Analog input isolation circuit and device
By using the MCU module, pull-up module and optocouple isolation module in the analog input isolation circuit, the analog signal is output to the IO port of the receiving MCU, which solves the problem of low scalability of the traditional analog input isolation circuit, and achieves higher scalability and lower cost.
Patent Information
- Application Number
- CN202421499200.1
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-06-27
- Publication Date
- 2025-05-13
- Estimated Expiration
- 2034-06-27
AI Technical Summary
The scalability of traditional analog input isolation circuits is low, mainly due to the tight use of MCU AD ports on the primary side, which makes it difficult to expand under the situation of multiple analog inputs.
An analog input isolation circuit is designed. Through the combination of the MCU module, the first pull-up module, the optocouple isolation module and the second pull-up module, the analog signal is input from the analog input module, and isolates and then pulls up, and is finally output to the IO port of the receiving MCU, reducing dependence on the AD port.
This design improves the scalability of analog input isolation circuits, reduces the need to use high-cost isolation op amps and dedicated chips, reduces the use of receiving MCU AD ports, and reduces the overall cost.
Smart Images
Figure CN222868912U_ABST
Abstract
Description
Technical Field
[0001] The present application relates to the field of analog quantity isolation technology, and in particular to an analog quantity input isolation circuit and device. Background Art
[0002] As the use of analog quantities on different devices continues to increase, users have also put forward higher requirements for analog input isolation.
[0003] The traditional analog input isolation circuit uses an isolation op amp to directly transmit the analog input signal of the secondary side (corresponding to the electrical side of the output analog quantity) to the primary side. The primary side (corresponding to the electrical side of the input analog quantity) collects the analog signal through the AD (Active Directory, network port) port of the MCU (Microcontroller Unit). This analog input isolation circuit will have low scalability due to the tight use of the AD port of the MCU on the primary side. The analog input isolation needs to use the AD port of the primary side (receiving) MCU to collect analog signals, but there are fewer available AD ports.
[0004] The above contents are only used to assist in understanding the technical solution of the present application and do not constitute an admission that the above contents are prior art. Utility Model Content
[0005] The main purpose of the present application is to provide an analog input isolation circuit and device, aiming to solve the technical problem of low scalability of the analog input isolation circuit.
[0006] To achieve the above object, the present application provides an analog input isolation circuit, the analog input isolation circuit comprising:
[0007] An MCU module, wherein the AD port of the MCU module is connected to the analog input module, and the MCU module is used to receive the analog signal of the analog input module and output a square wave signal based on the analog signal;
[0008] A first pull-up module, the first pull-up module is connected to the IO port of the MCU module, and the first pull-up module is used to pull up the square wave signal to obtain a first pull-up signal;
[0009] An optical coupler isolation module, wherein the input end of the optical coupler isolation module is respectively connected to the IO port of the MCU module and the first pull-up module, and the optical coupler isolation module is used to isolate and output the first pull-up signal to obtain an isolated output signal;
[0010] The second pull-up module is respectively connected to the output end of the optocoupler isolation module and the IO port of the receiving MCU, and the second pull-up module is used to pull up the isolated output signal to obtain a second pull-up signal, and output the second pull-up signal to the IO port of the receiving MCU.
[0011] In one embodiment, the analog input module includes a plurality of analog input ports, and the MCU module includes:
[0012] A plurality of AD ports, each of the AD ports being connected to one of the analog input ports;
[0013] A plurality of first IO ports, wherein the first IO ports are respectively connected to the input end of the optical coupling isolation module and the first pull-up module, wherein one AD port corresponds to one first IO port.
[0014] In one embodiment, the first pull-up module includes:
[0015] A plurality of first resistors, a first end of each of the first resistors is connected to one of the first IO ports, and a second end of each of the first resistors is connected to a first system power supply.
[0016] In one embodiment, the optical coupling isolation module includes:
[0017] A plurality of independent optical couplers, wherein the input end of each independent optical coupler is connected to one of the first IO ports, and the output end of each independent optical coupler is respectively connected to the second pull-up module and the IO port of the receiving MCU.
[0018] In one embodiment, the optical coupling isolation module includes:
[0019] An integrated optocoupler, wherein the integrated optocoupler comprises a plurality of the independent optocouplers.
[0020] In one embodiment, the independent optical coupler includes:
[0021] A first input end, the first input end serving as an input end of the independent optical coupler and connected to one of the IO ports;
[0022] A second input terminal, wherein the second input terminal is grounded;
[0023] A first output end, the first output end serving as an output end of the independent optical coupler and being respectively connected to one of the second pull-up modules and an IO port of the receiving MCU;
[0024] A second output terminal is grounded.
