Range switching circuit, method and electronic load

Abstract

This application discloses a range switching circuit, method, and electronic load. The circuit includes a control module, a first current loop and at least one second current loop, a switching module, and a sampling module. The control module is connected to the control terminal of the second current loop through the switching module. The sampling module includes a first sampling circuit and at least one second sampling circuit. When the electronic load performs range switching, the control module controls the switching module to input a current control quantity to the second current loop within the corresponding range and disconnects the input current control quantity to the second current loop outside the range. Furthermore, the control module dynamically adjusts the magnitude of the current control quantity according to the switched range to ensure current stability during the switching process. This application can reduce the probability of current fluctuations during range switching and improve stability.

Description

Technical Field

[0001] This application relates to the field of power supply testing, and in particular to a range switching circuit, method, and electronic load. Background Technology

[0002] Electronic loads are specialized instruments used to test power supply performance. They typically have multiple ranges to meet different power supply testing needs, such as 0-10A, 0-50A, and 0-100A. When performing different power supply tests, electronic loads need to switch between different ranges depending on the test scenario to improve sampling and control accuracy.

[0003] In related technologies, current fluctuations and poor stability are prone to occur during the range switching process of electronic loads. Summary of the Invention

[0004] This application proposes a range switching circuit, method, and electronic load that can reduce the probability of current fluctuations during range switching and improve stability.

[0005] A range switching circuit according to an embodiment of the first aspect of this application is used for an electronic load having at least two ranges, the electronic load including a power supply, the range switching circuit comprising:

[0006] A control module, wherein the control module is provided with a current control terminal for outputting current control quantity;

[0007] A first current loop and at least one second current loop, one end of the first current loop and the second current loop are both connected to the power supply, and the other end of the first current loop and the second current loop are both grounded. The control module is connected to the control terminal of the first current loop for inputting current control quantities.

[0008] A switching module, wherein the control module is connected to the control terminal of the second current loop through the switching module, and the control module is connected to the control terminal of the switching module to control the input of the current control quantity of the corresponding number of second current loops according to the range of the electronic load;

[0009] A sampling module includes a first sampling circuit and at least one second sampling circuit. The number of second sampling circuits is one less than the number of ranges of the electronic load. The first sampling circuit corresponds to the minimum range, and each second sampling circuit corresponds to one of the remaining ranges other than the minimum range. The input terminal of the first sampling circuit is connected to the first current loop, and the output terminal of the first sampling circuit is connected to a current sampling terminal of the control module. The input terminal of the second sampling circuit is connected to the second current loop corresponding to the range, and the output terminal of the second sampling circuit is connected to the current sampling terminal of the control module.

[0010] When the electronic load switches ranges, the control module controls the switch module to input a current control quantity to the second current loop within the corresponding range and disconnects the input current control quantity of the second current loop outside the range. The control module also dynamically adjusts the magnitude of the current control quantity according to the switched range to ensure current stability during the switching process.

[0011] According to some embodiments of this application, the control module includes:

[0012] FPGA;

[0013] The FPGA is connected to the DAC for outputting current control quantities.

[0014] According to some embodiments of this application, the first current loop includes:

[0015] A first error amplifier, wherein the control module is connected to the non-inverting input of the first error amplifier for input current control quantity;

[0016] The first switching transistor is connected to the control terminal of the first error amplifier, and one end of the first switching transistor is connected to the power supply.

[0017] A first sampling resistor, one end of which is connected to the other end of the first switching transistor, and the other end of which is grounded;

[0018] A first differential amplifier is provided, wherein the non-inverting and inverting inputs of the first differential amplifier are respectively connected to the two ends of the first sampling resistor, and the output of the first differential amplifier is connected to the inverting input of the first error amplifier.

[0019] According to some embodiments of this application, the first sampling circuit includes:

[0020] The first ADC has its input terminal connected to the output terminal of the first differential amplifier, and its output terminal connected to a current sampling terminal of the control module.

[0021] According to some embodiments of this application, the second current loop includes:

[0022] The second error amplifier is connected to the non-inverting input of the second error amplifier via the switching module.

[0023] The second switching transistor is connected to the control terminal of the second error amplifier, and one end of the second switching transistor is connected to the power supply.

[0024] The second sampling resistor has one end connected to the other end of the second switching transistor, and the other end of the second sampling resistor is grounded.

[0025] The second differential amplifier has its non-inverting and inverting inputs connected to the two ends of the second sampling resistor, respectively, and its output is connected to the inverting input of the second error amplifier.

[0026] According to some embodiments of this application, the second sampling circuit is connected to multiple second current loops, and the second sampling circuit includes:

[0027] An adder, wherein the input terminals of the adder are respectively connected to the output terminals of multiple second differential amplifiers;

[0028] The second ADC has its input connected to the output of the adder, and its output connected to a current sampling terminal of the control module.

[0029] A range switching method according to a second aspect embodiment of this application is used for an electronic load including a range switching circuit as described in the first aspect embodiment. The method includes:

[0030] Obtain a range switching command, which is used to instruct the electronic load to switch from the first range to the second range;

[0031] According to the range switching command, the control switch module inputs a current control quantity to the second current loop within the corresponding range and disconnects the input current control quantity of the second current loop outside the range. Furthermore, it dynamically adjusts the magnitude of the current control quantity according to the switched range to ensure current stability during the switching process.

[0032] According to some embodiments of this application, the step of dynamically adjusting the magnitude of the current control quantity based on the switched range includes:

[0033] A range comparison result is generated based on the range switching command, and the range comparison result is used to indicate the size of the first range and the second range.

