Optical coupling cascade transmission device and communication equipment

Abstract

The application provides an optical coupling cascade transmission device and communication equipment, and relates to the technical field of communication.The optical coupling cascade transmission device comprises an input end, a first-stage optical coupler, a second-stage optical coupler and an output end arranged in sequence.The electrical signal is input into the first-stage optical coupler through the input end, the first-stage optical coupler is used for converting and transmitting the electrical signal, and the converted electrical signal is transmitted to the second-stage optical coupler.The second-stage optical coupler is used for converting and transmitting the electrical signal converted by the first-stage optical coupler again to obtain an output signal, and the output signal is output through the output end.The communication rate of the electrical signal is determined by the delay parameters of the first-stage optical coupler and the second-stage optical coupler.The optical coupling cascade transmission device and the communication equipment provided by the application can offset the absolute time difference between the on-delay parameter and the off-delay parameter through two-stage optical couplers, and further improve the upper limit of the communication rate of the optical coupler to meet the communication demand of the high communication rate scene.

Description

Technical Field

[0001] This invention relates to the field of communication technology, and in particular to an optical coupler cascade transmission device and communication equipment. Background Technology

[0002] An optocoupler, or simply optocoupler, is a photoelectric conversion device that uses light as a medium to transmit electrical signals. With its advantages of good electrical isolation and immunity to common-mode interference, it is widely used in isolation scenarios such as industrial communication, power electronics, and embedded interfaces.

[0003] As the power grid continues to evolve towards intelligence and automation, the demand for data acquisition, transmission, and interaction in the power system is growing rapidly. The efficient acquisition and reliable transmission of massive amounts of power grid operation status information has become a critical issue that urgently needs to be addressed. The RS485 communication interface, as an important technical means for data interaction in smart meters and terminal devices, is also facing increasingly higher data transmission rate requirements. Currently, communication rates have gradually increased from the early 1200bps to 4800bps and 9600bps, and high-speed application demands of 115200bps have emerged, with this rate trending towards becoming the mainstream standard in future power communication scenarios. However, traditional optocouplers suffer from problems such as a large difference between conduction and turn-off delays and slow edge response, limiting the upper limit of their communication rate and making it difficult to meet the requirements of high communication rates. Summary of the Invention

[0004] In view of this, the purpose of the present invention is to provide an optical coupler cascade transmission device and communication equipment to alleviate the above-mentioned technical problems.

[0005] In a first aspect, embodiments of the present invention provide an optical coupler cascade transmission device, the device comprising an input terminal, a first-stage optical coupler, a second-stage optical coupler, and an output terminal arranged sequentially; wherein, an input electrical signal enters the first-stage optical coupler through the input terminal, the first-stage optical coupler is used to convert and transmit the electrical signal, and transmits the converted electrical signal to the second-stage optical coupler; the second-stage optical coupler is used to convert and transmit the electrical signal converted by the first-stage optical coupler again to obtain an output signal, the output signal being output through the output terminal; and the communication rate of the electrical signal is determined by the delay parameters of the first-stage optical coupler and the second-stage optical coupler.

[0006] In conjunction with the first aspect, the present invention provides a first possible implementation of the first aspect, wherein the first-stage optocoupler includes a first optocoupler device, the input terminal of which is connected to the input side pin of the first optocoupler device; the output side pin of the first optocoupler device is connected to the second-stage optocoupler device; the second-stage optocoupler includes a second optocoupler device, the output side pin of the first optocoupler device is connected to the input side pin of the second optocoupler device, forming a cascaded structure; the output side pin of the second-stage optocoupler device is connected to the output terminal.

[0007] In conjunction with the first possible implementation of the first aspect, the present invention provides a second possible implementation of the first aspect, wherein the input terminal is connected to the cathode pin on the input side of the first optocoupler; the emitter pin on the output side of the first optocoupler is connected to the cathode pin on the input side of the second optocoupler, and the emitter pin on the output side of the second optocoupler is connected to the output terminal; and a current-limiting resistor is connected in series between the first optocoupler and the second optocoupler.

[0008] In conjunction with the second possible implementation of the first aspect, the present invention provides a third possible implementation of the first aspect, wherein the anode pins on the input side of the first optocoupler and the second optocoupler are further connected to pull-up resistors; and the emitter pins on the output side of the first optocoupler and the second optocoupler are further connected to pull-down resistors.

