A multi-channel output circuit

Abstract

The utility model relates to output test board card technical field discloses a kind of multi-channel output circuit, comprising: power module, main control module, multiple output module and multiple communication module, wherein, the input end of power module inputs external power supply voltage, and each output end is connected with the power supply end of communication module, main control module and multiple output module respectively;The input end of each communication module inputs instruction signal, and the output end is connected with the input end of main control module correspondingly one, and the communication end is connected with the communication end of main control module correspondingly one, and the communication protocol used by each communication module is different;The output end of main control module is connected with the input end of multiple output module;The output end of multiple output module is connected with the input end of external testing device one respectively.The utility model can convert instruction signal under multiple communication protocols into analog voltage, and provide multiple output, provide multiple reference test voltage for various automation testing device simultaneously, improve test efficiency.

Description

Technical Field

[0001] This utility model relates to the field of output test board technology, specifically to a multi-channel output circuit. Background Technology

[0002] With the rapid evolution of the new energy vehicle industry, the application scope of Battery Management Systems (BMS) is continuously expanding. High-voltage output boards, as key equipment for testing the accuracy and stability of BMS, play a crucial role in ensuring the operational performance and system reliability of new energy vehicles. They also have a positive impact on improving the quality of vehicle controllers and reducing testing costs. Currently, BMS high-voltage testing devices are rapidly developing towards electronification and intelligence, with the market size continuously expanding, technology iteration accelerating, and both supply and demand showing robust growth. As the automotive industry's electrification and intelligent transformation deepens, the value share of related hardware and software in the vehicle is rapidly increasing, which also places higher demands on the technological upgrading of high-voltage output devices.

[0003] However, with the increasing intelligence and connectivity of automotive electronics, traditional high-voltage testing methods for battery packs have gradually revealed their limitations, especially in terms of communication speed and system response time, which can no longer meet the stringent requirements of most current BMS controllers for testing efficiency and real-time performance. Utility Model Content

[0004] In view of this, the present invention provides a multi-channel output circuit to solve the problem of low efficiency in existing power supply testing devices.

[0005] This invention provides a multi-channel output circuit, comprising: a power supply module, a main control module, a multi-output module, and multiple communication modules. The power supply module receives an external power supply voltage at its input terminal. Each output terminal of the power supply module is connected to the power supply terminals of the communication module, the main control module, and the multi-output modules, respectively. The power supply module is used to convert the voltage level of the external power supply voltage. Each communication module receives a command signal at its input terminal. Each communication module's output terminal is connected to one corresponding input terminal of the main control module, and each communication module's communication terminal is connected to one corresponding communication terminal of the main control module. Each communication module uses a different communication protocol and is used to convert the command signal into a corresponding message command based on its own communication protocol. The main control module's output terminal is connected to the input terminal of the multi-output module, and the main control module is used to convert the message command into a voltage control command. Each output terminal of the multi-output module is connected to one input terminal of an external testing device. The multi-output module is used to output at least one corresponding analog voltage based on the voltage control command, and the analog voltage is used to provide a reference test voltage for the external testing device.

[0006] The multi-channel output circuit provided by this utility model can be matched with communication modules of various communication protocols. When there is a command signal, different communication protocols convert the command signal into corresponding message commands. The main control module controls the multi-output module to output one or more analog voltages based on the message commands, which serve as the reference test voltage for external testing devices. Multiple analog voltages can be output simultaneously, meeting the needs of external testing devices to measure different electrical parameters at the same time and improving testing efficiency.

[0007] In one optional embodiment, the power supply module includes a step-down unit and a voltage regulator unit. The step-down unit receives an external power supply voltage at its input terminal and its output terminal is connected to the input terminal of the voltage regulator unit. The step-down unit is used to reduce the voltage level of the external power supply voltage and eliminate interference in the external power supply voltage. The output terminal of the voltage regulator unit is connected to the power supply terminals of the communication module, the main control module, and the multi-output module, respectively. The voltage regulator unit is used to eliminate interference in the stepped-down external power supply voltage.

[0008] In one optional embodiment, the step-down unit includes: a first filter circuit and a step-down output circuit, wherein the input terminal of the first filter circuit receives an external power supply voltage, and the output terminal of the first filter circuit is connected to the input terminal of the step-down output circuit. The first filter circuit is used to suppress external power supply voltage overload and high-frequency interference. The output terminal of the step-down output circuit is connected to the input terminal of the voltage regulator unit. The step-down output circuit is used to reduce the voltage level of the external power supply voltage and eliminate ripple.

[0009] In one optional implementation, the communication module employs either Modbus RTU communication or CAN communication. When the communication module employs Modbus RTU communication, it includes a second filtering circuit and a first output control circuit. The input terminal of the second filtering circuit receives a command signal, and the output terminal of the second filtering circuit is connected to the input terminal of the first output control circuit. The second filtering circuit is used to suppress common-mode interference in the command signal. The enable terminal of the first output control circuit is connected to a corresponding communication terminal of the main control module, and the output terminal of the first output control circuit is connected to an input terminal of the main control module. The first output control circuit is used to convert the command signal into a voltage control command based on the enable signal of the main control module.

