Sensor detection circuit for die bonder

Abstract

The utility model relates to the technical field of die bonder detection circuits, in particular to a sensor detection circuit for a die bonder, which comprises a master control module, a sensor interface module, a display control module, a signal processing module and a power supply module. The power supply module is used for supplying power to the main control module, the sensor interface module and the display control module; the sensor interface module and the display control module are respectively connected with the main control module; the main control module comprises a main processor and an auxiliary processor, the signal processing module comprises an AD7730 chip, the input end of the AD7730 chip is connected with a low-pass filter, and the main processor is connected with the auxiliary processor through an SPI interface. According to the utility model, a plurality of sensor interface circuits are arranged and can be used for high-speed and high-precision data detection of the die bonder, so that high-speed, low-noise and rapid system response of the die bonder is met, the connection complexity of the die bonder sensor is reduced, and the requirements of high precision and high sampling rate of the die bonder sensor are met.

Description

Technical Field

[0001] This utility model relates to the field of detection circuit technology for die bonders, and in particular to a sensor detection circuit for die bonders. Background Technology

[0002] With the continuous advancement of semiconductor manufacturing technology and the widespread application of automated equipment, the performance and precision requirements of die bonders, as one of the core pieces of equipment in the semiconductor packaging field, are constantly increasing. During operation, die bonders need to monitor various parameters in real time, such as pressure, Hall effect, and flow rate, to ensure the stability and efficiency of the production process. However, traditional die bonder sensor detection circuits often suffer from problems such as low data acquisition accuracy, slow system response speed, high sensor connection complexity, and inability to meet the demands for high precision and high sampling rates.

[0003] Traditional die bonder sensor detection circuits typically employ a single processor architecture, handling multiple tasks such as communication protocol processing, data acquisition, real-time control, and human-machine interaction. This design not only increases the processor's workload and reduces the system's real-time performance and stability but also makes it difficult to efficiently acquire and process signals from multiple sensors. Furthermore, traditional sensor interface circuits often lack dedicated signal conditioning circuits, resulting in unsatisfactory sensor signal acquisition and further impacting the die bonder's performance and accuracy. Summary of the Invention

[0004] This invention addresses the problems of existing technologies by providing a sensor detection circuit for a die bonder. It is equipped with multiple sensor interface circuits and can be used for high-speed and high-precision data detection in the die bonder. This satisfies the requirements of high speed, low noise, and fast system response in the die bonder, reduces the complexity of sensor connections in the die bonder, and meets the high precision and high sampling rate requirements of the die bonder sensors. Furthermore, the pressure sensor interface circuit is input to the AD7730 chip after low-pass filtering, which can reduce high-frequency noise interference.

[0005] To solve the above-mentioned technical problems, the present invention adopts the following technical solution:

[0006] This invention provides a sensor detection circuit for a die bonder, comprising a main control module, a sensor interface module, a display control module, a signal processing module, and a power supply module. The power supply module supplies power to the main control module, sensor interface module, and display control module, which are respectively connected to the main control module. The sensor interface module includes a pressure sensor interface circuit, a Hall sensor interface circuit, a flow sensor interface circuit, and a general-purpose sensor interface circuit. The main control module includes a main processor and a sub-processor, with the sub-processor connected to the Hall sensor interface circuit, flow sensor interface circuit, and general-purpose sensor interface circuit, respectively. The signal processing module includes an AD7730 chip. The main processor is connected to the pressure sensor interface circuit through the AD7730 chip, and a low-pass filter is connected to the input terminal of the AD7730 chip. The main processor is connected to the sub-processor via an SPI interface and communicates with a host computer via an EtherCAT interface.

[0007] The main processor includes a chip U8, which is model AX58200.

[0008] The secondary processor includes chip U10, which is an STM32H730 chip.

[0009] The pressure sensor interface circuit includes interface CN2, resistors R32 and R39, and capacitors C32, C33, C35, and C36. The first pin of interface CN2 is connected to one end of capacitor C32 and the fifteenth pin of the AD7730 chip, while the other end of capacitor C32 is grounded. The second pin of interface CN2 is connected to one end of resistor R32, while the other end of resistor R32 is connected to one end of capacitor C33, one end of capacitor C35, and the tenth pin of the AD7730 chip. The third pin of interface CN2 is connected to one end of resistor R39, while the other end of resistor R39 is connected to the other end of capacitor C35, one end of capacitor C36, and the eleventh pin of the AD7730 chip. The other ends of capacitors C33 and C36, and the fifth pin of interface CN2 are grounded. The main processor is connected to the AD7730 chip via an SPI interface.

