Ethernet communication isolation circuit and communication system

Abstract

The invention relates to the technical field of Ethernet communication, in particular to an Ethernet communication isolation circuit and a communication system. The isolation circuit comprises a network port transformer, a first power supply module, an Ethernet connector and a second power supply module, a primary coil of the network port transformer is connected to an analog communication end of a PHY chip, and an output end of the network port transformer is connected to a first communication end of the Ethernet connector. The second communication end of the Ethernet connector is connected to external communication equipment; wherein the first communication end and the second communication end of the Ethernet connector are mutually isolated and communicated; the primary coil of the network port transformer is also connected with a first driving module, and the first power supply module supplies power to the first driving module; the first communication end of the Ethernet connector is also connected with a second driving module, and the second power supply module supplies power to the second driving module. By adopting the isolation circuit provided by the invention, the security of Ethernet communication in a high-voltage environment can be improved.

Description

Technical Field

[0001] The present application relates to the technical field of electrical isolation, and in particular to an Ethernet communication isolation circuit and a communication system. Background Art

[0002] Ethernet communication is a widely used computer network technology that enables data transmission and sharing between devices through standardized communication protocols and interfaces. Figure 1 As shown in the figure, a typical Ethernet communication system includes a host computer, a PHY (Physical) chip and an Ethernet connector. The Ethernet connector is used to connect external communication equipment. The PHY chip performs digital-to-analog conversion so that the communication equipment and the host computer can communicate normally. In addition, in order to prevent the electrical signal and ground wire loopback from affecting the quality of Ethernet communication, a transformer device is usually built into the Ethernet connector to achieve signal isolation, thereby improving the reliability and stability of Ethernet communication.

[0003] However, the withstand voltage of the transformer device built into most Ethernet connectors is usually around 1500V. In some special scenarios with higher withstand voltage requirements, such as power distribution cabinets, automotive power domain control, flywheel energy storage and other high-voltage circuit scenarios that require communication, the communication system using Ethernet connectors cannot meet the withstand voltage requirements, which may cause electrical insulation failure and affect the safety of the communication system.

[0004] Therefore, how to improve the security of Ethernet communications in high-voltage environments is an urgent problem that needs to be solved. Summary of the invention

[0005] Based on this, it is necessary to provide an Ethernet communication isolation circuit and communication system that can improve the security of Ethernet communication in a high-voltage environment in order to address the above technical problems.

[0006] In a first aspect, the present application discloses an Ethernet communication isolation circuit, the isolation circuit comprising a network port transformer, a first power module, an Ethernet connector and a second power module, wherein:

[0007] The primary coil of the network port transformer is connected to the analog communication end of the PHY chip, the output end of the network port transformer is connected to the first communication end of the Ethernet connector, and the second communication end of the Ethernet connector is connected to an external communication device; wherein the first communication end and the second communication end of the Ethernet connector communicate in isolation from each other;

[0008] The primary coil of the network port transformer is also connected to a first driving module, and the first power supply module supplies power to the first driving module;

[0009] The first communication end of the Ethernet connector is also connected to a second driving module, and the second power supply module supplies power to the second driving module.

[0010] In one embodiment, the network port transformer is connected to a first reference ground, the Ethernet connector is connected to a second reference ground, and the first reference ground and the second reference ground are different reference grounds.

[0011] In one of the embodiments, both the uplink connection and the downlink connection between the analog input terminal of the PHY chip and the network port transformer are in a differential connection mode.

[0012] In one of the embodiments, an impedance matching module is connected between the primary coil of the network port transformer and the analog communication end of the PHY chip, and between the uplink connection path and the downlink connection path.

[0013] In one embodiment, the impedance matching module includes a first pull-up resistor for pulling up and a first capacitor for filtering; wherein one end of the first pull-up resistor is connected to the upstream connection path or the downstream connection path, the other end of the first pull-up resistor is connected to one end of the first capacitor, and the other end of the first capacitor is connected to the first reference ground.

[0014] In one embodiment, the secondary coil of the network port transformer is connected to the first communication end of the Ethernet connector via a twisted pair cable, and two BST resistors are connected in series between the twisted pair cables, one end of the two BST resistors is connected to a jumper capacitor, and the other end of the jumper capacitor is connected to the first reference ground.

