One-path analog signal high-precision synchronous transmission isolation multi-channel circuit

Abstract

The utility model discloses a one-path analog signal high-precision synchronous transmission isolation multichannel circuit, which comprises a commonly controlled analog adjustable signal module, a plurality of channel modules and a power supply VCC, and is characterized in that the plurality of channel modules are connected with the commonly controlled analog adjustable signal module; the common control analog adjustable signal module and the plurality of channel modules are all connected with a power supply VCC, each channel module comprises a signal modulation circuit, an isolation module, an I / V conversion circuit, a channel output module and a DCDC isolation power supply circuit, the transmission change of a plurality of groups of isolation channels can be synchronously controlled through a group of analog signals, the structure is simple, the cost is low, and the application range is wide. The control precision is high and the response speed is fast.

Description

Technical Field

[0001] The utility model relates to a circuit for isolating multiple channels of a one-way analog signal with high-precision synchronous transmission. Background Art

[0002] In order to cope with the complex battery environment and improve its own anti-interference ability in the measurement and control system, multiple channels are usually in an isolated state. Often during use, the master control needs to control the simultaneous changes of multiple independent channels. The usual application scenario is to share an analog signal to control the changes of analog signals of multiple groups of isolated channels. At this time, one-to-many transmission and synchronous control of multiple channels are required, and the consistency and high precision of signal changes must be guaranteed and the multiple groups must be isolated. At present, there is an increasing demand for one-way input analog control and multiple isolated channel transmission scenarios in industrial control systems. Especially in the power supply system, multiple groups of isolated power supplies are required to receive the same analog signal and change the output at the same time. The consistency and synchronization of multiple groups of output voltages are very high. There is an urgent need for a stable, reliable and high-precision one-way analog signal synchronous transmission isolation multi-channel circuit.

[0003] The existing one-to-one isolated transmission devices are usually connected in parallel and cannot share a single analog signal control channel. In addition, they require the participation of a single-chip microcomputer in the control and cannot be purely hardware-controlled. Their circuit structure is complex and costly. They cannot synchronously control the signal changes of isolated multiple channels. There is a delay in the changes between channels, and the consistency and accuracy of the changes between channels are difficult to guarantee. Therefore, they cannot meet people's diverse needs. Utility Model Content

[0004] The purpose of the utility model is to overcome the deficiencies in the prior art and provide a circuit for isolating multiple channels of analog signals with high-precision synchronous transmission.

[0005] In order to achieve the above object, the present invention is implemented through the following technical solutions:

[0006] A circuit for high-precision synchronous transmission and isolation of multiple channels of analog signals includes a commonly controlled analog adjustable signal module, multiple channel modules, and a power supply VCC. The multiple channel modules are all connected to the commonly controlled analog adjustable signal module. The commonly controlled analog adjustable signal module and the multiple channel modules are all connected to the power supply VCC. The channel module includes a signal modulation circuit, an isolation module, an I / V conversion circuit, a channel output module, and a DC-DC isolation power supply circuit. The signal modulation circuit is connected to the I / V conversion circuit via the isolation module. The I / V conversion circuit is connected to the channel output module. The isolation module and the multiple channel modules are all connected to the DC-DC isolation power supply circuit.

[0007] Preferably, the shared control analog adjustable signal module includes a resistor R208, a capacitor C210, a capacitor C209, a resistor R207, a resistor R212, an adjustable voltage reference chip U202, a resistor R21, a variable resistor R22, and an analog signal input terminal VERFDJ. One end of the resistor R208 is connected to the power supply VCC, and the other end of the resistor R208 is connected to the ground signal GND through the capacitor C210. The capacitor C209 is connected in parallel with the capacitor C210, and the A end of the adjustable voltage reference chip U202 is connected to the ground. Signal GND, the R end of the adjustable voltage reference chip U202 is connected to the ground signal GND through the resistor R212, and the R end of the adjustable voltage reference chip U202 is also connected to the other end of the resistor R208 through the resistor R207. The K end of the adjustable voltage reference chip U202 is connected to one end of the resistor R21, and the other end of the resistor R21 is connected to the ground signal GND through the variable resistor R22. The other end of the resistor R21 is connected to the analog signal input terminal VERFDJ, and the other end of the resistor R21 is connected to several channel modules.

