Electronic load dynamic slope control circuit and method

Abstract

The invention provides an electronic load dynamic slope control circuit and method, and relates to the technical field of integrated circuit design. The reference generation circuit receives and stores different current reference values and provides basic data support for the system. The slope generation circuit accurately adjusts and controls the current according to a set slope, cooperates with the comparison / selection circuit, provides an accurate current control basis for the MOS control circuit according to a working mode determined by a pulse width modulation signal generated by the PWM generation circuit, and further accurately controls the actual current. The waveform parameter of the pulse width modulation signal is adjusted by the programmable characteristic of the PWM generation circuit, and the time point and duration of current loading are controlled. Meanwhile, by introducing a time sequence control mechanism, when current values are switched in different working modes, accurate control over the slope is achieved, the defect that the current is unstable due to the fact that effective time sequence coordination is lacked when the current set value is frequently and rapidly changed in the prior art is overcome, and the safety and reliability of current control are improved.

Description

Technical Field

[0001] The present application relates to the technical field of integrated circuit design, and in particular to an electronic load dynamic slope control circuit and method, which can be applied to emerging software and new information technology services. Background Art

[0002] In today's era of rapid technological development, the performance requirements for electronic loads in the field of electronic testing continue to rise. Electronic loads occupy a key position in the research and development, production, and quality inspection of various electronic equipment. They need to accurately simulate various actual load conditions to ensure the performance reliability and stability of related equipment. Whether it is the testing of consumer electronic devices or industrial-grade power equipment, extremely stringent requirements are placed on the current control capabilities of electronic loads, especially in test scenarios involving dynamic current changes. Slight current control deviations may cause inaccurate test results, thereby affecting the development process and quality control of the entire product.

[0003] Most existing electronic loads use a more traditional control architecture. Among them, current control mainly relies on a controller with pre-set fixed parameters, such as a common fixed-gain amplifier to adjust the current. In terms of current change control, different current setting values ​​are switched based on simple timing logic. For example, when performing a current increase operation, the input signal of the amplifier is gradually increased according to a fixed time period, so that the current gradually increases. This method can achieve basic current control tasks to a certain extent, and can maintain the current regulation within a certain range under a relatively stable test environment.

[0004] However, in the face of increasingly complex and changing test requirements, this traditional control architecture has exposed many problems. When encountering situations where the current setting value needs to be changed frequently and quickly, such as in the fast dynamic response test of simulating some new power supplies, due to the limitations of its fixed parameter controller and simple timing logic, the rate of current change cannot be flexibly adjusted. When the current switches the set value, there will be an obvious sense of frustration and a smooth transition cannot be achieved. This results in the inability to accurately simulate the dynamic changes of the real load during the test, resulting in large errors in the test data, and this sudden change in current may also cause additional stress shocks to the device under test, reduce the service life of the device under test, and may even cause equipment failures, seriously affecting the accuracy and reliability of the test.

[0005] In summary, the related technology is not smooth enough when the current setting value needs to be changed frequently and quickly, which affects the accuracy of control. Summary of the invention

[0006] The present application provides an electronic load dynamic slope control circuit and method, which are used to overcome the problem of the related art that the current setting value is not smooth enough when changing frequently and quickly, and improve the safety and reliability of current control.

[0007] In a first aspect, the present application provides an electronic load dynamic slope control circuit, comprising: a reference generating circuit, the reference generating circuit is connected to a comparison / selection circuit, and is used to receive different current reference values, store and output different current reference values; a slope generating circuit, the slope generating circuit is connected to the comparison / selection circuit, and is used to gradually adjust the control current at a set slope so that it gradually changes from a current value to a selected current reference value; a PWM generating circuit, the PWM generating circuit is connected to the comparison / selection circuit, and is used to generate a pulse width modulation signal; a comparison / selection circuit, the comparison / selection circuit is respectively connected to the PWM generating circuit, the slope generating circuit and the MOS control circuit, and is used to select different operating modes according to the pulse width modulation signal, wherein different operating modes correspond to different current reference values; a MOS control circuit, the MOS control circuit is connected to the comparison / selection circuit, and is used to control the magnitude of the actual current according to the control current.

[0008] By adopting the above technical solution, the reference generation circuit receives and stores different current reference values ​​to provide basic data support for the system. The slope generation circuit accurately adjusts the control current according to the set slope, and cooperates with the comparison / selection circuit to provide the MOS control circuit with an accurate control current basis according to the working mode determined by the pulse width modulation signal generated by the PWM generation circuit, thereby accurately controlling the actual current size. The programmable characteristics of the PWM generation circuit adjust the pulse width modulation signal waveform parameters to control the timing and duration of current loading. At the same time, by introducing a timing control mechanism, when the current value switches in different working modes, each circuit cooperates in an orderly manner according to the precise timing, realizing accurate control of the slope, avoiding equipment damage caused by slope loss of control, and overcoming the current instability caused by the lack of effective timing coordination when the current setting value is frequently and quickly changed in related technologies, improving the safety and reliability of current control, and ensuring the stable operation of the electronic load system.

[0009] In combination with some embodiments of the first aspect, in some embodiments, it also includes: a main control chip, which is connected to the PWM generating circuit, the slope generating circuit, the comparison / selection circuit, the reference generating circuit and the MOS control circuit, and is used to control the operation of the PWM generating circuit, the slope generating circuit, the comparison / selection circuit, the reference generating circuit and the MOS control circuit.

[0010] By adopting the above technical solutions, the main control chip becomes the control core of the entire circuit system. It can flexibly adjust the working status of the PWM generation circuit, slope generation circuit, comparison / selection circuit, reference generation circuit and MOS control circuit according to system requirements, further improving the accuracy and reliability of the dynamic slope control of the electronic load.

[0011] In combination with some embodiments of the first aspect, in some embodiments, the slope generating circuit includes an adjustable slope setting unit, and the adjustable slope setting unit sets a corresponding slope value by inputting different codes through an external control signal.

[0012] By adopting the above technical solution, the adjustable slope setting unit of the slope generating circuit sets the slope value by inputting different codes through external control signals. This feature enhances the system's flexible control over the current change slope. It effectively improves the accuracy and comprehensiveness of the electronic load in simulating real load scenarios, making the current control more in line with actual needs and improving the credibility of the test results.

