Isolated switching value input and output compatible circuit

Abstract

The invention provides an isolated switching value input and output compatible circuit, which belongs to the technical field of industrial control, and comprises an input signal processing unit electrically connected with an output signal amplification unit and used for obtaining an external input signal, obtaining a first processing signal based on the external input signal, and outputting the first processing signal; the isolation conversion unit is electrically connected with the isolation conversion unit, obtains a third output control signal based on the second output control signal and outputs the third output control signal to external control equipment, and the output signal processing unit is electrically connected with the isolation conversion unit and is used for obtaining a second processing signal based on the first processing signal, obtaining a second output control signal based on the first output control signal and outputting the second output control signal to external control equipment. And the isolation conversion unit is in communication connection with the MCU unit and is used for performing isolation transmission on the second processing signal and the first output control signal, and the MCU unit is used for obtaining a switch output control instruction based on the second processing signal and generating the first output control signal.

Description

Technical Field

[0001] The present invention relates to the technical field of industrial control, and in particular to an isolated switch value input-output compatible circuit. Background Art

[0002] In the field of industrial control, switch input and output signals are often used, where switch input signals are used to collect the status of external input signals, and switch output signals are used to output current or voltage signals to control the operation of equipment. Currently, switch input and output ports are mostly implemented using independent interfaces, and the number of input and output ports required in different occasions is often uncertain. Therefore, in order to adapt to different scenarios, it is often necessary to add equipment, which causes certain inconvenience and waste of resources.

[0003] At the same time, in industrial application scenarios, high-power and high-voltage applications are often involved, and a large number of interference signals are often coupled in the switch input and output lines, seriously affecting the normal operation of the circuit. Therefore, isolation measures need to be set up. In previous designs, optocoupler isolation technology was mostly used, but the characteristics of optocouplers are greatly affected by temperature, and their lifespan is greatly affected by the environment, which has an adverse effect on functional reliability.

[0004] For devices with high reliability, the devices are often required to have a self-test function, but the traditional means require a separate external detection circuit, which increases the cost and complexity of the system. Therefore, the prior art has the technical problems of high cost and complex circuits for switch input and output circuits. Summary of the invention

[0005] In view of this, it is necessary to provide an isolated switch input and output compatible circuit to solve the technical problems of high cost and complex circuit of switch input and output circuit in the prior art.

[0006] In order to solve the above technical problems, the present invention provides an isolated switch input-output compatible circuit, comprising: an input signal processing unit, electrically connected to the output signal amplifying unit, configured to obtain an external input signal, obtain a first processing signal based on the external input signal, obtain a third output control signal based on the second output control signal, and output the third output control signal to an external control device; an output signal processing unit, electrically connected to the isolation conversion unit, and configured to amplify the first processed signal to obtain a second processed signal, and amplify the first output control signal to obtain a second output control signal; an isolation conversion unit, which is communicatively connected to the MCU unit, and is used to perform an isolation operation based on the second processing signal and transmit it to the MCU unit, and to perform an isolation operation based on the first output control signal and transmit it to the output signal processing unit; The MCU unit is used to obtain a switch output control instruction based on the second processing signal, and generate a first output control signal based on the switch output control instruction.

[0007] In a possible implementation, obtaining the third output control signal based on the second output control signal includes: Current limiting and voltage limiting are performed based on the second output control signal to obtain a third output control signal.

[0008] In a possible implementation, the isolation conversion unit includes: An isolation conversion chip, a first capacitor, a second capacitor, a third capacitor, a fourth capacitor, a fifth capacitor and a sixth capacitor; The first capacitor, the second capacitor and the third capacitor are connected in parallel; The fourth capacitor, the fifth capacitor and the sixth capacitor are connected in parallel; The first pin of the isolation conversion chip is electrically connected to one end of the first capacitor, the second capacitor and the third capacitor; The fourth pin of the isolation conversion chip is electrically connected to the other ends of the first capacitor, the second capacitor and the third capacitor; The eighth pin of the isolation conversion chip is electrically connected to one end of the fourth capacitor, the fifth capacitor and the sixth capacitor; The fifth pin of the isolation conversion chip is electrically connected to the other ends of the fourth capacitor, the fifth capacitor and the sixth capacitor; The second pin of the isolation conversion chip is electrically connected to the output end of the MCU unit; The third pin of the isolation conversion chip is electrically connected to the input terminal of the MCU unit; The seventh pin of the isolation conversion chip is electrically connected to the input signal processing unit; The sixth pin of the isolation conversion chip is electrically connected to the output signal processing unit.

[0009] In a possible implementation, the input signal processing unit includes: A first resistor, a seventh capacitor and a voltage stabilizing diode; The seventh capacitor and the voltage zener diode are connected in parallel; The first resistor is electrically connected to the seventh capacitor and the voltage stabilizing diode; The first resistor, the seventh capacitor and the voltage-stabilizing diode are all electrically connected to the seventh pin of the isolation conversion chip.

[0010] In a possible implementation, the output signal processing unit includes: A second resistor, a third resistor, an eighth capacitor and a first MOS tube; The first MOS tube is electrically connected to the second resistor, the third resistor and the eighth capacitor respectively; The third resistor and the eighth capacitor are connected in parallel; The second resistor is electrically connected to the third resistor; The second resistor is electrically connected to the sixth pin of the isolation conversion chip.

[0011] In a possible implementation manner, obtaining a first processed signal based on the filtered signal includes: Current limiting and voltage limiting are performed based on the filtered signal to obtain a first processed signal.

[0012] In a possible implementation, the filtering unit includes: The common mode filter unit is electrically connected to the differential mode filter unit and is used to filter out interference of the common mode signal based on the external input signal to obtain a common mode filtered signal; The differential mode filtering unit is used to filter out interference of the differential mode signal based on the common mode filtering signal to obtain a filtered signal.

[0013] In a possible implementation, the differential mode filter unit includes: a ninth capacitor, and the first resistor is electrically connected to the ninth capacitor.

[0014] In a possible implementation, the common mode filtering unit includes: a second inductor, a tenth capacitor and an eleventh capacitor; The first end of the second inductor is electrically connected to one end of the ninth capacitor; The second end of the second inductor is electrically connected to the other end of the ninth capacitor; The third end of the second inductor is electrically connected to the capacitor; The fourth terminal of the second inductor is electrically connected to the eleventh capacitor.