[0008] Preferably, the signal modulation circuit includes an operational amplifier U2A, an operational amplifier U2B, a capacitor C8, a resistor R2, a resistor R3, a resistor R5, a capacitor C10, a resistor R10, a capacitor C5, and a capacitor C6, wherein the same-direction input terminal of the operational amplifier U2A is connected to one end of the resistor R2, the other end of the resistor R2 is connected to the ground signal GND through the capacitor C8, the other end of the resistor R2 is connected to the other end of the resistor R21, the reverse input terminal of the operational amplifier U2A is connected to the output terminal of the operational amplifier U2A through the resistor R10, and the operational amplifier U2A, The operational amplifier U2B is connected to the power supply VCC, which is connected to the ground signal GND through the capacitor C5. The capacitor C6 is connected in parallel with the capacitor C5. The output end of the operational amplifier U2A is connected to the non-inverting input end of the operational amplifier U2B through the resistor R3. The inverting input end of the operational amplifier U2B is connected to the ground signal GND through the resistor R5. The inverting input end of the operational amplifier U2B is connected to the output end of the operational amplifier U2B through the capacitor C10. The output end of the operational amplifier U2B and the inverting input end of the operational amplifier U2B are both connected to the isolation module.

[0009] Preferably, the isolation module includes a resistor R4, a capacitor C9, and an optocoupler U3. The reverse input end of the operational amplifier U2B is connected to pin 4 of the optocoupler U3, the output end of the operational amplifier U2B is connected to pin 2 of the optocoupler U3 through the resistor R4, pin 3 of the optocoupler U3 is connected to the ground signal GND through the capacitor C9, pin 3 of the optocoupler U3 is connected to the power supply VCC, pin 6 of the optocoupler U3 is connected to the DCDC isolation power supply circuit, and pin 5 of the optocoupler U3 is connected to the I / V conversion circuit.

[0010] Preferably, the DCDC isolated power supply circuit includes a polarity capacitor C1, a capacitor C2, a polarity capacitor C3, a capacitor C4, and an isolated power supply module U1, wherein pin 1 of the isolated power supply module U1 is connected to the ground signal GND through the polarity capacitor C1, pin 1 of the isolated power supply module U1 is connected to the power supply VCC, the capacitor C2 is connected in parallel with the polarity capacitor C1, pin 2 of the isolated power supply module U1 is connected to the ground signal GND, pin 4 of the isolated power supply module U1 is connected to the isolated ground GE_GND_1, pin 6 of the isolated power supply module U1 is connected to the isolated ground GE_GND_1 through the polarity capacitor C3, pin 6 of the isolated power supply module U1 is connected to the isolated ground GE_GND_1 through the capacitor C4, and pin 6 of the isolated power supply module U1 outputs a 12V isolated power supply 12V_1.

[0011] Preferably, a capacitor C7 is further included, and the 6th pin of the optocoupler U3 is connected to the 12V isolated power supply 12V_1, and the 6th pin of the optocoupler U3 is connected to the isolated ground GE_GND_1 through the capacitor C7.

[0012] Preferably, the I / V conversion circuit includes an operational amplifier U5B, a resistor R8, a capacitor C12, a resistor R1, and a resistor R7. The non-inverting input terminal of the operational amplifier U5B is connected to pin 5 of the optocoupler U3, the reverse input terminal of the operational amplifier U5B is connected to the output terminal of the operational amplifier U5B through the resistor R1, the non-inverting input terminal of the operational amplifier U5B is connected to one end of the resistor R7 through the resistor R8, the other end of the resistor R7 is connected to the output terminal of the operational amplifier U5B, the capacitor C12 is connected in parallel with the resistor R8, and the output terminal of the operational amplifier U5B is connected to the channel output module.

[0013] Preferably, the channel output module includes a resistor R6, a capacitor C11, and a calibration resistor R9. The output end of the operational amplifier U5B is connected to one end of the resistor R6, and the other end of the resistor R6 is connected to the isolation ground GE_GND_1 through the capacitor C11. The calibration resistor R9 is connected in parallel with the capacitor C11, and the other end of the resistor R6 is the output end.

[0014] Preferably, the number of channel modules is two.

[0015] Preferably, the power supply VCC is 12V.