[0009] In conjunction with the third possible implementation of the first aspect, this embodiment of the invention provides a fourth possible implementation of the first aspect, wherein the anode pins on the input side of the first optocoupler and the second optocoupler are further provided with a matching circuit; the matching circuit is connected in parallel with the pull-up resistor; the matching circuit is used to adjust the upper limit of the communication rate, such that the upper limit of the communication rate is determined by the turn-off delay parameter of the first optocoupler and the second optocoupler.

[0010] In conjunction with the first possible implementation of the first aspect, this embodiment of the invention provides a fifth possible implementation of the first aspect, wherein the input terminal is connected to the anode pin of the input side of the first optocoupler; the cathode pin of the input side of the first optocoupler is grounded; the collector pin of the output side of the first optocoupler is connected to the anode pin of the input side of the second optocoupler through an isolation resistor; the emitter pin of the output side of the first optocoupler and the cathode pin of the input side of the second optocoupler are grounded; and the collector pin of the output side of the second optocoupler is connected to the output terminal.

[0011] In conjunction with the first possible implementation of the first aspect, this embodiment of the invention provides a sixth possible implementation of the first aspect, wherein the input terminal is connected to the cathode pin of the input side of the first optocoupler; the emitter pin of the output side of the first optocoupler is grounded, and the collector pin of the output side of the first optocoupler is connected to a first level-flipping circuit, which is used to convert and transmit the electrical signal and send it to the cathode pin of the input side of the second optocoupler; the emitter pin of the output side of the second optocoupler is grounded, and the collector pin of the output side of the second optocoupler is connected to a second level-flipping circuit, which is used to convert and transmit the electrical signal again and send it to the output terminal; wherein the output terminal is connected to the output terminal of the second level-flipping circuit.

[0012] In conjunction with the first possible implementation of the first aspect, this embodiment of the invention provides a seventh possible implementation of the first aspect, wherein the aforementioned input terminal is connected to the anode pin of the input side of the first optocoupler, and the cathode pin of the input side of the first optocoupler is grounded; the emitter pin of the output side of the first optocoupler is connected to a first level-flipping circuit, which is used to convert and transmit the electrical signal and send it to the anode pin of the input side of the second optocoupler, and the cathode pin of the input side of the second optocoupler is grounded; the collector pin of the output side of the second optocoupler is connected to a second level-flipping circuit, which is used to convert and transmit the electrical signal again and send it to the output terminal; wherein the output terminal is connected to the output terminal of the second level-flipping circuit.

[0013] In conjunction with the sixth or seventh possible implementation of the first aspect, this embodiment of the invention provides an eighth possible implementation of the first aspect, wherein the first level-flipping circuit and the second level-flipping circuit are based on a NOT gate circuit composed of transistors to realize the conversion of electrical signals.

[0014] Secondly, embodiments of the present invention also provide a communication device, wherein the communication device is configured with the above-mentioned optical coupler cascade transmission device.

[0015] The embodiments of the present invention bring the following beneficial effects: This invention provides an optical coupler cascade transmission device and communication equipment. The optical coupler cascade transmission device includes an input terminal, a first-stage optical coupler, a second-stage optical coupler, and an output terminal arranged sequentially. An input electrical signal enters the first-stage optical coupler through the input terminal. The first-stage optical coupler converts and transmits the electrical signal, sending the converted signal to the second-stage optical coupler. The second-stage optical coupler further converts and transmits the converted electrical signal to obtain an output signal, which is output through the output terminal. The communication rate of the electrical signal is determined by the delay parameters of the first-stage and second-stage optical couplers. Since the output electrical signal has undergone conversion by the first and second-stage optical couplers, the absolute time difference between the turn-on delay parameter and the turn-off delay parameter can be canceled out by the two stages of optical couplers, thereby increasing the upper limit of the optical coupler's communication rate to meet the communication requirements of high-communication-rate scenarios.

[0016] Other features and advantages of the invention will be set forth in the description which follows, and will be apparent in part from the description, or may be learned by practicing the invention. The objects and other advantages of the invention are realized and obtained in accordance with the structures particularly pointed out in the description, claims and drawings.

