PCBA board of multi-channel data acquisition circuit

Abstract

The utility model relates to the technical field of steering systems, in particular to a PCBA (Printed Circuit Board Assembly) board of a multichannel data acquisition circuit. The PCBA board of the multichannel data acquisition circuit comprises a metal shell and a PCBA circuit board, and is characterized in that the metal shell is arranged on the outer side of the PCBA circuit board, the metal shell is of a cuboid structure, and six panels of the metal shell are connected through screws respectively; the side surface of the metal housing is provided with eight input ports and one USB output port. The PCBA circuit board is a double-layer FR4 board and comprises a first analog-to-digital conversion module, a first signal conditioning module, a microcontroller, a second signal conditioning module, a second analog-to-digital conversion module, an output module and a power supply module. Compared with the prior art, the PCBA board of the multi-channel data acquisition circuit is provided, the PCBA board is fixed through the screws, good electromagnetic shielding and friction protection are provided for the PCBA board through the metal shell, and low-cost and multi-channel rapid communication supporting USB3.0 is achieved by reasonably selecting the mcu.

Description

Technical Field

[0001] The utility model relates to the technical field of steering systems, in particular to a PCBA board of a multi-channel data acquisition circuit. Background Art

[0002] The eight-channel data acquisition PCB processing board is an acquisition board with eight-channel signal acquisition. It can convert analog signals into digital signals, thus facilitating data processing, analysis and storage.

[0003] In the fields of electronic measurement and laboratory research, it is often necessary to capture and analyze small signals and send them to the host computer for analysis and processing. This system helps to collect and analyze signals at low cost and in real time.

[0004] The system has a double-layer board structure, and synchronously collects voltage signals through eight input channels based on serial port transmission. It is connected to the host computer via USB and has a metal casing for electromagnetic protection.

[0005] However, the existing eight-channel acquisition PCB processing boards mostly use FPGA. Due to too many data connectors, when they are carried independently or installed in the control box of the equipment, sufficient space is required to ensure the integrity of the equipment and the stability of the PCBA board after installation. The cost is not easy to control and good electromagnetic protection effect cannot be guaranteed. Summary of the invention

[0006] In order to overcome the deficiencies of the prior art, the utility model provides a PCBA board for a multi-channel data acquisition circuit. The PCBA board is fixed by screws, and a metal shell is used to provide good electromagnetic shielding and friction protection for the PCBA board. Low-cost, multi-channel, and fast communication supporting USB3.0 are achieved by reasonably selecting an MCU.

[0007] To achieve the above purpose, a PCBA board of a multi-channel data acquisition circuit is designed, including a metal shell and a PCBA circuit board, characterized in that: a metal shell is provided on the outside of the PCBA circuit board, the metal shell is a rectangular parallelepiped structure, and six panels of the metal shell are respectively connected by screws; 8 input ports and 1 USB output port are provided on the side of the metal shell; the PCBA circuit board is a double-layer FR4 board, and the PCBA circuit board includes a first analog-to-digital conversion module, a first signal conditioning module, a microcontroller, a second signal conditioning module, a second analog-to-digital conversion module, an output module, and a power module.