[0010] In one optional embodiment, the second filter circuit includes: a common-mode filter, a first resistor, a second resistor, a third resistor, a fourth resistor, a fifth resistor, a first transient voltage suppression diode, and a second transient voltage suppression diode. The first terminal of the first resistor is connected to the output terminal of the power supply module; the second terminal of the first resistor is connected to the first terminals of the second and third resistors and the first terminal of the common-mode filter. The second terminal of the second resistor is connected to the first terminal of the first transient voltage suppression diode and receives a first-level command signal. The second terminal of the third resistor is connected to the first terminals of the fourth and fifth resistors and the second terminal of the common-mode filter. The second terminal of the fourth resistor is connected to the first terminal of the second transient voltage suppression diode and receives a second-level command signal. The second terminals of the fifth resistor, the first transient voltage suppression diode, and the second transient voltage suppression diode are all grounded. The third and fourth terminals of the common-mode filter are connected to the first and second input terminals of the first output control circuit, respectively. The first and second levels are logically opposite.

[0011] In one optional implementation, the communication module employs either Modbus RTU communication or CAN communication. When the communication module employs CAN communication, it includes a third filtering circuit and a second output control circuit. The input terminal of the third filtering circuit receives a command signal, and its output terminal is connected to the input terminal of the second output control circuit. The third filtering circuit is used to suppress interference in the command signal. The enable terminal of the second output control circuit is connected to a corresponding communication terminal of the main control module, and its output terminal is connected to an input terminal of the main control module. The second output control circuit is used to convert the command signal into a voltage control command based on the enable signal of the main control module.

[0012] In one optional implementation, the multi-output module includes: a signal output unit and multiple power amplifier units, wherein the first input terminal of the signal output unit is connected to the output terminal of the main control module, the second input terminal of the signal output unit is connected to a reference voltage, and the output terminal of the signal output unit is connected to the input terminal of each power amplifier unit respectively. The signal output unit is used to convert the reference voltage into a corresponding analog voltage based on a voltage control command; each power amplifier unit is used to amplify the analog voltage and output it.

[0013] In one optional implementation, the signal output unit includes a current limiting circuit, a digital-to-analog converter circuit, and an amplifier circuit. The first terminal of the current limiting circuit is connected to the output terminal of the main control module, and the second terminal of the current limiting circuit is connected to the first input terminal of the digital-to-analog converter circuit. The current limiting circuit is used to limit the magnitude of the current in the voltage control command. The second input terminal of the digital-to-analog converter circuit receives a reference voltage, and the output terminal of the digital-to-analog converter circuit is connected to the input terminal of the amplifier circuit. The digital-to-analog converter circuit is used to convert the reference voltage into a corresponding initial analog voltage based on the voltage control command. The output terminal of the amplifier circuit is connected to the input terminal of each power amplifier unit. The amplifier circuit is used to amplify and filter the initial analog voltage before outputting an analog voltage.

[0014] In one optional embodiment, the amplifier circuit includes: a sixth resistor, a seventh resistor, an eighth resistor, a ninth resistor, an operational amplifier, a first capacitor, a second capacitor, and a third capacitor. The first terminal of the sixth resistor is connected to the output terminal of the digital-to-analog converter circuit; the second terminal of the sixth resistor is connected to the non-inverting input terminal of the operational amplifier and the first terminal of the first capacitor; the second terminal of the first capacitor is connected to the first terminal of the seventh resistor; the second terminal of the seventh resistor is connected to the inverting input terminal of the operational amplifier, the first terminal of the eighth resistor, and the first terminal of the second capacitor; the second terminal of the eighth resistor is connected to the first terminal of the ninth resistor; the second terminal of the ninth resistor is connected to the input terminal of the power amplifier unit; the second terminal of the second capacitor is connected to the output terminal of the operational amplifier; and the third capacitor is connected in series between the two power supply terminals of the operational amplifier.

[0015] In one optional embodiment, the power amplifier unit includes: a third filter circuit and an amplification output circuit, wherein the input terminal of the third filter circuit is connected to the output terminal of the power supply module, and the output terminal of the third filter circuit is connected to the power supply terminal of the amplification output circuit, and the third filter circuit is used to filter out interference at the power supply terminal of the amplification output circuit; the input terminal of the amplification output circuit is connected to the output terminal of the signal output unit, and the amplification output circuit is used to output the amplified analog voltage. Attached Figure Description

[0016] To more clearly illustrate the specific embodiments of this utility model or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this utility model. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0017] Figure 1 This is a structural diagram of a multi-channel output circuit according to an embodiment of the present invention; Figure 2 This is a structural diagram of another multi-channel output circuit according to an embodiment of the present utility model; Figure 3 This is a detailed circuit diagram of the step-down unit according to an embodiment of the present utility model; Figure 4 This is a detailed circuit diagram of the voltage regulator unit according to an embodiment of the present invention; Figure 5 This is a detailed circuit diagram of the Modbus RTU communication module according to an embodiment of the present utility model; Figure 6 This is a detailed circuit diagram of the CAN communication module according to an embodiment of the present invention; Figure 7 This is a detailed circuit diagram of the signal output unit according to an embodiment of the present invention; Figure 8 This is a detailed circuit diagram of the power amplifier unit according to an embodiment of the present utility model; Figure 9 This is a detailed circuit diagram of the main control module according to an embodiment of the present utility model. Detailed Implementation

[0018] To make the objectives, technical solutions, and advantages of the embodiments of this utility model clearer, the technical solutions of the embodiments of this utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this utility model, not all embodiments. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of this utility model.