[0013] In combination with some embodiments of the first aspect, in some embodiments, the PWM generating circuit includes a programmable unit, and the programmable unit can change the waveform parameters of the pulse width modulation signal according to instructions.

[0014] By adopting the above technical solution, the programmable unit of the PWM generation circuit can change the waveform parameters of the pulse width modulation signal according to the instruction. This makes it possible to accurately adjust the timing and duration of current loading according to different current reference values ​​and actual working requirements during the current control process, ensuring that the electronic load can work stably and accurately under most working conditions.

[0015] In combination with some embodiments of the first aspect, in some embodiments, the MOS control circuit is provided with a current feedback detection unit, and the current feedback detection unit is used to monitor the actual current size in real time and transmit the feedback information to the main control chip.

[0016] By adopting the above technical solution, the current feedback detection unit of the MOS control circuit monitors the actual current in real time and transmits the feedback information to the main control chip. The main control chip can timely understand the actual state of the current based on this feedback information, and when a current deviation occurs, it can quickly adjust the working parameters of other circuits, thereby realizing closed-loop control of the current.

[0017] In the second aspect, the present application provides an electronic load dynamic slope control method including: in the startup phase, the reference generating circuit receives a first current reference value and a second current reference value, wherein the second current reference value is 0 and the first current reference value is greater than the second current reference value; when a load signal is received, the actual current is gradually increased from 0 to the first current reference value according to the slope set by the slope generating circuit.

[0018] By adopting the above technical solution, in the startup phase, the reference generation circuit receives a specific first current reference value and a second current reference value (the second current reference value is 0), which provides a clear target and starting point for the current rise. When the load signal is triggered, the slope generation circuit drives the actual current to rise steadily from 0 to the first current reference value according to the set slope. This orderly control process avoids the sudden change and instability of the current at startup in traditional control, so that the current can change according to the predetermined trajectory in the initial stage, laying a good foundation for the entire test process, improving the accuracy and reliability of the current control of the electronic load in the startup phase, and ensuring the validity of subsequent test data.

[0019] In combination with some embodiments of the second aspect, in some embodiments, it also includes: when the electronic load switches from OFF to ON, at the falling edge of the pulse width modulation signal generated by the PWM generating circuit, the load enable signal is turned on, and the slope generating circuit takes effect, and the control current rises from 0 to the first current reference value under the action of the slope generating circuit; when the first current reference value is reached, the slope generating circuit exits according to the control logic of the comparison / selection circuit; the reference generating circuit receives the new first current reference value and the new second current reference value, and latches and takes effect at the rising edge of the pulse width modulation signal generated by the PWM generating circuit; during the current value switching process, the comparison / selection circuit determines the entry / exit timing of the slope generating circuit according to the characteristics of the pulse width modulation signal generated by the PWM generating circuit.

[0020] By adopting the above technical solution, in the stage of the electronic load switching from OFF to ON, each circuit strictly follows the precise timing to work together, which has a significant beneficial effect. First, the load enable signal is turned on at the falling edge of the pulse width modulation signal generated by the PWM generating circuit, so that the slope generating circuit can be accurately effective, and then the control current is allowed to rise from 0 to the first current reference value smoothly and orderly under the action of the slope generating circuit, avoiding the adverse effects of sudden current changes on the load and the entire system, and ensuring the smoothness and controllability of the current rising process. When the current reaches the first current reference value, the slope generating circuit exits in time according to the control logic of the comparison / selection circuit, which ensures that the current can be stably maintained after reaching the target value, which meets the expected working state of the system. At the same time, the reference generating circuit receives the new first current reference value and the new second current reference value, and latches them into effect at the rising edge of the pulse width modulation signal generated by the PWM generating circuit. This rigorous timing arrangement makes the update of the current reference value orderly. Moreover, during the current value switching process, the comparison / selection circuit determines the entry / exit timing of the slope generating circuit according to the pulse width modulation signal characteristics, thereby avoiding problems such as the current not working according to the set slope and the current changing directly from the maximum current to the minimum current due to improper reference value conversion timing. The entire electronic load system can achieve stable, accurate and set slope current control during the OFF to ON and current value switching stages.

[0021] In combination with some embodiments of the second aspect, in some embodiments, it also includes: it also includes: in the stage of changing the load value midway, when the actual current needs to be changed midway, the new first current reference value or the new second current reference value needs to be written into the reference generating circuit after the last change is latched, and it needs to be latched and take effect at the rising edge of the pulse width modulation signal generated by the next PWM generating circuit.

[0022] By adopting the above technical solution, when changing the load value midway, the new first current reference value or the second current reference value is written into the reference generation circuit after the last change latch, and latched to take effect at the rising edge of the pulse width modulation signal generated by the next PWM generation circuit. This operation process ensures a smooth transition of the current value during the change process and avoids sudden jumps in the current. Compared with traditional control methods, it can effectively reduce the additional stress impact on the device under test caused by sudden current changes, improve the electronic load's ability to accurately control current changes during dynamic loading, and make the test process closer to the actual load changes, thereby improving the accuracy and reliability of the test results.

[0023] In combination with some embodiments of the second aspect, in some embodiments, it also includes: it also includes: the main control chip writes the values ​​of the first current reference value and the second current reference value to the reference generating circuit.

[0024] By adopting the above technical solution, the main control chip writes the values ​​of the first current reference value and the second current reference value into the reference generation circuit, thereby realizing active setting and control of the current reference value.

[0025] In combination with some embodiments of the second aspect, in some embodiments, it also includes: it also includes: the main control chip writes a new first current reference value and a new second current reference value to the reference generating circuit.

[0026] By adopting the above technical solution, the main control chip writes the new first current reference value and the new second current reference value into the reference generation circuit, thereby realizing dynamic update of the current reference value during the current control process.