[0016] The beneficial effects of the present invention are as follows: the present invention can synchronously control the transmission changes of multiple groups of isolated channels through a group of analog signals, with a simple structure and low cost; the pure hardware control of the present invention does not require the participation of the MCU, so the control accuracy is high and the response speed is fast; when the main control analog signal changes, the multiple groups of channels change synchronously without delay; the consistency of the changes of each group of analog signals is ensured by adjusting the calibration resistor R9, and the high-precision synchronous transmission of the analog signal is guaranteed by the optical coupler. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 This is the module connection diagram of the utility model;

[0018] Figure 2 This is the module composition diagram of the channel module;

[0019] Figure 3 The schematic diagram of the circuit for the analog adjustable signal module with shared control;

[0020] Figure 4 This is the circuit schematic diagram of the DCDC isolated power supply circuit;

[0021] Figure 5 This is the circuit schematic diagram of the signal modulation circuit, isolation module, I / V conversion circuit, and channel output module. DETAILED DESCRIPTION

[0022] The technical solution of the present invention will be further described below in conjunction with the accompanying drawings:

[0023] like Figure 1 、 Figure 2 The circuit for high-precision synchronous transmission of analog signals through multiple channels of isolation is shown, comprising a commonly controlled analog adjustable signal module 2, two channel modules 1, and a power supply VCC3. The multiple channel modules 1 are all connected to the commonly controlled analog adjustable signal module 2. The commonly controlled analog adjustable signal module 2 and the multiple channel modules 1 are all connected to the power supply VCC3. The channel module 1 includes a signal modulation circuit 11, an isolation module 12, an I / V conversion circuit 13, a channel output module 14, and a DC-DC isolation power supply circuit 15. The signal modulation circuit 11 is connected to the I / V conversion circuit 13 via the isolation module 12. The I / V conversion circuit 13 is connected to the channel output module 14. The isolation module 12 and the two channel modules 1 are all connected to the DC-DC isolation power supply circuit 15. There may also be multiple channel modules 1.

[0024] like Figure 3As shown, the shared control analog adjustable signal module 2 includes a resistor R208, a capacitor C210, a capacitor C209, a resistor R207, a resistor R212, an adjustable voltage reference chip U202, a resistor R21, a variable resistor R22, and an analog signal input terminal VERFDJ. One end of the resistor R208 is connected to the power supply VCC3, and the other end of the resistor R208 is connected to the ground signal GND through the capacitor C210. The capacitor C209 is connected in parallel with the capacitor C210. The A end of the adjustable voltage reference chip U202 is connected to the ground signal GND. The R terminal of the adjustable voltage reference chip U202 is connected to the ground signal GND through a resistor R212. The R terminal of the adjustable voltage reference chip U202 is also connected to the other end of the resistor R208 through a resistor R207. The K terminal of the adjustable voltage reference chip U202 is connected to one end of a resistor R21. The other end of the resistor R21 is connected to the ground signal GND through a variable resistor R22. The other end of the resistor R21 is connected to the analog signal input terminal VERFDJ. The other end of the resistor R21 is connected to several channel modules 1. The model of the adjustable voltage reference chip U202 is AZ431AN.

[0025] like Figure 5 As shown, the signal modulation circuit 11 includes an operational amplifier U2A, an operational amplifier U2B, a capacitor C8, a resistor R2, a resistor R3, a resistor R5, a capacitor C10, a resistor R10, a capacitor C5, and a capacitor C6. The same-direction input terminal of the operational amplifier U2A is connected to one end of the resistor R2, the other end of the resistor R2 is connected to the ground signal GND through the capacitor C8, the other end of the resistor R2 is connected to the other end of the resistor R21, the inverting input terminal of the operational amplifier U2A is connected to the output terminal of the operational amplifier U2A through the resistor R10, and the operational amplifier U2A and the operational amplifier U2B are connected to the output terminal of the operational amplifier U2A through the resistor R10. The amplifier U2B is connected to the power supply VCC3, and the power supply VCC3 is connected to the ground signal GND through the capacitor C5. The capacitor C6 is connected in parallel with the capacitor C5. The output end of the operational amplifier U2A is connected to the same-direction input end of the operational amplifier U2B through the resistor R3. The reverse input end of the operational amplifier U2B is connected to the ground signal GND through the resistor R5. The reverse input end of the operational amplifier U2B is connected to the output end of the operational amplifier U2B through the capacitor C10. The output end of the operational amplifier U2B and the reverse input end of the operational amplifier U2B are both connected to the isolation module 12.

[0026] like Figure 5As shown, the isolation module 12 includes a resistor R4, a capacitor C9, and an optocoupler U3. The reverse input end of the operational amplifier U2B is connected to pin 4 of the optocoupler U3. The output end of the operational amplifier U2B is connected to pin 2 of the optocoupler U3 through the resistor R4. Pin 3 of the optocoupler U3 is connected to the ground signal GND through the capacitor C9. Pin 3 of the optocoupler U3 is connected to the power supply VCC3. Pin 6 of the optocoupler U3 is connected to the DCDC isolation power supply circuit 15. Pin 5 of the optocoupler U3 is connected to the I / V conversion circuit 13.

