A dual-wire Ethernet repeater circuit

Abstract

This invention relates to dual-wire Ethernet power and data transmission in smart factories, specifically to a dual-wire Ethernet repeater circuit, including an input-side EMI filter circuit, a DC transmission circuit, a data signal transmission circuit, an isolation-side EMI filter circuit, and an output-side EMI filter circuit. The input-side EMI filter circuit is used for input-side common-mode voltage suppression and power-on current limiting; the DC transmission circuit is used to transmit and enhance DC power and inductor energy storage freewheeling current; the data signal transmission circuit is used to transmit and relay high-frequency data signals; the isolation-side EMI filter circuit is used for common-mode voltage suppression on both the primary and secondary sides of the network transformer; and the output-side EMI filter circuit is used for output-side common-mode voltage suppression. This invention significantly enhances anti-interference capabilities, strengthens data signals, improves DC voltage levels, and extends the transmission distance of DC power and data signals through DC power, various circuits, and shielding layers.

Description

Technical Field

[0001] This invention relates to a dual-wire Ethernet power and data transmission (PoDL) system for smart factories, specifically a dual-wire Ethernet relay circuit. Background Technology

[0002] IEEE 802.3cg-2019 is the IEEE Ethernet standard. Amendment 5, made in November 2019, specifies physical layer specifications and management parameters for 10Mb / s operation and associated power transfer over a single pair of balanced conductors. This amendment to IEEE standard 802.3-2018 adds clauses and appropriate modifications to increase physical layer (PHY) specifications and management parameters for 10Mb / s operation over a single pair of balanced conductors, as well as related optional power supplies. The IEEE 802.3cg standard, also known as 10BASE-T1L, is an industrial Ethernet network protocol. This protocol breaks down the barriers between basic operational equipment (sensors, valves, actuators, and controls) performing front-line services in the factory and the enterprise data, bit and byte libraries that enable smart factories. 10BASE-T1L networks will be a significant driver of the shift towards data- and analytics-driven factory operating models, a trend known as Industry 4.0. The IEEE 802.3cg standard marks a significant shift in how factory operators can connect devices at the network edge, no longer limited by infrastructure based on traditional 4mA to 20mA and HART communication interfaces.

[0003] 10BASE-T1L connectivity offers the following features: Maximum data rates of 10 Mbps over cables up to 1 km long; up to 500 mW of power to endpoints in intrinsically safe Zone 0 applications, enabling operation of a wider range of more complex endpoints than supported by 4mA to 20mA or HART systems; up to 60 W of power to non-intrinsically safe applications, depending on cabling; the ability to reuse existing, installed twisted-pair cabling; extensive device management options, including providing diagnostic data from connected devices and providing software updates; and an Internet Protocol (IP) address for each node, extending IoT capabilities to the edge of the factory network. Nodes can be monitored and managed remotely via IP addresses. Implementing 10BASE-T1L devices is typically straightforward, as the physical medium for 10BASE-T1L communication is a single twisted-pair cable. It is even possible to use the same cable for 4mA to 20mA or HART communication. The 802.3cg standard supports installation in hazardous (explosion-proof) environments. The network transformer uses a differential-mode coupled coil to couple and filter the differential signal from the PHY to enhance the signal, and then couples it to the other end of the network cable through electromagnetic field conversion. This not only transmits the signal without a physical connection between the network cable and the PHY, but also isolates the DC component of the signal, allowing data transmission between devices with different 0V levels. The network transformer itself has a withstand voltage of 2kV to 3kV and also provides lightning protection. Isolation transformers meet the insulation requirements of IEEE 802.3, but cannot suppress EMI. In a twisted pair cable, each conductor is intertwined in a double helix structure. The magnetic field generated by the current flowing through each conductor is constrained by the helix shape. The direction of the current flowing through each conductor in the twisted pair determines the degree of noise emission from each pair. The emission levels caused by differential-mode and common-mode currents flowing through each pair of conductors are different; the noise emission caused by differential-mode current is relatively small, so the noise is mainly determined by the common-mode current.

[0004] The cable shield can act as a simple isolation layer reflecting noise energy, or it can absorb noise and conduct it to the ground, becoming a return path for the noise signal. Braided shielding, typically made of bare copper or tinned copper wire, provides a low-impedance grounding path for electromagnetic noise and can be crimped or soldered when using connectors. The shielding layer ensures that the signal is not affected by external electromagnetic interference, allowing for longer transmission distances.