[0015] In one embodiment, the first driving module includes a first driving resistor and a first decoupling capacitor; one end of the first driving resistor is connected to the first power supply module, the other end of the first driving resistor is simultaneously connected to the secondary coil of the network port transformer and one end of the first decoupling capacitor, and the other end of the first decoupling capacitor is connected to the first reference ground.

[0016] In one embodiment, the second driving module includes a second driving resistor and a second decoupling capacitor, one end of the second driving resistor is connected to the second power supply module, the other end of the second driving resistor is simultaneously connected to the first communication end of the Ethernet connector and one end of the second decoupling capacitor, and the other end of the second decoupling capacitor is connected to the second reference ground.

[0017] In one embodiment, the second power supply module includes a pre-filter module, a voltage stabilization module and a post-filter module, wherein:

[0018] One end of the pre-filter module is connected to the input end of the voltage stabilizing module, and the other end of the voltage stabilizing module is connected to the external input voltage; one end of the post-filter module is connected to the output end of the voltage stabilizing module, and the other end of the post-filter module is connected to the second driving module.

[0019] In a second aspect, the present application further provides an isolated communication system, the system comprising a host computer, a PHY chip, and an Ethernet communication isolation circuit as described in any one of the first aspects;

[0020] Among them, the communication end of the host computer is connected to the digital communication end of the PHY chip, and the analog communication end of the PHY chip is connected to the Ethernet communication isolation circuit.

[0021] In the above-mentioned Ethernet communication isolation circuit and communication system, the network port transformer in the isolation circuit performs the first-level isolation of the signal between the PHY chip and the external communication device, and the Ethernet connector has a separate transformer device built in, so the Ethernet connector isolates the signal as the second-level isolation. Since the isolation circuit adopts double-stage isolation, the overall withstand voltage level is relatively high, so that the Ethernet communication system can maintain stable operation under higher voltage signals, improving the stability and reliability of signal transmission; and due to the improvement of the withstand voltage level, the Ethernet communication system can also more stably cope with possible voltage shocks, thereby effectively preventing insulation breakdown of components or equipment due to overvoltage, reducing the occurrence of accidents such as short circuits and leakage, and improving the safety of the Ethernet communication system. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the conventional technology, the drawings required for use in the embodiments or the conventional technology descriptions will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without assuming creative work.

[0023] Figure 1 A schematic diagram of an Ethernet communication system in the related art;

[0024] Figure 2 A schematic diagram of the connection relationship between modules in an Ethernet communication isolation circuit in an embodiment;

[0025] Figure 3 A schematic diagram of the wiring relationship of a network port transformer in an embodiment;

[0026] Figure 4 A schematic diagram of the wiring relationship of an Ethernet connector in one embodiment;

[0027] Figure 5 is a schematic structural diagram of a second power supply module in one embodiment;

[0028] Figure 6 FIG. 1 is a schematic diagram of an Ethernet communication system in one embodiment. DETAILED DESCRIPTION

[0029] In order to facilitate understanding of the present application, the present application will be described more fully below with reference to the relevant drawings. Embodiments of the present application are provided in the drawings. However, the present application can be implemented in many different forms and is not limited to the embodiments described herein. On the contrary, the purpose of providing these embodiments is to make the disclosure of the present application more thorough and comprehensive.

[0030] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art to which this application belongs. The terms used herein in the specification of this application are only for the purpose of describing specific embodiments and are not intended to limit this application.

[0031] It is understood that the terms "first", "second", etc. used in this application may be used herein to describe various elements, but these elements are not limited by these terms. These terms are only used to distinguish a first element from another element. For example, without departing from the scope of this application, a first resistor may be referred to as a second resistor, and similarly, a second resistor may be referred to as a first resistor. Both the first resistor and the second resistor are resistors, but they are not the same resistor.

[0032] It can be understood that the “connection” in the following embodiments should be understood as “electrical connection”, “communication connection”, etc. if the connected circuits, modules, units, etc. have electrical signals or data transmission between each other.

[0033] It can be understood that “at least one” means one or more, “plurality” means two or more, and “at least part of an element” means part or all of an element.

[0034] When used herein, the singular forms "a", "an" and " / the" may also include the plural forms, unless the context clearly indicates otherwise. It should also be understood that the terms "include / comprise" or "have" and the like specify the presence of stated features, wholes, steps, operations, components, parts or combinations thereof, but do not exclude the possibility of the presence or addition of one or more other features, wholes, steps, operations, components, parts or combinations thereof. At the same time, the term "and / or" used in this specification includes any and all combinations of the relevant listed items.