[0027] One or more technical solutions provided in the embodiments of the present application have at least the following technical effects or advantages: 1. The reference generation circuit receives and stores different current reference values ​​to provide basic data support for the system. The slope generation circuit accurately adjusts the control current according to the set slope, and cooperates with the comparison / selection circuit to provide the MOS control circuit with an accurate control current basis according to the working mode determined by the pulse width modulation signal generated by the PWM generation circuit, thereby accurately controlling the actual current size. The programmable characteristics of the PWM generation circuit adjust the pulse width modulation signal waveform parameters to control the timing and duration of current loading. At the same time, by introducing a timing control mechanism, when the current value switches in different working modes, each circuit cooperates in an orderly manner according to the precise timing, achieving precise control of the slope, avoiding equipment damage caused by out-of-control slope, and overcoming the current instability caused by the lack of effective timing coordination when the current setting value is frequently and quickly changed in related technologies, improving the safety and reliability of current control, and ensuring the stable operation of the electronic load system.

[0028] 2. In the startup phase, the reference generation circuit receives a specific first current reference value and a second current reference value (the second current reference value is 0), which provides a clear target and starting point for the current rise. When the load signal is triggered, the slope generation circuit drives the actual current to rise steadily from 0 to the first current reference value according to the set slope. This orderly control process avoids the sudden change and instability of the current at startup in traditional control, so that the current can change according to the predetermined trajectory in the initial stage, laying a good foundation for the entire test process, improving the accuracy and reliability of the current control of the electronic load in the startup phase, and ensuring the validity of subsequent test data.

[0029] 3. In the stage when the electronic load switches from OFF to ON, each circuit strictly follows the precise timing to work together, which has significant beneficial effects. First, the load enable signal is turned on at the falling edge of the pulse width modulation signal generated by the PWM generation circuit, so that the slope generation circuit can take effect accurately, and then the control current can rise from 0 to the first current reference value smoothly and orderly under the action of the slope generation circuit, avoiding the adverse effects of sudden current changes on the load and the entire system, and ensuring the smoothness and controllability of the current rise process. When the current reaches the first current reference value, the slope generation circuit exits in time according to the control logic of the comparison / selection circuit, which ensures that the current can be maintained stably after reaching the target value, which meets the expected working state of the system. At the same time, the reference generation circuit receives the new first current reference value and the new second current reference value, and latches them into effect at the rising edge of the pulse width modulation signal generated by the PWM generation circuit. This rigorous timing arrangement makes the update of the current reference value orderly. Moreover, during the current value switching process, the comparison / selection circuit determines the entry / exit timing of the slope generating circuit according to the pulse width modulation signal characteristics, thereby avoiding problems such as the current not working according to the set slope and the current changing directly from the maximum current to the minimum current due to improper reference value conversion timing. The entire electronic load system can achieve stable, accurate and set slope current control during the OFF to ON and current value switching stages.

[0030] 4. When changing the load value midway, write the new first current reference value or second current reference value into the reference generation circuit after the last change latch, and latch it to take effect at the rising edge of the pulse width modulation signal generated by the next PWM generation circuit. This operation process ensures a smooth transition of the current value during the change process and avoids sudden jumps in the current. Compared with traditional control methods, it can effectively reduce the additional stress impact on the device under test caused by sudden current changes, improve the electronic load's ability to accurately control current changes during dynamic loading, and make the test process closer to the actual load changes, thereby improving the accuracy and reliability of the test results. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 is a schematic diagram of a dynamic slope control circuit of an electronic load in an embodiment of the present application; Figure 2 is a waveform diagram of the dynamic slope control circuit of the electronic load in the embodiment of the present application; DETAILED DESCRIPTION The terms used in the following embodiments of the present application are only for the purpose of describing specific embodiments, and are not intended to be used as limitations to the present application. As used in the specification and appended claims of the present application, the singular expressions "one", "a kind of", "said", "above", "the" and "this" are intended to also include plural expressions, unless there is a clear indication to the contrary in the context. It should also be understood that the term "and / or" used in the present application refers to and includes any or all possible combinations of one or more listed items.

[0032] In the following, the terms "first" and "second" are used for descriptive purposes only and are not to be understood as suggesting or implying relative importance or implicitly indicating the number of the indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the features, and in the description of the embodiments of the present application, unless otherwise specified, "plurality" means two or more.

[0033] See also Figure 1 , Figure 1 is a schematic diagram of a dynamic slope control circuit of an electronic load in an embodiment of the present application; An electronic load dynamic slope control circuit, comprising: A reference generating circuit, the reference generating circuit is connected to the comparison / selection circuit, and is used to receive different current reference values, store and output different current reference values; The reference generation circuit represents a circuit module that provides an accurate current reference standard for the entire electronic load dynamic slope control system, and other circuits work based on the reference value it provides. For example, the reference generation circuit can provide corresponding current reference values ​​according to preset parameters, such as different current references such as REF1 and REF2, to ensure that the electronic load can accurately simulate the required load conditions.

[0034] In some embodiments, the reference generation circuit starts working at the system initialization stage, receives different current reference values ​​from the main control chip or external settings, and stores these values ​​in its internal storage unit, such as a register or memory. During the system operation, according to the request of the comparison / selection circuit, the corresponding current reference value is accurately output, providing a target basis for the slope generation circuit to adjust the control current, thereby indirectly affecting the MOS control circuit's control of the actual current.

[0035] In some specific embodiments, a high-precision voltage reference source chip is used in combination with a digital-to-analog converter (DAC). The voltage reference source chip provides a stable reference voltage, and then converts the digital signal into a corresponding analog voltage through the DAC. The analog voltage is converted and amplified by a certain circuit to obtain the required current reference value; optionally, a special current reference chip is used, which integrates a precise current source circuit, and selects different internal current source channels through external control signals (such as address lines and data lines), thereby outputting different current reference values. It is understandable that other methods can also be used to implement the function of the reference generation circuit, which is not limited here.

[0036] A slope generating circuit, the slope generating circuit is connected to the comparison / selection circuit and is used to gradually adjust the control current at a set slope so that the control current gradually changes from a current value to a selected current reference value; The slope generating circuit is the circuit part that can change the magnitude of the controlled current at a preset rate. It determines how fast the current changes from one value to another. In some embodiments, when the system needs to change the current and enters the dynamic load state, the slope generation circuit starts to work according to the working mode determined by the comparison / selection circuit and the current reference value provided by the reference generation circuit. The adjustable slope setting unit inside it determines the corresponding slope value by receiving different codes of the external control signal input. Then, according to this slope value, the control current is gradually adjusted so that it gradually changes from the current value to the selected current reference value. This process is a continuous and smooth transition, which ensures the stability of the current change.