[0008] The structures of the first analog-to-digital conversion module and the second analog-to-digital conversion module are consistent. The first analog-to-digital conversion module is provided with an analog-to-digital conversion circuit, which includes an analog-to-digital conversion chip. The model of the analog-to-digital conversion chip is AD7606. Port 1 of the analog-to-digital conversion chip is respectively connected to the AVCC power supply, the first resistor, the first capacitor, and one end of the second capacitor. The other ends of the first capacitor and the second capacitor are combined and grounded. The other end of the first resistor is respectively connected to one end of the inductor and one end of the third capacitor. The other end of the third capacitor is grounded, and the other end of the inductor is connected to a 5V voltage; Port 6 of the analog-to-digital conversion chip is respectively connected to one end of the second resistor and the third resistor, the other end of the second resistor is connected to a 3.3V voltage, and the other end of the third resistor is grounded; Port 7 of the analog-to-digital conversion chip is connected to a 3.3V voltage; Port 23 of the analog-to-digital conversion chip is respectively connected to a 3.3V voltage and one end of the fourth capacitor, and the other end of the fourth capacitor is grounded; Ports 2, 8, and 10 of the analog-to-digital conversion chip are respectively connected to a 3.3V voltage and one end of the fourth capacitor, and the other end of the fourth capacitor is grounded; Port No. 1 to Port No. 22, and Port No. 26 to Port No. 32 are grounded together; Port No. 34 of the analog-to-digital conversion chip is connected to one end of the fourth resistor and the fifth resistor respectively, the other end of the fourth resistor is connected to a 3.3V voltage, the other end of the fifth resistor, Port No. 35, Port No. 40, Port No. 41, Port No. 43, Port No. 46, and Port No. 47 of the analog-to-digital conversion chip are grounded together; Port No. 36 of the analog-to-digital conversion chip is connected to one end of the fifth capacitor, the other end of the fifth capacitor is connected to one end of the sixth resistor, and the other end of the sixth resistor is grounded; Port No. 39 of the analog-to-digital conversion chip is connected to one end of the sixth capacitor, Port No. 42 of the analog-to-digital conversion chip is connected to one end of the seventh capacitor, Port No. 44 and Port No. 45 of the analog-to-digital conversion chip are connected to one end of the eighth capacitor, and the other ends of the sixth capacitor, the seventh capacitor, and the eighth capacitor are grounded together; Port No. 37, Port No. 38, and Port No. 48 to Port No. 64 of the analog-to-digital conversion chip are connected to the AVCC power supply together.

[0009] The structures of the first signal conditioning module and the second signal conditioning module are consistent. The first signal conditioning module is provided with a signal conditioning circuit, which includes an amplifier. The model of the amplifier is OPA2170. The positive power supply terminal of the amplifier is respectively connected to one end of the ninth capacitor, the tenth capacitor and the seventh resistor, and the other ends of the ninth capacitor and the tenth capacitor are combined and grounded; the other end of the seventh resistor is connected to a 5V voltage; the negative power supply terminal of the amplifier is grounded; the output end of the amplifier is respectively connected to the reverse input end of the amplifier and one end of the eighth resistor, the other end of the eighth resistor is respectively connected to one end of the eleventh capacitor and port 35 of the microcontroller, and the other end of the eleventh capacitor is grounded; the forward input end of the amplifier is respectively connected to one end of the ninth resistor and the twelfth capacitor, the other end of the ninth resistor is respectively connected to one end of the tenth resistor and the eleventh resistor, the other ends of the eleventh resistor and the twelfth capacitor are combined and grounded, and the other end of the tenth resistor is connected to the IN1 input signal.

[0010] The microcontroller comprises a main control chip, the model of the main control chip is STM32F103, and port No. 4, port No. 15 to port No. 17, port No. 38 to port No. 46, port No. 55 to port No. 57, port No. 61 to port No. 64, port No. 95, and port No. 96 of the main control chip are respectively connected to the analog-to-digital conversion chip; port No. 12 of the main control chip and port No. 13 of the main control chip are respectively connected to two ends of a piezoelectric crystal, and the two ends of the piezoelectric crystal are respectively connected to one end of a thirteenth capacitor and a fourteenth capacitor, and the other ends of the thirteenth capacitor and the fourteenth capacitor are combined and grounded; port No. 14 of the main control chip is respectively connected to one end of a fifteenth capacitor and a twelfth resistor, the other end of the twelfth resistor is connected to a 3.3V voltage, and the other end of the fifteenth capacitor is grounded; port No. 94 of the main control chip is grounded.

[0011] The power module includes a first power chip and a second power chip. The model of the first power chip is LT1962, and the model of the second power chip is LM1117. Port 1 and port 2 of the first power chip and one end of the sixteenth capacitor, the seventeenth capacitor and the eighteenth capacitor are connected to a 3.3V voltage, and the other end of the sixteenth capacitor is connected to port 3 of the first power chip. Port 5 and port 8 of the first power chip and one end of the nineteenth capacitor and the twentieth capacitor are connected to a 5V voltage, and the other ends of the nineteenth capacitor, the twentieth capacitor, the seventeenth capacitor and the eighteenth capacitor are connected to port 4 of the first power chip and grounded; port 2 of the second power chip and one end of the twenty-first capacitor and the twenty-second capacitor are connected to a 3.3V voltage, port 3 of the second power chip and one end of the twenty-third capacitor and the twenty-fourth capacitor are connected to a 5V voltage, and the other ends of the twenty-first capacitor, the twenty-second capacitor, the twenty-third capacitor and the twenty-fourth capacitor are connected to port 1 of the second power chip and grounded.