[0035] In an exemplary embodiment, an Ethernet communication isolation circuit is provided, referring to Figure 2The isolation circuit may specifically include a network port transformer, a first power module, an Ethernet connector, and a second power module. The primary coil of the network port transformer is connected to the analog communication terminal of the PHY chip, the output terminal of the network port transformer is connected to the first communication terminal of the Ethernet connector, and the second communication terminal of the Ethernet connector is connected to an external communication device.

[0036] Specifically, refer to Figure 2 , the first communication end and the second communication end of the Ethernet connector communicate in isolation from each other; that is, the first communication end is connected to the coil on one side of the transformer device inside the Ethernet connector, and the second communication end is connected to the coil on the other side of the transformer device, so that the signal between the first communication end and the second communication end can be isolated. Furthermore, in the embodiment of the present application, the model of the Ethernet connector is not specifically limited, as long as it has a transformer device capable of signal isolation built in. In one possible example, the Ethernet connector uses an RJ45 connector.

[0037] When the above isolation circuit is applied to an Ethernet communication system, the network port transformer in the isolation circuit performs the first level of signal isolation between the PHY chip and the external communication device; since the Ethernet connector has a separate transformer device built in, the Ethernet connector can isolate the signal as the second level of isolation. Since the isolation circuit adopts double-stage isolation, the overall withstand voltage level is higher, so that the Ethernet communication system can maintain stable operation under higher voltage signals, improving the stability and reliability of signal transmission; and due to the improvement of the withstand voltage level, the Ethernet communication system can also more stably cope with possible voltage shocks, thereby reducing the probability of insulation breakdown of components or equipment due to overvoltage, reducing the occurrence of accidents such as short circuits and leakage, and improving the safety of the Ethernet communication system.

[0038] Since both the first-level isolation and the second-level isolation in the present application adopt transformer isolation, there will be signal loss during the signal isolation process, resulting in reduced signal driving capability. In order to reduce the loss after signal isolation, in one embodiment, referring to Figure 2 The primary coil of the network port transformer is also connected to a first driving module, and the first power supply module supplies power to the first driving module; the first communication end of the Ethernet connector is also connected to a second driving module, and the second power supply module supplies power to the second driving module.

[0039] Specifically, the first power supply module supplies power to the first driver module, so that the first driver module can input voltage on the primary coil side of the network port transformer, thereby improving the signal driving capability; the second power supply module supplies power to the second driver module, so that the second driver module can input voltage on the first communication end of the Ethernet connector, thereby improving the signal driving capability. In addition, since the first driver module and the second driver module are powered by different power supply modules, the external input voltage (voltage input by the driver module) is isolated between the network port transformer and the Ethernet connector, thereby improving the signal stability.

[0040] Further, refer to Figure 2 In order to reduce the introduction of external interference signals, in an embodiment of the present application, different reference grounds are set for the network port transformer and the Ethernet connector. Specifically, the network port transformer is connected to the first reference ground (GND1), and the Ethernet connector is connected to the second reference ground (ISO GND2); the first reference ground (GND1) and the second reference ground (ISO GND2) are different reference grounds. Since the network port transformer and the Ethernet connector use different reference grounds, the influence of ground wire loopback can be reduced, thereby reducing the probability of introducing interference signals into the Ethernet communication system, so that the quality of the signal transmitted in the Ethernet communication system is higher.

[0041] In one embodiment, referring to Figure 2 , a differential connection is used between the primary coil of the network port transformer and the analog communication end of the PHY chip; specifically, both the uplink signal and the downlink signal are connected in a differential manner. The uplink signal from the PHY chip to the network port transformer includes the uplink positive signal TXD-P and the uplink negative signal TXD-N; the downlink signal from the PHY chip to the network port transformer includes the downlink positive signal RXD-P and the uplink negative signal RXD-N.

[0042] Furthermore, if Figure 2 As shown, a differential connection is also adopted between the secondary coil of the network port transformer and the first communication end of the Ethernet connector; the signal transmitted between the secondary coil of the network port transformer and the first communication end of the Ethernet connector includes an uplink positive signal TX-P and an uplink negative signal TX-N, and also includes a downlink positive signal RX-P and an uplink negative signal RX-N.