[0037] In some specific embodiments, an integrator circuit is used for implementation. First, the external input code is converted into a corresponding voltage signal, which is used as the input of the integrator, and the output of the integrator is the control current. By changing the size and polarity of the input voltage signal, the slope of the integrator output current can be adjusted; optionally, a digitally controlled current source array is used. According to the input code, different current source combinations are selected, and these current sources are switched and superimposed according to a certain timing and weight, so as to realize the control current changing according to the set slope. It can be understood that other methods can also be used to implement the function of the slope generating circuit, which is not limited here.

[0038] A PWM generating circuit, the PWM generating circuit is connected to the comparison / selection circuit and is used to generate a pulse width modulation signal; Among them, the PWM generating circuit is a circuit module used to generate a pulse width modulation signal. The pulse width modulation signal is a periodic signal that controls the working state or energy transfer of other circuits by adjusting the time ratio (duty cycle) of the high level and the low level.

[0039] In some embodiments, the PWM generating circuit continues to operate after the system is started, and generates a pulse width modulation signal according to the instructions of the main control chip or the internal preset parameters. Its programmable unit can change the waveform parameters of the pulse width modulation signal according to the instructions, including the frequency and duty cycle of the signal. The change of these waveform parameters can control the time point and duration of current loading. For example, increasing the duty cycle can make the MOS control circuit conduction time longer, thereby allowing more current to pass through the load, realizing the increase control of current.

[0040] In some specific embodiments, a dedicated PWM chip is used, and different digital signals are input through the control pins of the chip to set parameters such as frequency and duty cycle. The circuit modules such as oscillators and comparators inside the chip generate corresponding pulse width modulation signals according to these parameters; optionally, the timer function of a microcontroller (such as a single-chip microcomputer) is used to achieve this. The count cycle and comparison value of the timer are set by programming, and the level state of the output pin is switched in the timer interrupt service program to generate a PWM signal. It is understandable that other methods can also be used to implement the function of the PWM generation circuit, which is not limited here.

[0041] A comparison / selection circuit, the comparison / selection circuit is connected to the PWM generation circuit, the slope generation circuit and the MOS control circuit respectively, and is used to select different working modes according to the pulse width modulation signal, wherein different working modes correspond to different current reference values; Among them, the comparison / selection circuit is a circuit that plays a role in decision-making and signal distribution in the entire system, directing the direction of the current and the working mode of the circuit according to different situations. It analyzes and judges the input pulse width modulation signal, selects the appropriate working mode, and distributes related signals to other circuits, such as the slope generation circuit, MOS control circuit, etc. For example, when a parameter of the pulse width modulation signal meets a specific condition, the comparison / selection circuit will select the slope generation circuit to enter the working state to adjust the current slope.

[0042] In some embodiments, the comparison / selection circuit is always in working state, and monitors the pulse width modulation signal generated by the PWM generation circuit in real time. When receiving the signal, it will compare and judge according to the internal preset logic rules. If the parameters such as the level, frequency or duty cycle of the pulse width modulation signal meet the setting conditions of a certain working mode, it will select the corresponding working mode and send the corresponding control signal to the slope generation circuit, MOS control circuit, etc. For example, when the duty cycle of the pulse width modulation signal is greater than 50%, the high current working mode is selected. At this time, the slope generation circuit will be notified to adjust the control current according to the high current slope, and the MOS control circuit will adjust the conduction degree to adapt to the high current output.

[0043] In some specific embodiments, a combination of multiple comparators and logic gate circuits is used. Different comparators compare different parameters of the pulse width modulation signal respectively, and the comparison results are input into the logic gate circuit. The logic gate circuit generates a control signal according to a preset logical relationship to achieve the selection of the working mode and signal distribution; optionally, a programmable logic device (such as CPLD or FPGA) is used. By programming the internal logic circuit, flexible processing of the pulse width modulation signal and intelligent selection of the working mode are achieved. It is understandable that other methods can also be used to implement the function of the comparison / selection circuit, which is not limited here.

[0044] The MOS control circuit is connected to the comparison / selection circuit and is used to control the size of the actual current according to the control current.

[0045] Among them, the MOS control circuit is the circuit part that uses the MOS tube to control the actual current size. The MOS tube is like an electrically controlled valve, which adjusts the amount of current passing through by changing its conduction degree. For example, in the power supply circuit, the MOS control circuit adjusts the conduction resistance of the MOS tube according to the control signal, thereby controlling the output current size.

[0046] In some embodiments, the MOS control circuit operates according to the working mode determined by the comparison / selection circuit and the control current adjusted by the slope generation circuit. The current feedback detection unit inside it monitors the actual current size in real time and transmits the feedback information to the main control chip. The main control chip determines whether the current deviates from the preset value based on this feedback information. If it deviates, it will adjust the working parameters of other circuits, thereby affecting the control of the MOS tube by the MOS control circuit. For example, if it is detected that the actual current is greater than the preset value, the main control chip may reduce the slope of the slope generation circuit or adjust the duty cycle of the PWM generation circuit, thereby reducing the conduction degree of the MOS tube and reducing the actual current.

[0047] It can be seen that the reference generation circuit receives and stores different current reference values ​​to provide basic data support for the system. The slope generation circuit accurately adjusts the control current according to the set slope, and cooperates with the comparison / selection circuit to provide the MOS control circuit with an accurate control current basis according to the working mode determined by the pulse width modulation signal generated by the PWM generation circuit, thereby accurately controlling the actual current size. The programmable characteristics of the PWM generation circuit adjust the pulse width modulation signal waveform parameters to control the timing and duration of current loading. At the same time, by introducing a timing control mechanism, when the current value switches in different working modes, each circuit cooperates in an orderly manner according to the precise timing, achieving precise control of the slope, avoiding equipment damage caused by slope loss of control, and overcoming the current instability caused by the lack of effective timing coordination when the current setting value is frequently and quickly changed in related technologies, improving the safety and reliability of current control, and ensuring the stable operation of the electronic load system.