[0012] The output module comprises an output chip, the model of the output chip is CH34ON, and the No. 1 port and the No. 2 port of the output chip are signal input ports of USB D+ and USB D-; the No. 3 port of the output chip is grounded; the No. 5 port of the output chip is connected to one end of the twenty-fifth capacitor, and the other end of the twenty-fifth capacitor is grounded; the No. 6 port and the No. 7 port of the output chip are respectively connected to one end of the first pull-up resistor and the second pull-up resistor, the No. 2 port of the first transistor and the second transistor, and the other ends of the first pull-up resistor and the second pull-up resistor are combined and connected to the No. 5 port of the output chip; the No. 1 port of the first transistor and the second transistor are combined and connected to the 3.3V voltage, and the No. 3 ports of the first transistor and the second transistor are respectively connected to the UART protocol port; the No. 8 port of the output chip is connected to one end of the twenty-sixth capacitor, and the other end of the twenty-sixth capacitor is grounded.

[0013] The thickness of the metal shell panel is 2 mm.

[0014] The thickness of the PCBA circuit board is 2 mm.

[0015] The diameter of the threaded hole on the metal housing panel is 1.5 mm.

[0016] Compared with the prior art, the utility model provides a PCBA board of a multi-channel data acquisition circuit, fixes the PCBA board by screws, provides good electromagnetic shielding and friction protection for the PCBA board by a metal shell, and realizes low-cost, multi-channel, and fast communication supporting USB3.0 by reasonably selecting an MCU. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is a schematic diagram of the structure of the utility model.

[0018] Figure 2 This is a schematic diagram of the internal module connection of the PCBA board in the present utility model.

[0019] Figure 3 This is the circuit connection diagram of the analog-to-digital conversion module in the PCBA board.

[0020] Figure 4 This is the circuit connection diagram of the signal conditioning module in the PCBA board.

[0021] Figure 5 This is the connection diagram of the microcontroller circuit in the PCBA board.

[0022] Figure 6 , Figure 7 This is the circuit connection diagram of the power module in the PCBA board.

[0023] Figure 8 , Fig. 9 This is the circuit connection diagram of the output module in the PCBA board. DETAILED DESCRIPTION

[0024] The utility model is further described below with reference to the accompanying drawings.

[0025] like Figure 1 , Figure 2 As shown, a metal shell 1 is provided on the outside of the PCBA circuit board 2. The metal shell 1 is a rectangular parallelepiped structure, and the six panels of the metal shell 1 are connected by screws respectively; 8 input ports 1-1 and 1 USB output port 1-2 are provided on the side of the metal shell 1; the PCBA circuit board 2 is a double-layer FR4 board, and the PCBA circuit board 2 includes a first analog-to-digital conversion module 3, a first signal conditioning module 4, a microcontroller 5, a second signal conditioning module 6, a second analog-to-digital conversion module 7, an output module 8, and a power module 9. The thickness of the panel of the metal shell 1 is 2 mm. The thickness of the PCBA circuit board 2 is 2 mm. The diameter of the threaded hole on the panel of the metal shell 1 is 1.5 mm.

[0026] The two opposite sides of the metal shell 1 have 8 input ports and 1 output USB port, 4 screw holes on each side, and matching screws on them. The other two sides do not have any through holes. There is a through hole at the corners of the upper and lower sides for fixing the PCBA circuit board 2. The PCBA circuit board 2 is placed in the metal shell 1. The PCBA circuit board 2 is a rectangular parallelepiped structure with screw holes at the four corners for easy installation and fixing.

[0027] like Figure 1 As shown, when installing the PCBA circuit board 2, place it inside the metal housing 1, and then screw 4 screws into the 12 threaded holes in three layers that penetrate at the same coordinates, thereby pressing the PCBA circuit board 2. At the same time, there are 4 threaded holes, 8 circular input holes, and 1 GND circular hole around one side of the metal housing 1; there are 4 threaded holes and 1 output circular hole around the other side. The 4 threaded holes with the same coordinates on both sides need to be screwed in and fixed by 4 screws.