[0019] In the description of this utility model, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the accompanying drawings and are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this utility model. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0020] In the description of this utility model, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or a simple connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can also refer to the internal connection of two components; and they can refer to a wireless connection or a wired connection. Those skilled in the art can understand the specific meaning of the above terms in this utility model based on the specific circumstances.

[0021] Furthermore, the technical features involved in the different embodiments of this utility model described below can be combined with each other as long as they do not conflict with each other.

[0022] With the trend towards intelligent and connected automotive electronics, conventional high-voltage testing using battery packs is no longer sufficient to meet the testing requirements of many BMS controllers in terms of communication speed and response time. Currently, high-voltage output devices must possess higher precision and efficiency in drive capability, seamless integration with automated testing systems to improve testing efficiency and data processing capabilities, and real-time monitoring and data analysis capabilities. With the rapid development of new energy vehicle technology, BMS high-voltage testing devices will place greater emphasis on simulating and testing the complex characteristics of complex controllers, and are required to collect real-time operating data from the controllers to provide strong and effective data support for software optimization, fault diagnosis, and prediction.

[0023] This embodiment provides a multi-channel output circuit, such as Figure 1 As shown, it includes: power supply module 1, main control module 2, multi-output module 3 and multiple communication modules (#41~#4n).

[0024] Figure 1 In the process, the input terminal of the power supply module 1 receives the external power supply voltage, and each output terminal of the power supply module 1 is connected to the power supply terminals of the communication module (#41~#4n), the main control module 2 and the multi-output module 3 respectively. The power supply module 1 is used to convert the voltage level of the external power supply voltage.

[0025] Specifically, the power supply module filters and regulates the external power supply voltage, then boosts or bucks the power supply voltage to different voltage levels to power each module.

[0026] Figure 1 In this system, each communication module receives a command signal at its input terminal, and each communication module's output terminal is connected to one of the input terminals of the main control module 2. Each communication module's communication terminal is connected to one of the communication terminals of the main control module 2. Each communication module uses a different communication protocol and is used to convert command signals into corresponding message commands based on its own communication protocol.

[0027] Specifically, each communication module has a built-in different communication protocol. Users can enable the required communication modules and disable the others through the main control module 2 to save overall circuit power consumption, based on actual needs. The main control module 2 controls the corresponding communication module to turn on or off via the communication terminal based on external enable commands. The enabled communication modules convert command signals into corresponding message commands based on their internal communication protocols and input them to the main control module 2. The command signals carry parameters such as the voltage amplification factor required and the number of output channels that need to be enabled by the multiple output modules 3.

[0028] Optionally, the communication module may use CAN bus communication, Modbus RTU bus communication, or other communication protocols.

[0029] Figure 1 In this module, the output terminal of the main control module 2 is connected to the input terminal of the multi-output module 3. The main control module 2 is used to convert message commands into voltage control commands.

[0030] Optionally, the voltage control command may include the number of output channels of the multi-output module that are enabled, the voltage level multiple of each output channel, etc.

[0031] Figure 1 In this configuration, each output terminal of the multi-output module 3 is connected to one input terminal of an external test device. The multi-output module 3 is used to output at least one corresponding analog voltage based on voltage control commands. The analog voltage is used to provide a reference test voltage for the external test device.

[0032] Specifically, the multi-output module activates a corresponding number of output channels according to the voltage control command, and amplifies the internal reference voltage to different voltage levels based on the voltage control command before outputting analog voltage. The analog voltage level output by each output channel can be the same or different.

[0033] It should be noted that both the main control module and the multi-output module utilize existing mature software to implement functions such as message command conversion and communication module control. Those skilled in the art can program the main control module and the multi-output module according to the mature control programs in the existing technology and in combination with actual needs, adjust the message command conversion and communication module enabling logic of the main control module, and adjust the voltage conversion level and analog voltage output logic of the multi-output module. That is, this embodiment only protects the structure of the multi-channel output circuit, and does not protect the control methods inside the power supply module, the main control module, the multi-output module and the communication module.

[0034] The multi-channel output circuit provided in this embodiment can be matched with communication modules of various communication protocols. When there is a command signal, different communication protocols convert the command signal into corresponding message commands. The main control module controls the multi-output module to output one or more analog voltages based on the message commands, which serve as the reference test voltage for external testing devices. Multiple analog voltages can be output simultaneously to meet the needs of external testing devices to measure different electrical parameters at the same time, thereby improving testing efficiency.