[0017] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, preferred embodiments are described below in detail with reference to the accompanying drawings. Attached Figure Description

[0018] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0019] Figure 1 This is a schematic diagram of the structure of an optical coupler cascaded transmission device provided in an embodiment of the present invention; Figure 2 A circuit diagram of an optical coupler cascaded transmission device provided in an embodiment of the present invention; Figure 3 A circuit diagram of another optical coupler cascaded transmission device provided in an embodiment of the present invention; Figure 4 A circuit diagram of another optical coupler cascaded transmission device provided in an embodiment of the present invention; Figure 5 A circuit diagram of another optical coupler cascaded transmission device provided in an embodiment of the present invention; Figure 6 A circuit diagram of another optical coupler cascade transmission device provided in an embodiment of the present invention. Detailed Implementation

[0020] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions 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, 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.

[0021] Traditional single-stage optocouplers suffer from problems such as large differences between turn-on and turn-off delays and slow edge response, which limit the upper limit of optocoupler communication rate. In response to the increasing demand for higher communication rates, there are usually two directions in circuit design. Direction 1: Use electronic components with lower communication delays (such as high-speed optocouplers and isolation devices) to replace the original ordinary optocouplers to meet the requirements of high communication rates. Direction 2: On the original ordinary optocoupler circuit, optimize the design parameters and logic to match the requirements of high communication rates. The methods corresponding to this direction 2 are usually as follows: (1) Using the compensation method: that is, combining the characteristics of the optocoupler having a turn-on delay T1 and a turn-off delay T2, by changing the transmission time of the rising or falling edge of the optocoupler input signal (that is, advancing the transmission time to T2-T1), the logic "1" and logic "0" are equal in time, thereby increasing the upper limit of the optocoupler's communication rate in the communication device. (2) Set up an output delay matching circuit: reduce the matching resistor at the output end to increase the current of Ic at the output end, add a fast switching circuit composed of transistors to the primary side of the optocoupler, and add a level holding circuit composed of transistors to the secondary side to match the input and output delays of the optocoupler to meet the requirements of higher communication rates. (3) Set up a shaping circuit: match and adjust the parameters of the circuit, and add a circuit unit composed of transistors, capacitors and other devices at the output end to improve the turn-off delay time, reduce the absolute time difference between the turn-on delay and the turn-off delay, and improve the communication rate.

[0022] However, in the above methods, such as the first approach, electronic components with lower communication delays are used to improve the communication rate. While this method is feasible, the material cost of electronic components with lower communication delays is also higher. Although the communication rate is improved, the cost of use also increases accordingly. In the second approach, the absolute time difference between logic "1" and logic "0" at the output end is reduced by optimizing the design parameters and communication logic to achieve the requirement of high communication rate. In (1), since there is a time difference ΔT between the turn-on delay and the turn-off delay of the optocoupler, a compensation value is set in the program through software compensation so that the logic "1" and logic "0" at the output end are of equal time, thereby improving the communication rate. This solution only changes the software and does not change the existing circuit, so there is no change in material cost. However, the time difference between the turn-on delay and the turn-off delay of each optocoupler is not consistent, while the compensation value configured by the software is fixed. This results in this solution not being compatible with all optocouplers, and the higher the communication rate, the narrower the range of optocouplers that this solution is compatible with.

[0023] Furthermore, in method (2) of the above direction two, a level maintenance circuit is added to the primary stage, and Ic is increased and a fast turn-off circuit is added to the secondary stage. Compared with the original circuit, the hardware cost is increased; in addition, increasing Ic will also increase Vce, which may lead to the risk that the output cannot be pulled to a high level after conduction due to excessive VCE. Moreover, this defect will be further amplified at high temperatures. In the above method (3), only the output is adjusted. The added shaping circuit standardizes the output waveform, but no processing is done on the input delay. Although it can improve the communication rate to a certain extent, the improvement is limited. Its effect on high speeds (such as 115200bps) is very limited, and it is difficult to meet the requirements of high communication rates.

[0024] Based on this, the optical coupler cascaded transmission device and communication equipment provided in this embodiment of the invention can effectively improve the upper limit of the communication rate of the optical coupler in the RS485 circuit of the communication equipment, thereby meeting the usage requirements of high communication rate scenarios.

[0025] To facilitate understanding of this embodiment, a detailed description of an optical coupler cascade transmission device disclosed in this embodiment of the invention will be provided first.