[0025] In one embodiment, the independent optical coupler includes:
[0026] A light emitting diode, wherein the anode of the light emitting diode serves as the first input terminal, and the cathode of the light emitting diode serves as the second input terminal;
[0027] A phototransistor, wherein the base of the phototransistor is photosensitively coupled with the light-emitting diode, the emitter of the phototransistor serves as the second output terminal, and the collector of the phototransistor serves as the first output terminal.
[0028] In one embodiment, the second pull-up module includes:
[0029] a plurality of second resistors, wherein a first end of each second resistor is connected to one of the first output ends, and a second end of each second resistor is connected to a second system power supply, or;
[0030] There are a plurality of first resistors, a first end of each of the first resistors is connected to one of the first output ends, and a second end of each of the first resistors is connected to the first system power supply.
[0031] In one embodiment, the receiving MCU includes:
[0032] A plurality of second IO ports, each of the second IO ports is connected to one of the first output ports.
[0033] In addition, to achieve the above-mentioned purpose, the present application also provides an analog input isolation device, and the analog input isolation device includes the above-mentioned analog input isolation circuit.
[0034] The embodiment of the present application provides an analog input isolation circuit, comprising an MCU module, wherein the AD port of the MCU module is connected to the analog input module, the MCU module is used to receive the analog signal of the analog input module, and output a square wave signal based on the analog signal; a first pull-up module, the first pull-up module is connected to the IO port of the MCU module, the first pull-up module is used to pull up the square wave signal to obtain a first pull-up signal; an optocoupler isolation module, the input end of the optocoupler isolation module is respectively connected to the IO port of the MCU module and the first pull-up module, the optocoupler isolation module is used to isolate and output the first pull-up signal to obtain an isolated output signal; a second pull-up module, the second The pull-up module is respectively connected to the output end of the optical coupling isolation module and the IO port of the receiving MCU. The second pull-up module is used to pull up the isolated output signal to obtain a second pull-up signal, and output the second pull-up signal to the IO port of the receiving MCU. The analog signal of the analog input module is input through the IO (Input / Output) port of the MCU module, and is pulled up by the first pull-up module, isolated by the optical coupling isolation module, and pulled up by the second pull-up module, and finally output to the IO port of the receiving MCU. The use of the AD port of the receiving MCU can be reduced. By using the IO port of the receiving MCU (less demand for use), the scalability of the analog input isolation circuit can be improved. BRIEF DESCRIPTION OF THE DRAWINGS
[0035] Figure 1 This is a schematic diagram of the framework of the first embodiment of the analog input isolation circuit of the present application;
[0036] Figure 2 This is a circuit connection diagram of the second embodiment of the analog input isolation circuit of the present application;
[0037] Figure 3 A circuit connection diagram of the third embodiment of the analog input isolation circuit of the present application;
[0038] Figure 4 This is another circuit connection diagram of the third embodiment of the analog input isolation circuit of the present application;
[0039] Figure 5 This is an overall circuit diagram of the analog input isolation circuit of this application;
[0040] Figure 6 This is another overall circuit diagram of the analog input isolation circuit of the present application.
[0041] The realization of the purpose, functional features and advantages of this application will be further explained in conjunction with embodiments and with reference to the accompanying drawings.
[0042] Description of Figure Numbers:
[0043] 100, analog input module; 200, receiving MCU; 10, MCU module; 20, first pull-up module; 30, optocoupler isolation module; 40, second pull-up module; VCC1, first system power supply; R1, first resistor; AD (1-8), AD port; IO (1-8), first IO port (IO port of MCU module); VCC2, second system power supply; R2, second resistor; U1, independent optocoupler; U2, integrated optocoupler; D, light-emitting diode; Q, phototransistor; io (1-8), second IO port (IO port of receiving MCU); 300, secondary side; 400, primary side. DETAILED DESCRIPTION
[0044] It should be understood that the specific embodiments described herein are only used to explain the present application and are not used to limit the present application.
[0045] In order to better understand the technical solution of the present application, a detailed description will be given below in conjunction with the accompanying drawings and specific implementation methods.