[0027] like Figure 4 As shown, the DCDC isolated power supply circuit 15 includes polarized capacitor C1, capacitor C2, polarized capacitor C3, capacitor C4, and isolated power supply module U1. Pin 1 of the isolated power supply module U1 is connected to the ground signal GND via polarized capacitor C1. Pin 1 of the isolated power supply module U1 is connected to the power supply VCC3. Capacitor C2 is connected in parallel with polarized capacitor C1. Pin 2 of the isolated power supply module U1 is connected to the ground signal GND. Pin 4 of the isolated power supply module U1 is connected to the isolated ground GE_GND_1. Pin 6 of the isolated power supply module U1 is connected to the isolated ground GE_GND_1 via polarized capacitor C3. Pin 6 of the isolated power supply module U1 is connected to the isolated ground GE_GND_1 via capacitor C4. Pin 6 of the isolated power supply module U1 outputs a 12V isolated power supply 12V_1. The model of the isolated power supply module U1 is B1212S-3WR2.

[0028] like Figure 4 As shown, a capacitor C7 is also included. Pin 6 of the optocoupler U3 is connected to the 12V isolated power supply 12V_1, and pin 6 of the optocoupler U3 is connected to the isolated ground GE_GND_1 through the capacitor C7. The model of the optocoupler U3 is HCNR201.

[0029] like Figure 5 As shown, the I / V conversion circuit 13 includes an operational amplifier U5B, a resistor R8, a capacitor C12, a resistor R1, and a resistor R7. The non-inverting input terminal of the operational amplifier U5B is connected to pin 5 of the optocoupler U3, the inverting input terminal of the operational amplifier U5B is connected to the output terminal of the operational amplifier U5B through the resistor R1, the non-inverting input terminal of the operational amplifier U5B is connected to one end of the resistor R7 through the resistor R8, the other end of the resistor R7 is connected to the output terminal of the operational amplifier U5B, the capacitor C12 is connected in parallel with the resistor R8, and the output terminal of the operational amplifier U5B is connected to the channel output module 14.

[0030] like Figure 5As shown, the channel output module 14 includes a resistor R6, a capacitor C11, and a calibration resistor R9. The output end of the operational amplifier U5B is connected to one end of the resistor R6, and the other end of the resistor R6 is connected to the isolation ground GE_GND_1 through the capacitor C11. The calibration resistor R9 is connected in parallel with the capacitor C11, and the other end of the resistor R6 is the output end.

[0031] The power supply VCC3 is 12V.

[0032] Here’s how it works:

[0033] The utility model can connect multiple groups of isolation channels in parallel infinitely. The channel module 1 includes a signal modulation circuit 11, an isolation module 12, an I / V conversion circuit 13, a channel output module 14, a DCDC isolation power supply circuit 15, a resistor R208, a capacitor C210, a capacitor C209, a resistor R207, a resistor R212, an adjustable voltage reference chip U202, a resistor R21, a variable resistor R22, and an analog signal input terminal VERFDJ to form a commonly controlled analog adjustable signal module 2. Operational amplifier U2A, operational amplifier U2B, capacitor C8, resistor R2, resistor R3, resistor R5, capacitor C10, resistor R10, capacitor C5, and capacitor C6 form a signal modulation circuit 11, which modulates the analog signal. Resistor R4, capacitor C9, and optocoupler U3 form an isolation module 12, which converts the analog signal into an optical signal for transmission. Operational amplifier U5B, resistor R8, capacitor C12, resistor R1, and resistor R7 form an I / V conversion circuit. Resistor R6, capacitor C11, and calibration resistor R9 form a channel output module 14. Resistor R6, capacitor C11, and calibration resistor R9 are a calibration circuit, which adjusts the error of each group to ensure the consistency of each group of signal changes.

[0034] The signal modulation circuit 11 is connected to the I / V conversion circuit 13 via the isolation module 12 . The I / V conversion circuit 13 is connected to the channel output module 14 . The isolation module 12 and the two channel modules 1 are both connected to the DCDC isolation power supply circuit 15 .