[0026] In one possible implementation, embodiments of the present invention provide an optical coupler cascade transmission device, such as... Figure 1The diagram shows a structural schematic of an optical coupler cascaded transmission device. The device includes an input terminal 10, a first-stage optical coupler 20, a second-stage optical coupler 30, and an output terminal 40 arranged sequentially. The input electrical signal enters the first-stage optical coupler 20 through the input terminal. The first-stage optical coupler 20 converts and transmits the electrical signal, sending the converted signal to the second-stage optical coupler 30. The second-stage optical coupler 30 then converts and transmits the electrical signal converted by the first-stage optical coupler to obtain an output signal, which is output through the output terminal. The communication rate of the output electrical signal is determined by the delay parameters of the first-stage and second-stage optical couplers.

[0027] In practical applications, the cascaded optical coupler transmission device in this embodiment of the invention can be applied to the communication circuits of smart terminal devices such as smart meters, for example, to the RS485 communication interface of the smart terminal device, thereby increasing the upper limit of the communication rate of the interface. Furthermore, in this embodiment of the invention, since the output electrical signal undergoes conversion through a first-stage and a second-stage optical coupler, the absolute time difference between the turn-on delay parameter and the turn-off delay parameter can be mutually canceled by the two stages of optical couplers, thereby increasing the upper limit of the optical coupler's communication rate to meet the communication requirements of high-communication-rate scenarios.

[0028] In practical use, the first-stage optocoupler in the embodiments of the present invention includes a first optocoupler device, the input end of which is connected to the input side pin of the first optocoupler device; the output side pin of the first optocoupler device is connected to the second-stage optocoupler; the second-stage optocoupler includes a second optocoupler device, the output side pin of the first optocoupler device is connected to the input side pin of the second optocoupler device, forming a cascaded structure; the output side pin of the second-stage optocoupler is connected to the output end of the entire device.

[0029] Specifically, for ease of understanding, Figure 2 A circuit diagram of an optocoupler cascade structure is shown, such as... Figure 2 As shown, U1 and U2 represent the first optocoupler and the second optocoupler, respectively. Figure 2 As shown, INPUT represents the input terminal of the cascaded optocoupler transmission device, and OUTPUT represents the output terminal. The input terminal is connected to the cathode pin on the input side of the first optocoupler U1; the emitter pin on the output side of the first optocoupler is connected to the cathode pin on the input side of the second optocoupler, and the emitter pin on the output side of the second optocoupler is connected to the output terminal; furthermore, a current-limiting resistor is connected in series between the first optocoupler U1 and the second optocoupler U2. Figure 2 The current-limiting resistor R3 in the middle.

[0030] Furthermore, such as Figure 2 As shown, the anode pins on the input side of the first optocoupler U1 and the second optocoupler U2 are also connected to pull-up resistors; that is... Figure 2Furthermore, the output emitter pins of the first optocoupler U1 and the second optocoupler U2 are also connected to pull-up resistors R1 and R4, i.e. Figure 2 The pull-down resistors R2 and R5 are included. Among them, Figure 2 The diagram further shows the power supply pins VCC1, VCC2, and VCC3, as well as the ground pins GND2 and GND3.

[0031] For ease of understanding, the following is based on Figure 2 The optical coupler cascade transmission device provided in the embodiments of the present invention will be further described.

[0032] In communication circuits composed of optocouplers, there is typically a time delay parameter Ton between the primary winding of the optocoupler being turned on and the secondary winding responding to turn on; this time delay parameter is also called the turn-on delay parameter. Similarly, there is a time delay parameter Toff between the primary winding being turned off and the secondary winding responding to turn off; this time delay parameter is also called the turn-off delay parameter. Due to the characteristics of the optocoupler material, the duration of the turn-off delay parameter Toff is longer than the duration of the turn-on delay parameter Ton.

[0033] In a traditional single optocoupler circuit, when the communication rate is V1 (unit baud rate bps), the time or period for transmitting one bit is... Since the optocoupler has a delay parameter, the pulse widths corresponding to the logic states "1" and "0" can be expressed as follows: , , among which, T off1 and T on1 These are the delay parameters for a single optocoupler circuit, namely, the turn-off delay parameter and the turn-on delay parameter.