[0046] There are generally two types of analog input isolation schemes, one is to directly use an isolation amplifier to transmit the analog signal of the secondary side (the electrical side corresponding to the analog input module) to the primary side (the electrical side corresponding to the receiving MCU). The AD port of the receiving MCU on the primary side collects analog signals. The disadvantage of this scheme is that the internal design of the isolation amplifier is complex (the isolation amplifier itself belongs to a high-cost component, and the cost of a single isolation amplifier is higher than the sum of the optocoupler, MCU and resistor used in this application), which causes the use cost of analog input isolation to increase, and at the same time, it will occupy the AD port of the receiving MCU, which is already tight. If there are multiple analog inputs, multiple isolation amplifiers and multiple AD ports need to be used, which is not convenient for the expansion of multiple analog inputs. Another scheme is to use a dedicated chip for analog conversion PWM wave, such as the NJM4151M model chip, by converting the analog quantity into PWM wave, and then transmitting the PWM wave to the primary side through a common optocoupler. At this time, the receiving MCU on the primary side uses the IO port to collect the voltage value of the PWM wave converted into analog quantity. The disadvantages of this solution are that it requires the use of a dedicated chip, the chip peripheral circuit is relatively complex, and if there are multiple analog inputs, multiple dedicated chips are required, which is not convenient for the expansion of multiple analog inputs.
[0047] Therefore, based on the shortcomings of the above analog input isolation circuit, an analog input isolation circuit of the present application is proposed. The analog signal of the analog input module of the embodiment of the present application is input through the IO port of the MCU module, and after being pulled up by the first pull-up module, isolated by the optocoupler isolation module and pulled up by the second pull-up module, it is finally output to the IO port of the receiving MCU, which can reduce the use of the AD port of the receiving MCU. By using the IO port of the receiving MCU (less demand for use), the scalability of the analog input isolation circuit can be improved.
[0048] Based on this, the embodiment of the present application provides an analog input isolation circuit, referring to Figure 1 , Figure 1 This is a schematic diagram of the framework of the first embodiment of the analog input isolation circuit of the present application.
[0049] Reference Figure 1 The present application provides an analog input isolation circuit, the analog input isolation circuit comprising:
[0050] An MCU module 10, wherein an AD port AD of the MCU module 10 is connected to an analog input module 100, and the MCU module 10 is used to receive an analog signal from the analog input module 100 and output a square wave signal based on the analog signal;
[0051] A first pull-up module 20, wherein the first pull-up module 20 is connected to the IO port IO of the MCU module 10, and the first pull-up module 20 is used to pull up the square wave signal to obtain a first pull-up signal;
[0052] An optical coupling isolation module 30, wherein the input end of the optical coupling isolation module 30 is respectively connected to the IO port IO of the MCU module 10 and the first pull-up module 20, and the optical coupling isolation module 30 is used to isolate and output the first pull-up signal to obtain an isolated output signal;
[0053] The second pull-up module 40 is respectively connected to the output end of the optical coupling isolation module 30 and the IO port io of the receiving MCU200, and the second pull-up module 40 is used to pull up the isolated output signal to obtain a second pull-up signal, and output the second pull-up signal to the IO port io of the receiving MCU200.
[0054] In the present embodiment, the MCU module 10 can receive the analog signal from the analog input module 100 by connecting with the analog input module 100. At this time, the square wave signal will be converted inside the MCU module 10, wherein the analog signal refers to the analog signal that needs to be isolated, and the square wave signal refers to the square wave with a fixed frequency and adjustable duty cycle obtained by the MCU module 10. The conversion method can be a common MCU chip to convert the analog signal into a square wave, which is not limited here. Because the square wave signal output at this time does not have the driving ability, it is necessary to use the first pull-up module 20 to pull up the square wave signal to obtain the first pull-up signal. The first pull-up signal refers to the signal obtained after the parameters such as the amplitude of the square wave signal are pulled up. At this time, the first pull-up signal has the driving ability. The first pull-up signal will be input to the optical coupling isolation module 30, which can drive the device in the optical coupling isolation module 30 to achieve isolation. At this time, the optical coupling isolation module 30 outputs an isolated output signal based on the drive of the first pull-up signal, and the isolated output signal refers to the signal that the optical coupling isolation module 30 outputs in isolation. The same isolated output signal does not have driving capability, so it is necessary to use the second pull-up module 40 to pull up the isolated output signal to obtain the second pull-up signal, and the second pull-up signal refers to the signal obtained after the parameters such as the amplitude of the isolated output signal are pulled up. At this time, based on the second pull-up signal (having driving capability), the receiving MCU200 (at this time, the IO port io of the receiving MCU200) is driven, and the receiving MCU200 can parse the duty cycle information of the second pull-up signal, and then convert it into analog input voltage information, to complete analog sampling. Because the second pull-up signal is finally transmitted to the IO port io of the receiving MCU200, to reduce the use of the tense AD port, the scalability of the analog input isolation circuit can be greatly improved, and the cost of using the components based on the present embodiment is low than that of using the isolation amplifier, which can reduce the cost of the analog input isolation circuit.
