Full-duplex high-speed serial communication circuit

Abstract

The utility model relates to the field of serial communication, in particular to a full-duplex high-speed serial communication circuit. According to the technical scheme, a first pin of a first bus transceiver chip is connected with a control module, a second pin and a third pin are connected with a reference ground of an RS-485 bus through a first resistor, a seventh pin is connected with a first port of a first common mode inductor through a fourth resistor, and a sixth pin is connected with a third port of the first common mode inductor through a fifth resistor; a second port of the first common-mode inductor is connected with a second pin of the first bidirectional transient voltage suppression diode array, a fourth port of the first common-mode inductor is connected with a first pin of the first bidirectional transient voltage suppression diode array, and the second port and the fourth port of the first common-mode inductor receive differential signals of communication parties. The utility model is suitable for full-duplex high-speed serial communication.

Description

Technical Field

[0001] This utility model relates to the field of serial communication, specifically to a full-duplex high-speed serial communication circuit. Background Technology

[0002] In the field of high-speed data communication, full-duplex serial communication technology is the core means to achieve bidirectional real-time data transmission and is widely used in data centers, industrial automation, automotive electronics, and consumer electronics. Traditional parallel communication is difficult to meet the requirements of high-speed, long-distance transmission due to problems such as signal synchronization difficulties, complex wiring, and electromagnetic interference (EMI). Serial communication, through differential signal transmission, clock embedding technology, and efficient coding schemes, significantly improves the reliability and bandwidth utilization of the system.

[0003] Current serial communication standards (such as RS-232) are limited by single-ended signal transmission, resulting in poor anti-interference capabilities and low data rates (typically <20kbps). While technological advancements have increased communication rates to Gbps levels, common-mode noise and security issues still exist. Utility Model Content

[0004] The purpose of this invention is to overcome the shortcomings of the prior art and provide a full-duplex high-speed serial communication circuit that greatly reduces common-mode noise and improves circuit safety.

[0005] The present invention adopts the following technical solution to achieve the above objectives. The present invention provides a full-duplex high-speed serial communication circuit, including a first CAN bus transceiver chip U1, a first common-mode inductor L1, a first bidirectional transient voltage suppression diode array U2, a first resistor R1, a second resistor R2, a third resistor R3, a fourth resistor R4, a fifth resistor R5, and a sixth resistor R6.

[0006] The first pin of the first CAN bus transceiver chip U1 is connected to the control module. The second and third pins of the first CAN bus transceiver chip U1 are connected and connected to the reference ground of the RS-485 bus through the first resistor R1. The eighth pin of the first CAN bus transceiver chip U1 is connected to the power supply voltage terminal of the RS-485 bus. The fifth pin of the first CAN bus transceiver chip U1 is connected to the reference ground of the RS-485 bus. The seventh pin of the first CAN bus transceiver chip U1 is connected to the first port 1 of the first common mode inductor L1 through the fourth resistor R4. The seventh pin of the first CAN bus transceiver chip U1 is also connected to the reference ground of the RS-485 bus through the third resistor R3. The sixth pin of the first CAN bus transceiver chip U1 is connected to the third port 3 of the first common mode inductor L1 through the fifth resistor R5. The sixth pin of the first CAN bus transceiver chip U1 is also connected to the power supply voltage terminal of the RS-485 bus through the second resistor R2. The sixth resistor R6 is connected between the sixth and seventh pins of the first CAN bus transceiver chip U1.

[0007] The second pin of the first bidirectional transient voltage suppressor diode array U2 is connected to the second port 2 of the first common-mode inductor L1 and the positive terminal 422R+ of the RS-422 differential communication interface. The first pin of the first bidirectional transient voltage suppressor diode array U2 is connected to the fourth port 4 of the first common-mode inductor L1 and the negative terminal 422R- of the RS-422 differential communication interface. The third pin of the first bidirectional transient voltage suppressor diode array U2 is connected to the reference ground of the RS-485 bus.

[0008] Furthermore, the circuit also includes a second CAN bus transceiver chip U3, a second common-mode inductor L2, a second bidirectional transient voltage suppressor diode array U4, a seventh resistor R7, an eighth resistor R8, a ninth resistor R9, a tenth resistor R10, an eleventh resistor R11, and a twelfth resistor R12.