[0035] In some alternative implementations, such as Figure 2 As shown, the power supply module includes a step-down unit 11 and a voltage regulator unit 12. The input terminal of the step-down unit 11 is connected to the input terminal of the voltage regulator unit 12. The step-down unit 11 is used to reduce the voltage level of the external power supply voltage and eliminate interference in the external power supply voltage.

[0036] Specifically, Figure 3 The step-down unit includes a first filter circuit 111 and a step-down output circuit 112. The input terminal of the first filter circuit 111 receives the external power supply voltage U_PWR, and the output terminal of the first filter circuit 111 is connected to the input terminal of the step-down output circuit 112. The first filter circuit 111 is used to suppress external power supply voltage overload and high-frequency interference. The output terminal (i.e., VCC65 terminal) of the step-down output circuit 112 is connected to the input terminal of the voltage regulator unit 12. The step-down output circuit 112 is used to reduce the voltage level of the external power supply voltage and eliminate ripple.

[0037] Specifically, Figure 3 In this circuit, an external power supply is connected in series with a transient voltage suppressor diode D101 to GND. This diode quickly conducts in case of overload, diverting the overvoltage to ground and protecting against reverse voltage surges. Diode D102 is a reverse protection diode. The π-filter circuit, composed of capacitors C101 and C102 and inductor L101, prevents high-frequency interference signals from entering the circuit, reduces ripple, and provides a stable power input. Capacitors C103 and C104 primarily function as filters. Resistor R106 primarily limits current, and LED D104 serves as a power indicator.

[0038] Specifically, Figure 3In this circuit, the main function of the series capacitor C105 connected between the BOOT and SW pins of U101 is voltage storage, facilitating rapid driving of the high-side MOSFET and improving voltage conversion efficiency. The SW pin is connected to the external power inductor L102, controlling the switching state of the MOSFET to achieve energy transfer and conversion, thereby outputting a stable DC voltage. When the MOSFET is on, current flows from the VIN pin to the inductor L102 and the external load. When the MOSFET is off, the current direction remains constant due to the freewheeling effect of the inductor L102. Simultaneously, overcurrent protection is achieved by detecting the current at the SW pin and comparing it with an internally set peak current threshold.

[0039] Specifically, Figure 3 In this circuit, the main function of Schottky diode D103 is to ensure that the circuit can correctly convert and utilize the rectified DC voltage, while providing a stable operating environment. The FB pin compares the voltage divided by resistors R104 and R105 with an internal reference voltage to control the enable state of subsequent devices. When the voltage at the FB pin is higher than the threshold, the device enters normal operating mode; when the voltage at the FB pin is lower than the threshold, the device enters shutdown mode to reduce quiescent current. Capacitors C107 and C108 primarily function as filters to reduce output ripple. Resistors R104 and R105 primarily function as current limiters and voltage dividers.

[0040] Specifically, Figure 3 In the configuration, the SS pin of U101 is connected to the energy storage capacitor C106, which controls the soft-start time and prevents excessive current during startup. The TAB pin is grounded primarily to ensure good heat dissipation. The RT / SYBC pin, connected to GND via resistor R103, sets the switching frequency of U101; a higher resistance value of R103 results in a lower switching frequency. The enable pin EN is mainly used to control the switching state of U101 and provides precise enable input functionality. Resistors R101 and R102 primarily function as current limiters and voltage dividers. The VIN and GND pins provide power to U101.

[0041] The output terminals (i.e. VCC50 and VCC240 terminals) of the voltage regulator unit 12 are connected to the power supply terminals of the communication module, the main control module and the multi-output module, respectively. The voltage regulator unit 12 is used to eliminate interference in the external power supply voltage after step-down.

[0042] Specifically, Figure 4 In this circuit, the main function of U102 is to convert the voltage generated by U101 into a stable 5V output. Capacitors C109 and C110 primarily function as filters. Diodes D105 and D106 prevent reverse voltage supply, ensuring circuit stability. Capacitor C111 primarily provides electrostatic discharge protection.

[0043] In some optional implementations, the communication module uses either Modbus RTU communication or CAN communication. When the communication module uses Modbus RTU communication, such as... Figure 5 As shown, the communication module includes a second filtering circuit 411 and a first output control circuit 412. The input terminal of the second filtering circuit 411 receives command signals (RS485_A and RS485_B), and the output terminal of the second filtering circuit 411 is connected to the input terminal of the first output control circuit 412. The second filtering circuit 411 is used to suppress common-mode interference in the command signal. The enable terminal of the first output control circuit 412 (and pin 2 of U301) is connected to a communication terminal of the main control module, and the output terminal of the first output control circuit is connected to an input terminal of the main control module. The first output control circuit is used to convert the command signal into a voltage control command based on the enable signal of the main control module.