[0055] Further, based on the above-mentioned first embodiment of the present application, a second embodiment of the analog input isolation circuit of the present application is proposed, referring to Figure 2 , Figure 2 This is a circuit connection diagram of the second embodiment of the analog input isolation circuit of the present application. The analog input module 100 includes multiple analog input ports, and the MCU module 10 includes:
[0056] A plurality of AD ports AD, each of the AD ports AD being connected to one of the analog quantity input ports;
[0057] A plurality of first IO ports IO, wherein the first IO ports IO are respectively connected to the input end of the optical coupling isolation module 30 and the first pull-up module 20 , wherein one AD port AD corresponds to one first IO port IO.
[0058] In this embodiment, in order to avoid the one-to-one expansion mode of the isolation operational amplifier and the dedicated chip, the MCU module 10 used in this embodiment is a common MCU, and the MCU includes a plurality of AD ports AD and a first IO port IO corresponding to each AD port AD. Figure 2 As shown, if the number of analog input ports is less than 8 (i.e., less than 8 analog inputs), one MCU can be used directly to complete the analog input isolation; conversely, if the number of analog input ports is more than 8 (i.e., more than 8 analog inputs), multiple MCUs can be used directly to complete the analog input isolation or more MCUs of AD ports AD and the first IO port IO can be selected to implement, thereby greatly improving the scalability of the analog input isolation circuit.
[0059] In one embodiment, after the analog signal passes through the MCU module 10, a square wave with a fixed frequency and an adjustable duty cycle is output, and the square wave is isolated and output. It is worth noting that a selector can be designed at the AD port AD and / or the first IO port IO, so that the port to be used can be accurately selected, and other connection relationships can also be designed to achieve other functions, which is not limited here.
[0060] In one embodiment, the first pull-up module 20 includes:
[0061] A plurality of first resistors R1 are provided, wherein a first end of each of the first resistors R1 is connected to one of the first IO ports IO, and a second end of each of the first resistors R1 is connected to a first system power source VCC1.
[0062] In this embodiment, because the signal output by the MCU module 10 does not have a driving capability, it is necessary to pull up the signal output by the MCU module 10 before outputting it. At this time, the first pull-up module 20 includes a first resistor R1 connected to the first system power supply VCC1 and the first system power supply VCC1 and each first IO port IO, and can pull up the signal outputted from each first IO port IO based on the first system power supply VCC1 and the first resistor R1 to ensure that the signal has a driving capability, and then drive or control the subsequent optical coupling isolation module 30 to perform isolation, so as to ensure the accuracy of analog isolation.
[0063] In one embodiment, in order to save energy, a selection switch can be designed between the first system power supply VCC1 and the first resistor R1. When it is determined which first IO port IO needs to be used, the first resistor R1 connected to the first IO port IO is controlled to be connected to the first system power supply VCC1 for pull-up. The voltage value of the first system power supply VCC1 and the resistance value of the first resistor R1 can be adaptively selected according to actual needs.
[0064] Further, based on the first embodiment and / or the second embodiment of the present application, a third embodiment of the analog input isolation circuit of the present application is proposed, referring to Figure 3 , Figure 3 This is a circuit connection diagram of the third embodiment of the analog input isolation circuit of the present application. The optocoupler isolation module 30 includes:
[0065] A plurality of independent optical couplers U1 , the input end of each independent optical coupler U1 is connected to one of the first IO ports IO, and the output end of each independent optical coupler U1 is respectively connected to the second pull-up module 40 and the IO port io of the receiving MCU 200 .
[0066] In one embodiment, referring to Figure 4 , Figure 4 This is a circuit connection diagram of the third embodiment of the analog input isolation circuit of the present application. The optical coupling isolation module 30 includes:
[0067] The integrated optocoupler U2 includes a plurality of the independent optocouplers U1.
[0068] In this embodiment, the optocoupler isolation module 30 includes an independent optocoupler U1 and an integrated optocoupler U2. The difference between the two is that the integrated optocoupler U2 is a chip with multiple optocoupler input and output circuits inside, and the independent optocoupler U1 is a chip with one optocoupler input and output circuit inside. The integrated optocoupler U2 can improve the integration of the entire analog input isolation circuit. Whether it is an independent optocoupler U1 or an integrated optocoupler U2, a commonly used ordinary optocoupler can be used, which only plays the function of isolating the output, that is, the model and function of the optocoupler are not limited.