[0005] To further extend the 10BASE-T1L transmission distance, a network transformer relay scheme can be adopted. The relay scheme must have the following functions: (1) decoupling and coupling circuits for DC power and data signals, inductor energy storage and freewheeling mechanism, and power-on current limiting mechanism; (2) network transformer isolation and drive circuit; (3) common-mode voltage EMI filtering circuits on the input side, isolation side, and output side. On the other hand, IEEE 802.3cg-2019 stipulates that the power supply voltage of PSE (Power Supply Equipment) is 44-57V, and the voltage level cannot be increased. If the load is heavy, the line voltage drop is very large, the voltage received by the load is low, so the supply current increases, resulting in a larger line voltage drop and an even lower voltage received by the load. In view of this, it is necessary to adopt intermediate voltage boosting technology to increase the power supply voltage level of the downstream line, thereby reducing line loss and extending the power supply distance.

[0006] However, in the field of smart factory dual-line Ethernet power and data transmission (PoDL) technology, after searching, no publicly available passive high-efficiency dual-line Ethernet relay circuits and power supply voltage boosting circuits with the above functions, as well as decoupling and coupling circuits between the two, have been found. It is necessary to re-develop and redesign them specifically. Summary of the Invention

[0007] To address the shortcomings of existing technologies, this invention provides a dual-wire Ethernet repeater circuit, including an input-side EMI filter circuit, a DC transmission circuit, a data signal transmission circuit, an isolation-side EMI filter circuit, and an output-side EMI filter circuit. The input-side EMI filter circuit is used for input-side common-mode voltage suppression and power-on current limiting; the DC transmission circuit is used to transmit and boost DC power and inductor energy storage freewheeling current; the data signal transmission circuit is used to transmit and relay high-frequency data signals; the isolation-side EMI filter circuit is used for common-mode voltage suppression on both the primary and secondary sides of the network transformer; and the output-side EMI filter circuit is used for output-side common-mode voltage suppression.

[0008] Furthermore, the input-side EMI filter circuit includes a first NTC resistor, a second NTC resistor, a first transient voltage suppressor, and a first common-mode rejection coil. One end of the first NTC resistor is connected to the input terminal of the differential data signal, and the other end is connected to one end of the first transient voltage suppressor and the first pin of the first common-mode rejection coil. One end of the second NTC resistor is connected to the input terminal of the DC power supply, and the other end is connected to the other end of the first transient voltage suppressor and the second pin of the first common-mode rejection coil. The third and fourth pins of the first common-mode rejection coil serve as the input terminals of the data signal transmission circuit.

[0009] Furthermore, the DC transmission circuit includes first to third inductors, first to fourth diodes, a first control driver, a first resistor, a second resistor, a first power switch, a first potentiometer, a fifth capacitor, and a sixth capacitor. One end of the first inductor and the cathode of the third diode are connected to one input terminal of the data signal transmission circuit, and one end of the second inductor and the anode of the fourth diode are connected to one output terminal of the data signal transmission circuit. One end of the fifth capacitor, the anode of the first diode, pin 2 of the first control driver, one end of the first resistor, one end of the sixth capacitor, one end of the first potentiometer, another input terminal of the data signal transmission circuit, and another output terminal of the data signal transmission circuit are connected together. The first diode, the other end of the first inductor, one end of the third inductor, the other end of the fifth capacitor, the cathode of the first diode, and the first pin of the first control driver are connected together; the other end of the third inductor is connected to the anode of the second diode and the drain of the first power switch; the cathode of the second diode, the cathode of the fourth diode, one end of the second resistor, the other end of the second inductor, and the other end of the sixth capacitor are connected together; the other end of the second resistor, the other end of the first potentiometer, and the fourth pin of the first control driver are connected together; the gate of the first power switch is connected to the fifth pin of the first control driver; the source of the first power switch, the other end of the first resistor, and the third pin of the first control driver are connected together.

[0010] Furthermore, the data signal transmission circuit includes first to fourth capacitors and a first network transformer. One end of the first capacitor and the second capacitor serve as two input terminals of the data signal transmission circuit, and the other ends of the first capacitor and the second capacitor are connected to the input terminals of the first network transformer, respectively. The output terminals of the first network transformer are connected to one end of the third capacitor and the fourth capacitor, and the other ends of the third capacitor and the fourth capacitor serve as two output terminals of the data signal transmission circuit.

[0011] Furthermore, the isolation-side EMI filter circuit includes third to eighth resistors, a seventh capacitor, and an eighth capacitor. One end of the third resistor is located between the second capacitor and one of the input terminals of the first network transformer, and its other end is connected to one end of the seventh capacitor, one end of the fifth resistor, and one end of the sixth resistor, respectively. The other end of the fifth resistor is located between the first capacitor and the other input terminal of the first network transformer, and the other end of the sixth resistor is connected to the other end of the seventh capacitor and grounded. One end of the seventh resistor is located between the fourth capacitor and one of the output terminals of the first network transformer, and its other end is connected to one end of the fourth resistor, one end of the eighth resistor, and one end of the eighth capacitor, respectively. The other end of the fourth resistor is located between the third capacitor and the other output terminal of the first network transformer, and the other end of the eighth resistor is connected to the other end of the eighth capacitor and grounded.