[0009] The second and third pins of the second CAN bus transceiver chip U3 are connected, and are connected to the RS-485 bus power supply voltage terminal through the seventh resistor R7. The fourth pin of the second CAN bus transceiver chip U3 is connected to the control module. The eighth pin of the second CAN bus transceiver chip U3 is connected to the RS-485 bus power supply voltage terminal. The fifth pin of the second CAN bus transceiver chip U3 is connected to the reference ground of the RS-485 bus. The seventh pin of the second CAN bus transceiver chip U3 is connected to the first port 1 of the second common mode inductor L2 through the tenth resistor R10. The seventh pin of the second CAN bus transceiver chip U3 is also connected to the reference ground of the RS-485 bus through the ninth resistor R9. The sixth pin of the second CAN bus transceiver chip U3 is connected to the third port 3 of the second common mode inductor L2 through the eleventh resistor R11. The sixth pin of the second CAN bus transceiver chip U3 is also connected to the RS-485 bus power supply voltage terminal through the eighth resistor R8. The twelfth resistor R12 is connected between the sixth and seventh pins of the second CAN bus transceiver chip U3.

[0010] The second pin of the second bidirectional transient voltage suppressor diode array U4 is connected to the second port 2 of the second common-mode inductor L2 and to the positive terminal 422T+ of the RS-422 differential communication interface. The first pin of the second bidirectional transient voltage suppressor diode array U4 is connected to the fourth port 4 of the second common-mode inductor L2 and to the negative terminal 422T- of the RS-422 differential communication interface. The third pin of the second bidirectional transient voltage suppressor diode array U4 is connected to the reference ground of the RS-485 bus.

[0011] The beneficial effects of this utility model are:

[0012] This invention uses a common-mode inductor to suppress common-mode noise in signals and improve signal quality.

[0013] This invention adds a bidirectional transient voltage suppression diode array to the RS-422 differential communication interface to protect the circuit from damage caused by electrostatic discharge, surge voltage, and transient overvoltage, thereby further improving circuit safety. Attached Figure Description

[0014] Figure 1 This is a schematic diagram of a full-duplex high-speed serial communication circuit structure provided by an embodiment of this utility model. Detailed Implementation

[0015] To make the objectives, technical solutions, and advantages of the embodiments of this utility model clearer, the technical solutions of the embodiments of this utility model will be clearly and completely described below with reference to the accompanying drawings.

[0016] This utility model provides a full-duplex high-speed serial communication circuit, such as Figure 1 As shown, it includes a first CAN bus transceiver chip U1, a second CAN bus transceiver chip U3, a first common-mode inductor L1, a second common-mode inductor L2, a first bidirectional transient voltage suppressor diode array U2, a second bidirectional transient voltage suppressor diode array U4, a first resistor R1, a second resistor R2, a third resistor R3, a fourth resistor R4, a fifth resistor R5, a sixth resistor R6, a seventh resistor R7, an eighth resistor R8, a ninth resistor R9, a tenth resistor R10, an eleventh resistor R11, and a twelfth resistor R12.

[0017] The first pin of the first CAN bus transceiver chip U1 is connected to the control module. The second and third pins of the first CAN bus transceiver chip U1 are connected and connected to the reference ground of the RS-485 bus through the first resistor R1. The eighth pin of the first CAN bus transceiver chip U1 is connected to the power supply voltage terminal of the RS-485 bus. The fifth pin of the first CAN bus transceiver chip U1 is connected to the reference ground of the RS-485 bus. The seventh pin of the first CAN bus transceiver chip U1 is connected to the first port 1 of the first common mode inductor L1 through the fourth resistor R4. The seventh pin of the first CAN bus transceiver chip U1 is also connected to the reference ground of the RS-485 bus through the third resistor R3. The sixth pin of the first CAN bus transceiver chip U1 is connected to the third port 3 of the first common mode inductor L1 through the fifth resistor R5. The sixth pin of the first CAN bus transceiver chip U1 is also connected to the power supply voltage terminal of the RS-485 bus through the second resistor R2. The sixth resistor R6 is connected between the sixth and seventh pins of the first CAN bus transceiver chip U1.