[0034] Taking half-cycle sampling as an example, the pulse width must satisfy the following relationship: ≤ ——① ≤ ——② From ① and ②, we get That is, the upper limit of the communication rate is the difference between the turn-on delay parameter and the turn-off delay parameter of the optocoupler. The difference between Toff1 and Ton1 determines the communication rate. The smaller the difference, the higher the upper limit of the communication rate; the larger the difference, the lower the upper limit of the communication rate. Therefore, increasing the communication rate V1 essentially means reducing the difference between Toff1 and Ton1.

[0035] In this embodiment of the invention, a two-stage optocoupler scheme is adopted, consisting of a first-stage optocoupler and a second-stage optocoupler. Both stages employ a NOT gate design, enabling two-stage inversion of the electrical signal. The turn-on and turn-off delays of the two optocouplers cancel each other out. Specifically, the explanation is based on a communication rate V2. Figure 2 In a communication circuit with a communication rate of V2, the input level, as an electrical signal, passes through the first-stage optocoupler, and the output level is converted. After superimposing the turn-on delay and turn-off delay of the first optocoupler U1 of the first-stage optocoupler, the following pulse width is obtained: The pulse width of the output logic "1": ; The pulse width for outputting logic "0": .

[0036] In this system, the output of the first-stage optocoupler serves as the input of the second-stage optocoupler. After the electrical signal passes through the second optocoupler device U2 in the second stage, the output electrical signal (level) is converted again. At this point, after superimposing the turn-on delay and turn-off delay of the second optocoupler device U2, the pulse width can be expressed as: The pulse width of the output logic "1": ; The pulse width for outputting logic "0": .

[0037] Wherein, T off1 and T on1 These are the delay parameters of the first optocoupler, namely, the turn-off delay parameter and the turn-on delay parameter of the first optocoupler; T off2 and T on2 These are the delay parameters of the second optocoupler, namely, the turn-off delay parameter and the turn-on delay parameter of the second optocoupler.

[0038] Taking half a cycle as an example (the signal pulse width needs to be greater than...), At this point, the following relationship must be satisfied: ≤ ——③ ≤ ——④ From ③ and ④, we get That is, the upper limit of the communication rate V2 is the difference between the turn-on delay parameter and the turn-off delay parameter of the two optocouplers. |Decision.

[0039] Obviously | |<| Therefore, in terms of the upper limit of communication rate, the upper limit of communication rate V2 is greater than the upper limit of communication rate V1.

[0040] Furthermore, for optocouplers in the same batch, the consistency of their turn-on delay is usually good, so it can be approximated that Ton1≈Ton2; similarly, the consistency of their turn-off delay is also relatively good, i.e., Toff1≈Toff2, so the upper limit of V2 is much greater than the upper limit of V1.

[0041] Furthermore, as can be seen from the foregoing, Figure 2 In the circuit shown, the formula that satisfies the upper limit of the communication rate V2 contains two sets of four variables, Toff1-Ton1 and Toff2-Ton2. In order to further improve the communication rate and enhance stability, in this embodiment of the invention, a matching circuit can be added to the input side of the two optocouplers.

[0042] For ease of understanding, Figure 2 On this basis, Figure 3 A circuit diagram of another optocoupler cascade structure is also shown, specifically, as follows: Figure 3 As shown, the anode pins on the input side of the first optocoupler U1 and the second optocoupler U2 are also provided with a matching circuit; the matching circuit is connected in parallel with the pull-up resistor; specifically, the matching circuit is used to adjust the upper limit of the communication rate so that the upper limit of the communication rate is determined by the turn-off delay parameter of the first optocoupler and the second optocoupler.

[0043] In specific implementation, the matching circuit in this embodiment of the invention consists of a matching resistor and a matching capacitor, for example, Figure 3 In the first optocoupler U1, the matching circuit consists of a resistor R6 and a capacitor C1. The resistor R6 and capacitor C1 are first connected in series and then connected in parallel to the two ends of the pull-up resistor R1. Similarly, the matching circuit of the second optocoupler U2 consists of a resistor R7 and a capacitor C2. The resistor R7 and capacitor C2 are first connected in series and then connected in parallel to the two ends of the pull-up resistor R4. Based on Figure 3 After adding the matching circuit, the conduction delay parameters Ton1 and Ton2 can be controlled within 0.5µs based on the matching circuit, and these conduction delay parameters can be fixed, denoted by ΔT. The following derivation relationship can then be used: | |→| |=| In other words, the upper limit of the communication rate in the entire optocoupler cascaded transmission device is only determined by the difference between the turn-off delay parameters of the two optocouplers |T|. off1 -T off2 The decision is that fewer variables lead to improved stability and general applicability.