[0015] The beneficial effects of the present invention are as follows: the isolated switch input-output compatible circuit provided by the present invention comprises: an input signal processing unit, electrically connected to the output signal amplifying unit, for obtaining an external input signal, obtaining a first processing signal based on the external input signal, and obtaining a third output control signal based on the second output control signal, and outputting the third output control signal to an external control device; an output signal processing unit, electrically connected to the isolation conversion unit, for amplifying based on the first processing signal to obtain a second processing signal, and amplifying based on the first output control signal to obtain a second output control signal; an isolation conversion unit, communicatively connected to the MCU unit, for performing an isolation operation based on the second processing signal and transmitting it to the MCU unit, and performing an isolation operation based on the first output control signal and transmitting it to the output signal processing unit; the MCU unit, for obtaining a switch output control instruction based on the second processing signal, and generating a first output control signal based on the switch output control instruction. The isolated switch quantity input and output compatible circuit provided by the present invention mainly controls the isolation conversion unit through the MCU unit, realizes the multiplexing of the switch quantity input and output interface, avoids the application limitation caused by the non-fixed input and output interface requirements, and provides effective isolation means based on the magnetic isolator in the isolation conversion unit to collect the input and output signals at the same time, and combined with the logical judgment of the MCU, can realize the functional self-check of the circuit state, avoid the introduction of interference, and improve the reliability and stability of the circuit. Compared with the traditional optocoupler isolation technology, the magnetic isolation technology proposed by the present invention can effectively reduce the circuit cost and reduce the complexity of the circuit through the multiplexing of the switch quantity input and output interface. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative work.

[0017] Figure 1 A schematic diagram of the structure of an embodiment of an isolated switching input-output compatible circuit provided by the present invention; Figure 2 The isolated switch input and output compatible circuit diagram provided by the present invention; Figure 3 A schematic structural diagram of an isolation conversion unit of an embodiment of an isolated switching input-output compatible circuit provided by the present invention. DETAILED DESCRIPTION

[0018] The technical solutions in the embodiments of the present invention will be described clearly and completely below in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative work are within the scope of protection of the present invention.

[0019] In the description of the embodiments of the present application, unless otherwise specified, “plurality” means two or more than two.

[0020] The terms "including" and "having" and any variations thereof in the embodiments of the present invention are intended to cover non-exclusive inclusions. For example, a process, method, apparatus, product or equipment comprising a series of steps or modules is not necessarily limited to those steps or modules clearly listed, but may include other steps or modules not clearly listed or inherent to these processes, methods, products or equipment.

[0021] The naming or numbering of the steps in the embodiments of the present invention does not mean that the steps in the method flow must be executed in the time / logical sequence indicated by the naming or numbering. The execution order of the named or numbered process steps can be changed according to the technical purpose to be achieved, as long as the same or similar technical effects can be achieved.

[0022] Reference to "embodiments" herein means that a particular feature, structure, or characteristic described in conjunction with the embodiments may be included in at least one embodiment of the present invention. The appearance of the phrase in various places in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment that is mutually exclusive with other embodiments. It is explicitly and implicitly understood by those skilled in the art that the embodiments described herein may be combined with other embodiments.

[0023] The present invention provides an isolated switch value input-output compatible circuit, which is described below.

[0024] Figure 1 A schematic diagram of an embodiment of the isolated switch input-output compatible circuit provided by the present invention and Figure 2 The isolated switch quantity input and output compatible circuit diagram provided by the present invention comprises: The input signal processing unit 103 is electrically connected to the output signal amplifying unit, and is used to obtain an external input signal, obtain a first processing signal based on the external input signal, obtain a third output control signal based on the second output control signal, and output the third output control signal to an external control device; The output signal processing unit 104 is electrically connected to the isolation conversion unit 102, and is used to amplify the first processed signal to obtain a second processed signal, and to amplify the first output control signal to obtain a second output control signal; The isolation conversion unit 102 is communicatively connected with the MCU unit 101, and is used to perform an isolation operation based on the second processing signal and transmit it to the MCU unit 101, and to perform an isolation operation based on the first output control signal and transmit it to the output signal processing unit 104; The MCU unit 101 is used to obtain a switch output control instruction based on the second processing signal, and generate a first output control signal based on the switch output control instruction.

[0025] It can be understood that the isolated switch input and output compatible circuit disclosed in the present invention includes several parts such as MCU (Micro Controller Unit), isolation conversion unit 102, input signal processing unit 103, output signal processing unit 104, differential mode filtering, common mode filtering, etc. The MCU unit 101 is responsible for the acquisition of input signals and the control of output signals; the isolation conversion unit 102 isolates the relevant signals and provides isolated power supply, provides a stable level reference for the subsequent stage, and avoids the external level change from affecting the circuit stability; the differential mode filtering and common mode filtering are used to eliminate signal interference and improve stability.

[0026] The external signal is input into the circuit through the DI / DO+ and DI / DO- interfaces, and first passes through the common mode filter unit and the differential mode filter unit to filter out the common mode interference and differential mode interference of the external signal, thereby improving the stability of the signal; then the processed signal is connected to the input signal processing unit 103 and the output signal processing unit 104 respectively; the input signal processing unit 103 performs current limiting, voltage limiting, filtering and other processing on the signal, and then inputs it into the digital quantity input pre-isolation interface of the isolation conversion unit 102, and after isolation, it is sent to the MCU unit 101 through the digital quantity input post-isolation interface; when the circuit is used as a switch output function, the MCU unit 101 first sends out a control signal, and after passing through the isolation conversion unit 102, the isolated control signal is sent to the output signal processing unit 104, and after the signal is amplified by the MOS tube (or transistor), it is filtered through differential mode and common mode, and then connected to the external device to control the action of the external device.

[0027] Capacitors C1, C2, C3, C4, C5, and C6 are filter capacitors of the isolation conversion unit 102, which include several capacitors with different capacities. The large-capacity capacitors are used to filter out low-frequency interference of the power supply, and the small-capacity capacitors are used to filter out high-frequency interference of the power supply, thereby ensuring the normal realization of their functions.

[0028] The output signal processing unit 104 in the switch output function circuit, wherein the resistor R2 is a driving resistor, and its function is to limit the driving switching speed, thereby reducing the jitter in the switching process, while preventing signal crosstalk and improving the driving reliability; the resistor R3 and the capacitor C8 together constitute the driving filtering function, on the one hand, the interference signal of the driving signal is filtered out by C8, and on the other hand, a charge discharge channel is provided for the signal through C8 to improve the shutdown speed and reliability; Q1 is a current amplifier device, which can generally adopt a MOS tube or a triode, which can pass a larger current and withstand a higher voltage, thereby completing the conversion from a small control signal to a large driving signal, avoiding the trouble of adding an external driving amplifier component, and improving the system integration.