[0028] By providing sufficient fixing and installation space for the PCBA circuit board 2, the metal housing 1 provides electromagnetic protection for the PCBA circuit board 2, and after the screws are screwed in, the PCBA circuit board 2 can be pressed tightly, thereby improving the stability of the overall function.

[0029] The main control chip U3A of the acquisition board of the utility model adopts the STM32F103 series chip. The electrical signal is collected through the input module, and the analog-to-digital conversion is realized through the analog-to-digital conversion chip U1 with the model number AD7606. The amplifier U11B with the model number OPA2170 is used for signal amplification and conditioning. After the microcontroller performs data storage and processing, it passes through the signal conditioning module, and the DAC converts the digital signal into an analog signal output, and the output chip U9 with the model number CH340N is used to map the USB to the serial port to the host computer. In addition, the LT and LM series chips are used for on-board voltage conversion and power supply to the analog and digital circuits for data output, and miniSD is used for data storage and backup. At the same time, in order to better shield electromagnetic interference and reduce wear, the PCBA board shell adopts an all-metal structure, which is compact and portable.

[0030] like Figure 3As shown, the structures of the first analog-to-digital conversion module 3 and the second analog-to-digital conversion module 7 are consistent. The first analog-to-digital conversion module 3 is provided with an analog-to-digital conversion circuit, which includes an analog-to-digital conversion chip U1. The model of the analog-to-digital conversion chip U1 is AD7606. Port 1 of the analog-to-digital conversion chip U1 is respectively connected to the AVCC power supply, the first resistor R1, the first capacitor C2, and one end of the second capacitor C3. The other ends of the first capacitor C2 and the second capacitor C3 are combined and grounded. The other end of the first resistor R1 is respectively connected to one end of the inductor L1 and one end of the third capacitor C1. The other end of the third capacitor C1 is grounded, and the other end of the inductor L1 is connected to a 5V voltage; port 6 of the analog-to-digital conversion chip U1 is respectively connected to one end of the second resistor R8 and the third resistor R11, the other end of the second resistor R8 is connected to a 3.3V voltage, and the other end of the third resistor R11 is grounded; port 7 of the analog-to-digital conversion chip U1 is connected to a 3.3V voltage; port 23 of the analog-to-digital conversion chip U1 is respectively connected to a 3.3V voltage and one end of the fourth capacitor C14, and the other end of the fourth capacitor C14 is grounded; port 2 and port 8 of the analog-to-digital conversion chip U1 are respectively connected to a 3.3V voltage and one end of the fourth capacitor C14, and the other end of the fourth capacitor C14 is grounded; Port 34 of the analog-to-digital conversion chip U1 is connected to one end of the fourth resistor R22 and one end of the fifth resistor R23 respectively, the other end of the fourth resistor R22 is connected to a 3.3V voltage, the other end of the fifth resistor R23, ports 35, 40, 41, 43, 46, and 47 of the analog-to-digital conversion chip U1 are grounded; port 36 of the analog-to-digital conversion chip U1 is connected to one end of the fifth capacitor C16, and the other end of the fifth capacitor C16 is connected to the sixth One end of the resistor R21 and the other end of the sixth resistor R21 are grounded; port 39 of the analog-to-digital conversion chip U1 is connected to one end of the sixth capacitor C15, port 42 of the analog-to-digital conversion chip U1 is connected to one end of the seventh capacitor C13, ports 44 and 45 of the analog-to-digital conversion chip U1 are connected to one end of the eighth capacitor C12, and the other ends of the sixth capacitor C15, the seventh capacitor C13, and the eighth capacitor C12 are combined and grounded; ports 37, 38, 48 to 64 of the analog-to-digital conversion chip U1 are combined and connected to the AVCC power supply.

[0031] The analog-to-digital conversion chip U1 is an AD7606 architecture, with port 1 being VCC, port 2 being GND, port 6 being serial-parallel selection, port 11 being reset, port 12 being clock, port 34 being reference source setting, and ports 49 to 64 being 8-way ADC inputs and matching GND. The 8-way electrical signals are converted through AIN 1-8 channels. Taking AIN1 as an example, the function corresponds to pin 49, namely V1, including the 20th resistor R20 and the 11th capacitor C11, and the pull-up capacitor and the 17th resistor R17 correspond to VGND1.