[0044] In practical applications, considering the inherent turn-on and turn-off delays of optocouplers, and the good consistency of both turn-on and turn-off delays between them, the process of increasing the upper limit of communication speed in this embodiment of the invention utilizes these characteristics. Specifically, it employs a cascaded arrangement of two optocouplers to superimpose only one turn-on delay and one turn-off delay onto the same logic level signal (e.g., level "1" or "0"). To achieve this, the circuit's logic levels need to be flipped twice. Figure 2 and Figure 3 In this embodiment, the cathode pins on the input side of the first optocoupler U1 and the second optocoupler U2 are used as input terminals. In other embodiments, the anode pins on the input side can also be used as input terminals, that is, the optocouplers are turned on when a high level is input.

[0045] Specifically, for ease of understanding, in the above Figure 2 and Figure 3 On this basis, Figure 4 A circuit diagram of another optocoupler cascade structure is shown, in which the input terminal is connected to the anode pin on the input side of the first optocoupler device, i.e. Figure 4 In the INPUT configuration, the cathode pin on the input side of the first optocoupler U1 is grounded to GND1; the collector pin on the output side of the first optocoupler U1 is connected to the anode pin on the input side of the second optocoupler U2 through an isolation resistor R5; the emitter pin on the output side of the first optocoupler U1 and the cathode pin on the input side of the second optocoupler U2 are grounded; the collector pin on the output side of the second optocoupler U2 is connected to the output terminal, i.e. Figure 4 OUTPUT in the context of OUTPUT. Figure 4 The implementation of the matching circuit is also shown in the figure, based on Figure 4 It can be seen that when the optocoupler is high-level conducting, the matching circuit is connected in parallel with the current-limiting resistor connected to the anode pin on the output side. That is, Figure 4 In the first stage, resistor R1 and capacitor C1 are connected in series and then in parallel with resistor R2. In the second stage optocoupler, resistor R4 and capacitor C2 are connected in series and then in parallel with resistor R5.

[0046] Furthermore, in this embodiment of the invention, the conversion of electrical signals can be achieved without using optocouplers. That is, the first optocoupler and the second optocoupler do not achieve level switching, but a level switching circuit is connected after the output side of each optocoupler to achieve level switching.

[0047] Specifically, Figure 5 A circuit diagram of another optical coupler cascaded transmission device is shown, in which, Figure 5 The illustration uses the example of the first and second optocouplers having their cathode pins on the input side as the input terminals for electrical signals. Figure 5 The matching circuit is also shown. Specifically, as... Figure 5 As shown, the input terminal is connected to the cathode pin on the input side of the first optocoupler U1, that is, Figure 5 In the INPUT section, the emitter pin of the output side of the first optocoupler U1 is grounded, and the collector pin of the output side of the first optocoupler U1 is connected to a first level-flipping circuit. The circuit shown by the dashed line is a level-flipping circuit, which is used to convert and transmit the electrical signal and send it to the cathode pin of the input side of the second optocoupler U2. The emitter pin of the output side of the second optocoupler U2 is grounded, and the collector pin of the output side of the second optocoupler U2 is connected to a second level-flipping circuit. The second level-flipping circuit is used to convert and transmit the electrical signal again and send it to the output terminal OUTPUT. The output terminal OUTPUT is connected to the output terminal of the second level-flipping circuit.

[0048] further, Figure 6 A circuit diagram of another optical coupler cascaded transmission device is also shown, in which, Figure 5 The illustration uses the example of the first and second optocouplers having their anode pins on the input side as the input terminals for electrical signals. Figure 6 The matching circuit is also shown. Specifically, as... Figure 6 As shown, the input terminal is connected to the anode pin on the input side of the first optocoupler U1, that is, Figure 6 In the INPUT section, the cathode pin on the input side of the first optocoupler U1 is grounded; the emitter pin on the output side of the first optocoupler U1 is connected to a first level-flipping circuit, which is used to convert and transmit the electrical signal and send it to the anode pin on the input side of the second optocoupler U2, and the cathode pin on the input side of the second optocoupler U2 is grounded; the collector pin on the output side of the second optocoupler U2 is connected to a second level-flipping circuit, which is used to convert and transmit the electrical signal again and send it to the output terminal. Figure 6 In the first optocoupler U1 and the second optocoupler U2, the emitter pins on the output side are grounded through pull-down resistors R3 and R8, and the output terminal is connected to the output terminal of the second level-flipping circuit.