[0010] The Hall sensor interface circuit includes interface CN3, resistors R40, R43, R44, R48, R53, capacitors C41 and C45, and amplifier U16.1. The second pin of interface CN3 is connected to one end of resistor R43. The other end of resistor R43 is connected to one end of resistor R40, one end of capacitor C41, and the inverting input of amplifier U16.1. The non-inverting input of amplifier U16.1 is connected to one end of resistor R48 and one end of resistor R53. The other end of resistor R53 is grounded. The output of amplifier U16.1, the other end of resistor R40, and the other end of capacitor C41 are each connected to one end of resistor R44. The other end of resistor R44 is connected to one end of capacitor C45 and the sub-processor.

[0011] The flow sensor interface circuit includes a first flow sensor interface module and a second flow sensor interface module.

[0012] The first flow sensor interface module includes interface CN6, resistors R54, R56, R60, R61, R63, R64, R65, R68, and R69, capacitors C47 and C49, and amplifier U16.2. The second pin of interface CN6 is connected to one end of resistor R60 and one end of resistor R63. The other end of resistor R60 is connected to one end of resistor R56 and one end of resistor R61. The other end of resistor R56 is grounded. The other end of resistor R63 is connected to resistor R64. One end of resistor R64 is connected to one end of resistor R68. The other end of resistor R64 is connected to one end of resistor R69 and the non-inverting input terminal of amplifier U16.2. The other end of resistor R69 is grounded. The other end of resistor R61 is connected to one end of resistor R54 and the inverting input terminal of amplifier U16.2. Capacitor C47 is connected in parallel with resistor R54. The other end of resistor R54 is connected to the output terminal of amplifier U16.2 and one end of resistor R65. The other end of resistor R65 is connected to one end of capacitor C49 and the subprocessor. The other end of capacitor C49 is grounded.

[0013] The second flow sensor interface module includes interface CN4, resistors R41, R42, R45, R46, R47, R49, R50, R51, R52, capacitors C42 and C46, ​​and amplifier U17.1. The second pin of interface CN4 is connected to one end of resistor R45 and one end of resistor R49. The other end of resistor R45 is connected to one end of resistor R42 and one end of resistor R46. The other end of resistor R42 is grounded. The other end of resistor R49 is connected to resistor R50. One end of resistor R50 is connected to one end of resistor R51. The other end of resistor R50 is connected to one end of resistor R52 and the non-inverting input terminal of amplifier U17.1. The other end of resistor R52 is grounded. The other end of resistor R46 is connected to one end of resistor R41 and the inverting input terminal of amplifier U17.1. Capacitor C42 is connected in parallel with resistor R41. The other end of resistor R41 is connected to the output terminal of amplifier U17.1 and one end of resistor R47. The other end of resistor R47 is connected to one end of capacitor C46 and the subprocessor. The other end of capacitor C46 is grounded.

[0014] The general-purpose sensor interface circuit includes interface CN5, resistors R55, R57, R58, R59, R62, R66, R67, R70, R71, capacitors C48 and C50, and amplifier U17.2. The second pin of interface CN5 is connected to one end of resistors R58 and R66. The other end of resistor R58 is connected to one end of resistors R57 and R59. The other end of resistor R57 is grounded. The other end of resistor R66 is connected to resistor R67. One end of resistor R70 is connected to the output terminal of amplifier U17.2. The other end of resistor R67 is connected to one end of resistor R71 and the non-inverting input terminal of amplifier U17.2. The other end of resistor R71 is grounded. The other end of resistor R59 is connected to one end of resistor R55 and the inverting input terminal of amplifier U17.2. Capacitor C48 is connected in parallel with resistor R55. The other end of resistor R55 is connected to the output terminal of amplifier U17.2 and one end of resistor R62. The other end of resistor R62 is connected to one end of capacitor C50 and the subprocessor. The other end of capacitor C50 is grounded.