[0029] After the external switch input signal is input through the interface connector, the interference of the external signal is filtered out through common mode filtering and differential mode filtering, and then the processed signal is sent to the input signal processing unit 103. After the signal is processed by the circuit, it is sent to the isolation conversion unit 102, and the external input signal is subjected to magnetic isolation processing. The processed signal is sent to the MCU unit 101 to complete the collection of the external input state. The resistor R1 in the input signal processing unit 103 is a current limiting resistor, which limits the input current to a reasonable range to avoid excessive current causing excessive heating and damaging the device; DZ1 is a voltage stabilizing diode, which stabilizes the external input signal to a fixed voltage, and the voltage value matches the voltage range of port 7 in the isolation conversion unit 102. When the external input voltage changes, the port 7 voltage can always be maintained in a fixed range, so that the circuit can adapt to a wider range of applications; the capacitor C7 in the input signal processing unit 103 is a filter capacitor, which can effectively filter out interference signals in the input signal, maintain the stability of the input signal, and is used to improve the reliability of the circuit.

[0030] The function of the voltage regulator D1 is to prevent external impulse voltage from damaging internal devices. When the external impulse voltage exceeds the threshold, it conducts and discharges, thereby protecting the internal circuit; the capacitor C9 included in the differential mode filter is used to filter out the differential mode interference signal in the input and output circuits; the inductor L2 included in the power filter is a common mode inductor, and one end of the capacitors C10 and C11 are connected to the casing, and they work together to filter out common mode interference in the line.

[0031] When the circuit is used as a switch output function, the switch input path can simultaneously collect external states. When the switch output state is disconnected, the value collected by the switch input path should be logic 1; when the switch output state is closed, the value collected by the switch input path should be logic 0; therefore, based on the logical relationship between the two states, it can be determined whether the external circuit has fault information such as broken wires and output abnormalities, thereby realizing self-test of the function.

[0032] It can be further understood that the MCU unit 101 is used for collecting switch input and controlling switch output, and performs self-test of circuit functions according to the logic states of the two. Its scope includes but is not limited to DSP, ARM, FPGA and other chips with relevant functions.

[0033] The isolation conversion unit 102 is used to implement the isolation of input and output signals and generate an isolated power supply to generate a stable level standard for the back end.

[0034] The input signal processing unit 103 is used to convert the external input switch signal into a level signal that can be received by the isolation unit, and control the power consumption to be as small as possible.

[0035] The output signal processing unit 104 is used to use MOS tubes to increase the output current capacity and achieve further isolation between control and output.

[0036] The differential mode filtering and common mode filtering units are used to eliminate interference signals coupled into high-power and high-voltage application scenarios, thereby improving functional reliability.

[0037] It can be further understood that the switch input and output use the same port. After the signal enters the interior, it is respectively connected to the input signal processing unit 103 and the output signal processing unit 104 for processing, thereby realizing the decoupling of the two functional circuits. After being processed, the signal is respectively sent to the isolation conversion unit 102, and then sent to the MCU unit 101 after being processed by the signal isolation unit. The MCU unit 101 collects the input signal status and generates an output control signal according to the control instruction. At the same time, the MCU unit 101 can realize functional integrity self-check according to the logical status of the input and output.

[0038] In some embodiments of the present invention, obtaining a third output control signal based on the second output control signal includes: Current limiting and voltage limiting are performed based on the second output control signal to obtain a third output control signal. Figure 3 The structural diagram of the isolation conversion unit 102 of an embodiment of the isolated switching input-output compatible circuit provided by the present invention includes: An isolation conversion chip, a first capacitor, a second capacitor, a third capacitor, a fourth capacitor, a fifth capacitor and a sixth capacitor; The first capacitor, the second capacitor and the third capacitor are connected in parallel; The fourth capacitor, the fifth capacitor and the sixth capacitor are connected in parallel; The first pin of the isolation conversion chip is electrically connected to one end of the first capacitor, the second capacitor and the third capacitor; The fourth pin of the isolation conversion chip is electrically connected to the other ends of the first capacitor, the second capacitor and the third capacitor; The eighth pin of the isolation conversion chip is electrically connected to one end of the fourth capacitor, the fifth capacitor and the sixth capacitor; The fifth pin of the isolation conversion chip is electrically connected to the other ends of the fourth capacitor, the fifth capacitor and the sixth capacitor; The second pin of the isolation conversion chip is electrically connected to the output end of the MCU unit 101; The third pin of the isolation conversion chip is electrically connected to the input terminal of the MCU unit 101; The seventh pin of the isolation conversion chip is electrically connected to the input signal processing unit 103; The sixth pin of the isolation conversion chip is electrically connected to the output signal processing unit 104 .

[0039] It can be understood that the isolation conversion unit 102 realizes the simultaneous acquisition of switch input and output signals through a bidirectional magnetic isolation device. At the same time, the hysteresis characteristic of the isolation unit improves the anti-interference ability of the circuit. The use of magnetic isolation can provide an isolated power supply for the subsequent stage to ensure the stability of the control level of the subsequent circuit.

[0040] By isolating the conversion unit 102 and the input signal processing unit 103, adaptation to a wide range of input signals is achieved without adjusting the internal circuit.

[0041] The isolated power supply and output signal processing unit 104 provided by the isolation conversion unit 102 can effectively isolate the control signal from the working signal on the one hand, and provide a stable level for the control circuit when the external input changes on the other hand, thereby improving the anti-interference performance of the circuit.

[0042] It can be further understood that the isolated primary power positive and the isolated primary power ground are generated after OSC and magnetic isolation processing, and the isolated power secondary positive and the isolated power secondary ground provide reference levels for the subsequent circuits; the digital input isolation front interface is sent to the digital input isolation rear interface after passing through the hysteresis amplifier, ENCODE, magnetic isolator, DECODE, and output amplifier to convert the external input signal into an isolated internal signal; the digital output primary is first sent to the digital output control secondary side after passing through the hysteresis amplifier, ENCODE, magnetic isolator, DECODE, and output amplifier, and then the digital output signal is sent to the output signal processing unit 104, and the signal is sent to the differential mode filter and common mode filter for filtering after amplification, and finally sent to the external control device through the external interface.

[0043] In some embodiments of the present invention, the input signal processing unit 103 includes: A first resistor, a seventh capacitor and a voltage stabilizing diode; The seventh capacitor and the voltage zener diode are connected in parallel; The first resistor is electrically connected to the seventh capacitor and the voltage stabilizing diode; The first resistor, the seventh capacitor and the voltage-stabilizing diode are all electrically connected to the seventh pin of the isolation conversion chip.