[0032] like Figure 4As shown, the structures of the first signal conditioning module 4 and the second signal conditioning module 6 are consistent. The first signal conditioning module 4 is provided with a signal conditioning circuit, and the signal conditioning circuit includes an amplifier U11B. The model of the amplifier U11B is OPA2170. The positive power supply terminal of the amplifier U11B is respectively connected to one end of the ninth capacitor C51, the tenth capacitor C50, and the seventh resistor R42, and the other ends of the ninth capacitor C51 and the tenth capacitor C50 are combined and grounded; the other end of the seventh resistor R42 is connected to a 5V voltage; the negative power supply terminal of the amplifier U11B is grounded; the output ends of the amplifier U11B are respectively connected to the amplifier The reverse input terminal of the amplifier U11B and one end of the eighth resistor R43, and the other end of the eighth resistor R43 are respectively connected to one end of the eleventh capacitor C52 and port 35 of the microcontroller 5, and the other end of the eleventh capacitor C52 is grounded; the positive input terminal of the amplifier U11B is respectively connected to the ninth resistor R45 and one end of the twelfth capacitor C53, the other end of the ninth resistor R45 is respectively connected to one end of the tenth resistor R44 and the eleventh resistor R46, the other ends of the eleventh resistor R46 and the twelfth capacitor C53 are combined and grounded, and the other end of the tenth resistor R44 is connected to the IN1 input signal.

[0033] The IN1 channel includes the tenth resistor R44, the ninth resistor R45, the eleventh resistor R46, and the twelfth capacitor C53, which are connected to the positive feedback port of the amplifier U11B. At the same time, the amplifier U11B is connected to the seventh resistor R42, the tenth capacitor C50, and the ninth capacitor C51. The output port of the amplifier U11B is connected to the eighth resistor R43 and the eleventh capacitor C52. The IN1 channel completes the acquisition of the voltage signal, performs signal conditioning through the amplifier U11B, and then outputs it to the ADC IN1 pin.

[0034] like Figure 5 As shown, the microcontroller 5 includes a main control chip U3A, the model of the main control chip U3A is STM32F103, and ports 4, 15 to 17, 38 to 46, 55 to 57, 61 to 64, 95 and 96 of the main control chip U3A are respectively connected to the analog-to-digital conversion chip U1; port 12 of the main control chip U3A and port 13 of the main control chip U3A are respectively connected to the two ends of the piezoelectric crystal Y2, and the two ends of the piezoelectric crystal Y2 are respectively connected to one end of the thirteenth capacitor C43 and the fourteenth capacitor C46, ​​and the other ends of the thirteenth capacitor C43 and the fourteenth capacitor C46 are combined and grounded; port 14 of the main control chip U3A is respectively connected to one end of the fifteenth capacitor C49 and the twelfth resistor R39, the other end of the twelfth resistor R39 is connected to a 3.3V voltage, and the other end of the fifteenth capacitor C49 is grounded; port 94 of the main control chip U3A is grounded.

[0035] The main control chip U3A is responsible for adjusting the clock of each functional chip and communicating. The STM32F103 chip is selected as the main control, and its port 4, port 15-17, port 38-46, port 55-57, port 61-64, port 95-96 are connected to the analog-to-digital conversion chip U1, its port 23 is the self-wake-up function, port 68-69 is connected to the UART protocol module, port 70-71 is connected to the USB module, port 65-80 is connected to the MINISD module (MINISD module is SDIO and SD, used for memory storage, a more common module), port 11, 22, 28, 50, 75, 100 are VDD, port 35 is defined as ADC IN1, and port 89-91 is connected to the clock and calibration module of DAC.

[0036] like Figure 6 , Figure 7 As shown, the power module 9 includes a first power chip U5 and a second power chip U7. The model of the first power chip U5 is LT1962, and the model of the second power chip U7 is LM1117. Port 1 and port 2 of the first power chip U5 and one end of the sixteenth capacitor C24, the seventeenth capacitor C28, and the eighteenth capacitor C26 are combined to connect to a 3.3V voltage, and the other end of the sixteenth capacitor C24 is connected to port 3 of the power chip U5. Port 5 and port 8 of the first power chip U5 and one end of the nineteenth capacitor C25 and the twentieth capacitor C27 are combined to connect to a 5V voltage. 25. The other ends of the twentieth capacitor C27, the seventeenth capacitor C28, and the eighteenth capacitor C26 are combined with port No. 4 of the first power chip U5 and grounded; port No. 2 of the second power chip U7 and one ends of the twenty-first capacitor C44 and the twenty-second capacitor C45 are combined and connected to a 3.3V voltage, port No. 3 of the second power chip U7 and one ends of the twenty-third capacitor C47 and the twenty-fourth capacitor C48 are combined and connected to a 5V voltage, and the other ends of the twenty-first capacitor C44, the twenty-second capacitor C45, the twenty-third capacitor C47, and the twenty-fourth capacitor C48 are combined and grounded.