[0048] In some embodiments, the electronic load dynamic slope control circuit further includes: The main control chip is connected to the PWM generating circuit, the slope generating circuit, the comparison / selection circuit, the reference generating circuit and the MOS control circuit, and is used to control the operation of the PWM generating circuit, the slope generating circuit, the comparison / selection circuit, the reference generating circuit and the MOS control circuit.

[0049] Among them, the main control chip is the core control unit of the entire electronic load dynamic slope control system. It coordinates and directs the work of each circuit module. It is responsible for processing various data, issuing control instructions and monitoring system status. For example, when the system starts, the main control chip is responsible for initializing the parameters of each circuit; during operation, it adjusts the working mode and parameters of each circuit according to external input or internal preset programs.

[0050] In some embodiments, the main control chip first initializes itself after the system is powered on, including setting internal registers, initializing communication interfaces, etc. Then, it writes the initial current reference values, such as REF1 and REF2, to the reference generation circuit, and initializes the configuration of the slope generation circuit, the PWM generation circuit, etc. During the operation of the system, it continuously monitors the working status of each circuit, such as determining whether the current is normal by receiving the current feedback information of the MOS control circuit. When it is necessary to change the current reference value or the working mode, the main control chip calculates the corresponding parameters according to the preset algorithm, and sends instructions to each related circuit, such as notifying the reference generation circuit to update the current reference value, controlling the PWM generation circuit to change the waveform parameters of the pulse width modulation signal, etc.

[0051] It can be seen that the main control chip becomes the control core of the entire circuit system. It can flexibly adjust the working status of the PWM generation circuit, slope generation circuit, comparison / selection circuit, reference generation circuit and MOS control circuit according to system requirements, further improving the accuracy and reliability of the dynamic slope control of the electronic load.

[0052] The slope generating circuit comprises an adjustable slope setting unit, and the adjustable slope setting unit is used to set corresponding slope values ​​by inputting different codes through external control signals.

[0053] Among them, the adjustable slope setting unit refers to a functional module in the slope generating circuit that is specifically used to flexibly set the current change slope. It is equivalent to a slope regulator, which can accurately adjust the rate at which the current changes from the current value to the target value according to different external input instructions, so that the speed of the current change can be customized as needed to meet the diverse dynamic control needs of electronic loads.

[0054] In some embodiments, when the electronic load system faces different test tasks or needs to simulate different load characteristics, and thus requires changing the current change rate, the adjustable slope setting unit begins to play a role. For example, in the scenario of switching from simulating a low-power device load to a high-power device load, the current needs to rise or fall at different slopes to match the new load conditions. The adjustable slope setting unit receives a control signal from the outside, and this external control signal is presented in different coding forms. These codes correspond to specific slope values ​​according to pre-set rules. When the unit receives a specific code, the internal circuit will perform corresponding processing operations based on the code, such as by adjusting the combination of some internal current sources, changing the parameters of the integration circuit, or modifying the coefficients of the digital control, so that the output control current changes according to the corresponding slope value, thereby allowing the current of the entire electronic load to achieve smooth and dynamic adjustment that meets the requirements.

[0055] It can be seen that the adjustable slope setting unit of the slope generating circuit sets the slope value by inputting different codes through external control signals. This feature enhances the system's ability to flexibly control the current change slope. It effectively improves the accuracy and comprehensiveness of the electronic load when simulating real load scenarios, making the current control more in line with actual needs and improving the credibility of the test results.

[0056] The PWM generating circuit includes a programmable unit, which can change the waveform parameters of the pulse width modulation signal according to instructions.

[0057] Among them, the programmable unit is a key component in the PWM generating circuit. It is like a signal editor with intelligent programming capabilities. It can flexibly modify the waveform parameters (such as frequency, duty cycle, phase, etc.) of the pulse width modulation signal according to the various instructions received, so that the pulse width modulation signal can accurately adapt to the electronic load's control requirements on the current loading time point, duration, etc. under different working stages and different load requirements.

[0058] In some embodiments, whether it is necessary to initialize the PWM signal parameters at the beginning of system startup, or when the current control strategy needs to be changed due to load changes, test phase conversion, etc. during the operation of the electronic load, the programmable unit will work according to the instructions sent by the main control chip. For example, when the electronic load enters the dynamic load state from a stable operation state, the current size needs to be adjusted quickly, and the main control chip will send corresponding instructions to the programmable unit. After the programmable unit receives the instruction, the internal logic circuit or digital processing module will analyze and adjust the waveform parameters of the current pulse width modulation signal. If the current is to be increased, the high level time may be extended by increasing the duty cycle of the signal, so that the MOS control circuit is turned on for a longer time per unit time, allowing more current to pass through the load; if the signal frequency is to be changed, it will also adjust the internal clock source or counter and other related component parameters accordingly, so as to change the waveform characteristics of the entire pulse width modulation signal and realize flexible changes in current control.

[0059] It can be seen that the programmable unit of the PWM generation circuit can change the waveform parameters of the pulse width modulation signal according to the instructions. This makes it possible to accurately adjust the timing and duration of current loading according to different current reference values ​​and actual working requirements during the current control process, ensuring that the electronic load can work stably and accurately under most working conditions.

[0060] The MOS control circuit is provided with a current feedback detection unit, which is used to monitor the actual current size in real time and transmit the feedback information to the main control chip.

[0061] Among them, the current feedback detection unit is a functional module in the MOS control circuit that is responsible for obtaining the actual current size information in real time. It constantly detects the actual current passing through the load and accurately feeds this information back to the main control chip, so that the main control chip can make corresponding control decisions in time according to the actual current conditions, ensuring that the current of the entire electronic load system is in a stable and satisfactory state.

[0062] In some embodiments, as long as the electronic load system is in the power-on state, the current feedback detection unit will continue to work and monitor the actual current size in real time. It usually uses high-precision current sensors or sampling resistors to obtain current information. For example, when using a sampling resistor, the current passing through the sampling resistor will generate a corresponding voltage drop, which is proportional to the current size. The measurement circuit in the current feedback detection unit will accurately measure this voltage drop and convert it into a corresponding digital signal (through an analog-to-digital converter) or directly transmit it to the main control chip in the form of an analog signal. After receiving this feedback information, the main control chip will compare it with the preset current reference value. If it is found that the actual current deviates from the reference value, it will send adjustment instructions to other related circuits (such as slope generation circuit, PWM generation circuit, etc.) according to the deviation size and the control strategy set by the system, prompting the entire system to correct the current and ensure accurate control of the current.