[0044] It can be understood that the isolated switch input and output compatible circuit disclosed in the present invention includes several parts such as MCU (Micro Controller Unit), isolation conversion unit 102, input signal processing unit 103, output signal processing unit 104, differential mode filtering, common mode filtering, etc. The MCU unit 101 is responsible for the acquisition of input signals and the control of output signals; the isolation conversion unit 102 isolates the relevant signals and provides isolated power supply, provides a stable level reference for the subsequent stage, and avoids the external level change from affecting the circuit stability; the differential mode filtering and common mode filtering are used to eliminate signal interference and improve stability.

[0045] The external signal is input into the circuit through the DI / DO+ and DI / DO- interfaces, and first passes through the common mode filter unit and the differential mode filter unit to filter out the common mode interference and differential mode interference of the external signal, thereby improving the stability of the signal; then the processed signal is connected to the input signal processing unit 103 and the output signal processing unit 104 respectively; the input signal processing unit 103 performs current limiting, voltage limiting, filtering and other processing on the signal, and then inputs it into the digital quantity input pre-isolation interface of the isolation conversion unit 102, and after isolation, it is sent to the MCU unit 101 through the digital quantity input post-isolation interface; when the circuit is used as a switch output function, the MCU unit 101 first sends out a control signal, and after passing through the isolation conversion unit 102, the isolated control signal is sent to the output signal processing unit 104, and after the signal is amplified by the MOS tube (or transistor), it is filtered through differential mode and common mode, and then connected to the external device to control the action of the external device.

[0046] Capacitors C1, C2, C3, C4, C5, and C6 are filter capacitors of the isolation conversion unit 102, which include several capacitors with different capacities. The large-capacity capacitors are used to filter out low-frequency interference of the power supply, and the small-capacity capacitors are used to filter out high-frequency interference of the power supply, thereby ensuring the normal realization of their functions.

[0047] The output signal processing unit 104 in the switch output function circuit, wherein the resistor R2 is a driving resistor, and its function is to limit the driving switching speed, thereby reducing the jitter in the switching process, while preventing signal crosstalk and improving the driving reliability; the resistor R3 and the capacitor C8 together constitute the driving filtering function, on the one hand, the interference signal of the driving signal is filtered out by C8, and on the other hand, a charge discharge channel is provided for the signal through C8 to improve the shutdown speed and reliability; Q1 is a current amplifier device, which can generally adopt a MOS tube or a triode, which can pass a larger current and withstand a higher voltage, thereby completing the conversion from a small control signal to a large driving signal, avoiding the trouble of adding an external driving amplifier component, and improving the system integration.

[0048] After the external switch input signal is input through the interface connector, the interference of the external signal is filtered out through common mode filtering and differential mode filtering, and then the processed signal is sent to the input signal processing unit 103. After the signal is processed by the circuit, it is sent to the isolation conversion unit 102, and the external input signal is subjected to magnetic isolation processing. The processed signal is sent to the MCU unit 101 to complete the collection of the external input state. The resistor R1 in the input signal processing unit 103 is a current limiting resistor, which limits the input current to a reasonable range to avoid excessive current causing excessive heating and damaging the device; DZ1 is a voltage stabilizing diode, which stabilizes the external input signal to a fixed voltage, and the voltage value matches the voltage range of port 7 in the isolation conversion unit 102. When the external input voltage changes, the port 7 voltage can always be maintained in a fixed range, so that the circuit can adapt to a wider range of applications; the capacitor C7 in the input signal processing unit 103 is a filter capacitor, which can effectively filter out interference signals in the input signal, maintain the stability of the input signal, and is used to improve the reliability of the circuit.

[0049] The function of the voltage regulator D1 is to prevent external impulse voltage from damaging internal devices. When the external impulse voltage exceeds the threshold, it conducts and discharges, thereby protecting the internal circuit; the capacitor C9 included in the differential mode filter is used to filter out the differential mode interference signal in the input and output circuits; the inductor L2 included in the power filter is a common mode inductor, and one end of the capacitors C10 and C11 are connected to the casing, and they work together to filter out common mode interference in the line.

[0050] When the circuit is used as a switch output function, the switch input path can simultaneously collect external states. When the switch output state is disconnected, the value collected by the switch input path should be logic 1; when the switch output state is closed, the value collected by the switch input path should be logic 0; therefore, based on the logical relationship between the two states, it can be determined whether the external circuit has fault information such as broken wires and output abnormalities, thereby realizing self-test of the function.

[0051] In some embodiments of the present invention, the output signal processing unit 104 includes: A second resistor, a third resistor, an eighth capacitor and a first MOS tube; The first MOS tube is electrically connected to the second resistor, the third resistor and the eighth capacitor respectively; The third resistor and the eighth capacitor are connected in parallel; The second resistor is electrically connected to the third resistor; The second resistor is electrically connected to the sixth pin of the isolation conversion chip.

[0052] It can be understood that the isolated switch input and output compatible circuit disclosed in the present invention includes several parts such as MCU (Micro Controller Unit), isolation conversion unit 102, input signal processing unit 103, output signal processing unit 104, differential mode filtering, common mode filtering, etc. The MCU unit 101 is responsible for the acquisition of input signals and the control of output signals; the isolation conversion unit 102 isolates the relevant signals and provides isolated power supply, provides a stable level reference for the subsequent stage, and avoids the external level change from affecting the circuit stability; the differential mode filtering and common mode filtering are used to eliminate signal interference and improve stability.

[0053] The external signal is input into the circuit through the DI / DO+ and DI / DO- interfaces, and first passes through the common mode filter unit and the differential mode filter unit to filter out the common mode interference and differential mode interference of the external signal, thereby improving the stability of the signal; then the processed signal is connected to the input signal processing unit 103 and the output signal processing unit 104 respectively; the input signal processing unit 103 performs current limiting, voltage limiting, filtering and other processing on the signal, and then inputs it into the digital quantity input pre-isolation interface of the isolation conversion unit 102, and after isolation, it is sent to the MCU unit 101 through the digital quantity input post-isolation interface; when the circuit is used as a switch output function, the MCU unit 101 first sends out a control signal, and after passing through the isolation conversion unit 102, the isolated control signal is sent to the output signal processing unit 104, and after the signal is amplified by the MOS tube (or transistor), it is filtered through differential mode and common mode, and then connected to the external device to control the action of the external device.

[0054] Capacitors C1, C2, C3, C4, C5, and C6 are filter capacitors of the isolation conversion unit 102, which include several capacitors with different capacities. The large-capacity capacitors are used to filter out low-frequency interference of the power supply, and the small-capacity capacitors are used to filter out high-frequency interference of the power supply, thereby ensuring the normal realization of their functions.