[0015] The beneficial effects of this utility model are:

[0016] This invention employs a dual-processor architecture (main processor AX58200 + secondary processor STM32H730) to achieve task splitting: the main processor handles communication protocol processing and human-machine interaction, while the secondary processor focuses on data acquisition and real-time control. The AD7730 chip, in conjunction with a low-pass filter, forms an independent high-precision measurement channel, enabling the detection of minute pressure changes. The SPI bus facilitates high-speed data exchange between multiple processors (theoretical rate up to 50Mbps). The EtherCAT interface utilizes a distributed clock synchronization mechanism to ensure accurate time synchronization with the host computer. This invention includes multiple sensor interface circuits for high-speed, high-precision data detection in the die bonder, meeting the requirements of high-speed, low-noise, and rapid system response in the die bonder, reducing the complexity of sensor connections, and adapting to the high precision and high sampling rate requirements of the die bonder sensors. Furthermore, the pressure sensor interface circuit, after low-pass filtering, inputs to the AD7730 chip, reducing high-frequency noise interference. Attached Figure Description

[0017] Figure 1 This is the circuit diagram of the main processor of this utility model.

[0018] Figure 2 This is a circuit diagram of the secondary processor of this utility model.

[0019] Figure 3 This is a circuit diagram of the pressure sensor interface circuit of this utility model.

[0020] Figure 4 This is a circuit diagram of the signal processing module of this utility model.

[0021] Figure 5 This is a circuit diagram of the Hall sensor interface circuit of this utility model.

[0022] Figure 6 This is a circuit diagram of the first flow sensor interface module of this utility model.

[0023] Figure 7 This is a circuit diagram of the second flow sensor interface module of this utility model.

[0024] Figure 8 This is a circuit diagram of the universal sensor interface circuit of this utility model.

[0025] Figure 9 This is a circuit diagram of the power supply module of this utility model. Detailed Implementation

[0026] To facilitate understanding by those skilled in the art, the present invention will be further described below with reference to embodiments and accompanying drawings. The content mentioned in the embodiments is not intended to limit the present invention. The present invention will be described in detail below with reference to the accompanying drawings.

[0027] A sensor detection circuit for a die bonder, such as Figures 1 to 9 As shown, it includes a main control module, a sensor interface module, a display control module, a signal processing module, and a power supply module. The power supply module supplies power to the main control module, sensor interface module, and display control module, which are connected to the main control module. The sensor interface module includes a pressure sensor interface circuit, a Hall sensor interface circuit, a flow sensor interface circuit, and a general-purpose sensor interface circuit. The main control module includes a main processor and a sub-processor. The sub-processor is connected to the Hall sensor interface circuit, flow sensor interface circuit, and general-purpose sensor interface circuit, respectively. The signal processing module includes an AD7730 chip (i.e., chip U11). The main processor is connected to the pressure sensor interface circuit through the AD7730 chip. A low-pass filter is connected to the input terminal of the AD7730 chip. The main processor is connected to the sub-processor through an SPI interface and communicates with the host computer through an EtherCAT interface. The main processor includes a chip U8, model AX58200. The sub-processor includes a chip U10, model STM32H730. Specifically, this invention employs a dual-processor architecture (main processor AX58200 + secondary processor STM32H730) to achieve task splitting: the main processor handles communication protocol processing and human-machine interaction, while the secondary processor focuses on data acquisition and real-time control. The AD7730 chip, in conjunction with a low-pass filter, forms an independent high-precision measurement channel, enabling the detection of minute pressure changes. The SPI bus enables high-speed data exchange between multiple processors (theoretical rate up to 50Mbps). The EtherCAT interface uses a distributed clock synchronization mechanism to ensure accurate time synchronization with the host computer. This invention includes multiple sensor interface circuits for high-speed, high-precision data detection in the die bonder, meeting the requirements of high-speed, low-noise, and fast system response in the die bonder, reducing the complexity of sensor connections, and adapting to the high precision and high sampling rate requirements of the die bonder sensors. Furthermore, the pressure sensor interface circuit, after low-pass filtering, is input to the AD7730 chip, reducing high-frequency noise interference.

[0028] In this embodiment, the AX58200 core board is mainly used as the central processing unit, responsible for trigger control, display output, and barometric pressure sensor data acquisition. It communicates with the secondary processor via the SPI interface to acquire analog inputs from the flow sensor and other sensors. It also acquires analog data from the barometric pressure sensor from the AD7730 chip via the SPI interface and communicates with the host computer via the EtherCAT interface. The STM32H730 serves as the secondary processor, acquiring analog inputs from the flow sensor and other sensors. It also has 12 PWM outputs, which can control PWM-modulated light sources, fans, etc. The secondary processor communicates with the main processor via the SPI interface. The main processor controls the PWM duty cycle and the number of ADC acquisition channels by sending different configuration data. Reducing the number of ADC acquisition channels can accelerate SPI communication and reduce acquisition time.