[0063] It can be seen that the current feedback detection unit of the MOS control circuit monitors the actual current in real time and transmits the feedback information to the main control chip. The main control chip can timely understand the actual state of the current based on this feedback information. When a current deviation occurs, the operating parameters of other circuits can be quickly adjusted, thereby achieving closed-loop control of the current.

[0064] A method for controlling a dynamic slope of an electronic load, referring to the above-mentioned dynamic slope control circuit of an electronic load, comprising: In the startup phase, the reference generating circuit receives a first current reference value and a second current reference value, wherein the second current reference value is 0 and the first current reference value is greater than the second current reference value; When the load signal is received, the actual current is gradually increased from 0 to the first current reference value according to the slope set by the slope generating circuit.

[0065] In the startup phase, the second current reference value is set to 0 as the basis for the current start. The purpose is to make the load current (actual current) rise from 0A to REF1 (first current reference value) at a certain slope when the load signal is started. If the first current reference value is greater than 0, it is the target value for the current rise. In some embodiments, when the electronic load system is powered on and the initialization preparation is completed, the startup phase begins. The main control chip first writes a preset first current reference value (such as 2A) and a second current reference value (0A) to the reference generation circuit. At this time, the system is in a state of waiting for a load signal, and each circuit is on standby but not fully activated. When a load signal is received, such as a start-up instruction from an external test device or a trigger condition preset in the system is met, the entire system begins to enter the current loading process. The slope generation circuit starts working according to the previously set slope parameter, and it adjusts the size of the control current through the internal circuit structure. The MOS control circuit adjusts the path of the actual current through the load according to the change of this control current, so that the actual current starts from 0A and gradually increases according to the slope set by the slope generation circuit. In this process, the current feedback detection unit continuously monitors the actual current size and feeds back the information to the main control chip. The main control chip ensures the stability and accuracy of the current rising process based on these feedback information to avoid current fluctuations or loss of control until the actual current rises to the first current reference value 2A.

[0066] It can be seen that in the startup phase, the reference generation circuit receives a specific first current reference value and a second current reference value (the second current reference value is 0), which provides a clear target and starting point for the current rise. When the load signal is triggered, the slope generation circuit drives the actual current to rise steadily from 0 to the first current reference value according to the set slope. This orderly control process avoids the sudden change and instability of the current at startup in traditional control, so that the current can change according to the predetermined trajectory in the initial stage, laying a good foundation for the entire test process, improving the accuracy and reliability of the current control of the electronic load in the startup phase, and ensuring the validity of subsequent test data.

[0067] In some embodiments, it also includes: When the electronic load switches from OFF to ON, at the falling edge of the pulse width modulation signal generated by the PWM generating circuit, the load enable signal is turned on, at which time the slope generating circuit takes effect, and the control current rises from 0 to the first current reference value under the action of the slope generating circuit; When the first current reference value is reached, the slope generating circuit exits according to the control logic of the comparison / selection circuit; The reference generation circuit receives the new first current reference value and the new second current reference value, and latches and takes effect at the rising edge of the pulse width modulation signal generated by the PWM generation circuit; During the current value switching process, the comparison / selection circuit determines the switching-in / out timing of the slope generation circuit according to the pulse width modulation signal characteristics generated by the PWM generation circuit.

[0068] The electronic load transitions from OFF to ON, which indicates the transition process of the electronic load system from a completely power-off or standby state to a normal working power-on state. The "load enable signal" is a control signal used to open or close the load current path.

[0069] In some embodiments, when the electronic load system receives an external power-on command or an internal wake-up signal, the electronic load starts from the OFF to ON stage. The PWM generation circuit starts to generate a pulse width modulation signal with a specific frequency and duty cycle. When the falling edge of the pulse width modulation signal appears, this moment is used by the system as a key synchronization point. At this time, the main control chip controls the load enable signal to be turned on, so that the load current path is ready. At the same time, the slope generation circuit begins to take effect, and it starts to adjust the control current according to the preset slope parameter (for example, the rising slope from 0A to the first current reference value 3A is 1A per second). The control current starts to rise from 0A under the action of the slope generation circuit, and the MOS control circuit adjusts the size of the actual current passing through the load according to this control current, so that the actual current also rises accordingly. When the control current rises to the first current reference value 3A, the comparison / selection circuit judges that the task of the slope generation circuit is completed at this time according to the preset logic rule (for example, according to the comparison result of the control current and the first current reference value), so a control signal is sent to make the slope generation circuit exit the working state, and the actual current is stabilized at the level corresponding to the first current reference value. In this process, the reference generation circuit receives a new first current reference value (such as 2A) and a new second current reference value (such as 0.5A). These new values ​​are calculated and sent by the main control chip according to the subsequent work requirements of the system (such as simulating different load changes). After receiving the new value, the reference generation circuit waits for the rising edge of the pulse width modulation signal generated by the PWM generation circuit to arrive. At the rising edge, the new current reference value is latched by the latch to make it effective and prepare for the subsequent current value switching. During the current value switching process, the comparison / selection circuit continuously monitors the pulse width modulation signal characteristics generated by the PWM generation circuit, such as the duty cycle change, frequency change or specific pulse sequence of the signal. When it is detected that certain specific signal changes meet the pre-set conditions (for example, the duty cycle changes from 30% to 40%), the comparison / selection circuit will decide that the slope generation circuit will start working again to achieve a smooth transition from the current value to the new current reference value, ensuring that the current switching process always changes according to the set slope, and there will be no current mutation or loss of control.