[0012] In another implementation, if the network transformer in the data signal transmission circuit is a tapped network transformer, then the isolation-side EMI filter circuit includes a third resistor, a fourth resistor, a seventh capacitor, and an eighth capacitor. The primary center tap of the tapped network transformer is connected to one end of the third resistor, the other end of the third resistor is connected to one end of the seventh capacitor, and the other end of the seventh capacitor is grounded. The secondary center tap of the tapped network transformer is connected to one end of the fourth resistor, the other end of the fourth resistor is connected to one end of the eighth capacitor, and the other end of the eighth capacitor is grounded.

[0013] Furthermore, the output-side EMI filter circuit includes a third NTC resistor, a fourth NTC resistor, a second transient voltage suppressor, and a second common-mode rejection coil. The first and second output terminals of the data signal transmission circuit are respectively connected to the two input ports of the second common-mode rejection coil. One output terminal of the second common-mode rejection coil is connected to one end of the second transient voltage suppressor and the third NTC resistor, and the other end of the third NTC resistor serves as the output terminal of the differential data signal. The other output terminal of the second common-mode rejection coil is connected to one end of the second transient voltage suppressor and the fourth NTC resistor, and the other end of the fourth NTC resistor serves as the output terminal of the DC power.

[0014] In another implementation scheme, the DC transmission circuit includes a first resistor, a second resistor, a fifth capacitor, a sixth capacitor, a first inductor, a second inductor, and first to fourth diodes. One end of the first resistor is connected to one end of the fifth capacitor and one end of the first inductor, and then connected to the first input terminal of the data signal transmission circuit. The other end of the first resistor is connected to the other end of the fifth capacitor and then connected to the cathode of the first diode. The anode of the first diode is connected to the cathode of the second diode. The anode of the second diode is connected to the other end of the first inductor and then connected to the first output terminal of the data signal transmission circuit. One end of the second resistor is connected to one end of the sixth capacitor and one end of the second inductor, and then connected to the second input terminal of the data signal transmission circuit. The other end of the second resistor is connected to the other end of the sixth capacitor and then connected to the cathode of the third diode. The anode of the third diode is connected to the cathode of the fourth diode. The anode of the fourth diode is connected to the other end of the second inductor and then connected to the second output terminal of the data signal transmission circuit.

[0015] Compared with the prior art, the dual-wire Ethernet repeater circuit provided by the present invention has the following beneficial effects:

[0016] (1) Capacitors (C1~C2) and inductors (L1) form a decoupling circuit between DC voltage and data signal, and capacitors (C3~C4) and inductors (L2) form a coupling circuit between DC voltage and data signal.

[0017] (2) After the DC voltage and data signal are decoupled, they are coupled together again. The network transformer isolates and drives the data signal, while the boost DC-DC converter increases the DC voltage level to achieve the purpose of bidirectional Ethernet relay and extend the transmission distance of power and data signals.

[0018] (3) The input side, isolation side and output side common mode suppression circuit can effectively suppress the interference of the working mode voltage at each point. In addition, the dual-line Ethernet relay circuit also has essential functions such as power-on current limiting, transient voltage suppression and inductor freewheeling. The inductor freewheeling circuit is mainly used to absorb the inductive surge voltage generated when the system is powered off or when the load current is discontinuous.

[0019] (4) The entire passive circuit is ingeniously designed, simple in structure, complete in function, good in performance and low in cost. Attached Figure Description

[0020] Figure 1 This is one of the variations of a two-wire Ethernet relay circuit provided in the embodiments of the present invention;

[0021] Figure 2 This is a second variation of a two-wire Ethernet relay circuit provided in an embodiment of the present invention;

[0022] Figure 3 This is a third variation of a two-wire Ethernet relay circuit provided in the embodiments of the present invention;