[0069] In one embodiment, the independent optical coupler U1 includes:
[0070] A first input end, the first input end serving as an input end of the independent optical coupler U1 and connected to one of the IO ports IO;
[0071] A second input terminal, wherein the second input terminal is grounded;
[0072] A first output end, the first output end serving as an output end of the independent optical coupler U1, and connected to one of the second pull-up modules 40 and an IO port of the receiving MCU 200 respectively;
[0073] A second output terminal is grounded.
[0074] In one embodiment, the independent optical coupler U1 includes:
[0075] a light emitting diode D, wherein the anode of the light emitting diode D serves as the first input terminal, and the cathode of the light emitting diode D serves as the second input terminal;
[0076] A phototransistor Q, wherein the base of the phototransistor Q is coupled to the light-emitting diode photosensitive D, the emitter of the phototransistor Q serves as the second output terminal, and the collector of the phototransistor Q serves as the first output terminal.
[0077] In this embodiment, the independent optocoupler U1 includes two input terminals and two output terminals, and is connected to the analog input isolation circuit in the above connection method. The independent optocoupler U1 is composed of a light-emitting diode D and a phototransistor Q. When the light-emitting diode D is controlled to emit light, the base of the corresponding phototransistor Q will be coupled to control the collector of the phototransistor Q to output a corresponding signal. Because the signal is output by the phototransistor Q, it does not have the driving capability and needs to be pulled up before it can be output. It is worth noting that the above is only one internal connection method of the independent optocoupler U1, and other connection methods can also be used, which are not limited here.
[0078] In one embodiment, the optical coupling isolation module 30 is only used to play an isolation role. If other components also have an isolation role, other components can also be used, which is not limited here.
[0079] Further, based on the first embodiment, the second embodiment and / or the third embodiment of the present application, a fourth embodiment of the analog input isolation circuit of the present application is proposed, referring to Figure 5 , Figure 5 This is a schematic diagram of an overall circuit of an analog input isolation circuit of the present application, wherein the second pull-up module 40 includes:
[0080] A plurality of second resistors R2, wherein a first end of each second resistor R2 is connected to one of the first output ends, and a second end of each second resistor R2 is connected to a second system power supply VCC2, or;
[0081] There are a plurality of first resistors R1 , a first end of each of the first resistors R1 is connected to one of the first output ends, and a second end of each of the first resistors R1 is connected to the first system power source VCC1 .
[0082] Specifically, the receiving MCU 200 includes:
[0083] A plurality of second IO ports io, each of the second IO ports io is connected to one of the first output terminals.
[0084] In this embodiment, because the signal output by the optocoupler isolation module 30 does not have a driving capability, it is necessary to pull up the signal output by the optocoupler isolation module 30 before outputting it. At this time, the second pull-up module 40 includes a second resistor R2 connected to the second system power supply VCC1, and the second system power supply VCC2 and each first output terminal, so that the signal outputted from each first output terminal can be pulled up based on the second system power supply VCC2 and the second resistor R2 to ensure that the signal has a driving capability, thereby driving or controlling the input of the subsequent receiving IO port of the MCU200 to ensure the accuracy of analog quantity isolation.
[0085] In one embodiment, in order to save energy consumption, a selection switch can be designed between the second system power supply VCC2 and the second resistor R2. When it is determined which first output terminal needs to be used, the second resistor R2 connected to the first output terminal is controlled to be connected to the second system power supply VCC2 for pull-up. Among them, the voltage value of the second system power supply VCC2 and the resistance value of the second resistor R2 can be adaptively selected according to actual needs, or can be the same as the voltage value of the first system power supply VCC1 and the resistance value of the first resistor R1 in the first pull-up module 20, which is not limited here. It is worth noting that the first pull-up module 20 and the second pull-up module 40 here can be shared to reduce the cost of the entire analog input isolation circuit.
[0086] In one embodiment, referring to Figure 6 , Figure 6 This is another overall circuit diagram of the analog input isolation circuit of the present application. Part of the circuit design in the analog input isolation circuit can be in the second side 300, and the remaining circuit design in the analog input isolation circuit can be in the first side 400, so as to realize the analog input isolation between the analog input module 100 in the second side 300 and the receiving MCU 200 in the first side 400. At this time, the analog input isolation circuit can be selectively designed in the first side 400 and / or the second side 300 according to the actual situation, which is not limited here. Because the IO port of the receiving MCU 200 in the first side 400 is used, if the number of analog inputs is increased at this time, only the AD port AD on the MCU module 10 and the first IO port IO are needed, without adding an isolation amplifier, thereby reducing the cost of the analog input isolation circuit.