[0029] In this embodiment, the pressure sensor interface circuit includes an interface CN2, resistors R32 and R39, capacitors C32, C33, C35, and C36. The first pin of the interface CN2 is connected to one end of capacitor C32 and the fifteenth pin of the AD7730 chip, and the other end of capacitor C32 is grounded. The second pin of the interface CN2 is connected to one end of resistor R32, and the other end of resistor R32 is connected to one end of capacitor C33, one end of capacitor C35, and the tenth pin of the AD7730 chip. The third pin of the interface CN2 is connected to one end of resistor R39, and the other end of resistor R39 is connected to the other end of capacitor C35, one end of capacitor C36, and the eleventh pin of the AD7730 chip. The other ends of capacitors C33 and C36, and the fifth pin of the interface CN2 are grounded respectively. The main processor is connected to the AD7730 chip via an SPI interface. Specifically, the pressure sensor is connected to this embodiment via a CN2 interface. The AD7730 chip is used for high-precision signal acquisition, and its input terminal is conditioned by a precision resistor network (such as resistors R30-R39). The AD7730 chip communicates with the main processor via an SPI interface (SCLK, DIN, DOUT, CS#). Multiple filter capacitors (such as capacitors C32-C36) are also added to the circuit to improve signal quality. With the above settings, the use of a high-precision ADC significantly improves the accuracy and resolution of pressure measurement. The reasonable signal conditioning circuit improves the signal-to-noise ratio and enhances the reliability of measurement. The SPI interface enables fast data transmission, allowing this embodiment to respond to pressure changes in real time.

[0030] In this embodiment, the Hall sensor interface circuit includes an interface CN3, resistors R40, R43, R44, R48, R53, capacitors C41 and C45, and an amplifier U16.1. The second pin of the interface CN3 is connected to one end of resistor R43. The other end of resistor R43 is connected to one end of resistor R40, one end of capacitor C41, and the inverting input of amplifier U16.1. The non-inverting input of amplifier U16.1 is connected to one end of resistor R48 and one end of resistor R53. The other end of resistor R53 is grounded. The output of amplifier U16.1, the other end of resistor R40, and the other end of capacitor C41 are respectively connected to one end of resistor R44. The other end of resistor R44 is respectively connected to one end of capacitor C45 and the sub-processor.

[0031] In this embodiment of the application, the flow sensor interface circuit includes a first flow sensor interface module and a second flow sensor interface module;

[0032] The first flow sensor interface module includes interface CN6, resistors R54, R56, R60, R61, R63, R64, R65, R68, and R69, capacitors C47 and C49, and amplifier U16.2. The second pin of interface CN6 is connected to one end of resistor R60 and one end of resistor R63. The other end of resistor R60 is connected to one end of resistor R56 and one end of resistor R61. The other end of resistor R56 is grounded. The other end of resistor R63 is connected to resistor R64. One end of resistor R64 is connected to one end of resistor R68. The other end of resistor R64 is connected to one end of resistor R69 and the non-inverting input terminal of amplifier U16.2. The other end of resistor R69 is grounded. The other end of resistor R61 is connected to one end of resistor R54 and the inverting input terminal of amplifier U16.2. Capacitor C47 is connected in parallel with resistor R54. The other end of resistor R54 is connected to the output terminal of amplifier U16.2 and one end of resistor R65. The other end of resistor R65 is connected to one end of capacitor C49 and the subprocessor. The other end of capacitor C49 is grounded.

[0033] The second flow sensor interface module includes interface CN4, resistors R41, R42, R45, R46, R47, R49, R50, R51, R52, capacitors C42 and C46, ​​and amplifier U17.1. The second pin of interface CN4 is connected to one end of resistor R45 and one end of resistor R49. The other end of resistor R45 is connected to one end of resistor R42 and one end of resistor R46. The other end of resistor R42 is grounded. The other end of resistor R49 is connected to resistor R50. One end of resistor R50 is connected to one end of resistor R51. The other end of resistor R50 is connected to one end of resistor R52 and the non-inverting input terminal of amplifier U17.1. The other end of resistor R52 is grounded. The other end of resistor R46 is connected to one end of resistor R41 and the inverting input terminal of amplifier U17.1. Capacitor C42 is connected in parallel with resistor R41. The other end of resistor R41 is connected to the output terminal of amplifier U17.1 and one end of resistor R47. The other end of resistor R47 is connected to one end of capacitor C46 and the subprocessor. The other end of capacitor C46 is grounded.