[0023] Wherein, R1 is the first resistor; R2 is the second resistor; R3 is the third resistor; R4 is the fourth resistor; R5 is the fifth resistor; R6 is the sixth resistor; R7 is the seventh resistor; R8 is the eighth resistor; P1 is the first potentiometer; C1 is the first capacitor; C2 is the second capacitor; C3 is the third capacitor; C4 is the fourth capacitor; C5 is the fifth capacitor; C6 is the sixth capacitor; C7 is the seventh capacitor; C8 is the eighth capacitor; D1 is the first diode; D2 is the second diode; D3 is the third diode; D4 is the fourth diode; S1 is the first power switch; C D1, First control driver; NTC1, First NTC resistor; NTC2, Second NTC resistor; NTC3, Third NTC resistor; NTC4, Fourth NTC resistor; TVS1, First transient voltage suppressor; TVS2, Second transient voltage suppressor; CH1, First common-mode rejection coil; CH2, Second common-mode rejection coil; TR1, First network transformer; L1, First inductor; L2, Second inductor; L3, Third inductor; L4, Fourth inductor; CS1, First current sensor; CD1, First control driver. Detailed Implementation

[0024] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0025] This invention provides a dual-wire Ethernet repeater circuit, including an input-side EMI filter circuit, a DC transmission circuit, a data signal transmission circuit, an isolation-side EMI filter circuit, and an output-side EMI filter circuit. The input-side EMI filter circuit is used for input-side common-mode voltage suppression and power-on current limiting; the DC transmission circuit is used for transmitting and boosting DC power and inductor energy storage freewheeling current; the data signal transmission circuit is used for transmitting and relaying high-frequency data signals; the isolation-side EMI filter circuit is used for common-mode voltage suppression on both the primary and secondary sides of the network transformer; and the output-side EMI filter circuit is used for output-side common-mode voltage suppression.

[0026] In this embodiment, a dual-wire Ethernet repeater circuit is provided, specifically including an input-side EMI filter circuit 1, a DC transmission circuit 2, a data signal transmission circuit 3, an isolation-side EMI filter circuit 4, and an output-side EMI filter circuit 5. The input-side EMI filter circuit 1 is responsible for input-side common-mode voltage suppression and power-on current limiting; the DC transmission circuit 2 is responsible for transmitting and boosting DC power and inductor energy storage freewheeling; the data signal transmission circuit 3 is responsible for transmitting and relaying high-frequency data signals; the isolation-side EMI filter circuit 4 is responsible for common-mode voltage suppression on both the primary and secondary sides of the network transformer; and the output-side EMI filter circuit 5 is responsible for output-side common-mode voltage suppression. Figure 1 PS1 and NS1 are the input terminals for differential data signals and DC power, with PS1 being the positive DC terminal and NS1 the negative DC terminal. PS2 and NS2 are the output terminals for differential data signals and DC power, with PS2 being the positive DC terminal and NS2 the negative DC terminal. In the long-distance dual-wire Ethernet power and data simultaneous transmission architecture (PoDL), the decoupling and coupling circuits for DC power and data signals, the network transformer drive circuit, and the EMI filter circuit greatly enhance the anti-interference capability, strengthen the data signal, and extend the transmission distance without affecting DC power transmission.

[0027] As an alternative implementation scheme, such as Figure 1The input-side EMI filter circuit 1 includes two NTC resistors, namely the first NTC resistor NTC1 and the second NTC resistor NTC2, a first transient voltage suppressor TVS1, and a first common-mode rejection coil CH1. One end of the first NTC resistor NTC1 is connected to PS1, and the other end is connected to one end of the first transient voltage suppressor TVS1 and the first pin of the first common-mode rejection coil CH1. One end of the second NTC resistor NTC2 is connected to NS1, and the other end is connected to the other end of the first transient voltage suppressor TVS1 and the second pin of the first common-mode rejection coil CH1. The fourth pin of the first common-mode rejection coil CH1 is connected to point A, and the third pin of the first common-mode rejection coil CH1 is connected to point B. Points A and B are the two input terminals of the data signal transmission circuit 3. In this circuit, the first NTC resistor NTC1 and the second NTC resistor NTC2 are used to limit the current in the DC circuit when the circuit is powered on, to prevent overcurrent in the powered devices, and to prevent overcurrent in the first to fourth capacitors (C1 to C4) and large current and high voltage in the network transformer windings during power-on. After the DC circuit is working, the resistance value is close to zero. The first transient voltage suppressor (TVS1) is used to limit voltage spikes between the two lines, and the first common mode suppression coil (CH1) is used to suppress interference caused by common mode voltage.