[0043] In one of the embodiments, when a differential signal is transmitted in the transmission line between the PHY chip and the network port transformer, if the characteristic impedance of the transmission line does not match the impedance of the signal source and the load, reflection will occur, resulting in signal distortion and energy loss. In order to reduce the loss of the differential signal, an impedance matching module is connected to the transmission line transmitting the differential signal in the embodiment of the present application, so that the characteristic impedance of the transmission line is close to the impedance of the signal source and the load.

[0044] The above embodiments describe the structure of each module and the signal transmission relationship of the Ethernet communication isolation circuit from the perspective of the overall structure. The following embodiments describe the structure of each module and the connection relationship between components from a more specific perspective.

[0045] In one embodiment, the network port transformer includes two transformers, which are used to isolate the uplink signal and the downlink signal respectively; specifically, the network port transformer can be a chip integrating two transformers (a first transformer and a second transformer). In the isolation circuit, the performance requirement of the network port transformer is that it can work stably between -40°C and +85°C, and the supported withstand voltage level (ISO) is 1500Vrms. The first transformer is responsible for the isolation of the uplink signal TX, the uplink signal TX output by the PHY chip is connected to the primary coil of the first transformer, and the secondary coil of the first transformer is connected to the Ethernet isolator. The second transformer is responsible for the isolation of the downlink signal RX, the downlink signal RX output by the PHY chip is connected to the primary coil of the second transformer, and the secondary coil of the second transformer is connected to the Ethernet isolator.

[0046] Furthermore, two transformers are integrated inside the Ethernet connector, namely the third transformer and the fourth transformer; the Ethernet connector can also be an interface element integrating two transformers. Specifically, the secondary coil of the first transformer in the network port transformer is connected to the primary coil of the third transformer of the Ethernet connector, and the secondary coil of the second transformer is connected to the primary coil of the fourth transformer. The isolated transmission of the uplink signal TX is realized between the first transformer and the third transformer, and the isolated transmission of the downlink signal RX is realized between the second transformer and the fourth transformer.

[0047] In the embodiments of this application, refer to Figure 3, taking the network port transformer model H1102NLT as an example, the connection relationship of the network port transformer in the isolation circuit is explained in detail. Among them, the network port transformer of H1102NLT has 16 pins, and two transformers are integrated inside. Pins 1 and 3 are respectively the two ends of the primary coil of the first transformer, and pin 2 is the middle end of the primary coil of the first transformer; pins 14 and 16 are respectively the two ends of the secondary coil of the first transformer, and pin 15 is the middle end of the secondary coil of the first transformer. Pins 6 and 8 are respectively the two ends of the primary coil of the second transformer, and pin 7 is the middle end of the primary coil of the second transformer; pins 9 and 11 are respectively the two ends of the secondary coil of the second transformer, and pin 10 is the middle section of the secondary coil of the second transformer. Pins 4, 5, 12 and 13 are set to be suspended.

[0048] Further, in the embodiments of the present application, refer to Figure 4 , taking the Ethernet connector model J8064D628ANL_3 as an example, the connection relationship between the network port transformer and the Ethernet connector is further explained. Specifically, the Ethernet connector includes 12 input pins B1-B12, among which the B1 and B2 pins are the two end points of the primary coil of the third transformer, and the B4 pin is the middle end of the primary coil of the third transformer. B3 and B6 are the two end points of the primary coil of the fourth transformer, and B5 is the middle end of the primary coil of the fourth transformer. The B7 pin is set to be suspended. The connection relationship of the B8-B12 pins will be explained in detail later.

[0049] Specifically, refer to Figure 3 and Figure 4 , the PHY chip simulates the uplink positive signal TXD-P of the communication end and connects to the 1st pin of the network port transformer through the transmission line, and the uplink negative signal TXD-N connects to the 3rd pin of the network port transformer through the transmission line. The 16th pin of the network port transformer is connected to the B1 pin of the Ethernet connector, and the uplink positive signal TXP after the first level of isolation is transmitted between the 16th pin and the B1 pin. The 14th pin of the network port transformer is connected to the B2 pin of the Ethernet connector, and the uplink negative signal TXN after the first level of isolation is transmitted between the 14th pin and the B2 pin.