[0055] The output signal processing unit 104 in the switch output function circuit, wherein the resistor R2 is a driving resistor, and its function is to limit the driving switching speed, thereby reducing the jitter in the switching process, while preventing signal crosstalk and improving the driving reliability; the resistor R3 and the capacitor C8 together constitute the driving filtering function, on the one hand, the interference signal of the driving signal is filtered out by C8, and on the other hand, a charge discharge channel is provided for the signal through C8 to improve the shutdown speed and reliability; Q1 is a current amplifier device, which can generally adopt a MOS tube or a triode, which can pass a larger current and withstand a higher voltage, thereby completing the conversion from a small control signal to a large driving signal, avoiding the trouble of adding an external driving amplifier component, and improving the system integration.

[0056] After the external switch input signal is input through the interface connector, the interference of the external signal is filtered out through common mode filtering and differential mode filtering, and then the processed signal is sent to the input signal processing unit 103. After the signal is processed by the circuit, it is sent to the isolation conversion unit 102, and the external input signal is subjected to magnetic isolation processing. The processed signal is sent to the MCU unit 101 to complete the collection of the external input state. The resistor R1 in the input signal processing unit 103 is a current limiting resistor, which limits the input current to a reasonable range to avoid excessive current causing excessive heating and damaging the device; DZ1 is a voltage stabilizing diode, which stabilizes the external input signal to a fixed voltage, and the voltage value matches the voltage range of port 7 in the isolation conversion unit 102. When the external input voltage changes, the port 7 voltage can always be maintained in a fixed range, so that the circuit can adapt to a wider range of applications; the capacitor C7 in the input signal processing unit 103 is a filter capacitor, which can effectively filter out interference signals in the input signal, maintain the stability of the input signal, and is used to improve the reliability of the circuit.

[0057] The function of the voltage regulator D1 is to prevent external impulse voltage from damaging internal devices. When the external impulse voltage exceeds the threshold, it conducts and discharges, thereby protecting the internal circuit; the capacitor C9 included in the differential mode filter is used to filter out the differential mode interference signal in the input and output circuits; the inductor L2 included in the power filter is a common mode inductor, and one end of the capacitors C10 and C11 are connected to the casing, and they work together to filter out common mode interference in the line.

[0058] When the circuit is used as a switch output function, the switch input path can simultaneously collect external states. When the switch output state is disconnected, the value collected by the switch input path should be logic 1; when the switch output state is closed, the value collected by the switch input path should be logic 0; therefore, based on the logical relationship between the two states, it can be determined whether the external circuit has fault information such as broken wires and output abnormalities, thereby realizing self-test of the function.

[0059] In some embodiments of the present invention, the circuit further comprises: The filtering unit is electrically connected to the input signal processing unit 103, and is used to obtain an external input signal, perform interference filtering based on the external input signal, obtain a filtered signal, obtain a first processed signal based on the filtered signal, and output a third output control signal to an external control device. It can be understood that the isolated switch input and output compatible circuit disclosed in the present invention includes an MCU (Micro Controller Unit) unit, an isolation conversion unit 102, an input signal processing unit 103, an output signal processing unit 104, differential mode filtering, common mode filtering and other parts. The MCU unit 101 is responsible for the acquisition of input signals and the control of output signals; the isolation conversion unit 102 isolates the relevant signals and provides isolated power supply, provides a stable level reference for the subsequent stage, and avoids the external level change from affecting the circuit stability; the differential mode filtering and common mode filtering are used to eliminate signal interference and improve stability.

[0060] The external signal is input into the circuit through the DI / DO+ and DI / DO- interfaces, and first passes through the common mode filter unit and the differential mode filter unit to filter out the common mode interference and differential mode interference of the external signal, thereby improving the stability of the signal; then the processed signal is connected to the input signal processing unit 103 and the output signal processing unit 104 respectively; the input signal processing unit 103 performs current limiting, voltage limiting, filtering and other processing on the signal, and then inputs it into the digital quantity input pre-isolation interface of the isolation conversion unit 102, and after isolation, it is sent to the MCU unit 101 through the digital quantity input post-isolation interface; when the circuit is used as a switch output function, the MCU unit 101 first sends out a control signal, and after passing through the isolation conversion unit 102, the isolated control signal is sent to the output signal processing unit 104, and after the signal is amplified by the MOS tube (or transistor), it is filtered through differential mode and common mode, and then connected to the external device to control the action of the external device.

[0061] Capacitors C1, C2, C3, C4, C5, and C6 are filter capacitors of the isolation conversion unit 102, which include several capacitors with different capacities. The large-capacity capacitors are used to filter out low-frequency interference of the power supply, and the small-capacity capacitors are used to filter out high-frequency interference of the power supply, thereby ensuring the normal realization of their functions.

[0062] The output signal processing unit 104 in the switch output function circuit, wherein the resistor R2 is a driving resistor, and its function is to limit the driving switching speed, thereby reducing the jitter in the switching process, while preventing signal crosstalk and improving the driving reliability; the resistor R3 and the capacitor C8 together constitute the driving filtering function, on the one hand, the interference signal of the driving signal is filtered out by C8, and on the other hand, a charge discharge channel is provided for the signal through C8 to improve the shutdown speed and reliability; Q1 is a current amplifier device, which can generally adopt a MOS tube or a triode, which can pass a larger current and withstand a higher voltage, thereby completing the conversion from a small control signal to a large driving signal, avoiding the trouble of adding an external driving amplifier component, and improving the system integration.

[0063] After the external switch input signal is input through the interface connector, the interference of the external signal is filtered out through common mode filtering and differential mode filtering, and then the processed signal is sent to the input signal processing unit 103. After the signal is processed by the circuit, it is sent to the isolation conversion unit 102, and the external input signal is subjected to magnetic isolation processing. The processed signal is sent to the MCU unit 101 to complete the collection of the external input state. The resistor R1 in the input signal processing unit 103 is a current limiting resistor, which limits the input current to a reasonable range to avoid excessive current causing excessive heating and damaging the device; DZ1 is a voltage stabilizing diode, which stabilizes the external input signal to a fixed voltage, and the voltage value matches the voltage range of port 7 in the isolation conversion unit 102. When the external input voltage changes, the port 7 voltage can always be maintained in a fixed range, so that the circuit can adapt to a wider range of applications; the capacitor C7 in the input signal processing unit 103 is a filter capacitor, which can effectively filter out interference signals in the input signal, maintain the stability of the input signal, and is used to improve the reliability of the circuit.

[0064] The function of the voltage regulator D1 is to prevent external impulse voltage from damaging internal devices. When the external impulse voltage exceeds the threshold, it conducts and discharges, thereby protecting the internal circuit; the capacitor C9 included in the differential mode filter is used to filter out the differential mode interference signal in the input and output circuits; the inductor L2 included in the power filter is a common mode inductor, and one end of the capacitors C10 and C11 are connected to the casing, and they work together to filter out common mode interference in the line.