[0037] The first power chip U5 converts 5V into 3.3V power to power the analog circuit, and the second power chip U7 converts 5V into 3.3V to power other digital circuits. The 5V voltage is input to port No. 8, passes through the 20th capacitor C27 and the 19th capacitor C25 in parallel, and outputs a 3.3VA voltage from the No. 1 port of the first power chip U5 through the 16th capacitor C24 and the 18th capacitor C26 and the 17th capacitor C28 in parallel. Similarly, the 5V voltage is input to port No. 3, passes through the 23rd capacitor C47 and the 24th capacitor C48 in parallel, and outputs a 3.3V voltage from the No. 2 port of the second power chip U7 through the 21st capacitor C44 and the 22nd capacitor C45 in parallel.

[0038] like Figure 8 , Fig. 9 As shown, the output module 8 includes an output chip U9, the model of the output chip U9 is CH34ON, and the port 1 and port 2 of the output chip U9 are signal input ports of USB D+ and USB D-; the port 3 of the output chip U9 is grounded; the port 5 of the output chip U9 is connected to one end of the twenty-fifth capacitor CP2, and the other end of the twenty-fifth capacitor CP2 is grounded; the port 6 and the port 7 of the output chip U9 are respectively connected to one end of the first pull-up resistor R40 and the second pull-up resistor R41, the port 2 of the first transistor Q1 and the second transistor Q2, and the other ends of the first pull-up resistor R40 and the second pull-up resistor R41 are combined and connected to the port 5 of the output chip U9; the port 1 of the first transistor Q1 and the second transistor Q2 are combined and connected to the 3.3V voltage, and the ports 3 of the first transistor Q1 and the second transistor Q2 are respectively connected to the UART protocol port; the port 8 of the output chip U9 is connected to one end of the twenty-sixth capacitor CP1, and the other end of the twenty-sixth capacitor CP1 is grounded.

[0039] The No. 1 and No. 2 ports of the output chip U9 are the signal inputs of USB D+ and USB D-, the No. 3 port is GND, the No. 5 port is VCC, the No. 6 port is for sending according to its own protocol, and the No. 7 port is for receiving according to its own protocol. The chip converts the USB signal into a serial port signal and then transmits and receives it according to the UART protocol. CH340_RX and CH340_TX pass through the first pull-up resistor R40 and the second pull-up resistor R41 respectively, and then pass through the first transistor Q1 and the second transistor Q2 to convert them into UART1_RX and UART1_TX.

[0040] The utility model fixes the PCBA board by screws and screw holes, provides sufficient heat dissipation space for the PCBA circuit board internally, provides good electromagnetic shielding and friction protection for the PCBA circuit board by the metal shell, and realizes low-cost, multi-channel, and USB3.0-supporting fast communication design by reasonably selecting MCU.

Claims

1. A PCBA board for a multi-channel data acquisition circuit, comprising a metal housing and a PCBA circuit board, characterized in that: A metal shell (1) is provided on the outside of a PCBA circuit board (2); the metal shell (1) is a rectangular parallelepiped structure, and six panels of the metal shell (1) are connected by screws respectively; eight input ports (1-1) and one USB output port (1-2) are provided on the side of the metal shell (1); the PCBA circuit board (2) is a double-layer FR4 board, and the PCBA circuit board (2) comprises a first analog-to-digital conversion module (3), a first signal conditioning module (4), a microcontroller (5), a second signal conditioning module (6), a second analog-to-digital conversion module (7), an output module (8), and a power supply module (9).