[0087] The present application also provides an analog input isolation device, comprising the above-mentioned analog input isolation circuit.
[0088] The device provided by the present application can solve the technical problem of low scalability of analog input isolation circuits. Compared with the prior art, the beneficial effects of the device provided by the present application are the same as those of the device circuit provided by the above embodiment, which will not be repeated here.
[0089] The above descriptions are only some embodiments of the present application, and are not intended to limit the patent scope of the present application. All equivalent structural changes made using the contents of the present application specification and drawings under the technical concept of the present application, or direct / indirect applications in other related technical fields are included in the patent protection scope of the present application.
Claims
1. An analog input isolation circuit, characterized in that: The analog input isolation circuit comprises: An MCU module, wherein the AD port of the MCU module is connected to the analog input module, and the MCU module is used to receive the analog signal of the analog input module and output a square wave signal based on the analog signal; A first pull-up module, the first pull-up module is connected to the IO port of the MCU module, and the first pull-up module is used to pull up the square wave signal to obtain a first pull-up signal; An optocoupler isolation module, wherein the input end of the optocoupler isolation module is respectively connected to the IO port of the MCU module and the first pull-up module, and the optocoupler isolation module is used to isolate and output the first pull-up signal to obtain an isolated output signal; The second pull-up module is respectively connected to the output end of the optocoupler isolation module and the IO port of the receiving MCU, and the second pull-up module is used to pull up the isolated output signal to obtain a second pull-up signal, and output the second pull-up signal to the IO port of the receiving MCU.
2. The analog input isolation circuit according to claim 1, characterized in that: The analog input module includes a plurality of analog input ports, and the MCU module includes: A plurality of AD ports, each of the AD ports being connected to one of the analog input ports; A plurality of first IO ports, wherein the first IO ports are respectively connected to the input end of the optical coupling isolation module and the first pull-up module, wherein one AD port corresponds to one first IO port.
3. The analog input isolation circuit according to claim 2, characterized in that: The first pull-up module comprises: A plurality of first resistors, a first end of each of the first resistors is connected to one of the first IO ports, and a second end of each of the first resistors is connected to a first system power supply.
4. The analog input isolation circuit according to claim 3, characterized in that: The optical coupling isolation module comprises: A plurality of independent optocouplers, wherein the input end of each independent optocoupler is connected to one of the first IO ports, and the output end of each independent optocoupler is respectively connected to the second pull-up module and the IO port of the receiving MCU.
5. The analog input isolation circuit according to claim 4, characterized in that: The optical coupling isolation module comprises: An integrated optocoupler, wherein the integrated optocoupler comprises a plurality of the independent optocouplers.
6. The analog input isolation circuit according to claim 4, characterized in that: The independent optical coupler comprises: A first input end, the first input end serving as an input end of the independent optical coupler and connected to one of the IO ports; A second input terminal, wherein the second input terminal is grounded; A first output end, the first output end serving as an output end of the independent optical coupler and being respectively connected to one of the second pull-up modules and an IO port of the receiving MCU; A second output terminal is grounded.
7. The analog input isolation circuit according to claim 6, characterized in that: The independent optical coupler comprises: A light emitting diode, wherein the anode of the light emitting diode serves as the first input terminal, and the cathode of the light emitting diode serves as the second input terminal; A phototransistor, wherein the base of the phototransistor is photosensitively coupled with the light-emitting diode, the emitter of the phototransistor serves as the second output terminal, and the collector of the phototransistor serves as the first output terminal.
8. The analog input isolation circuit according to claim 6, characterized in that: The second pull-up module comprises: a plurality of second resistors, wherein a first end of each second resistor is connected to one of the first output ends, and a second end of each second resistor is connected to a second system power supply, or; There are a plurality of first resistors, a first end of each of the first resistors is connected to one of the first output ends, and a second end of each of the first resistors is connected to the first system power supply.
9. The analog input isolation circuit according to claim 6, characterized in that: The receiving MCU comprises: A plurality of second IO ports, each of the second IO ports is connected to one of the first output ports.
10. An analog input isolation device, characterized in that: The analog input isolation device comprises the analog input isolation circuit according to any one of claims 1 to 9.