[0018] The second pin of the first bidirectional transient voltage suppressor diode array U2 is connected to the second port 2 of the first common-mode inductor L1 and the positive terminal 422R+ of the RS-422 differential communication interface. The first pin of the first bidirectional transient voltage suppressor diode array U2 is connected to the fourth port 4 of the first common-mode inductor L1 and the negative terminal 422R- of the RS-422 differential communication interface. The third pin of the first bidirectional transient voltage suppressor diode array U2 is connected to the reference ground of the RS-485 bus.

[0019] The second and third pins of the second CAN bus transceiver chip U3 are connected, and are connected to the RS-485 bus power supply voltage terminal through the seventh resistor R7. The fourth pin of the second CAN bus transceiver chip U3 is connected to the control module. The eighth pin of the second CAN bus transceiver chip U3 is connected to the RS-485 bus power supply voltage terminal. The fifth pin of the second CAN bus transceiver chip U3 is connected to the reference ground of the RS-485 bus. The seventh pin of the second CAN bus transceiver chip U3 is connected to the first port 1 of the second common mode inductor L2 through the tenth resistor R10. The seventh pin of the second CAN bus transceiver chip U3 is also connected to the reference ground of the RS-485 bus through the ninth resistor R9. The sixth pin of the second CAN bus transceiver chip U3 is connected to the third port 3 of the second common mode inductor L2 through the eleventh resistor R11. The sixth pin of the second CAN bus transceiver chip U3 is also connected to the RS-485 bus power supply voltage terminal through the eighth resistor R8. The twelfth resistor R12 is connected between the sixth and seventh pins of the second CAN bus transceiver chip U3.

[0020] The second pin of the second bidirectional transient voltage suppressor diode array U4 is connected to the second port 2 of the second common-mode inductor L2 and to the positive terminal 422T+ of the RS-422 differential communication interface. The first pin of the second bidirectional transient voltage suppressor diode array U4 is connected to the fourth port 4 of the second common-mode inductor L2 and to the negative terminal 422T- of the RS-422 differential communication interface. The third pin of the second bidirectional transient voltage suppressor diode array U4 is connected to the reference ground of the RS-485 bus.

[0021] Working principle of this utility model:

[0022] This utility model's full-duplex high-speed serial communication circuit uses two sets of high-speed RS422 / 485 bus transceiver chips, one set responsible for receiving differential signals and the other set responsible for transmitting differential signals, realizing full-duplex transmission of differential signals and significantly improving the communication rate.

[0023] In the differential signal receiving circuit, the differential signal from the communicating partner is input via the bus. This signal first passes through a bidirectional transient voltage suppressor diode to suppress excessively high transient voltages, thus providing overvoltage protection for the bus transceiver chip. The signal then passes through a common-mode inductor to suppress common-mode noise and improve signal quality. The signal continues through a series resistor for overcurrent protection and pull-up / pull-down resistors to stabilize the signal level. Finally, the signal enters the RS422 / 485 bus transceiver chip, where the differential signal is converted to a TTL level signal for further transmission to the CPU (Central Processing Unit).

[0024] In the differential signal transmission circuit, the TTL level signal to be transmitted is first obtained from the CPU. Then, the RS422 / 485 bus transceiver chip converts the TTL level signal into a differential signal. Pull-up and pull-down resistors and series resistors are used to ensure the stability of the differential signal level. Common-mode noise is further suppressed by a common-mode inductor before being sent to the bus. A bidirectional transient voltage suppression diode suppresses excessively high transient voltages on the bus, thereby achieving overvoltage protection for the bus transceiver chip.

[0025] The above description is merely a preferred embodiment of this utility model. It should be understood that this utility model is not limited to the forms disclosed herein and should not be construed as excluding other embodiments. It can be used in various other combinations, modifications, and environments, and can be altered within the scope of the concept described herein through the above teachings or related technologies or knowledge. Modifications and variations made by those skilled in the art that do not depart from the spirit and scope of this utility model should be protected within the scope of the appended claims.