2. The PCBA board of a multi-channel data acquisition circuit according to claim 1, characterized in that: The first analog-to-digital conversion module (3) and the second analog-to-digital conversion module (7) have the same structure. The first analog-to-digital conversion module (3) is provided with an analog-to-digital conversion circuit, which comprises an analog-to-digital conversion chip (U1). The model of the analog-to-digital conversion chip (U1) is AD7606. Port 1 of the analog-to-digital conversion chip (U1) is respectively connected to an AVCC power supply, a first resistor (R1), a first capacitor (C2), and one end of a second capacitor (C3). The other ends of the first capacitor (C2) and the second capacitor (C3) are combined and grounded. The other end of the first resistor (R1) is respectively connected to one end of an inductor (L1), a third capacitor (C1), and a The other end of the third capacitor (C1) is grounded, and the other end of the inductor (L1) is connected to a 5V voltage; the No. 6 port of the analog-to-digital conversion chip (U1) is respectively connected to one end of the second resistor (R8) and one end of the third resistor (R11), the other end of the second resistor (R8) is connected to a 3.3V voltage, and the other end of the third resistor (R11) is grounded; the No. 7 port of the analog-to-digital conversion chip (U1) is connected to a 3.3V voltage; the No. 23 port of the analog-to-digital conversion chip (U1) is respectively connected to a 3.3V voltage and one end of a fourth capacitor (C14), and the other end of the fourth capacitor (C14) is grounded; the No. 2 port of the analog-to-digital conversion chip (U1) is respectively connected to a 3.3V voltage and one end of a fourth capacitor (C14), and the other end of the fourth capacitor (C14) is grounded; Port 8 to port 22, and port 26 to port 32 are grounded; port 34 of the analog-to-digital conversion chip (U1) is connected to one end of a fourth resistor (R22) and a fifth resistor (R23), respectively, the other end of the fourth resistor (R22) is connected to a 3.3V voltage, the other end of the fifth resistor (R23), port 35, port 40, port 41, port 43, port 46, and port 47 of the analog-to-digital conversion chip (U1) are grounded; port 36 of the analog-to-digital conversion chip (U1) is connected to one end of a fifth capacitor (C16), and the other end of the fifth capacitor (C16) is connected to a sixth capacitor (C16). One end of the sixth resistor (R21) is connected to the analog-to-digital conversion chip (U1), and the other end of the sixth resistor (R21) is grounded; port 39 of the analog-to-digital conversion chip (U1) is connected to one end of the sixth capacitor (C15), port 42 of the analog-to-digital conversion chip (U1) is connected to one end of the seventh capacitor (C13), ports 44 and 45 of the analog-to-digital conversion chip (U1) are connected to one end of the eighth capacitor (C12), and the other ends of the sixth capacitor (C15), the seventh capacitor (C13), and the eighth capacitor (C12) are combined and grounded; ports 37, 38, and ports 48 to 64 of the analog-to-digital conversion chip (U1) are combined and connected to the AVCC power supply.

3. The PCBA board of a multi-channel data acquisition circuit according to claim 1, characterized in that: The first signal conditioning module (4) and the second signal conditioning module (6) have the same structure. The first signal conditioning module (4) is provided with a signal conditioning circuit, which includes an amplifier (U11B). The model of the amplifier (U11B) is OPA2170. The positive power supply end of the amplifier (U11B) is respectively connected to one end of the ninth capacitor (C51), the tenth capacitor (C50), and the seventh resistor (R42). The other ends of the ninth capacitor (C51) and the tenth capacitor (C50) are combined and grounded. The other end of the seventh resistor (R42) is connected to a 5V voltage. The negative power supply end of the amplifier (U11B) is grounded. The output ends of the amplifier (U11B) are respectively connected to the amplifier (C51). The reverse input end of the amplifier (U11B) and one end of the eighth resistor (R43) are connected to one end of the eleventh capacitor (C52) and port 35 of the microcontroller (5), respectively, and the other end of the eleventh capacitor (C52) is grounded; the positive input end of the amplifier (U11B) is connected to the ninth resistor (R45) and one end of the twelfth capacitor (C53), respectively, and the other end of the ninth resistor (R45) is connected to one end of the tenth resistor (R44) and one end of the eleventh resistor (R46), respectively, and the other end of the eleventh resistor (R46) and the twelfth capacitor (C53) are grounded together, and the other end of the tenth resistor (R44) is connected to the IN1 input signal.