[0044] Figure 5 The second filter circuit 411 includes: a common-mode filter L301, a first resistor R305, a second resistor R308, a third resistor R306, a fourth resistor R309, a fifth resistor R307, a first transient voltage suppression diode D301, and a second transient voltage suppression diode D302. The first terminal of the first resistor R305 is connected to the output terminal of the power supply module and receives VCC50. The second terminal of the first resistor R305 is connected to the first terminals of the second resistor R308, the third resistor R306, and the common-mode filter L301. The second terminal of the second resistor R308 is connected to the first terminal of the first transient voltage suppression diode D301 and receives a first-level command. Signal RS485_A; the second terminal of the third resistor R306 is connected to the first terminal of the fourth resistor R309, the first terminal of the fifth resistor R307, and the second terminal of the common-mode filter L301; the second terminal of the fourth resistor R309 is connected to the first terminal of the second transient voltage suppression diode D302 and receives the second-level command signal RS485_B; the second terminal of the fifth resistor R307, the second terminal of the first transient voltage suppression diode D301, and the second terminal of the second transient voltage suppression diode D302 are all grounded; the third and fourth terminals of the common-mode filter L301 are connected to the first and second input terminals of the first output control circuit 412, respectively; the first level and the second level are logically opposite.

[0045] Specifically, Figure 5In this circuit, the 5V voltage VCC50 generated by the power supply module is connected to the VCC pin of U301 as the power supply. The main function of capacitor C301 is filtering to ensure the stability of the power supply. The main control module 1 controls U301 through the RE pin. When the RE pin is low, the RO pin will output a high or low level to the main control module according to the differential voltage of the input terminals A and B. When the RE pin is high and the RO pin is set to a high-impedance state, the RO pin will not output any signal. When the RE pin is high and the DE pin is low, U301 is in low-power shutdown mode. Connecting the RO pin to a 5V pull-up via R301 can improve the reliability and signal integrity of the circuit, ensure that the bus is high when there is no signal input, and improve the drive capability.

[0046] Specifically, Figure 5 In this circuit, the DI pin is connected to the main control module, which can control the output state of the communication module by controlling the DI pin. R302, R303, and R304 primarily function as current limiting protection, improve signal integrity, and provide electrical isolation, thereby enhancing the circuit's reliability and performance. Pins A and B are connected to external interface devices through the common-mode filter L301. The common-mode filter L301 primarily suppresses common-mode interference on the bus, improving the stability and reliability of the communication module. Resistors R305, R306, and R307 primarily function as current limiting and voltage dividers, ensuring voltage clamping on the bus, preventing signal floating, improving signal integrity, and enhancing the circuit's reliability and stability. R308 and R309 primarily function as current limiting devices. D301 and D302 connected to GND primarily suppress transient level changes, ensuring system stability.

[0047] In some optional implementations, the communication module uses either Modbus RTU communication or CAN communication. When the communication module uses CAN communication, such as... Figure 6 As shown, the communication module includes a third filtering circuit 421 and a second output control circuit 422. The input terminal of the third filtering circuit 421 receives command signals (CAN_H and CAN_L), and the output terminal of the third filtering circuit 421 is connected to the input terminal of the second output control circuit 422. The third filtering circuit 421 is used to suppress interference in the command signals. The enable terminal of the second output control circuit 422 (i.e., the STB pin of U302) is connected to a corresponding communication terminal of the main control module, and the output terminal of the second output control circuit 422 is connected to an input terminal of the main control module. The second output control circuit 422 is used to convert the command signals into voltage control commands based on the enable signal of the main control module.

[0048] Specifically, Figure 6In this configuration, the 5V voltage VCC50 generated by the power supply module is connected to the VCC pin of U302. Capacitor C302's main function is filtering to ensure stable power supply. The STB pin of U302 is connected to the communication terminal of the main control module. By configuring the high and low levels of the STB pin, the transceiver's normal and standby modes can be switched: when the STB pin is low, the transceiver can send and receive data normally, operating in normal mode. When the STB pin is high, the transceiver stops sending and receiving data to reduce power consumption. In this case, only a low-power differential receiver monitors the activity on the bus line, and the transceiver operates in standby mode.

[0049] Specifically, Figure 6 In standby mode, the transceiver stops sending and receiving data, thus reducing power consumption. The RXD pin is connected to the main control module. When the low-power receiver in standby mode detects a message on the CAN bus, it outputs a low-level signal through the RXD pin to request the transceiver to wake up and enter normal mode. The TXD pin is connected to the main control module, mainly to input data sent by other modules into the CAN transceiver for transmission via the CAN bus. When the CAN bus is in recessive mode, the RXD pin outputs a high level, and the pull-up resistor R310 ensures stable output. Resistors R311, R312, and R313 mainly serve to limit current.

[0050] Specifically, Figure 6 In this configuration, the CANH and CANL pins of U302 are connected to the CAN bus, responsible for sending and receiving message data. The SPLIT pin is grounded through capacitor C303, which stabilizes the recessive level on the CAN bus and prevents recessive level fluctuations caused by common-mode voltage changes, thereby improving communication reliability. Termination resistors R314 and R315 are connected in series between CANH and CANL to stabilize the level on the CAN bus and prevent level fluctuations caused by signal reflection. Capacitors C304 and C305 primarily function as filters. Diodes D303 and D304 connected to GND primarily suppress transient level changes and ensure system stability.