[0070] It can be seen that in the stage when the electronic load switches from OFF to ON, the various circuits strictly follow the precise timing to work together, which has a significant beneficial effect. First, the load enable signal is turned on at the falling edge of the pulse width modulation signal generated by the PWM generation circuit, so that the slope generation circuit can take effect accurately, and then the control current can rise from 0 to the first current reference value smoothly and orderly under the action of the slope generation circuit, avoiding the adverse effects of sudden current changes on the load and the entire system, and ensuring the smoothness and controllability of the current rise process. When the current reaches the first current reference value, the slope generation circuit exits in time according to the control logic of the comparison / selection circuit, which ensures that the current can be stably maintained after reaching the target value, which meets the expected working state of the system. At the same time, the reference generation circuit receives the new first current reference value and the new second current reference value, and latches them at the rising edge of the pulse width modulation signal generated by the PWM generation circuit. This rigorous timing arrangement makes the update of the current reference value orderly. Moreover, during the current value switching process, the comparison / selection circuit determines the entry / exit timing of the slope generating circuit according to the pulse width modulation signal characteristics, thereby avoiding problems such as the current not working according to the set slope and the current changing directly from the maximum current to the minimum current due to improper reference value conversion timing. The entire electronic load system can achieve stable, accurate and set slope current control during the OFF to ON and current value switching stages.

[0071] In some embodiments, it also includes: During the mid-change load value stage, when the actual current needs to be changed midway, the new first current reference value or the new second current reference value needs to be written into the reference generating circuit after the last change is latched, and latched to take effect at the next rising edge of the pulse width modulation signal generated by the PWM generating circuit.

[0072] The mid-course change of the load value stage refers to the process in which the electronic load system needs to adjust the current load current value during normal operation due to changes in test requirements or simulation of different load conditions.

[0073] In some embodiments, when the electronic load system is performing power supply testing or simulating load operation, if the load current needs to be changed to simulate different load characteristics or power supply output characteristics, the midway change load value stage begins. For example, when testing the output characteristics of a power supply under different load resistances, it is necessary to change from the current load current value to a new current value. At this time, the main control chip first calculates a new first current reference value (such as changing from the current 2A to 1.5A) and a new second current reference value (such as 0.8A) according to the new test requirements. Then, the main control chip writes the new first current reference value or the new second current reference value into the reference generation circuit, but at this time, the new value will not take effect immediately because the system needs to ensure a smooth transition of the current. The system continues to operate according to the current current control state until the next rising edge of the pulse width modulation signal generated by the PWM generation circuit arrives. At the rising edge moment, the latch in the reference generation circuit latches the new current reference value and makes it effective, and the entire system begins to adjust the current size according to the new current reference value. In this process, the slope generation circuit, MOS control circuit, and comparison / selection circuit will work together to achieve a smooth transition from the current value to the new target value based on the new current reference value and the current state of the system. The current feedback detection unit continuously monitors the actual current size and feeds back the information to the main control chip. The main control chip fine-tunes the operation of each circuit based on this feedback information to ensure the stability and accuracy of the current change process and avoid adverse effects of current mutations on the power supply and electronic load system itself.

[0074] It can be seen that in the stage of changing the load value midway, the new first current reference value or the second current reference value is written into the reference generating circuit after the last change latch, and latched to take effect at the rising edge of the pulse width modulation signal generated by the next PWM generating circuit. This operation process ensures a smooth transition of the current value during the change process and avoids sudden jumps in the current. Compared with traditional control methods, it can effectively reduce the additional stress impact on the device under test caused by sudden current changes, improve the electronic load's ability to accurately control current changes during dynamic loading, and make the test process closer to the actual load changes, thereby improving the accuracy and reliability of the test results.

[0075] In some embodiments, the main control chip writes the values ​​of the first current reference value and the second current reference value to the reference generation circuit.

[0076] It can be seen that the main control chip writes the values ​​of the first current reference value and the second current reference value to the reference generation circuit, thereby realizing active setting and control of the current reference value.

[0077] In some embodiments, the main control chip writes a new first current reference value and a new second current reference value into the reference generation circuit.

[0078] It can be seen that the main control chip writes the new first current reference value and the new second current reference value into the reference generation circuit, thereby realizing dynamic update of the current reference value during the current control process.

[0079] See also Figure 2 , Figure 2 is a waveform diagram of the dynamic slope control circuit of the electronic load in the embodiment of the present application; PWM waveform: corresponds to the pulse width modulation signal generated by the PWM generating circuit. In the electronic load dynamic slope control method, the signal generated by the PWM generating circuit plays a triggering role in multiple key steps. For example, when the electronic load switches from OFF to ON, its falling edge is used to turn on the load enable signal, and its rising edge is used to latch the new current reference value of the reference generating circuit.

[0080] I2C waveform: related to the communication between the main control chip and the reference generation circuit. The main control chip writes the first current reference value, the second current reference value, and the new first current reference value and the new second current reference value to the reference generation circuit through the I2C protocol.

[0081] LATCH waveform: related to the latching operation in the reference generation circuit. At the rising edge of PWM, the reference generation circuit needs to latch a new current reference value. The LATCH waveform is used to indicate the moment of this latching operation.

[0082] LOAD - EN waveform: corresponds to the load enable signal. When the electronic load switches from OFF to ON, when the falling edge of the pulse width modulation signal generated by the PWM generation circuit arrives, the load enable signal is turned on to enable the slope generation circuit to take effect, and the control current rises from 0 to the first current reference value.

[0083] L1 and L2 waveforms: related to the slope generating circuit, L1 and L2 respectively represent different control signals in the slope generating circuit or current control conditions at different stages. When the electronic load switches from OFF to ON, the slope generating circuit takes effect and controls the current to rise from 0 to the first current reference value. These waveforms reflect this process.

[0084] Phase 1: corresponds to the startup phase. In the startup phase, the reference generation circuit receives the first current reference value and the second current reference value (where the second current reference value is 0). When receiving the load signal, the actual current gradually increases from 0 to the first current reference value according to the slope set by the slope generation circuit. Some waveforms in the figure (such as L1 and L2) show the process of the current rising from 0 in this phase.

[0085] Phase 2: corresponds to the stage when the electronic load switches from OFF to ON. In this phase, when the pulse width modulation signal generated by the PWM generating circuit reaches the falling edge, the load enable signal is turned on, the slope generating circuit takes effect, and the control current rises from 0 to the first current reference value under the action of the slope generating circuit; when the first current reference value is reached, the slope generating circuit exits according to the control logic of the comparison / selection circuit; the reference generating circuit receives the new first current reference value and the new second current reference value, and latches and takes effect at the rising edge of the pulse width modulation signal generated by the PWM generating circuit. Multiple waveforms in the figure (such as PWM, LOAD-EN, L1, L2, etc.) have obvious changes in this phase, which is consistent with the operation of this process.