[0050] The PHY chip simulates the downlink positive signal RXD-P of the communication end, and connects to the 6th pin of the network port transformer through the transmission line. The downlink negative signal RXD-N is connected to the 8th pin of the network port transformer through the transmission line. The 11th pin of the network port transformer is connected to the B3 pin of the Ethernet connector, and the downlink positive signal TXP is transmitted between the 11th pin and the B3 pin. The 9th pin of the network port transformer is connected to the B6 pin of the Ethernet connector, and the downlink negative signal TXN is transmitted between the 9th pin and the B6 pin.

[0051] Further, refer to Figure 5, the second power supply module may specifically include a voltage stabilizing module, a pre-filtering module and a post-filtering module; wherein, the voltage stabilizing module may be a voltage stabilizing chip, and the model of the voltage stabilizing chip is not specifically limited in the embodiment of the present application. In one example of the present application, a voltage stabilizing chip U72 with model IB0503S-W75R3 is selected. Among them, the input pin VIN of the voltage stabilizing chip U72 is connected to the external input voltage, and a capacitor C262 is connected between the ground pin GND and the OV pin of the voltage stabilizing chip U72, and the output pin +VO is used to output a stable voltage. Among them, the voltage input to the VIN pin may be 5V, and the voltage output to the +VO pin may be 3.3V. Specifically, the capacitor C262 is used to eliminate oscillations, and the rated voltage of the capacitor C262 is greater than the rated voltage of the network port transformer.

[0052] The pre-filter module includes capacitor C257, capacitor C258 and capacitor C259, wherein capacitor C257, capacitor C258 and capacitor C259 are all connected in series between the VIN pin and the GND pin of the voltage stabilizing chip; the GND pin of the voltage stabilizing chip is grounded; and, since the second power supply module supplies power to the second drive module of the Ethernet connector, the GND pin of the voltage stabilizing chip of the second power supply module is connected to the second reference ground (ISO GND2). The pre-filter module is used to filter the input voltage of the voltage stabilizing chip so that the input voltage remains stable. The post-filter module includes capacitor C260 and capacitor C261, wherein capacitor C260 and capacitor C261 are all connected in series between the +VO pin and the 0V pin of the voltage stabilizing chip. The post-filter module is used to filter the voltage output by the voltage stabilizing chip so that the output voltage of the voltage stabilizing chip is stable and the voltage fluctuation is reduced.

[0053] Furthermore, the structure of the first power module can be completely the same as that of the second power module, or it can be different; wherein, the first power module can also use the same power supply module as the host computer in the Ethernet communication system. For example, when the host computer is a single-chip microcomputer, the first power module can be the power supply module of the single-chip microcomputer, and the first power module outputs a 3.3V voltage. In addition, since the first power module supplies power to the first driver module of the network port transformer, the ground pin of the voltage regulator chip in the first power module is connected to the first reference ground (GND1).

[0054] Further, refer to Figure 2 and Figure 3 The first driving module includes a first driving resistor and a first decoupling capacitor; one end of the first driving resistor is connected to the first power supply module, the other end of the first driving resistor is simultaneously connected to the secondary coil of the network port transformer and one end of the first decoupling capacitor, and the other end of the first decoupling capacitor is connected to the first reference ground (GND1).

[0055] Specifically, the first driving resistor includes a resistor R323 and a resistor R324, and the first decoupling capacitor includes a capacitor C176 and a capacitor C177. Among them, one end of the resistor R324 is connected to the output pin (+VO) of the first power module, the other end of the resistor R324 is connected to the 2 pin of the network port transformer and one end of the capacitor C177, and the other end of the capacitor C177 is connected to the first reference ground (GND1). The resistor R324 and the capacitor 177 jointly improve the driving capability of the uplink signal TXD between the PHY chip and the network port transformer. One end of the resistor R323 is connected to the output pin (+VO) of the first power module, the other end of the resistor R323 is connected to the 7 pin of the network port transformer and one end of the capacitor C176, and the other end of the capacitor C176 is connected to the first reference ground (GND1). The resistor R324 and the capacitor 176 jointly improve the driving capability of the downlink signal RXD between the PHY chip and the network port transformer.

[0056] Furthermore, an impedance matching module is connected between the primary coil of the network port transformer and the analog communication end of the PHY chip, and between the uplink connection path and the downlink connection path. The impedance matching module includes a pull-up resistor and a filter capacitor for filtering; wherein one end of the pull-up resistor is connected to the uplink connection path or the downlink connection path, the other end of the pull-up resistor is connected to one end of the filter capacitor, and the other end of the filter capacitor is connected to the first reference ground (GND1).

