An anti-interference circuit suitable for daisy chain cascade communication between boards

Abstract

The utility model relates to BMS communication technical field discloses a kind of anti-interference circuit suitable for inter-board daisy chain cascading communication, between preceding stage BMS single board and first piece AFE chip unit in board rear stage, including the common mode absorption and isolation unit, RC filter unit and ESD protection unit connected in turn;The common mode absorption and isolation unit is used to connect inter-board daisy chain signal input end, absorption common mode interference in communication signal;The RC filter unit is connected after the common mode absorption and isolation unit, and the signal after common mode absorption processing is filtered to remove noise;The ESD protection unit is used to carry out electrostatic discharge protection to filtered communication signal.By setting common mode absorption and isolation unit and RC filter unit, common mode interference can be effectively absorbed and filtered out noise, improve the anti-interference ability of communication signal, reduce bit error rate, ensure the stability of communication, to enhance anti-interference ability.

Description

Technical Field

[0001] This utility model relates to the field of BMS communication technology, specifically an anti-interference circuit suitable for inter-board daisy-chain cascade communication. Background Technology

[0002] In multi-board cascaded electronic systems, daisy-chain communication is widely used due to its simple wiring and strong scalability. This method allows multiple circuit boards to be connected sequentially to form a serial communication link, enabling data transmission cascaded through each stage.

[0003] However, existing inter-board cascaded daisy-chain communication circuits have the following problems: Weak anti-interference capability: In complex electromagnetic environments, communication signals are easily affected by external electromagnetic interference and noise introduced during inter-board transmission, resulting in signal distortion, increased bit error rate, and in severe cases, even communication interruption.

[0004] Lack of effective protection measures: Existing circuits are not adequately protected against transient interference such as electrostatic discharge (ESD), which may damage sensitive components in the circuit and affect the stability and lifespan of the entire communication system.

[0005] Poor signal integrity: In long-distance cascading or high-speed communication scenarios, problems such as signal attenuation and reflection are more prominent, which degrades signal quality and makes it difficult to guarantee the reliability of communication. Utility Model Content

[0006] The purpose of this utility model is to provide an anti-interference circuit suitable for inter-board daisy-chain cascade communication, and to solve the following technical problems: weak anti-interference capability, insufficient protection and poor signal integrity of inter-board daisy-chain communication circuits.

[0007] The purpose of this utility model can be achieved through the following technical solution: an anti-interference circuit suitable for inter-board daisy-chain cascaded communication, located between the front-end BMS board and the first AFE chip unit of the back-end within the board, including a common-mode absorption and isolation unit, an RC filtering unit and an ESD protection unit connected in sequence. The common-mode absorption and isolation unit is used to connect the signal input terminal of the inter-board daisy chain and absorb common-mode interference in the communication signal. The RC filter unit is connected after the common-mode absorption and isolation unit to filter the signal after the common-mode absorption process to remove noise. The ESD protection unit is used to protect the filtered communication signal from electrostatic discharge. The processed signal is then transmitted to the first AFE chip unit in the subsequent stage of the board.

[0008] As a preferred embodiment of this utility model: the common-mode absorption and isolation unit includes an ACT45B common-mode inductor; the input terminal of the ACT45B common-mode inductor is connected to the output terminal of the daisy-chain communication of the front-end BMS board, and the output terminal is connected to the RC filter unit.

[0009] As a preferred embodiment of this utility model: the common-mode absorption and isolation unit further includes an HMU2103NL isolation transformer; the HMU2103NL isolation transformer and the ACT45B common-mode inductor form a symmetrical common-mode absorption and isolation circuit, and the output terminal of the common-mode inductor inside the secondary side of the isolation transformer is connected to the RC filter unit.

[0010] As a preferred embodiment of this utility model: the RC filter unit includes resistor R1, resistor R2, capacitor C1, and capacitor C4; One end of the resistor R1 is connected to one output terminal of the common-mode absorption and isolation unit, and the other end is connected to one end of the capacitor C1 and one input terminal of the ESD protection unit. The other end of the capacitor C1 is grounded. One end of the resistor R2 is connected to the other output terminal of the common-mode absorption and isolation unit, and the other end is connected to one end of the capacitor C4 and the other input terminal of the ESD protection unit. The other end of the capacitor C4 is grounded.

[0011] As a preferred embodiment of this utility model: the resistance values ​​of resistors R1 and R2 are both 10R and the accuracy is 1%; the parameters of capacitors C1 and C4 are 100pF / 50V.

[0012] As a preferred embodiment of this utility model: the common-mode absorption and isolation unit further includes capacitor C2 and capacitor C3, and the center tap of the HMU2103NL isolation transformer is grounded through capacitor C2 and capacitor C3; the parameters of capacitor C2 are 10nF / 50V, and the parameters of capacitor C3 are 470pF / 100V.