[0049] In practical use, Figure 5 and Figure 6 The first and second level switching circuits in the diagram are based on NOT gate circuits composed of transistors to achieve the conversion of electrical signals, that is... Figure 5 and Figure 6 The transistors Q1 and Q2 shown are illustrated below. Specifically, the base of the transistor is connected to the output side of the optocoupler, the emitter is grounded, and the collector can be connected to the next stage of the circuit or used as an output terminal. Based on Figure 5 and Figure 6The embodiment shown can make the waveform of the electrical signal steeper by using a level-flipping circuit, thereby avoiding signal sticking. The specific implementation of the level-flipping circuit can be selected according to the actual use situation, and the embodiments of the present invention do not limit this.

[0050] In practical use, the two cascaded optocouplers in the embodiments of the present invention are usually made of the same type of material to ensure that the materials are relatively similar, which has a better effect on improving the communication rate of the circuit.

[0051] In summary, the cascaded optical coupler transmission device provided in this embodiment of the invention employs a two-stage cascaded optical coupler approach. Each stage of the optical coupler uses a NOT gate to invert the level of the input electrical signal and output it. The two stages of the optical coupler can achieve the following: the first stage optical coupler input is high level → the first stage optical coupler output is low level, and simultaneously the second stage optical coupler input is low level → the second stage optical coupler output is high level; or, the first stage optical coupler input is low level → the first stage optical coupler output is high, and simultaneously the second stage optical coupler input is high level → the second stage optical coupler output is low level. The advantage of this two-stage inversion circuit is that it can apply the turn-on delay of the first stage optical coupler and the turn-off delay of the second stage optical coupler (or the turn-off delay of the first stage optical coupler and the turn-on delay of the second stage optical coupler) to the same signal. Because the optical couplers are of the same type, these two sets of delay signals can cancel each other out, resulting in a significant reduction in the total delay of the communication signal and a significant increase in the upper limit of the communication rate, which can meet the requirements of high communication rates such as 115200bps.

[0052] Furthermore, based on the two-stage cascaded transmission scheme in this embodiment of the invention, the timing delay problem caused by the large difference between the turn-on delay and the turn-off delay and the slow edge response can be eliminated from the root through two-stage relay driving, edge acceleration and delay equalization design, thereby increasing the upper limit of the communication rate of the optocoupler circuit. At the same time, the cascaded structure also further improves the electrical isolation performance of the system, thereby improving the overall communication security and stability.

[0053] Furthermore, based on the above embodiments, this invention also provides a communication device configured with the aforementioned optical coupler cascade transmission device.

[0054] The communication device provided in this embodiment of the invention has the same technical features as the optical coupler cascade transmission device provided in the above embodiments, so it can also solve the same technical problems and achieve the same technical effects.

[0055] Those skilled in the art will understand that, for the sake of convenience and brevity, the specific working process of the communication device described above can be referred to the corresponding process in the foregoing embodiments, and will not be repeated here.

[0056] Furthermore, in the description of the embodiments of the present invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; 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; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in the present invention based on the specific circumstances.

[0057] If the aforementioned functions are implemented as software functional units and sold or used as independent products, they can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of this invention, essentially, or the part that contributes to the prior art, or a portion of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods described in the various embodiments of this invention. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, portable hard drives, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical disks.

[0058] In the description of this invention, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing the invention and for 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 the invention. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0059] Finally, it should be noted that the above embodiments are merely specific implementations of the present invention, used to illustrate the technical solutions of the present invention, and not to limit it. The scope of protection of the present invention is not limited thereto. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that any person skilled in the art can still modify or easily conceive of changes to the technical solutions described in the foregoing embodiments within the technical scope disclosed in the present invention, or make equivalent substitutions for some of the technical features; and these modifications, changes, or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention, and should all be covered within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. An optical coupler cascade transmission device, characterized in that, The device includes an input terminal, a first-stage optocoupler, a second-stage optocoupler, and an output terminal arranged sequentially. The input electrical signal enters the first-stage optocoupler through the input terminal. The first-stage optocoupler is used to convert and transmit the electrical signal, and then sends the converted electrical signal to the second-stage optocoupler. The second-stage optocoupler is used to further convert and transmit the electrical signal converted by the first-stage optocoupler to obtain an output signal, which is output through the output terminal; and the communication rate of the electrical signal is determined by the delay parameters of the first-stage optocoupler and the second-stage optocoupler.