[0057] Reference Figure 2 and Figure 3 Specifically, the impedance matching module between the uplink signal transmission line between the PHY chip and the network port transformer is a first impedance matching module, and the pull-up resistor in the first impedance matching module specifically includes a resistor R14 and a resistor R15; the filter capacitor in the first impedance matching module is a capacitor C52. Among them, one end of the capacitor C52 is connected to the output pin (+VO) of the first power module, and the other end is connected to the first reference ground (GND1). One end of the resistor R14 is connected to the output pin (+VO) of the first power module, and the other end is connected to pin 1 of the network port transformer. One end of the resistor R15 is connected to the output pin (+VO) of the first power module, and the other end is connected to pin 3 of the network port transformer.

[0058] Specifically, refer to Figure 2 and Figure 3, the impedance matching module between the downlink signal transmission line between the PHY chip and the network port transformer is a second impedance matching module, and the pull-up resistor in the second impedance matching module specifically includes a resistor R16 and a resistor R17; the filter capacitor in the second impedance matching module is a capacitor C53. One end of the resistor R16 is connected to the output pin (+VO) of the first power module, and the other end is connected to the 6-pin of the network port transformer. One end of the resistor R17 is connected to the output pin (+VO) of the first power module, and the other end is connected to the 8-pin of the network port transformer. Among them, the resistance values ​​of the resistors R14-R17 are the same, and are the same as the characteristic impedance of the Ethernet transmission line; in a possible example, the resistance values ​​of the resistors R14-R17 are all 49.9 ohms or 51 ohms.

[0059] For RX and TX differential signals, each signal line is required to be pulled down by a 49.9Ω or 51Ω resistor, and then grounded through a 0.1uF capacitor. Because when the signal is transmitted in the transmission line, if the characteristic impedance of the transmission line does not match the impedance of the signal source and the load, reflection will occur, resulting in signal distortion and energy loss. The characteristic impedance of common Ethernet transmission lines is generally around 50 ohms. Therefore, in order to minimize the signal output loss, it is required to connect a 49.9 ohm or 51 ohm resistor for pull-up between the two ends of the differential line output, so that the internal resistance of the signal source can be better matched with the transmission line impedance and the load impedance, thereby reducing reflections, ensuring the integrity and quality of the signal, and enabling the signal to be efficiently and stably transmitted on the transmission line. The function of capacitors C52 and C53 is to remove noise signals from the signal.

[0060] Further, refer to Figure 3 and Figure 4 , the secondary coil of the network port transformer is connected to the first communication end of the Ethernet connector through a twisted pair, and two BST resistors are connected in series between the twisted pairs, one end of the two BST resistors is connected to a jumper capacitor, and the other end of the jumper capacitor is connected to the first reference ground (GND1). The secondary coil of the network port transformer is connected to the first communication end of the Ethernet connector through a twisted pair; specifically, a twisted pair is used to transmit the uplink signal TX, and a twisted pair is used to transmit the downlink signal RX. Two BST resistors are connected in series between the two pairs of twisted pairs that transmit the uplink signal and the downlink signal. Specifically, the two BST resistors include a resistor R20 and a resistor R21, wherein one end of the resistor R21 is connected to the 15th pin of the network port transformer, the other end of the resistor R21 is connected to one end of the resistor R20, and the other end of the resistor R20 is connected to the 10th pin of the network port transformer. Among them, the connection end of the resistor R20 and the resistor R21 is simultaneously connected to one end of the jumper capacitor C57, and the other end of the capacitor C57 is connected to the first reference ground (GND1).

[0061] Furthermore, the second driving module includes a second driving resistor and a second decoupling capacitor, one end of the second driving resistor is connected to the second power supply module, the other end of the second driving resistor is simultaneously connected to the first communication end of the Ethernet connector and one end of the second decoupling capacitor, and the other end of the second decoupling capacitor is connected to the second reference ground (ISO GND2).

[0062] Specifically, refer to Figure 4 , the second decoupling capacitor includes a resistor R318, a resistor R321 and a resistor R322, and the second decoupling capacitor includes a capacitor C178 and a capacitor C179. Among them, one end of the resistor R322 is connected to the output pin (+VO) of the second power module, the other end of the resistor R322 is connected to one end of the resistor R318, the other end of the resistor R318 is connected to the B5 pin of the Ethernet connector and one end of the capacitor C178, and the other end of the capacitor C178 is connected to the second reference ground (ISO GND2). The resistor R322, the resistor R318 and the capacitor C178 jointly improve the driving capability of the downlink signal RX (RXP and RXN) between the network port transformer and the Ethernet connector.