[0051] In some alternative implementations, such as Figure 7 and Figure 8As shown, the multi-output module includes a signal output unit 31 and multiple power amplifier units 32. The first input terminal of the signal output unit 31 (i.e., pin 6 of U406) is connected to the output terminal of the main control module. The second input terminal of the signal output unit 31 (i.e., pin 3 of U406) receives a reference voltage. The output terminal of the signal output unit 31 (i.e., pin 1 of U406) is connected to the input terminal of each power amplifier unit. The signal output unit 31 is used to convert the reference voltage into a corresponding analog voltage based on voltage control commands. Each power amplifier unit 32 is used to amplify the analog voltage and output it.

[0052] Specifically, Figure 7 In the signal output unit 31, there are: a current limiting circuit 311, a digital-to-analog converter circuit 312, and an amplifier circuit 313. The first terminal of the current limiting circuit 311 (i.e., the left side of R408, R409, and R410) is connected to the output terminal of the main control module, and the second terminal of the current limiting circuit 311 (i.e., the left side of R408, R409, and R410) is connected to the first input terminal of the digital-to-analog converter circuit 312. The current limiting circuit 311 is used to limit the magnitude of the current in the voltage control command. The second input terminal of the digital-to-analog converter circuit 312 (i.e., pin 3 of U406) is input with a reference voltage, and the output terminal of the digital-to-analog converter circuit 312 is connected to the input terminal of the amplifier circuit 313. The digital-to-analog converter circuit 312 is used to convert the reference voltage into the corresponding initial analog voltage based on the voltage control command. The output terminal of the amplifier circuit 313 (i.e., the HV CMD terminal) is connected to the input terminal of each power amplifier unit. The amplifier circuit 313 is used to amplify and filter the initial analog voltage and output the analog voltage.

[0053] Specifically, Figure 7 The amplifier circuit includes: a sixth resistor R411, a seventh resistor R412, an eighth resistor R414, a ninth resistor R415, an operational amplifier U408, a first capacitor C421, a second capacitor C422, and a third capacitor C425. The first terminal of the sixth resistor R411 is connected to the output terminal of the digital-to-analog converter circuit 312, and the second terminal of the sixth resistor R411 is connected to the non-inverting input terminal of the operational amplifier U408 and the first terminal of the first capacitor C421. The second terminal of the first capacitor C421 is connected to the seventh resistor R412. The first terminal of resistor 12 is connected; the second terminal of the seventh resistor R412 is connected to the inverting input terminal of operational amplifier U408, the first terminal of the eighth resistor R414, and the first terminal of the second capacitor C422; the second terminal of the eighth resistor R414 is connected to the first terminal of the ninth resistor R415; the second terminal of the ninth resistor R415 is connected to the input terminal of the power amplifier unit; the second terminal of the second capacitor C422 is connected to the output terminal of operational amplifier U408; the third capacitor C425 is connected in series between the two power supply terminals of operational amplifier U408.

[0054] Specifically, Figure 9This is the circuit diagram of the main control module. The main control module uses the 5V voltage generated by the power supply module as its power supply, connected to pin 2. The main function of capacitor C202 is filtering to ensure the stability of the power supply. The BKGD pin is used as a pseudo-open-drain output, connected to external devices for non-intrusive memory access and on-chip programming. The RESET pin is a bidirectional control signal used to initialize the MCU. When an external device applies a low-level signal to the RESET pin, the MCU will perform a reset operation, setting all registers and internal states to their initial values.

[0055] Specifically, Figure 9 In this circuit, capacitor C201 primarily provides ESD protection, while pull-up resistors R205 and R206 primarily limit current. The XTAL / PE1 and EXTAL / PE0 pins are the input and output terminals for the crystal oscillator signal, providing an external clock signal to the MCU. A series resistor between the XTAL / PE1 and EXTAL / PE0 pins limits the current flowing through the crystal oscillator, preventing overcurrent damage to the crystal or drive circuit. Capacitors C203 and C204 primarily filter the signal. Pins 18, 20, 28, 29, and 30 are connected to the multi-output module for controlling high-voltage output. Pin 24 is connected to pins 2 and 3 of the Modbus RTU communication module for signal transmission between the main control module and the Modbus RTU communication module. Pins 25 and 26 are connected to the Modbus RTU communication module for Modbus RTU communication signal transmission. Pins 16, 31, and 32 are connected to the CAN communication module for controlling the transmission and reception of CAN messages.

[0056] Specifically, refer to Figure 7 and Figure 9 The three-channel digital-to-analog converter module U406 uses the 5V voltage generated by the power supply module, connected to the Va pin. The SYNC pin of U406 is connected to pins 18, 20, and 30 of the main control module. When the SYNC pin is set low, U406 is enabled normally and performs data transmission. The CLK pin is connected to pin 29 of the main control module and is the clock input pin of U406, used to control the clock of the data input register. The DIN pin is connected to pin 28 of the main control module. By inputting different data through the DIN pin, the output voltage of U406 can be controlled, thereby realizing the output of analog signals.