2. The optical coupler cascaded transmission device according to claim 1, characterized in that, The first-stage optocoupler includes a first optocoupler device, and the input terminal is connected to the input side pin of the first optocoupler device; The output pin of the first optocoupler is connected to the second-stage optocoupler; The second-stage optocoupler includes a second optocoupler device, and the output pin of the first optocoupler device is connected to the input pin of the second optocoupler device to form a cascaded structure; The output pin of the second-stage optocoupler is connected to the output terminal.

3. The optical coupler cascaded transmission device according to claim 2, characterized in that, The input terminal is connected to the cathode pin on the input side of the first optocoupler; the emitter pin on the output side of the first optocoupler is connected to the cathode pin on the input side of the second optocoupler, and the emitter pin on the output side of the second optocoupler is connected to the output terminal. Furthermore, a current-limiting resistor is connected in series between the first optocoupler and the second optocoupler.

4. The optical coupler cascaded transmission device according to claim 3, characterized in that, The anode pins on the input side of the first optocoupler and the second optocoupler are also connected to pull-up resistors; The emitter pins on the output side of the first optocoupler and the second optocoupler are also connected to pull-down resistors.

5. The optical coupler cascaded transmission device according to claim 4, characterized in that, The anode pins on the input side of the first optocoupler and the second optocoupler are also provided with matching circuits; The matching circuit is connected in parallel with the pull-up resistor; The matching circuit is used to adjust the upper limit of the communication rate, such that the upper limit of the communication rate is determined by the turn-off delay parameters of the first-stage optocoupler and the second-stage optocoupler.

6. The optical coupler cascaded transmission device according to claim 2, characterized in that, The input terminal is connected to the anode pin on the input side of the first optocoupler; the cathode pin on the input side of the first optocoupler is grounded. The collector pin on the output side of the first optocoupler is connected to the anode pin on the input side of the second optocoupler through an isolation resistor, and the emitter pin on the output side of the first optocoupler and the cathode pin on the input side of the second optocoupler are grounded. The collector pin on the output side of the second optocoupler is connected to the output terminal.

7. The optical coupler cascaded transmission device according to claim 2, characterized in that, The input terminal is connected to the cathode pin on the input side of the first optocoupler; the emitter pin on the output side of the first optocoupler is grounded, and the collector pin on the output side of the first optocoupler is connected to a first level switching circuit. The first level switching circuit is used to convert and transmit the electrical signal and send it to the cathode pin on the input side of the second optocoupler. The emitter pin on the output side of the second optocoupler is grounded, and the collector pin on the output side of the second optocoupler is connected to a second level-flipping circuit. The second level-flipping circuit is used to convert and transmit the electrical signal again and send it to the output terminal. The output terminal is connected to the output terminal of the second level-flipping circuit.

8. The optical coupler cascaded transmission device according to claim 2, characterized in that, The input terminal is connected to the anode pin on the input side of the first optocoupler, and the cathode pin on the input side of the first optocoupler is grounded. The emitter pin on the output side of the first optocoupler is connected to a first level-flipping circuit. The first level-flipping circuit is used to convert and transmit the electrical signal and send it to the anode pin on the input side of the second optocoupler. The cathode pin on the input side of the second optocoupler is grounded. The collector pin on the output side of the second optocoupler is connected to a second level-flipping circuit, which is used to convert and transmit the electrical signal again and send it to the output terminal. The output terminal is connected to the output terminal of the second level-flipping circuit.

9. The optical coupler cascaded transmission device according to claim 7 or 8, characterized in that, The first level-flipping circuit and the second level-flipping circuit are based on NOT gate circuits composed of transistors to realize the conversion of electrical signals.

10. A communication device, characterized in that, The communication device is equipped with the optical coupler cascade transmission device as described in any one of claims 1 to 9.

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