[0063] One end of the resistor R321 is connected to one end of the resistor R322 connected to the resistor R318, the other end of the resistor R321 is connected to one end of the capacitor C179 and the B4 pin of the Ethernet connector, and the other end of the capacitor C179 is connected to the second reference ground (ISO GND2). The resistor R322, the resistor R321 and the capacitor C179 together improve the driving capability of the uplink signal TX (TXP and TXN) between the network port transformer and the Ethernet connector.

[0064] Further, refer to Figure 4 and Figure 5 The Ethernet connector has two built-in light-emitting diodes, one of which has an anode connected to the B9 pin and a cathode connected to the B10 pin. The output pin (+V0) of the second power module is connected to the B9 pin of the Ethernet connector, so that the light-emitting diode connected to the B9 pin is powered and works. The B10 pin of the Ethernet connector is connected to one end of the protection resistor R319, and the other end of the protection resistor R319 outputs the SPEED-LED signal and can be collected by the host computer.

[0065] The anode of another light-emitting diode inside the Ethernet connector is connected to the B11 pin, and the cathode is connected to the B12 pin; the output pin (+V0) of the second power module is connected to the B11 pin of the Ethernet connector, so that the light-emitting diode connected to the B11 pin is powered and works. The B12 pin of the Ethernet connector is connected to one end of the protection resistor R432, and the other end of the protection resistor R432 outputs the LINK-LED signal and can be collected by the host computer. The working status of the Ethernet connector can be judged by the LINK-LED signal and the SPEED-LED signal. Among them, the B7 pin and the B8 pin of the Ethernet connector can be set according to specific needs.

[0066] The differential connection communication method can effectively suppress the generation of external electromagnetic interference on the one hand, and can also reduce the common mode noise in the Ethernet communication system on the other hand, thereby improving the signal quality in the Ethernet communication system.

[0067] It can be understood that the above modules can also adopt other forms, not limited to the forms mentioned in the above embodiments, as long as they can achieve the functions corresponding to the modules defined in the above embodiments. Those skilled in the art can understand that Figure 3-Figure 5 The structure shown in is merely a block diagram of a portion of the structure related to the present application scheme, and does not constitute a specific structural limitation on the modules used in the present application scheme.

[0068] Based on the same inventive concept, the embodiment of the present application also provides a communication system using the above Ethernet communication isolation circuit. Figure 6 The communication system may specifically include a host computer, a PHY chip, and an Ethernet communication isolation circuit as in the above-mentioned Ethernet isolation circuit embodiment. The communication end of the host computer is connected to the digital communication end of the PHY chip, the analog communication end of the PHY chip is connected to the Ethernet communication isolation circuit, and the second communication end of the Ethernet connector is connected to an external communication device.

[0069] Specifically, the host computer processes digital signals, and the digital signal output terminal of the host computer is connected to the digital communication terminal of the PHY chip. The digital communication terminal of the PHY chip and the digital signal output terminal of the host computer exchange digital data. After digital-to-analog conversion, the analog data of the external communication device and the digital data between the host computer can communicate.

[0070] Furthermore, the specific structure of the isolation circuit in the embodiment of the present application is the same as that defined in the embodiment of the above-mentioned Ethernet communication isolation circuit, and will not be elaborated herein.

[0071] The communication system in the embodiment of the present application, by introducing an innovative design of two-level electrical isolation, can maintain stable operation under higher voltage wake-up, improve the circuit's voltage resistance level, better withstand voltage shocks that may occur in the system, and effectively prevent accidents that endanger personal safety such as insulation breakdown and short circuits caused by overvoltage. Such a high voltage resistance level not only ensures the reliability and stability of the system, but also provides a reliable foundation for its wide application in various electrical engineering and application scenarios.

[0072] At the same time, based on the concept of multi-level isolation of signals in the present invention, it can be extended to not only two-level isolation, but also multi-level isolation to further improve the isolation voltage rating of the circuit. At the same time, the architecture of multiple physical isolations provides greater flexibility for network expansion. According to actual needs, it is convenient to add new physical isolation networks or upgrade existing networks without affecting the operation of existing networks, so as to adapt to the continuous development and changing business needs of enterprises.