[0028] x is an optional implementation scheme, such as Figure 1The DC transmission circuit 2 includes two resistors, namely the first resistor R1 and the second resistor R2, a potentiometer P1, two capacitors, namely the fifth capacitor C5 and the sixth capacitor C6, three inductors, namely the first inductor L1, the second inductor L2 and the third inductor L3, four diodes, namely the first diode D1, the second diode D2, the third diode D3 and the fourth diode D4, a first power switch S1, a first current sensor CS1 and a first control driver CD1. One end of the first inductor is connected to the cathode of the third diode and then to point A. One end of the fifth capacitor C5, the anode of the first diode D1, the second pin of the first control driver CD1, one end of the first resistor R1, one end of the sixth capacitor C6, and one end of the first potentiometer RP1 are connected to point B (i.e., point H). The other end of the first inductor L1 is connected to the third diode D4. After the anode of the third inductor is connected, it is connected to the other end of the fifth capacitor C5, the cathode of the first diode D1, the first pin of the first control driver CD1, and one end of the third inductor L3. The other end of the third inductor L3 is connected to the drain D of the first power switch S1 and the anode of the second diode D2. The cathode of the second diode D2 is connected to the other end of the sixth capacitor C6, one end of the second resistor R2, one end of the second inductor L2, and the cathode of the fourth diode D4. The other end of the second inductor L2 and the anode of the fourth diode D4 are connected to point G. The fifth pin of the first control driver CD1 is connected to the gate G of the first power switch S1. The fourth pin of the first control driver CD1 is connected to the other end of the second resistor R2 and the other end of the first potentiometer P1. The third pin of the first control driver CD1 is connected to the other end of the first resistor R1 and the source S of the first power switch S1.In this circuit, the first inductor L1 and the second inductor L2 serve to pass DC power and bidirectionally block high-frequency data signals. The current flows from left to right in the first inductor L1 and the second inductor L2, and the current flows from left to right in the third inductor L3. The third diode D3 provides a freewheeling and energy dissipation buffer path for the first inductor L1, and the fourth diode D4 provides a freewheeling and energy dissipation buffer path for the second inductor L2. Energy is dissipated by the diode voltage drop and on-resistance to prevent excessive induced voltage across the inductors. The first diode D1 provides a freewheeling and energy dissipation buffer path for the third inductor L3. The fifth capacitor C5 and the sixth capacitor C6 store energy and form a DC voltage. The first control driver CD1 is an analog control driver, with DC power introduced through its pin 1. The voltage is converted into the control and drive power required by the first control driver CD1 through an internal step-down transformer. The first resistor R1 receives the conduction current of the first power switch S1, which is input to pin 3 of the first control driver CD1. The current of the second diode D2 is then synthesized through an internal filter, which in turn generates the current of the third inductor L3 for the inner current loop control. The voltage division between the second resistor R2 and the first potentiometer P1 generates the voltage signal of the sixth output capacitor C6, which is input to pin 4 of the first control driver CD1 for the outer voltage loop control. Under the control of the first control driver CD1, the voltage of the sixth output capacitor C6 is higher than the voltage of the fifth input capacitor C5, thereby increasing the voltage level and enabling power transmission over longer distances.

[0029] As an alternative implementation scheme, such as Figure 1 The data signal transmission circuit 3 includes four capacitors: capacitor C1, capacitor C2, capacitor C3, and capacitor C4, and a first network transformer TR1. One end of capacitor C1 is connected to point A, and the other end is connected to point C. One end of capacitor C2 is connected to point B, and the other end is connected to point D. One end of capacitor C3 is connected to point G, and the other end is connected to point C. One end of capacitor C4 is connected to point H, and the other end is connected to point F. Pin 1 of the first network transformer TR1 is point C, pin 2 is point D, pin 3 is point F, and pin 4 is point E. In this circuit, capacitors C1 to C4 isolate DC voltage and transmit high-frequency data signals, preventing short circuits in the network transformer windings caused by DC voltage. The first network transformer TR1 isolates, drives, and transmits data signals, enabling data signal transmission over longer distances.

[0030] As an alternative implementation scheme, such as Figure 1The isolation-side EMI filter circuit 4 includes six resistors: the third resistor R3, the fourth resistor R4, the fifth resistor R5, the sixth resistor R6, the seventh resistor R7, and the eighth resistor R8; and two capacitors: the seventh capacitor C7 and the eighth capacitor C8. One end of the third resistor R3 is connected to point D, and one end of the fifth resistor R5 is connected to point C. The other end of the third resistor R3 is connected to the other end of the fifth resistor R5, and then connected to one end of the seventh capacitor C7 and one end of the sixth resistor R6. The other end of the seventh capacitor C7 and the other end of the sixth resistor R6 are then connected to ground. One end of the fourth resistor R4 is connected to point E, and one end of the seventh resistor R7 is connected to point F. The other end of the fourth resistor R4 is connected to the other end of the seventh resistor R7, and then connected to one end of the eighth capacitor C8 and one end of the eighth resistor R8. The other end of the eighth capacitor C8 and the other end of the eighth resistor R8 are then connected to ground. This circuit is used to filter out the common-mode voltage on both sides of the network transformer. The third resistor R3 and the fifth resistor R5 are connected to the seventh capacitor C7 to discharge the common-mode voltage to ground. The sixth resistor R6 is connected in parallel with the seventh capacitor C7 to release and reset the energy stored in the seventh capacitor C7.