[0035] Pin 5 of the optocoupler U3 is connected to the I / V conversion circuit 13. The output of the I / V conversion circuit is connected to the front stage of the calibration circuit, and the back stage of the calibration circuit is connected to the channel control terminal. 12VCC enters the adjustable voltage reference chip U202 through the current-limiting resistor R208. The voltage is stabilized by sampling resistors R207 and R212, and then an adjustable voltage divider circuit R21 and R22 is used to obtain an adjustable analog signal. C210 and C209 form the reference source filter circuit. The analog control signal is input to the analog signal input terminal VERFDJ. After passing through the low-pass filter formed by R2 and C8, it enters the voltage follower formed by U2A and R10 for impedance matching, and then enters the optocoupler drive circuit formed by U2B, R3, R5, and R4. C5 and C6 are filter capacitors that form the power supply of the op amp. The driven signal is input to the linear optocoupler U3, which converts the electrical signal into an optical signal and transmits it to the back stage of the channel module. C9 and C7 are filters that power the optocoupler. The post-stage optocoupler U3 converts the optical signal into a current signal, which then passes through a low-pass filter formed by C12 and R8 and is then fed into the I / V conversion circuit formed by U5B, R1, and R7. This current signal is converted into an analog voltage signal, which then passes through a voltage divider calibration circuit formed by R6, R9, and C11 to modulate the differences between each channel group to a uniform value. The input power supply VCC is filtered by C1 and C2, then fed into the isolated power supply module U1, which then filters through C3 and C4 to provide power to the isolated channels. Each channel module has the same circuit structure and connection relationship. This allows the present invention to synchronously control the changes of multiple isolated channels by using a single analog signal as described above.

[0036] The utility model realizes a circuit for controlling and isolating multiple channels with one analog signal, achieving low cost, simple structure, fast response speed and high precision of synchronous control transmission. The utility model can connect multiple groups of channel modules in parallel, so it has a wide range of applications.

[0037] It should be noted that the above is only one specific embodiment of the present invention. Obviously, the present invention is not limited to the above embodiment and may be subject to many variations. In short, all variations that can be directly derived or associated with the content of the present invention by a person skilled in the art should be considered to be within the scope of protection of the present invention.

Claims

1. A circuit for high-precision synchronous transmission of analog signals with multiple channels of isolation, characterized by: The invention comprises a commonly controlled analog adjustable signal module (2), a plurality of channel modules (1), and a power supply VCC (3); the plurality of channel modules (1) are all connected to the commonly controlled analog adjustable signal module (2); the commonly controlled analog adjustable signal module (2) and the plurality of channel modules (1) are all connected to the power supply VCC (3); the channel module (1) comprises a signal modulation circuit (11), an isolation module (12), an I / V conversion circuit (13), a channel output module (14), and a DCDC isolation power supply circuit (15); the signal modulation circuit (11) is connected to the I / V conversion circuit (13) via the isolation module (12); the I / V conversion circuit (13) is connected to the channel output module (14); the isolation module (12) and the plurality of channel modules (1) are all connected to the DCDC isolation power supply circuit (15).

2. The circuit for high-precision synchronous transmission and isolation of multiple channels of analog signals according to claim 1, characterized in that: The shared controlled analog adjustable signal module (2) comprises a resistor R208, a capacitor C210, a capacitor C209, a resistor R207, a resistor R212, an adjustable voltage reference chip U202, a resistor R21, a variable resistor R22, and an analog signal input terminal VERFDJ, one end of the resistor R208 is connected to a power supply VCC (3), the other end of the resistor R208 is connected to a ground signal GND via the capacitor C210, the capacitor C209 is connected in parallel with the capacitor C210, and the A end of the adjustable voltage reference chip U202 is connected to the ground. The R end of the adjustable voltage reference chip U202 is connected to the ground signal GND through the resistor R212, and the R end of the adjustable voltage reference chip U202 is also connected to the other end of the resistor R208 through the resistor R207. The K end of the adjustable voltage reference chip U202 is connected to one end of the resistor R21, and the other end of the resistor R21 is connected to the ground signal GND through the variable resistor R22. The other end of the resistor R21 is connected to the analog signal input terminal VERFDJ, and the other end of the resistor R21 is connected to a plurality of channel modules (1).