[0013] As a preferred embodiment of this utility model: the ESD protection unit adopts the APTLC05M-B electrostatic protection device; the input terminal of the APTLC05M-B electrostatic protection device is connected to the RC filter unit, and the output terminal of the APTLC05M-B electrostatic protection device is connected to the first AFE chip unit in the subsequent stage of the board.

[0014] The beneficial effects of this utility model are: (1) By setting a common-mode absorption and isolation unit and an RC filter unit, this utility model can effectively absorb common-mode interference and filter out noise, improve the anti-interference capability of communication signals, reduce the bit error rate, ensure the stability of communication, and thus enhance the anti-interference capability.

[0015] (2) The ESD protection unit of this utility model adopts APTLC05M-B electrostatic protection device, which can effectively deal with transient interference such as electrostatic discharge, protect sensitive components in the circuit, extend the service life of the system, and thus improve the protection effect.

[0016] (3) Each unit of this utility model uses mature components, the circuit design is simple, easy to implement and produce, the cost is low, and it is suitable for large-scale application. Attached Figure Description

[0017] The present invention will be further described below with reference to the accompanying drawings.

[0018] Figure 1 This is a structural block diagram of the present invention; Figure 2 This is a schematic diagram of the common mode absorption and isolation unit of this utility model; Figure 3 This is a schematic diagram of the RC filter unit in this utility model; Figure 4 This is a schematic diagram of the ESD protection unit in this utility model.

[0019] Figure descriptions: 1. Front-end BMS board; 2. Common-mode absorption and isolation unit; 3. RC filter unit; 4. ESD protection unit; 5. First AFE signal unit in the subsequent stage of the board. Detailed Implementation

[0020] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of the present utility model.

[0021] Please see Figures 1-4 As shown, this utility model is an anti-interference circuit suitable for daisy-chain cascaded communication between boards, located between the front-end BMS board 1 and the first AFE chip unit 5 of the back-end within the board, including a common-mode absorption and isolation unit 2, an RC filter unit 3 and an ESD protection unit 4 connected in sequence. Common-mode absorption and isolation unit 2 is used to connect the signal input terminal of the inter-board daisy chain to absorb common-mode interference in the communication signal; RC filter unit 3 is connected after common-mode absorption and isolation unit 2 to filter the signal after common-mode absorption to remove noise; ESD protection unit 4 is used to protect the filtered communication signal from electrostatic discharge, and the processed signal is transmitted to the first AFE chip unit 5 in the back stage of the board.

[0022] Common-mode absorption and isolation unit 2 includes an ACT45B common-mode inductor; the input terminal of the ACT45B common-mode inductor is connected to the output terminal of the daisy-chain communication of the front-end BMS board 1, and the output terminal is connected to the RC filter unit 3. Common-mode absorption and isolation unit 2 also includes an HMU2103NL isolation transformer; the HMU2103NL isolation transformer and the ACT45B common-mode inductor form a symmetrical common-mode absorption and isolation circuit, and the output terminal of the common-mode inductor inside the secondary side of the isolation transformer is connected to the RC filter unit 3. The ACT45B common-mode inductor has a strong absorption effect on common-mode signals, while having little impact on differential-mode signals (i.e., useful communication signals). The secondary side of the HMU2103NL isolation transformer is connected to an RC filter unit, and the output of the RC filter unit is connected to an ESD protection unit to absorb common-mode interference received on the inter-board daisy-chain communication link.

[0023] RC filter unit 3 includes resistor R1, resistor R2, capacitor C1, and capacitor C4; One end of resistor R1 is connected to one output terminal of common-mode absorption and isolation unit 2, and the other end is connected to one end of capacitor C1 and one input terminal of ESD protection unit 4. The other end of capacitor C1 is grounded. One end of resistor R2 is connected to the other output terminal of common-mode absorption and isolation unit 2, and the other end is connected to one end of capacitor C4 and the other input terminal of ESD protection unit 4. The other end of capacitor C4 is grounded. Resistors R1 and R2 both have a resistance of 10Ω and a tolerance of 1%; capacitors C1 and C4 have a value of 100pF / 50V. One end of resistors R1 and R2 is connected to the output of common-mode absorption and isolation unit 2, respectively. The other end of resistors R1 and R2 is connected to capacitors C1 and C4 respectively. The ground filter capacitor forms an RC filter circuit, which can further filter out high-frequency noise in the signal and improve signal quality.

[0024] The common-mode absorption and isolation unit 2 also includes capacitors C2 and C3. The center tap of the HMU2103NL isolation transformer is grounded through capacitors C2 and C3. The parameters of capacitor C2 are 10nF / 50V and the parameters of capacitor C3 are 470pF / 100V.