[0086] Phase 3: corresponds to the mid-way change load value phase. When the actual current needs to be changed midway, the new first current reference value or the new second current reference value needs to be written into the reference generation circuit after the last change latch, and latched to take effect at the rising edge of the pulse width modulation signal generated by the next PWM generation circuit. The waveforms in the figure show the changes of each signal in this process. For example, the I2C waveform represents the operation of the main control chip writing a new value to the reference generation circuit, while the PWM and LATCH waveforms reflect the process of latching the new value at the rising edge of PWM.

[0087] As used in the above embodiments, the term "when..." may be interpreted to mean "if..." or "after..." or "in response to determining..." or "in response to detecting...", depending on the context. Similarly, the phrases "upon determining..." or "if (the stated condition or event) is detected" may be interpreted to mean "if determining..." or "in response to determining..." or "upon detecting (the stated condition or event)" or "in response to detecting (the stated condition or event)", depending on the context.

[0088] In the above embodiments, it can be implemented in whole or in part by software, hardware, firmware or any combination thereof. When implemented using software, it can be implemented in whole or in part in the form of a computer program product. The computer program product includes one or more computer instructions. When the computer program instructions are loaded and executed on a computer, the process or function described in the embodiment of the present application is generated in whole or in part. The computer may be a general-purpose computer, a special-purpose computer, a computer network, or other programmable device. The computer instructions may be stored in a computer-readable storage medium, or transmitted from one computer-readable storage medium to another computer-readable storage medium. For example, the computer instructions may be transmitted from one website site, computer, server or data center to another website site, computer, server or data center by wired (e.g., coaxial cable, optical fiber, digital subscriber line) or wireless (e.g., infrared, wireless, microwave, etc.) means. The computer-readable storage medium may be any available medium that a computer can access or a data storage device such as a server or data center that includes one or more available media integrated. The available medium may be a magnetic medium (e.g., a floppy disk, a hard disk, a tape), an optical medium (e.g., a DVD), or a semiconductor medium (e.g., a solid-state hard disk), etc.

[0089] Those skilled in the art can understand that to implement all or part of the processes in the above-mentioned embodiments, the processes can be completed by computer programs to instruct related hardware, and the programs can be stored in computer-readable storage media. When the programs are executed, they can include the processes of the above-mentioned method embodiments. The aforementioned storage media include: ROM or random access memory RAM, magnetic disk or optical disk and other media that can store program codes.

Claims

1. An electronic load dynamic slope control circuit, characterized in that: include: A reference generating circuit, the reference generating circuit being connected to the comparison / selection circuit and configured to receive different current reference values, store and output the different current reference values; A slope generating circuit, the slope generating circuit being connected to the comparison / selection circuit and being used for gradually adjusting the control current at a set slope so that the control current gradually changes from a current value to the selected current reference value; A PWM generating circuit, the PWM generating circuit is connected to the comparison / selection circuit and is used to generate a pulse width modulation signal; The comparison / selection circuit is connected to the PWM generation circuit, the slope generation circuit and the MOS control circuit respectively, and is used to select different working modes according to the pulse width modulation signal, wherein different working modes correspond to different current reference values; The MOS control circuit is connected to the comparison / selection circuit and is used to control the size of the actual current according to the control current.

2. The circuit according to claim 1, characterized in that Also includes: A main control chip, wherein the main control chip is connected to the PWM generating circuit, the slope generating circuit, the comparison / selection circuit, the reference generating circuit and the MOS control circuit, and is used to control the operation of the PWM generating circuit, the slope generating circuit, the comparison / selection circuit, the reference generating circuit and the MOS control circuit.

3. The circuit according to claim 1, characterized in that The slope generating circuit comprises an adjustable slope setting unit, and the adjustable slope setting unit is used to set corresponding slope values ​​by inputting different codes through external control signals.

4. The circuit according to claim 1, characterized in that The PWM generating circuit includes a programmable unit, and the programmable unit can change the waveform parameters of the pulse width modulation signal according to instructions.

5. The circuit according to claim 2, characterized in that The MOS control circuit is provided with a current feedback detection unit, and the current feedback detection unit is used to monitor the actual current size in real time and transmit feedback information to the main control chip.

6. A method for controlling a dynamic slope of an electronic load, characterized in that: The electronic load dynamic slope control circuit according to any one of claims 1 to 5; The features include: In the startup phase, the reference generating circuit receives a first current reference value and a second current reference value, wherein the second current reference value is 0 and the first current reference value is greater than the second current reference value; When the load signal is received, the actual current is gradually increased from 0 to the first current reference value according to the slope set by the slope generating circuit.

7. The method according to claim 6, characterized in that Also includes: When the electronic load switches from OFF to ON, at the falling edge of the pulse width modulation signal generated by the PWM generating circuit, the load enable signal is turned on, at which time the slope generating circuit takes effect, and the control current rises from 0 to the first current reference value under the action of the slope generating circuit; When the first current reference value is reached, the slope generating circuit exits according to the control logic of the comparison / selection circuit; The reference generation circuit receives a new first current reference value and a new second current reference value, and latches and makes them effective at the rising edge of the pulse width modulation signal generated by the PWM generation circuit; During the current value switching process, the comparison / selection circuit determines the switching-in / out timing of the slope generation circuit according to the pulse width modulation signal characteristics generated by the PWM generation circuit.

8. The method according to claim 7, characterized in that Also includes: During the mid-change load value stage, when the actual current needs to be changed mid-way, the new first current reference value or the new second current reference value needs to be written into the reference generating circuit after the last change latch, and latched to take effect at the next rising edge of the pulse width modulation signal generated by the PWM generating circuit.

9. The method according to claim 8, characterized in that Also includes: The main control chip writes the first current reference value and the second current reference value into the reference generation circuit.

10. The method according to claim 9, characterized in that Also includes: The main control chip writes a new first current reference value and a new second current reference value into the reference generation circuit.

Images