[0065] When the circuit is used as a switch output function, the switch input path can simultaneously collect external states. When the switch output state is disconnected, the value collected by the switch input path should be logic 1; when the switch output state is closed, the value collected by the switch input path should be logic 0; therefore, based on the logical relationship between the two states, it can be determined whether the external circuit has fault information such as broken wires and output abnormalities, thereby realizing self-test of the function.

[0066] In some embodiments of the present invention, obtaining a first processed signal based on the filtered signal includes: Current limiting and voltage limiting are performed based on the filtered signal to obtain a first processed signal. In some embodiments of the present invention, the filtering unit includes: The common mode filter unit is electrically connected to the differential mode filter unit and is used to filter out interference of the common mode signal based on the external input signal to obtain a common mode filtered signal; The differential mode filtering unit is used to filter out interference of the differential mode signal based on the common mode filtering signal to obtain a filtered signal.

[0067] It can be understood that the isolated switch input and output compatible circuit disclosed in the present invention includes several parts such as MCU (Micro Controller Unit), isolation conversion unit 102, input signal processing unit 103, output signal processing unit 104, differential mode filtering, common mode filtering, etc. The MCU unit 101 is responsible for the acquisition of input signals and the control of output signals; the isolation conversion unit 102 isolates the relevant signals and provides isolated power supply, provides a stable level reference for the subsequent stage, and avoids the external level change from affecting the circuit stability; the differential mode filtering and common mode filtering are used to eliminate signal interference and improve stability.

[0068] The external signal is input into the circuit through the DI / DO+ and DI / DO- interfaces, and first passes through the common mode filter unit and the differential mode filter unit to filter out the common mode interference and differential mode interference of the external signal, thereby improving the stability of the signal; then the processed signal is connected to the input signal processing unit 103 and the output signal processing unit 104 respectively; the input signal processing unit 103 performs current limiting, voltage limiting, filtering and other processing on the signal, and then inputs it into the digital quantity input pre-isolation interface of the isolation conversion unit 102, and after isolation, it is sent to the MCU unit 101 through the digital quantity input post-isolation interface; when the circuit is used as a switch output function, the MCU unit 101 first sends out a control signal, and after passing through the isolation conversion unit 102, the isolated control signal is sent to the output signal processing unit 104, and after the signal is amplified by the MOS tube (or transistor), it is filtered through differential mode and common mode, and then connected to the external device to control the action of the external device.

[0069] Capacitors C1, C2, C3, C4, C5, and C6 are filter capacitors of the isolation conversion unit 102, which include several capacitors with different capacities. The large-capacity capacitors are used to filter out low-frequency interference of the power supply, and the small-capacity capacitors are used to filter out high-frequency interference of the power supply, thereby ensuring the normal realization of their functions.

[0070] The output signal processing unit 104 in the switch output function circuit, wherein the resistor R2 is a driving resistor, and its function is to limit the driving switching speed, thereby reducing the jitter in the switching process, while preventing signal crosstalk and improving the driving reliability; the resistor R3 and the capacitor C8 together constitute the driving filtering function, on the one hand, the interference signal of the driving signal is filtered out by C8, and on the other hand, a charge discharge channel is provided for the signal through C8 to improve the shutdown speed and reliability; Q1 is a current amplifier device, which can generally adopt a MOS tube or a triode, which can pass a larger current and withstand a higher voltage, thereby completing the conversion from a small control signal to a large driving signal, avoiding the trouble of adding an external driving amplifier component, and improving the system integration.

[0071] After the external switch input signal is input through the interface connector, the interference of the external signal is filtered out through common mode filtering and differential mode filtering, and then the processed signal is sent to the input signal processing unit 103. After the signal is processed by the circuit, it is sent to the isolation conversion unit 102, and the external input signal is subjected to magnetic isolation processing. The processed signal is sent to the MCU unit 101 to complete the collection of the external input state. The resistor R1 in the input signal processing unit 103 is a current limiting resistor, which limits the input current to a reasonable range to avoid excessive current causing excessive heating and damaging the device; DZ1 is a voltage stabilizing diode, which stabilizes the external input signal to a fixed voltage, and the voltage value matches the voltage range of port 7 in the isolation conversion unit 102. When the external input voltage changes, the port 7 voltage can always be maintained in a fixed range, so that the circuit can adapt to a wider range of applications; the capacitor C7 in the input signal processing unit 103 is a filter capacitor, which can effectively filter out interference signals in the input signal, maintain the stability of the input signal, and is used to improve the reliability of the circuit.

[0072] The function of the voltage regulator D1 is to prevent external impulse voltage from damaging internal devices. When the external impulse voltage exceeds the threshold, it conducts and discharges, thereby protecting the internal circuit; the capacitor C9 included in the differential mode filter is used to filter out the differential mode interference signal in the input and output circuits; the inductor L2 included in the power filter is a common mode inductor, and one end of the capacitors C10 and C11 are connected to the casing, and they work together to filter out common mode interference in the line.

[0073] When the circuit is used as a switch output function, the switch input path can simultaneously collect external states. When the switch output state is disconnected, the value collected by the switch input path should be logic 1; when the switch output state is closed, the value collected by the switch input path should be logic 0; therefore, based on the logical relationship between the two states, it can be determined whether the external circuit has fault information such as broken wires and output abnormalities, thereby realizing self-test of the function.

[0074] In some embodiments of the present invention, the differential mode filtering unit includes: a ninth capacitor, and the first resistor is electrically connected to the ninth capacitor.

[0075] It can be understood that the isolated switch input and output compatible circuit disclosed in the present invention includes several parts such as MCU (Micro Controller Unit), isolation conversion unit 102, input signal processing unit 103, output signal processing unit 104, differential mode filtering, common mode filtering, etc. The MCU unit 101 is responsible for the acquisition of input signals and the control of output signals; the isolation conversion unit 102 isolates the relevant signals and provides isolated power supply, provides a stable level reference for the subsequent stage, and avoids the external level change from affecting the circuit stability; the differential mode filtering and common mode filtering are used to eliminate signal interference and improve stability.

[0076] The external signal is input into the circuit through the DI / DO+ and DI / DO- interfaces, and first passes through the common mode filter unit and the differential mode filter unit to filter out the common mode interference and differential mode interference of the external signal, thereby improving the stability of the signal; then the processed signal is connected to the input signal processing unit 103 and the output signal processing unit 104 respectively; the input signal processing unit 103 performs current limiting, voltage limiting, filtering and other processing on the signal, and then inputs it into the digital quantity input pre-isolation interface of the isolation conversion unit 102, and after isolation, it is sent to the MCU unit 101 through the digital quantity input post-isolation interface; when the circuit is used as a switch output function, the MCU unit 101 first sends out a control signal, and after passing through the isolation conversion unit 102, the isolated control signal is sent to the output signal processing unit 104, and after the signal is amplified by the MOS tube (or transistor), it is filtered through differential mode and common mode, and then connected to the external device to control the action of the external device.