4. The PCBA board of a multi-channel data acquisition circuit according to claim 1, characterized in that: The microcontroller (5) comprises a main control chip (U3A), the model of the main control chip (U3A) is STM32F103, and port No. 4, port No. 15 to port No. 17, port No. 38 to port No. 46, port No. 55 to port No. 57, port No. 61 to port No. 64, port No. 95, and port No. 96 of the main control chip (U3A) are respectively connected to the analog-to-digital conversion chip (U1); port No. 12 of the main control chip (U3A) and port No. 13 of the main control chip (U3A) are respectively connected to the piezoelectric crystal (Y2 ), both ends of the piezoelectric crystal (Y2) are connected to one end of the thirteenth capacitor (C43) and the fourteenth capacitor (C46), and the other ends of the thirteenth capacitor (C43) and the fourteenth capacitor (C46) are combined and grounded; port No. 14 of the main control chip (U3A) is connected to one end of the fifteenth capacitor (C49) and the twelfth resistor (R39), the other end of the twelfth resistor (R39) is connected to a 3.3V voltage, and the other end of the fifteenth capacitor (C49) is grounded; port No. 94 of the main control chip (U3A) is grounded.

5. The PCBA board of a multi-channel data acquisition circuit according to claim 1, characterized in that: The power module (9) comprises a first power chip (U5) and a second power chip (U7), the model of the first power chip (U5) is LT1962, the model of the second power chip (U7) is LM1117, the No. 1 port and the No. 2 port of the first power chip (U5) and one end of the sixteenth capacitor (C24), the seventeenth capacitor (C28) and the eighteenth capacitor (C26) are connected to a 3.3V voltage, the other end of the sixteenth capacitor (C24) is connected to the No. 3 port of the first power chip (U5), the No. 5 port and the No. 8 port of the first power chip (U5) and one end of the nineteenth capacitor (C25) and the twentieth capacitor (C27) are connected to a 5V voltage, and the nineteenth capacitor (C 25), the other ends of the twentieth capacitor (C27), the seventeenth capacitor (C28), and the eighteenth capacitor (C26) and port No. 4 of the first power chip (U5) are combined and grounded; port No. 2 of the second power chip (U7) and one ends of the twenty-first capacitor (C44) and the twenty-second capacitor (C45) are combined and connected to a 3.3V voltage, port No. 3 of the second power chip (U7) and one ends of the twenty-third capacitor (C47) and the twenty-fourth capacitor (C48) are combined and connected to a 5V voltage, and the other ends of the twenty-first capacitor (C44), the twenty-second capacitor (C45), the twenty-third capacitor (C47), and the twenty-fourth capacitor (C48) are combined and grounded with port No. 1 of the second power chip (U7).

6. The PCBA board of a multi-channel data acquisition circuit according to claim 1, characterized in that: The output module (8) comprises an output chip (U9), the model of the output chip (U9) is CH34ON, and the port No. 1 and port No. 2 of the output chip (U9) are USB D+ and USB D- signal input port; port 3 of the output chip (U9) is grounded; port 5 of the output chip (U9) is connected to one end of the twenty-fifth capacitor (CP2), and the other end of the twenty-fifth capacitor (CP2) is grounded; port 6 and port 7 of the output chip (U9) are respectively connected to one end of the first pull-up resistor (R40) and the second pull-up resistor (R41), port 2 of the first transistor (Q1) and the second transistor (Q2), and the other end of the first pull-up resistor (R40) and the second pull-up resistor (R41) are combined and connected to port 5 of the output chip (U9); port 1 of the first transistor (Q1) and the second transistor (Q2) are combined and connected to a 3.3V voltage, and port 3 of the first transistor (Q1) and the second transistor (Q2) are respectively connected to the UART protocol port; port 8 of the output chip (U9) is connected to one end of the twenty-sixth capacitor (CP1), and the other end of the twenty-sixth capacitor (CP1) is grounded.

7. The PCBA board of a multi-channel data acquisition circuit according to claim 1, characterized in that: The thickness of the panel of the metal casing (1) is 2 mm.

8. The PCBA board of a multi-channel data acquisition circuit according to claim 1, characterized in that: The PCBA circuit board (2) has a thickness of 2 mm.

9. The PCBA board of a multi-channel data acquisition circuit according to claim 1, characterized in that: The diameter of the threaded hole on the panel of the metal housing (1) is 1.5 mm.

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