[0057] Specifically, refer to Figure 7 and Figure 9The main function of resistors R408, R409, and R410 is current limiting. The VOUT pin of U408 can output the corresponding analog voltage according to the control command from the DIN pin. The VOUT pin is connected to pin 3 of operational amplifier U408 through current-limiting resistor R411. Pin 4 is connected to output pin 1 through an RC filter circuit composed of resistor R414 and capacitor C422. The capacitor C425 connected in series between pins 2 and 5 ensures stable power input. The main function of capacitor C421 is filtering.

[0058] In some alternative implementations, such as Figure 8 As shown, the power amplifier unit includes a third filter circuit 321 and an amplification output circuit 322. The input terminal (i.e., the HV 24V terminal) of the third filter circuit 321 is connected to the output terminal of the power supply module, and the output terminal of the third filter circuit 321 is connected to the power supply terminal of the amplification output circuit 322. The third filter circuit 321 is used to filter out interference from the power supply terminal of the amplification output circuit 322. The input terminal of the amplification output circuit 322 is connected to the output terminal of the signal output unit 31, and the amplification output circuit 322 is used to output the amplified analog voltage.

[0059] Specifically, refer to Figure 8 and Figure 9 The main function of resistors R412 and R415 is current limiting. The signal output from pin 1 of U408 is connected to pin Adj of U407, serving as the control signal for U407. The RC filter circuit composed of resistor R413 and capacitor C422 ensures the stability of the control signal input to pin Adj. Pin Vin is connected to the power supply module, receiving DC voltage and providing the energy required for U407's operation. The main function of capacitors C420 and C423 is filtering, ensuring the stability of power supply input and output. Common-mode filter L402 suppresses common-mode interference and improves signal quality. Pin HV of U407 is the high-voltage positive output signal, pin GND is the high-voltage negative output signal, and pin HV_COM is the low-voltage ground pin. Resistors R416-R423 can be selected according to requirements for appropriate insulation resistance.

[0060] Optionally, Figure 8 This is a schematic diagram of one specific circuit for a power amplifier unit. Those skilled in the art can set the number of power amplifier units according to actual needs to achieve multi-channel output. In addition, those skilled in the art can also set each channel to output the same or different analog voltage levels according to usage requirements. That is, the parameters of the components in each power amplifier unit can be the same or different, and there are no restrictions here.

[0061] Although embodiments of the present invention have been described in conjunction with the accompanying drawings, those skilled in the art can make various modifications and variations without departing from the spirit and scope of the present invention, and such modifications and variations all fall within the scope defined by the appended claims.

Claims

1. A multi-channel output circuit, characterized in that, include: The system includes a power supply module, a main control module, a multi-output module, and multiple communication modules. The power supply module receives an external power supply voltage at its input terminal, and each output terminal of the power supply module is connected to the power supply terminals of the communication module, the main control module, and the multi-output module, respectively. The power supply module is used to convert the voltage level of the external power supply voltage. Each of the communication modules receives an instruction signal at its input terminal, and the output terminal of each of the communication modules is connected to one of the input terminals of the main control module. Each of the communication modules is also connected to one of the communication terminals of the main control module. Each of the communication modules uses a different communication protocol. The communication module is used to convert the instruction signal into a corresponding message instruction based on its own communication protocol. The output terminal of the main control module is connected to the input terminal of the multi-output module, and the main control module is used to convert the message command into a voltage control command. Each output terminal of the multi-output module is connected to one input terminal of an external testing device. The multi-output module is used to output at least one corresponding analog voltage based on the voltage control command. The analog voltage is used to provide a reference test voltage for the external testing device.

2. The multi-channel output circuit according to claim 1, characterized in that, The power supply module includes a step-down unit and a voltage regulator unit, wherein... The input terminal of the step-down unit receives the external power supply voltage, and the output terminal of the step-down unit is connected to the input terminal of the voltage regulator unit. The step-down unit is used to reduce the voltage level of the external power supply voltage and eliminate interference in the external power supply voltage. The output terminal of the voltage regulator unit is connected to the power supply terminals of the communication module, the main control module, and the multi-output module, respectively. The voltage regulator unit is used to eliminate interference in the external power supply voltage after voltage reduction.

3. The multi-channel output circuit according to claim 2, characterized in that, The step-down unit includes: a first filter circuit and a step-down output circuit, wherein... The input terminal of the first filter circuit receives the external power supply voltage, and the output terminal of the first filter circuit is connected to the input terminal of the step-down output circuit. The first filter circuit is used to suppress external power supply voltage overload and high-frequency interference. The output terminal of the buck output circuit is connected to the input terminal of the voltage regulator unit. The buck output circuit is used to reduce the voltage level of the external power supply voltage and eliminate ripple.