[0034] In this embodiment, the universal sensor interface circuit includes interface CN5, resistors R55, R57, R58, R59, R62, R66, R67, R70, R71, capacitor C48, capacitor C50, and amplifier U17.2. The second pin of interface CN5 is connected to one end of resistor R58 and one end of resistor R66. The other end of resistor R58 is connected to one end of resistor R57 and one end of resistor R59. The other end of resistor R57 is grounded. The other end of resistor R66 is connected to resistor R48. One end of R67 is connected to one end of resistor R70. The other end of resistor R67 is connected to one end of resistor R71 and the non-inverting input terminal of amplifier U17.2. The other end of resistor R71 is grounded. The other end of resistor R59 is connected to one end of resistor R55 and the inverting input terminal of amplifier U17.2. Capacitor C48 is connected in parallel with resistor R55. The other end of resistor R55 is connected to the output terminal of amplifier U17.2 and one end of resistor R62. The other end of resistor R62 is connected to one end of capacitor C50 and the subprocessor. The other end of capacitor C50 is grounded.

[0035] Specifically, under the above configuration, dedicated signal conditioning circuits were designed for the Hall sensor interface circuit, flow sensor interface circuit, and general sensor interface circuit to ensure the best acquisition effect of each sensor signal; efficient data acquisition was achieved by utilizing multiple interfaces of the main controller and the sub-processor, thereby improving the real-time performance of the system.

[0036] The above description is merely a preferred embodiment of the present utility model and is not intended to limit the present utility model in any way. Although the present utility model has been disclosed above with reference to a preferred embodiment, it is not intended to limit the present utility model. Any person skilled in the art can make some changes or modifications to the above-disclosed technical content to create equivalent embodiments without departing from the scope of the present utility model. Any simple modifications, equivalent changes, and modifications made to the above embodiments based on the present utility model without departing from the scope of the present utility model shall fall within the scope of the present utility model.

Claims

1. A sensor detection circuit for a die bonder, characterized in that: The application relates to a sensor interface module for a flowmeter, which comprises a main control module, a sensor interface module, a display control module, a signal processing module and a power supply module; the power supply module is used for supplying power for the main control module, the sensor interface module and the display control module; the sensor interface module and the display control module are connected with the main control module respectively; the sensor interface module comprises a pressure sensor interface circuit, a Hall sensor interface circuit, a flow sensor interface circuit and a general sensor interface circuit; the main control module comprises a main processor and a secondary processor; the secondary processor is connected with the Hall sensor interface circuit, the flow sensor interface circuit and the general sensor interface circuit respectively; the signal processing module comprises an AD7730 chip; the main processor is connected with the pressure sensor interface circuit through the AD7730 chip; the input end of the AD7730 chip is connected with a low-pass filter; the main processor is connected with the secondary processor through an SPI interface; and the main processor communicates with an upper computer through an EtherCAT interface.

2. The sensor detection circuit for a die bonder of claim 1, wherein: The main processor comprises a chip U8, and the model of the chip U8 is AX58200.

3. The sensor detection circuit for a die bonder of claim 1, wherein: The secondary processor comprises a chip U10, and the model of the chip U10 is STM32H730.

4. The sensor detection circuit for a die bonder of claim 1, wherein: The pressure sensor interface circuit comprises an interface CN2, resistors R32 and R39, capacitors C32, C33, C35 and C36; the first pin of the interface CN2 is connected with one end of the capacitor C32 and the fifteenth pin of the AD7730 chip; the other end of the capacitor C32 is grounded; the second pin of the interface CN2 is connected with one end of the resistor R32; the other end of the resistor R32 is connected with one end of the capacitor C33, one end of the capacitor C35 and the tenth pin of the AD7730 chip; the third pin of the interface CN2 is connected with one end of the resistor R39; the other end of the resistor R39 is connected with the other end of the capacitor C35, one end of the capacitor C36 and the eleventh pin of the AD7730 chip; the other end of the capacitor C33 and the other end of the capacitor C36 and the fifth pin of the interface CN2 are grounded respectively; and the main processor is connected with the AD7730 chip through an SPI interface.