[0031] As an alternative implementation scheme, such as Figure 1 The output-side EMI filter circuit 5 includes two NTC resistors, namely the third NTC resistor NTC3 and the fourth NTC resistor NTC4, a second transient voltage suppressor TVS2, and a second common-mode rejection coil CH2. One end of the third NTC resistor NTC3 is connected to PS2, and the other two ends are connected to one end of the second transient voltage suppressor TVS2 and the fourth pin of the second common-mode rejection coil CH2. One end of the fourth NTC resistor NTC4 is connected to NS2, and the other end is connected to the other end of the second transient voltage suppressor TVS2 and the third pin of the second common-mode rejection coil CH2. The first pin of the second common-mode rejection coil CH2 is connected to point G, and the second pin of the second common-mode rejection coil CH2 is connected to point H. In this circuit, the third NTC resistor NTC3 and the fourth NTC resistor NTC4 are used to limit the current in the DC circuit when the circuit is powered on, to prevent overcurrent in the powered devices. After the DC circuit is working, the resistance value is close to zero. The second transient voltage suppressor TVS2 is used to limit the voltage spike between the two lines, and the second common mode suppression coil CH2 is used to suppress interference caused by common mode voltage.

[0032] Example 2

[0033] As another alternative implementation scheme, such as Figure 2A dual-wire Ethernet repeater circuit includes an input-side EMI filter circuit 1, a DC transmission circuit 2, a data signal transmission circuit 3, an isolation-side EMI filter circuit 4, and an output-side EMI filter circuit 5. In this embodiment, the circuit structure, component designations, and functions of the input-side EMI filter circuit 1, the data signal transmission circuit 3, the isolation-side EMI filter circuit 4, and the output-side EMI filter circuit 5 are exactly the same as in embodiment 1. The main function of the DC transmission circuit 2 is also exactly the same. The difference is that the circuit structure of the DC transmission circuit 2 is different from that in embodiment 1.

[0034] In this embodiment, as Figure 2 The DC transmission circuit 2 includes two resistors, namely the first resistor R1 and the second resistor R2, two capacitors, namely the fifth capacitor C5 and the sixth capacitor C6, two inductors, namely the first inductor L1 and the second inductor L2, and four diodes, namely the first diode D1 to the fourth diode D4. One end of the first resistor R1 is connected to one end of the fifth capacitor C5 and one end of the first inductor L1, and then connected to point A. The other end of the first resistor R1 is connected to the other end of the fifth capacitor C5 and then connected to the cathode of the first diode D1. The anode of the first diode D1 is connected to the cathode of the second diode D2. The anode of the second diode D2 is connected to the other end of the first inductor L1 and then connected to point G. One end of the second resistor R2 is connected to one end of the sixth capacitor C6 and one end of the second inductor L2 and then connected to point B. The other end of the second resistor R2 is connected to the other end of the sixth capacitor C6 and then connected to the cathode of the third diode D3. The anode of the third diode D3 is connected to the cathode of the fourth diode D4. The anode of the fourth diode D4 is connected to the other end of the second inductor L2 and then connected to point G. In this circuit, the first inductor L1 and the second inductor L2 serve to pass DC power and block high-frequency data signals. The current in the first inductor L1 flows from left to right, and the current in the second inductor L2 flows from right to left. The first diode D1 to the fourth diode D4 serve to freewheel the current for the first inductor L1 and the second inductor L2 and to dissipate energy. They rely on the voltage drop of the diodes and the on-resistance to dissipate energy and prevent excessive induced voltage from appearing across the inductors. The fifth capacitor C5 and the sixth capacitor C6 serve to store energy quickly. The first resistor R1 and the second resistor R2 serve to freewheel the current and dissipate the energy stored in the fifth capacitor C5 and the sixth capacitor C6.

[0035] Example 3

[0036] As another alternative implementation scheme, such as Figure 3A dual-wire Ethernet repeater circuit includes an input-side EMI filter circuit 1, a DC transmission circuit 2, a data signal transmission circuit 3, an isolation-side EMI filter circuit 4, and an output-side EMI filter circuit 5. In this embodiment, the circuit structure, component designations, and functions of the input-side EMI filter circuit 1, the DC transmission circuit 2, and the output-side EMI filter circuit 5 are exactly the same as in embodiment 2. The functions of the data signal transmission circuit 3 and the isolation-side EMI filter circuit 4 are also exactly the same. The only difference is that the circuit structures of the data signal transmission circuit 3 and the isolation-side EMI filter circuit 4 are different.

