connected between the second control terminal and the ground terminal.

9. The communication circuit according to claim 1, characterized in that, The communication circuit further includes a power supply terminal, a ground terminal, and a protection circuit. The protection circuit is connected between the power supply terminal and the ground terminal. The protection circuit includes a first diode and a second diode connected in series, and the midpoint between the first diode and the second diode is connected to the switching circuit.

10. The communication circuit according to claim 1, characterized in that, The communication circuit further includes a bidirectional transient voltage suppression diode connected between the ground terminal and the power supply terminal; and / or, The communication circuit also includes a capacitor connected between the ground terminal and the power terminal.

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