[0077] Capacitors C1, C2, C3, C4, C5, and C6 are filter capacitors of the isolation conversion unit 102, which include several capacitors with different capacities. The large-capacity capacitors are used to filter out low-frequency interference of the power supply, and the small-capacity capacitors are used to filter out high-frequency interference of the power supply, thereby ensuring the normal realization of their functions.

[0078] The output signal processing unit 104 in the switch output function circuit, wherein the resistor R2 is a driving resistor, and its function is to limit the driving switching speed, thereby reducing the jitter in the switching process, while preventing signal crosstalk and improving the driving reliability; the resistor R3 and the capacitor C8 together constitute the driving filtering function, on the one hand, the interference signal of the driving signal is filtered out by C8, and on the other hand, a charge discharge channel is provided for the signal through C8 to improve the shutdown speed and reliability; Q1 is a current amplifier device, which can generally adopt a MOS tube or a triode, which can pass a larger current and withstand a higher voltage, thereby completing the conversion from a small control signal to a large driving signal, avoiding the trouble of adding an external driving amplifier component, and improving the system integration.

[0079] After the external switch input signal is input through the interface connector, the interference of the external signal is filtered out through common mode filtering and differential mode filtering, and then the processed signal is sent to the input signal processing unit 103. After the signal is processed by the circuit, it is sent to the isolation conversion unit 102, and the external input signal is subjected to magnetic isolation processing. The processed signal is sent to the MCU unit 101 to complete the collection of the external input state. The resistor R1 in the input signal processing unit 103 is a current limiting resistor, which limits the input current to a reasonable range to avoid excessive current causing excessive heating and damaging the device; DZ1 is a voltage stabilizing diode, which stabilizes the external input signal to a fixed voltage, and the voltage value matches the voltage range of port 7 in the isolation conversion unit 102. When the external input voltage changes, the port 7 voltage can always be maintained in a fixed range, so that the circuit can adapt to a wider range of applications; the capacitor C7 in the input signal processing unit 103 is a filter capacitor, which can effectively filter out interference signals in the input signal, maintain the stability of the input signal, and is used to improve the reliability of the circuit.

[0080] The function of the voltage regulator D1 is to prevent external impulse voltage from damaging internal devices. When the external impulse voltage exceeds the threshold, it conducts and discharges, thereby protecting the internal circuit; the capacitor C9 included in the differential mode filter is used to filter out the differential mode interference signal in the input and output circuits; the inductor L2 included in the power filter is a common mode inductor, and one end of the capacitors C10 and C11 are connected to the casing, and they work together to filter out common mode interference in the line.

[0081] When the circuit is used as a switch output function, the switch input path can simultaneously collect external states. When the switch output state is disconnected, the value collected by the switch input path should be logic 1; when the switch output state is closed, the value collected by the switch input path should be logic 0; therefore, based on the logical relationship between the two states, it can be determined whether the external circuit has fault information such as broken wires and output abnormalities, thereby realizing self-test of the function.

[0082] In some embodiments of the present invention, the common mode filtering unit includes: a second inductor, a tenth capacitor and an eleventh capacitor; The first end of the second inductor is electrically connected to one end of the ninth capacitor; The second end of the second inductor is electrically connected to the other end of the ninth capacitor; The third end of the second inductor is electrically connected to the capacitor; The fourth end of the second inductor is electrically connected to the eleventh capacitor. It can be understood that the isolated switch input and output compatible circuit disclosed in the present invention includes several parts such as MCU (Micro Controller Unit), isolation conversion unit 102, input signal processing unit 103, output signal processing unit 104, differential mode filtering, common mode filtering, etc. The MCU unit 101 is responsible for the acquisition of input signals and the control of output signals; the isolation conversion unit 102 isolates the relevant signals and provides isolated power supply, provides a stable level reference for the subsequent stage, and avoids the external level change from affecting the circuit stability; the differential mode filtering and common mode filtering are used to eliminate signal interference and improve stability.

[0083] The external signal is input into the circuit through the DI / DO+ and DI / DO- interfaces, and first passes through the common mode filter unit and the differential mode filter unit to filter out the common mode interference and differential mode interference of the external signal, thereby improving the stability of the signal; then the processed signal is connected to the input signal processing unit 103 and the output signal processing unit 104 respectively; the input signal processing unit 103 performs current limiting, voltage limiting, filtering and other processing on the signal, and then inputs it into the digital quantity input pre-isolation interface of the isolation conversion unit 102, and after isolation, it is sent to the MCU unit 101 through the digital quantity input post-isolation interface; when the circuit is used as a switch output function, the MCU unit 101 first sends out a control signal, and after passing through the isolation conversion unit 102, the isolated control signal is sent to the output signal processing unit 104, and after the signal is amplified by the MOS tube (or transistor), it is filtered through differential mode and common mode, and then connected to the external device to control the action of the external device.

[0084] Capacitors C1, C2, C3, C4, C5, and C6 are filter capacitors of the isolation conversion unit 102, which include several capacitors with different capacities. The large-capacity capacitors are used to filter out low-frequency interference of the power supply, and the small-capacity capacitors are used to filter out high-frequency interference of the power supply, thereby ensuring the normal realization of their functions.

[0085] The output signal processing unit 104 in the switch output function circuit, wherein the resistor R2 is a driving resistor, and its function is to limit the driving switching speed, thereby reducing the jitter in the switching process, while preventing signal crosstalk and improving the driving reliability; the resistor R3 and the capacitor C8 together constitute the driving filtering function, on the one hand, the interference signal of the driving signal is filtered out by C8, and on the other hand, a charge discharge channel is provided for the signal through C8 to improve the shutdown speed and reliability; Q1 is a current amplifier device, which can generally adopt a MOS tube or a triode, which can pass a larger current and withstand a higher voltage, thereby completing the conversion from a small control signal to a large driving signal, avoiding the trouble of adding an external driving amplifier component, and improving the system integration.