5. A sensor detection circuit for a die bonder according to claim 1, characterized in that: The Hall sensor interface circuit comprises an interface CN3, resistors R40, R43, R44, R48, R53, capacitors C41, C45 and an amplifier U16.1; the second pin of the interface CN3 is connected with one end of the resistor R43; the other end of the resistor R43 is connected with one end of the resistor R40, one end of the capacitor C41 and the inverting input end of the amplifier U16.1; the non-inverting input end of the amplifier U16.1 is connected with one end of the resistor R48 and one end of the resistor R53; the other end of the resistor R53 is grounded; the output end of the amplifier U16.1, the other end of the resistor R40 and the other end of the capacitor C41 are connected with one end of the resistor R44 respectively; the other end of the resistor R44 is connected with one end of the capacitor C45 and the secondary processor respectively.

6. The sensor detection circuit for a die bonder of claim 1, wherein: The flow sensor interface circuit comprises a first flow sensor interface module and a second flow sensor interface module. The first flow sensor interface module includes interface CN6, resistor R54, resistor R56, resistor R60, resistor R61, resistor R63, resistor R64, resistor R65, resistor R68, resistor R69, capacitor C47, capacitor C49 and amplifier U16.2, the second pin of interface CN6 is connected with one end of resistor R60 and one end of resistor R63, the other end of resistor R60 is connected with one end of resistor R56 and one end of resistor R61, the other end of resistor R56 is grounded, the other end of resistor R63 is connected with one end of resistor R64 and one end of resistor R68, the other end of resistor R64 is connected with one end of resistor R69 and the positive input end of amplifier U16.2, the other end of resistor R69 is grounded, the other end of resistor R61 is connected with one end of resistor R54 and the inverting input end of amplifier U16.2, capacitor C47 is connected with resistor R54 in parallel, the other end of resistor R54 is connected with the output end of amplifier U16.2 and one end of resistor R65, the other end of resistor R65 is connected with one end of capacitor C49 and the secondary processor, the other end of capacitor C49 is grounded; The second flow sensor interface module includes interface CN4, resistor R41, resistor R42, resistor R45, resistor R46, resistor R47, resistor R49, resistor R50, resistor R51, resistor R52, capacitor C42, capacitor C46 and amplifier U17.1, the second pin of interface CN4 is connected with one end of resistor R45 and one end of resistor R49, the other end of resistor R45 is connected with one end of resistor R42 and one end of resistor R46, the other end of resistor R42 is grounded, the other end of resistor R49 is connected with one end of resistor R50 and one end of resistor R51, the other end of resistor R50 is connected with one end of resistor R52 and the positive input end of amplifier U17.1, the other end of resistor R52 is grounded, the other end of resistor R46 is connected with one end of resistor R41 and the inverting input end of amplifier U17.1, capacitor C42 is connected with resistor R41 in parallel, the other end of resistor R41 is connected with the output end of amplifier U17.1 and one end of resistor R47, the other end of resistor R47 is connected with one end of capacitor C46 and the secondary processor, the other end of capacitor C46 is grounded.

7. The sensor detection circuit for a die bonder of claim 1, wherein: The universal sensor interface circuit includes interface CN5, resistor R55, resistor R57, resistor R58, resistor R59, resistor R62, resistor R66, resistor R67, resistor R70, resistor R71, capacitor C48, capacitor C50 and amplifier U17.2, the second pin of interface CN5 is connected with one end of resistor R58 and one end of resistor R66, the other end of resistor R58 is connected with one end of resistor R57 and one end of resistor R59, the other end of resistor R57 is grounded, the other end of resistor R66 is connected with one end of resistor R67 and one end of resistor R70, the other end of resistor R67 is connected with one end of resistor R71 and the positive input end of amplifier U17.2, the other end of resistor R71 is grounded, the other end of resistor R59 is connected with one end of resistor R55 and the inverting input end of amplifier U17.2, capacitor C48 is connected with resistor R55 in parallel, the other end of resistor R55 is connected with the output end of amplifier U17.2 and one end of resistor R62, the other end of resistor R62 is connected with one end of capacitor C50 and the secondary processor, the other end of capacitor C50 is grounded.

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