4. The multi-channel output circuit according to claim 1, characterized in that, The communication module employs either Modbus RTU communication or CAN communication. When the communication module uses Modbus RTU communication, it includes a second filtering circuit and a first output control circuit. The command signal is input to the input terminal of the second filter circuit, and the output terminal of the second filter circuit is connected to the input terminal of the first output control circuit. The second filter circuit is used to suppress common-mode interference in the command signal. The enable terminal of the first output control circuit is connected to a communication terminal of the main control module, and the output terminal of the first output control circuit is connected to an input terminal of the main control module. The first output control circuit is used to convert the instruction signal into a voltage control instruction based on the enable signal of the main control module.

5. The multi-channel output circuit according to claim 4, characterized in that, The second filter circuit includes: a common-mode filter, a first resistor, a second resistor, a third resistor, a fourth resistor, a fifth resistor, a first transient voltage suppression diode, and a second transient voltage suppression diode, wherein, The first end of the first resistor is connected to the output end of the power supply module, and the second end of the first resistor is connected to the first end of the second resistor, the first end of the third resistor, and the first end of the common-mode filter. The second terminal of the second resistor is connected to the first terminal of the first transient voltage suppression diode and receives the command signal of the first level; The second end of the third resistor is connected to the first end of the fourth resistor, the first end of the fifth resistor, and the second end of the common-mode filter; The second terminal of the fourth resistor is connected to the first terminal of the second transient voltage suppression diode and receives the command signal of the second level. The second terminal of the fifth resistor, the second terminal of the first transient voltage suppression diode, and the second terminal of the second transient voltage suppression diode are all grounded; The third and fourth terminals of the common-mode filter are respectively connected to the first input terminal and the second input terminal of the first output control circuit; The first level is the logical opposite of the second level.

6. The multi-channel output circuit according to claim 1, characterized in that, The communication module employs either Modbus RTU or CAN communication. When the communication module uses CAN communication, it includes a third filtering circuit and a second output control circuit. The command signal is input to the input terminal of the third filter circuit, and the output terminal of the third filter circuit is connected to the input terminal of the second output control circuit. The third filter circuit is used to suppress interference in the command signal. The enable terminal of the second output control circuit is connected to a communication terminal of the main control module, and the output terminal of the second output control circuit is connected to an input terminal of the main control module. The second output control circuit is used to convert the instruction signal into a voltage control instruction based on the enable signal of the main control module.

7. The multi-channel output circuit according to claim 1, characterized in that, The multi-output module includes: a signal output unit and multiple power amplifier units, wherein, The first input terminal of the signal output unit is connected to the output terminal of the main control module, the second input terminal of the signal output unit is input with a reference voltage, and the output terminal of the signal output unit is connected to the input terminal of each of the power amplifier units. The signal output unit is used to convert the reference voltage into a corresponding analog voltage based on the voltage control command. Each of the power amplifier units is used to amplify the analog voltage and output it.

8. The multi-channel output circuit according to claim 7, characterized in that, The signal output unit includes: a current limiting circuit, a digital-to-analog converter circuit, and an amplifier circuit, wherein... The first terminal of the current limiting circuit is connected to the output terminal of the main control module, and the second terminal of the current limiting circuit is connected to the first input terminal of the digital-to-analog converter circuit. The current limiting circuit is used to limit the magnitude of the current in the voltage control command. The second input terminal of the digital-to-analog converter circuit receives a reference voltage, and the output terminal of the digital-to-analog converter circuit is connected to the input terminal of the amplifier circuit. The digital-to-analog converter circuit is used to convert the reference voltage into a corresponding initial analog voltage based on the voltage control command. The output terminal of the amplifier circuit is connected to the input terminal of each of the power amplifier units. The amplifier circuit is used to amplify and filter the initial analog voltage and then output the analog voltage.

9. The multi-channel output circuit according to claim 8, characterized in that, The amplifier circuit includes: a sixth resistor, a seventh resistor, an eighth resistor, a ninth resistor, an operational amplifier, a first capacitor, a second capacitor, and a third capacitor, wherein... The first end of the sixth resistor is connected to the output end of the digital-to-analog converter circuit, and the second end of the sixth resistor is connected to the non-inverting input end of the operational amplifier and the first end of the first capacitor. The second terminal of the first capacitor is connected to the first terminal of the seventh resistor; The second end of the seventh resistor is connected to the inverting input of the operational amplifier, the first end of the eighth resistor, and the first end of the second capacitor; The second end of the eighth resistor is connected to the first end of the ninth resistor; The second end of the ninth resistor is connected to the input end of the power amplifier unit; The second terminal of the second capacitor is connected to the output terminal of the operational amplifier; The third capacitor is connected in series between the two power supply terminals of the operational amplifier.

10. The multi-channel output circuit according to claim 7, characterized in that, The power amplifier unit includes: a third filter circuit and an amplification output circuit, wherein... The input terminal of the third filter circuit is connected to the output terminal of the power supply module, and the output terminal of the third filter circuit is connected to the power supply terminal of the amplification output circuit. The third filter circuit is used to filter out interference from the power supply terminal of the amplification output circuit. The input terminal of the amplification output circuit is connected to the output terminal of the signal output unit, and the amplification output circuit is used to output the amplified analog voltage.

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