[0037] In this embodiment, the data signal transmission circuit 3 includes four capacitors, namely the first capacitor C1 to the fourth capacitor C4, and a network transformer with a center tap. One end of the first capacitor C1 is connected to point A, and the other end is connected to point C. One end of the second capacitor C2 is connected to point B, and the other end is connected to point D. One end of the third capacitor C3 is connected to point G, and the other end is connected to point C. One end of the fourth capacitor C4 is connected to point H, and the other end is connected to point F. The network transformer has a primary center tap (pin 5) and a secondary center tap (pin 6).

[0038] In this embodiment, in the isolation side EMI filter circuit 4, one end of the third resistor R3 is connected to the 5th pin of the network transformer in the data signal transmission circuit 3, and the other end is connected to one end of the seventh capacitor C7. The other end of the seventh capacitor C7 is connected to ground. One end of the fourth resistor R4 is connected to the 6th pin of the network transformer in the data signal transmission circuit 3, and the other end is connected to one end of the eighth capacitor C8. The other end of the eighth capacitor C8 is connected to ground.

[0039] The data signal transmission circuit 3 can improve signal integrity, thereby extending the transmission distance. The isolation-side EMI filter circuit 4 can suppress the common-mode voltage across the network transformer.

[0040] In the above embodiments, the network refers to a smart factory dual-wire Ethernet, i.e., a single-pair twisted-pair Ethernet (SPE); the network input DC voltage is 44–57V; the network input DC current is less than 1.15A; the network high-frequency data signal is a differential signal, +5.0V, 10MHz; the input side voltage in the above embodiments is 20–25V, based on the voltage drop of the dual-wire Ethernet line; the output side voltage in the above embodiments is 44–57V, based on the voltage drop of the dual-wire Ethernet line; in the above embodiments, the parameters of the first resistor are 20mΩ / 1W, and the parameters of the second resistor are 50kΩ / 1W. W, the parameters of the third to fifth resistors and the seventh resistor are 1.0kΩ, and the parameters of the sixth and eighth resistors are 100kΩ; the parameters of the first to fourth capacitors are 1.0μF / 100V or 1.0nF / 100V, the parameters of the fifth and sixth capacitors are 100μF / 100V, and the parameters of the seventh and eighth capacitors are Y capacitors with a parameter of 1.0nF / 2.0kV; the second diode and the third diode are fast diodes with a withstand voltage of 100V and a current carrying capacity of 5A / 85℃; the third diode and the fourth diode are 1N4148; the first power switch is SiC. MOSFET, withstand voltage 100V, current carrying capacity 5A / 85℃; the first control driver CD1 is a commonly used boost-type DC-DC converter analog controller or digital controller; the first NTC resistor to the fourth NTC resistor have a room temperature resistance of 25Ω, and close to 0Ω at ambient temperature; the first and second transient voltage suppressors have an operating voltage of 100V; the first and second common mode coils have Z = 2000Ω at 100MHz; the selected first network transformer is 2250V (DC), with a primary and secondary self-inductance of 350μH, and the selected tapped first network transformer is 2250V (DC), with a primary and secondary self-inductance of 350μH.

[0041] In the description of this invention, it should be understood that the terms "coaxial," "bottom," "one end," "top," "middle," "other end," "upper," "side," "top," "inner," "outer," "front," "center," "both ends," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0042] In this invention, unless otherwise explicitly specified and limited, the terms "installation," "setting," "connection," "fixing," "rotation," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal connection of two components or the interaction between two components. Unless otherwise explicitly limited, those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0043] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A dual-wire Ethernet repeater circuit, characterized in that, The circuit includes an input-side EMI filter circuit, a DC transmission circuit, a data signal transmission circuit, an isolation-side EMI filter circuit, and an output-side EMI filter circuit. The input-side EMI filter circuit is used for input-side common-mode voltage suppression and power-on current limiting. The DC transmission circuit is used to transmit and boost DC power and inductor energy storage freewheeling current. The data signal transmission circuit is used to transmit and relay high-frequency data signals. The isolation-side EMI filter circuit is used for common-mode voltage suppression on both the primary and secondary sides of the network transformer. The output-side EMI filter circuit is used for output-side common-mode voltage suppression. The DC transmission circuit includes first to third inductors, first to fourth diodes, a first control driver, a first resistor, a second resistor, a first power switch, a first potentiometer, a fifth capacitor, and a sixth capacitor. One end of the first inductor and the cathode of the third diode are connected to one input terminal of the data signal transmission circuit, and one end of the second inductor and the anode of the fourth diode are connected to one output terminal of the data signal transmission circuit. One end of the fifth capacitor and the first diode... The anode of the first diode, the second pin of the first control driver, one end of the first resistor, one end of the sixth capacitor, one end of the first potentiometer, the other input terminal of the data signal transmission circuit, and the other output terminal of the data signal transmission circuit are connected together; the anode of the third diode, the other end of the first inductor, one end of the third inductor, the other end of the fifth capacitor, the cathode of the first diode, and the first pin of the first control driver are connected together; the other end of the third inductor is connected to the anode of the second diode and the drain of the first power switch; the cathode of the second diode, the cathode of the fourth diode, one end of the second resistor, the other end of the second inductor, and the other end of the sixth capacitor are connected together; the other end of the second resistor, the other end of the first potentiometer, and the fourth pin of the first control driver are connected together; the gate of the first power switch is connected to the fifth pin of the first control driver; the source of the first power switch, the other end of the first resistor, and the third pin of the first control driver are connected together.