[0025] ESD protection unit 4 uses APTLC05M-B electrostatic protection device; the input terminal of APTLC05M-B electrostatic protection device is connected to RC filter unit 3, and the output terminal of APTLC05M-B electrostatic protection device is connected to the first AFE chip unit 5 in the back stage of the board. The APTLC05M-B electrostatic discharge protection device features low clamping voltage and fast response time, effectively discharging the large current generated by electrostatic discharge to ground and protecting subsequent circuits from damage. The input terminal of the APTLC05M-B electrostatic discharge protection device is connected to an RC filter unit, and the output terminal is connected to the subsequent AFE chip unit 5.

[0026] The working principle of this utility model is as follows: External communication signals enter the common-mode absorption and isolation unit 2, which absorbs common-mode interference in the signal; then the signal enters the RC filtering unit 3, where a low-pass filter composed of RC circuits further filters out high-frequency noise, making the signal purer; then the signal enters the ESD protection unit 4, where the APTLC05M-B electrostatic protection device protects the signal from electrostatic discharge, preventing electrostatic damage to subsequent circuits; finally, the signal after filtering, isolation, and ESD protection is transmitted to the first AFE chip unit 5 on the board, ensuring the stable operation of the entire communication link.

[0027] The above description details one embodiment of the present utility model, but it is merely a preferred embodiment and should not be construed as limiting the scope of the present utility model. All equivalent variations and improvements made within the scope of the present utility model application should still fall within the patent coverage of the present utility model.

Claims

1. An anti-interference circuit suitable for inter-board daisy-chain cascaded communication, located between the front-end BMS board (1) and the first AFE chip unit (5) of the back-end within the board, characterized in that, It includes a common-mode absorption and isolation unit (2), an RC filter unit (3), and an ESD protection unit (4) connected in sequence. The common-mode absorption and isolation unit (2) is used to connect the daisy-chain signal input terminal between boards and absorb common-mode interference in the communication signal; The RC filter unit (3) is connected after the common mode absorption and isolation unit (2) to filter the signal after the common mode absorption process to remove noise; The ESD protection unit (4) is used to protect the filtered communication signal from electrostatic discharge. The processed signal is transmitted to the first AFE chip unit (5) in the back stage of the board.

2. The anti-interference circuit for inter-board daisy-chain cascaded communication according to claim 1, characterized in that, The common-mode absorption and isolation unit (2) includes an ACT45B common-mode inductor; the input terminal of the ACT45B common-mode inductor is connected to the output terminal of the daisy-chain communication of the front-end BMS board (1), and the output terminal is connected to the RC filter unit (3).

3. The anti-interference circuit for inter-board daisy-chain cascaded communication according to claim 2, characterized in that, The common-mode absorption and isolation unit (2) also includes an HMU2103NL isolation transformer; the HMU2103NL isolation transformer and the ACT45B common-mode inductor form a symmetrical common-mode absorption and isolation circuit, and the output terminal of the common-mode inductor inside the secondary side of the isolation transformer is connected to the RC filter unit (3).

4. The anti-interference circuit for inter-board daisy-chain cascaded communication according to claim 1, characterized in that, The RC filter unit (3) includes resistor R1, resistor R2, capacitor C1, and capacitor C4; One end of the resistor R1 is connected to one output terminal of the common mode absorption and isolation unit (2), and the other end is connected to one end of the capacitor C1 and one input terminal of the ESD protection unit (4). The other end of the capacitor C1 is grounded. One end of the resistor R2 is connected to the other output terminal of the common mode absorption and isolation unit (2), and the other end is connected to one end of the capacitor C4 and the other input terminal of the ESD protection unit (4). The other end of the capacitor C4 is grounded.

5. An anti-interference circuit suitable for inter-board daisy-chain cascaded communication according to claim 4, characterized in that, The resistance values ​​of resistors R1 and R2 are both 10R with an accuracy of 1%; the parameters of capacitors C1 and C4 are 100pF / 50V.

6. The anti-interference circuit for inter-board daisy-chain cascaded communication according to claim 3, characterized in that, The common-mode absorption and isolation unit (2) also includes capacitors C2 and C3. The center tap of the HMU2103NL isolation transformer is grounded through capacitors C2 and C3. The parameters of capacitor C2 are 10nF / 50V and the parameters of capacitor C3 are 470pF / 100V.

7. The anti-interference circuit for inter-board daisy-chain cascaded communication according to claim 1, characterized in that, The ESD protection unit (4) adopts the APTLC05M-B electrostatic protection device; the input terminal of the APTLC05M-B electrostatic protection device is connected to the RC filter unit (3), and the output terminal of the APTLC05M-B electrostatic protection device is connected to the first AFE chip unit (5) in the back stage of the board.

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