[0073] The Ethernet communication system in the embodiment of the present application, through the voltage superposition principle of the network port transformer, the voltage resistance level of this circuit can reach 3750Vrms, which means that the system can maintain stable operation under higher voltage wake-up.

[0074] In the description of this specification, the description with reference to the terms "some embodiments", "other embodiments", etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present application. In this specification, the schematic description of the above terms does not necessarily refer to the same embodiment or example.

[0075] The technical features of the above-described embodiments may be arbitrarily combined. To make the description concise, not all possible combinations of the technical features in the above-described embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0076] The above-described embodiments only express several implementation methods of the present application, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the present application. It should be pointed out that, for a person of ordinary skill in the art, several variations and improvements can be made without departing from the concept of the present application, and these all belong to the protection scope of the present application. Therefore, the protection scope of the present application shall be subject to the attached claims.

Claims

1. An Ethernet communication isolation circuit, characterized in that: The isolation circuit includes a network port transformer, a first power module, an Ethernet connector and a second power module, wherein: The primary coil of the network port transformer is connected to the analog communication end of the PHY chip, the output end of the network port transformer is connected to the first communication end of the Ethernet connector, and the second communication end of the Ethernet connector is connected to an external communication device; wherein the first communication end and the second communication end of the Ethernet connector communicate in isolation from each other; The primary coil of the network port transformer is also connected to a first driving module, and the first power supply module supplies power to the first driving module; The first communication end of the Ethernet connector is also connected to a second driving module, and the second power supply module supplies power to the second driving module.

2. The circuit according to claim 1, characterized in that The network port transformer is connected to a first reference ground, and the Ethernet connector is connected to a second reference ground. The first reference ground and the second reference ground are different reference grounds.

3. The circuit according to claim 2, characterized in that The uplink connection and the downlink connection between the analog input terminal of the PHY chip and the network port transformer are both in a differential connection mode.

4. The circuit according to claim 3, characterized in that An impedance matching module is connected between the primary coil of the network port transformer and the analog communication end of the PHY chip, and between the uplink connection path and the downlink connection path.

5. The circuit according to claim 4, characterized in that The impedance matching module includes a first pull-up resistor for pull-up and a first capacitor for filtering; One end of the first pull-up resistor is connected to the upstream connection path or the downstream connection path, the other end of the first pull-up resistor is connected to one end of the first capacitor, and the other end of the first capacitor is connected to the first reference ground.

6. The circuit according to any one of claims 2 to 5, characterized in that The secondary coil of the network port transformer is connected to the first communication end of the Ethernet connector through a twisted pair cable, and two BST resistors are connected in series between the twisted pair cables. One end of the two BST resistors is connected to a jumper capacitor, and the other end of the jumper capacitor is connected to the first reference ground.

7. The circuit according to claim 2, characterized in that The first driving module includes a first driving resistor and a first decoupling capacitor; one end of the first driving resistor is connected to the first power supply module, the other end of the first driving resistor is simultaneously connected to the secondary coil of the network port transformer and one end of the first decoupling capacitor, and the other end of the first decoupling capacitor is connected to the first reference ground.

8. The circuit according to claim 2, characterized in that The second driving module includes a second driving resistor and a second decoupling capacitor, one end of the second driving resistor is connected to the second power supply module, the other end of the second driving resistor is simultaneously connected to the first communication end of the Ethernet connector and one end of the second decoupling capacitor, and the other end of the second decoupling capacitor is connected to the second reference ground.

9. The circuit according to claim 1 or 8, characterized in that: The second power supply module includes a pre-filter module, a voltage stabilization module and a post-filter module, wherein: One end of the pre-filter module is connected to the input end of the voltage stabilizing module, and the other end of the voltage stabilizing module is connected to the external input voltage; one end of the post-filter module is connected to the output end of the voltage stabilizing module, and the other end of the post-filter module is connected to the second driving module.

10. A communication system, characterized in that: The system comprises a host computer, a PHY chip and an Ethernet communication isolation circuit as described in any one of claims 1 to 9; Among them, the communication end of the host computer is connected to the digital communication end of the PHY chip, and the analog communication end of the PHY chip is connected to the Ethernet communication isolation circuit.

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