3. The circuit for high-precision synchronous transmission and isolation of multiple channels of analog signals according to claim 2, characterized in that: The signal modulation circuit (11) includes an operational amplifier U2A, an operational amplifier U2B, a capacitor C8, a resistor R2, a resistor R3, a resistor R5, a capacitor C10, a resistor R10, a capacitor C5, and a capacitor C6. The same-direction input terminal of the operational amplifier U2A is connected to one end of the resistor R2, the other end of the resistor R2 is connected to the ground signal GND through the capacitor C8, the other end of the resistor R2 is connected to the other end of the resistor R21, the inverting input terminal of the operational amplifier U2A is connected to the output terminal of the operational amplifier U2A through the resistor R10, and the operational amplifier U2A and the operational amplifier U2B is connected to a power supply VCC (3), the power supply VCC (3) is connected to a ground signal GND via a capacitor C5, the capacitor C6 is connected in parallel with the capacitor C5, the output end of the operational amplifier U2A is connected to the same-direction input end of the operational amplifier U2B via a resistor R3, the reverse input end of the operational amplifier U2B is connected to the ground signal GND via a resistor R5, the reverse input end of the operational amplifier U2B is connected to the output end of the operational amplifier U2B via a capacitor C10, and the output end of the operational amplifier U2B and the reverse input end of the operational amplifier U2B are both connected to an isolation module (12).

4. The circuit for high-precision synchronous transmission and isolation of multiple channels of analog signals according to claim 3, characterized in that: The isolation module (12) comprises a resistor R4, a capacitor C9, and an optocoupler U3; the reverse input end of the operational amplifier U2B is connected to pin 4 of the optocoupler U3; the output end of the operational amplifier U2B is connected to pin 2 of the optocoupler U3 via the resistor R4; the pin 3 of the optocoupler U3 is connected to a ground signal GND via the capacitor C9; the pin 3 of the optocoupler U3 is connected to a power supply VCC (3); the pin 6 of the optocoupler U3 is connected to a DCDC isolation power supply circuit (15); and the pin 5 of the optocoupler U3 is connected to an I / V conversion circuit (13).

5. The circuit for isolating multiple channels of analog signal with high precision synchronous transmission according to claim 4, characterized in that: The DCDC isolation power supply circuit (15) comprises a polarity capacitor C1, a capacitor C2, a polarity capacitor C3, a capacitor C4, and an isolation power supply module U1. Pin 1 of the isolation power supply module U1 is connected to a ground signal GND through the polarity capacitor C1, pin 1 of the isolation power supply module U1 is connected to a power supply VCC (3), the capacitor C2 is connected in parallel with the polarity capacitor C1, pin 2 of the isolation power supply module U1 is connected to a ground signal GND, pin 4 of the isolation power supply module U1 is connected to an isolation ground GE_GND_1, pin 6 of the isolation power supply module U1 is connected to an isolation ground GE_GND_1 through the polarity capacitor C3, pin 6 of the isolation power supply module U1 is connected to an isolation ground GE_GND_1 through the capacitor C4, and pin 6 of the isolation power supply module U1 outputs a 12V isolation power supply 12V_1.

6. The circuit for isolating multiple channels of analog signal with high precision synchronous transmission according to claim 5, characterized in that: A capacitor C7 is also included. Pin 6 of the optocoupler U3 is connected to a 12V isolated power supply 12V_1. Pin 6 of the optocoupler U3 is connected to an isolated ground GE_GND_1 through the capacitor C7.

7. The circuit for isolating multiple channels of analog signal with high-precision synchronous transmission according to claim 4, characterized in that: The I / V conversion circuit (13) includes an operational amplifier U5B, a resistor R8, a capacitor C12, a resistor R1, and a resistor R7. The non-inverting input end of the operational amplifier U5B is connected to pin 5 of the optocoupler U3. The inverting input end of the operational amplifier U5B is connected to the output end of the operational amplifier U5B through the resistor R1. The non-inverting input end of the operational amplifier U5B is connected to one end of the resistor R7 through the resistor R8. The other end of the resistor R7 is connected to the output end of the operational amplifier U5B. The capacitor C12 is connected in parallel with the resistor R8. The output end of the operational amplifier U5B is connected to the channel output module (14).

8. The circuit for isolating multiple channels of analog signal with high precision synchronous transmission according to claim 7, characterized in that: The channel output module (14) comprises a resistor R6, a capacitor C11, and a calibration resistor R9; the output end of the operational amplifier U5B is connected to one end of the resistor R6; the other end of the resistor R6 is connected to the isolation ground GE_GND_1 via the capacitor C11; the calibration resistor R9 is connected in parallel with the capacitor C11; and the other end of the resistor R6 is the output end.

9. The circuit for high-precision synchronous transmission and isolation of multiple channels of analog signals according to claim 1, characterized in that: There are two channel modules (1).

10. The circuit for high-precision synchronous transmission and isolation of multiple channels of analog signals according to claim 1, characterized in that: The power supply VCC (3) is 12V.

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