[0086] After the external switch input signal is input through the interface connector, the interference of the external signal is filtered out through common mode filtering and differential mode filtering, and then the processed signal is sent to the input signal processing unit 103. After the signal is processed by the circuit, it is sent to the isolation conversion unit 102, and the external input signal is subjected to magnetic isolation processing. The processed signal is sent to the MCU unit 101 to complete the collection of the external input state. The resistor R1 in the input signal processing unit 103 is a current limiting resistor, which limits the input current to a reasonable range to avoid excessive current causing excessive heating and damaging the device; DZ1 is a voltage stabilizing diode, which stabilizes the external input signal to a fixed voltage, and the voltage value matches the voltage range of port 7 in the isolation conversion unit 102. When the external input voltage changes, the port 7 voltage can always be maintained in a fixed range, so that the circuit can adapt to a wider range of applications; the capacitor C7 in the input signal processing unit 103 is a filter capacitor, which can effectively filter out interference signals in the input signal, maintain the stability of the input signal, and is used to improve the reliability of the circuit.

[0087] The function of the voltage regulator D1 is to prevent external impulse voltage from damaging internal devices. When the external impulse voltage exceeds the threshold, it conducts and discharges, thereby protecting the internal circuit; the capacitor C9 included in the differential mode filter is used to filter out the differential mode interference signal in the input and output circuits; the inductor L2 included in the power filter is a common mode inductor, and one end of the capacitors C10 and C11 are connected to the casing, and they work together to filter out common mode interference in the line.

[0088] When the circuit is used as a switch output function, the switch input path can simultaneously collect external states. When the switch output state is disconnected, the value collected by the switch input path should be logic 1; when the switch output state is closed, the value collected by the switch input path should be logic 0; therefore, based on the logical relationship between the two states, it can be determined whether the external circuit has fault information such as broken wires and output abnormalities, thereby realizing self-test of the function.

[0089] The isolated switch input-output compatible circuit provided by the present invention is introduced in detail above. Specific examples are used in this article to illustrate the principles and implementation methods of the present invention. The description of the above embodiments is only used to help understand the method of the present invention and its core idea; at the same time, for those skilled in the art, according to the idea of ​​the present invention, there will be changes in the specific implementation method and application scope. In summary, the content of this specification should not be understood as a limitation on the present invention.

Claims

1. An isolated switch input and output compatible circuit, characterized in that: include: an input signal processing unit, electrically connected to the output signal amplifying unit, configured to obtain an external input signal, obtain a first processing signal based on the external input signal, obtain a third output control signal based on the second output control signal, and output the third output control signal to an external control device; an output signal processing unit, electrically connected to the isolation conversion unit, and configured to amplify the first processed signal to obtain a second processed signal, and amplify the first output control signal to obtain a second output control signal; an isolation conversion unit, which is communicatively connected to the MCU unit, and is used to perform an isolation operation based on the second processing signal and transmit it to the MCU unit, and to perform an isolation operation based on the first output control signal and transmit it to the output signal processing unit; The MCU unit is used to obtain a switch output control instruction based on the second processing signal, and generate a first output control signal based on the switch output control instruction.

2. The isolated switch input-output compatible circuit according to claim 1, characterized in that: The step of obtaining a third output control signal based on the second output control signal comprises: Current limiting and voltage limiting are performed based on the second output control signal to obtain a third output control signal.

3. The isolated switch input-output compatible circuit according to claim 1, characterized in that: The isolation conversion unit comprises: An isolation conversion chip, a first capacitor, a second capacitor, a third capacitor, a fourth capacitor, a fifth capacitor and a sixth capacitor; The first capacitor, the second capacitor and the third capacitor are connected in parallel; The fourth capacitor, the fifth capacitor and the sixth capacitor are connected in parallel; The first pin of the isolation conversion chip is electrically connected to one end of the first capacitor, the second capacitor and the third capacitor; The fourth pin of the isolation conversion chip is electrically connected to the other ends of the first capacitor, the second capacitor and the third capacitor; The eighth pin of the isolation conversion chip is electrically connected to one end of the fourth capacitor, the fifth capacitor and the sixth capacitor; The fifth pin of the isolation conversion chip is electrically connected to the other ends of the fourth capacitor, the fifth capacitor and the sixth capacitor; The second pin of the isolation conversion chip is electrically connected to the output end of the MCU unit; The third pin of the isolation conversion chip is electrically connected to the input terminal of the MCU unit; The seventh pin of the isolation conversion chip is electrically connected to the input signal processing unit; The sixth pin of the isolation conversion chip is electrically connected to the output signal processing unit.

4. The isolated switch input-output compatible circuit according to claim 1 or 3, characterized in that: The input signal processing unit comprises: A first resistor, a seventh capacitor and a voltage stabilizing diode; The seventh capacitor and the voltage zener diode are connected in parallel; The first resistor is electrically connected to the seventh capacitor and the voltage stabilizing diode; The first resistor, the seventh capacitor and the voltage-stabilizing diode are all electrically connected to the seventh pin of the isolation conversion chip.

5. The isolated switch input-output compatible circuit according to claim 1 or 3, characterized in that: The output signal processing unit comprises: A second resistor, a third resistor, an eighth capacitor and a first MOS tube; The first MOS tube is electrically connected to the second resistor, the third resistor and the eighth capacitor respectively; The third resistor and the eighth capacitor are connected in parallel; The second resistor is electrically connected to the third resistor; The second resistor is electrically connected to the sixth pin of the isolation conversion chip.

6. The isolated switch input-output compatible circuit according to claim 1, characterized in that: The circuit further comprises: The filtering unit is electrically connected to the input signal processing unit, and is used to obtain an external input signal, perform interference filtering based on the external input signal to obtain a filtered signal, obtain a first processed signal based on the filtered signal, and output a third output control signal to an external control device.

7. The isolated switch input-output compatible circuit according to claim 6, characterized in that: The step of obtaining a first processed signal based on the filtered signal comprises: Current limiting and voltage limiting are performed based on the filtered signal to obtain a first processed signal.

8. The isolated switch input-output compatible circuit according to claim 7, characterized in that: The filtering unit comprises: The common mode filter unit is electrically connected to the differential mode filter unit and is used to filter out interference of the common mode signal based on the external input signal to obtain a common mode filtered signal; The differential mode filtering unit is used to filter out interference of the differential mode signal based on the common mode filtering signal to obtain a filtered signal.

9. The isolated switch input-output compatible circuit according to claim 4 or 8, characterized in that: The differential mode filter unit includes a ninth capacitor, and the first resistor is electrically connected to the ninth capacitor.

10. The isolated switch input-output compatible circuit according to claim 8 or 9, characterized in that: The common mode filtering unit comprises: a second inductor, a tenth capacitor and an eleventh capacitor; The first end of the second inductor is electrically connected to one end of the ninth capacitor; The second end of the second inductor is electrically connected to the other end of the ninth capacitor; The third end of the second inductor is electrically connected to the tenth capacitor; The fourth terminal of the second inductor is electrically connected to the eleventh capacitor.

Images