2. The dual-wire Ethernet repeater circuit according to claim 1, characterized in that, The input-side EMI filter circuit includes a first NTC resistor, a second NTC resistor, a first transient voltage suppressor, and a first common-mode rejection coil. One end of the first NTC resistor is connected to the input terminal of the differential data signal, and the other end is connected to one end of the first transient voltage suppressor and the first pin of the first common-mode rejection coil. One end of the second NTC resistor is connected to the input terminal of the DC power supply, and the other end is connected to the other end of the first transient voltage suppressor and the second pin of the first common-mode rejection coil. The third and fourth pins of the first common-mode rejection coil serve as the input terminals of the data signal transmission circuit.

3. A dual-wire Ethernet repeater circuit according to claim 1, characterized in that, The data signal transmission circuit includes first to fourth capacitors and a first network transformer. One end of the first capacitor and the second capacitor serve as two input terminals of the data signal transmission circuit, and the other ends of the first capacitor and the second capacitor are connected to the input terminals of the first network transformer, respectively. The output terminals of the first network transformer are connected to one end of the third capacitor and the fourth capacitor, and the other ends of the third capacitor and the fourth capacitor serve as two output terminals of the data signal transmission circuit.

4. A dual-wire Ethernet repeater circuit according to claim 3, characterized in that, The isolation-side EMI filter circuit includes third to eighth resistors, a seventh capacitor, and an eighth capacitor. One end of the third resistor is located between the second capacitor and one of the input terminals of the first network transformer, and its other end is connected to one end of the seventh capacitor, one end of the fifth resistor, and one end of the sixth resistor, respectively. The other end of the fifth resistor is located between the first capacitor and the other input terminal of the first network transformer, and the other end of the sixth resistor is connected to the other end of the seventh capacitor and grounded. One end of the seventh resistor is located between the fourth capacitor and one of the output terminals of the first network transformer, and its other end is connected to one end of the fourth resistor, one end of the eighth resistor, and one end of the eighth capacitor, respectively. The other end of the fourth resistor is located between the third capacitor and the other output terminal of the first network transformer, and the other end of the eighth resistor is connected to the other end of the eighth capacitor and grounded.

5. A dual-wire Ethernet repeater circuit according to claim 3, characterized in that, If the network transformer in the data signal transmission circuit is a tapped network transformer, then the isolation side EMI filter circuit includes a third resistor, a fourth resistor, a seventh capacitor, and an eighth capacitor. The primary center tap of the tapped network transformer is connected to one end of the third resistor, the other end of the third resistor is connected to one end of the seventh capacitor, and the other end of the seventh capacitor is grounded. The secondary center tap of the tapped network transformer is connected to one end of the fourth resistor, the other end of the fourth resistor is connected to one end of the eighth capacitor, and the other end of the eighth capacitor is grounded.

6. A dual-wire Ethernet repeater circuit according to claim 1, characterized in that, The output-side EMI filter circuit includes a third NTC resistor, a fourth NTC resistor, a second transient voltage suppressor, and a second common-mode rejection coil. The first and second output terminals of the data signal transmission circuit are respectively connected to the two input ports of the second common-mode rejection coil. One output terminal of the second common-mode rejection coil is connected to the second transient voltage suppressor and one end of the third NTC resistor. The other end of the third NTC resistor serves as the output terminal of the differential data signal. The other output terminal of the second common-mode suppression coil is connected to the second transient voltage suppressor and one end of the fourth NTC resistor, with the other end of the fourth NTC resistor serving as the output terminal of DC power.

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