Claims

1. A full-duplex high-speed serial communication circuit, characterized in that, It includes a first CAN bus transceiver chip (U1), a first common-mode inductor (L1), a first bidirectional transient voltage suppressor diode array (U2), a first resistor (R1), a second resistor (R2), a third resistor (R3), a fourth resistor (R4), a fifth resistor (R5), and a sixth resistor (R6); The first pin of the first CAN bus transceiver chip (U1) is connected to the control module. The second and third pins of the first CAN bus transceiver chip (U1) are connected and, through the first resistor (R1), to the reference ground of the RS-485 bus. The eighth pin of the first CAN bus transceiver chip (U1) is connected to the RS-485 bus power supply voltage terminal. The fifth pin of the first CAN bus transceiver chip (U1) is connected to the reference ground of the RS-485 bus. The seventh pin of the first CAN bus transceiver chip (U1) is connected to the first common-mode inductor (L1) through the fourth resistor (R4). The first port (1) is connected, the seventh pin of the first CAN bus transceiver chip (U1) is also connected to the reference ground of the RS-485 bus through the third resistor (R3), the sixth pin of the first CAN bus transceiver chip (U1) is connected to the third port (3) of the first common mode inductor (L1) through the fifth resistor (R5), the sixth pin of the first CAN bus transceiver chip (U1) is also connected to the RS-485 bus power supply voltage terminal through the second resistor (R2), and the sixth resistor (R6) is connected between the sixth pin and the seventh pin of the first CAN bus transceiver chip (U1); The second pin of the first bidirectional transient voltage suppressor diode array (U2) is connected to the second port (2) of the first common mode inductor (L1) and the positive terminal (422R+) of the RS-422 differential communication interface. The first pin of the first bidirectional transient voltage suppressor diode array (U2) is connected to the fourth port (4) of the first common mode inductor (L1) and the negative terminal (422R-) of the RS-422 differential communication interface. The third pin of the first bidirectional transient voltage suppressor diode array (U2) is connected to the reference ground of the RS-485 bus.

2. The full-duplex high-speed serial communication circuit according to claim 1, characterized in that, The circuit also includes a second CAN bus transceiver chip (U3), a second common-mode inductor (L2), a second bidirectional transient voltage suppressor diode array (U4), a seventh resistor (R7), an eighth resistor (R8), a ninth resistor (R9), a tenth resistor (R10), an eleventh resistor (R11), and a twelfth resistor (R12). The second and third pins of the second CAN bus transceiver chip (U3) are connected, and are also connected to the RS-485 bus power supply voltage terminal through the seventh resistor (R7). The fourth pin of the second CAN bus transceiver chip (U3) is connected to the control module. The eighth pin of the second CAN bus transceiver chip (U3) is connected to the RS-485 bus power supply voltage terminal. The fifth pin of the second CAN bus transceiver chip (U3) is connected to the RS-485 bus reference ground. The seventh pin of the second CAN bus transceiver chip (U3) is connected to the second common-mode inductor (L2) through the tenth resistor (R10). The first port (1) is connected, the seventh pin of the second CAN bus transceiver chip (U3) is also connected to the reference ground of the RS-485 bus through the ninth resistor (R9), the sixth pin of the second CAN bus transceiver chip (U3) is connected to the third port (3) of the second common mode inductor (L2) through the eleventh resistor (R11), the sixth pin of the second CAN bus transceiver chip (U3) is also connected to the RS-485 bus power supply voltage terminal through the eighth resistor (R8), and the twelfth resistor (R12) is connected between the sixth and seventh pins of the second CAN bus transceiver chip (U3); The second pin of the second bidirectional transient voltage suppressor diode array (U4) is connected to the second port (2) of the second common mode inductor (L2) and to the positive terminal (422T+) of the RS-422 differential communication interface. The first pin of the second bidirectional transient voltage suppressor diode array (U4) is connected to the fourth port (4) of the second common mode inductor (L2) and to the negative terminal (422T-) of the RS-422 differential communication interface. The third pin of the second bidirectional transient voltage suppressor diode array (U4) is connected to the reference ground of the RS-485 bus.

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