[0034] If the range comparison result indicates that the second range is greater than the first range, a first adjustment command is generated according to the descent curve model. The first adjustment command is used to indicate that the current control quantity is gradually reduced until the current is balanced.

[0035] If the range comparison result indicates that the second range is less than the first range, a second adjustment command is generated based on the rising curve model. The second adjustment command is used to indicate that the current control amount is gradually increased until the current is balanced.

[0036] According to some embodiments of this application, the step of dynamically adjusting the magnitude of the current control quantity based on the switched range includes:

[0037] Acquire a first current sample value and a second current sample value, wherein the first current sample value is the current sample value corresponding to the first range and the second current sample value is the current sample value corresponding to the second range;

[0038] The magnitude of the current control quantity is dynamically adjusted based on the first current sampling value and the second current sampling value.

[0039] An electronic load according to a third aspect embodiment of this application includes a range switching circuit as described in the first aspect embodiment.

[0040] The range switching circuit, method, and electronic load according to the embodiments of this application have at least the following beneficial effects:

[0041] In this embodiment, the control module controls the current control input of the second current loop through the switching module, thereby achieving current range adjustment for different ranges of the electronic load. Specifically, the control module acquires the current of the first current loop through the first sampling circuit to achieve current sampling at the minimum range. Furthermore, the control module acquires current samples of the second current loop at different ranges through the second sampling circuit. The control module obtains the current sample for the current range by adding the results from the first and second sampling circuits. When the electronic load switches ranges, the control module controls the switching module to input a current control quantity to the second current loop within the corresponding range and disconnects the input current control quantity to the second current loop outside the range. The control module also dynamically adjusts the magnitude of the current control quantity according to the switched range to ensure current stability during the switching process. This application can reduce the probability of current fluctuations during range switching, improve stability, and achieve smooth range switching of the electronic load.

[0042] Additional aspects and advantages of this application will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of this application. Attached Figure Description

[0043] The present application will be further described below with reference to the accompanying drawings and embodiments, wherein:

[0044] Figure 1 This is a schematic block diagram of the range switching circuit in the embodiments of this application;

[0045] Figure 2 This is a circuit diagram of the range switching circuit for two ranges in an embodiment of this application;

[0046] Figure 3 This is a schematic diagram of the fitting curve of the change in current control quantity during the switching process of switch S1 in this embodiment of the application;

[0047] Figure 4This is a circuit diagram of the range switching circuit for the three ranges in an embodiment of this application;

[0048] Figure 5 This is a flowchart of the range switching method in the embodiments of this application. Detailed Implementation

[0049] The embodiments of this application are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain this application, and should not be construed as limiting this application.

[0050] In the description of this application, it should be understood that the orientation descriptions, such as up, down, etc., are based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this application 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 application.

[0051] In the description of this application, "multiple" refers to two or more. The use of "first" and "second" is for the purpose of distinguishing technical features only and should not be construed as indicating or implying relative importance, or implicitly indicating the number of technical features indicated, or the order in which the technical features are indicated.

[0052] In the description of this application, unless otherwise expressly defined, terms such as "setup," "installation," and "connection" should be interpreted broadly, and those skilled in the art can reasonably determine the specific meaning of the above terms in this application in conjunction with the specific content of the technical solution.

[0053] Reference Figure 1 As shown, a range switching circuit is used for an electronic load having at least two ranges. The electronic load includes a power supply, and the range switching circuit includes:

[0054] The control module is equipped with a current control terminal for controlling the output current.

[0055] A first current loop and at least one second current loop, one end of the first current loop and the second current loop are both connected to a power supply, and the other end of the first current loop and the second current loop are both grounded. The control module is connected to the control terminal of the first current loop for inputting current control quantities.

[0056] The switching module and the control module are connected to the control terminal of the second current loop through the switching module. The control module is connected to the control terminal of the switching module to control the input of the current control quantity of the corresponding number of second current loops according to the range of the electronic load.

[0057] The sampling module includes a first sampling circuit and at least one second sampling circuit. The number of second sampling circuits is one less than the number of ranges of the electronic load. The first sampling circuit corresponds to the minimum range, and each second sampling circuit corresponds to one of the remaining ranges other than the minimum range. The input terminal of the first sampling circuit is connected to a first current loop, and the output terminal of the first sampling circuit is connected to a current sampling terminal of the control module. The input terminal of the second sampling circuit is connected to a second current loop corresponding to the range, and the output terminal of the second sampling circuit is connected to a current sampling terminal of the control module.

[0058] In the case of range switching of electronic load, the control module controls the switch module to input current control quantity to the second current loop within the corresponding range and disconnects the input current control quantity of the second current loop outside the range, and dynamically adjusts the magnitude of current control quantity according to the switched range to ensure current stability during the switching process.

[0059] In this embodiment, the control module controls the current control input of the second current loop through the switching module, thereby achieving current range adjustment for different ranges of the electronic load. Specifically, the control module acquires the current of the first current loop through the first sampling circuit to achieve current sampling at the minimum range. Furthermore, the control module acquires the current samples of the second current loop at different ranges through the second sampling circuit. The control module obtains the current sample for the current range by adding the results from the first and second sampling circuits. When the electronic load switches ranges, the control module controls the input of the current control quantity to the second current loop within the corresponding range through the switching module, and dynamically adjusts the magnitude of the current control quantity according to the switched range to ensure current stability during the switching process. This application can reduce the probability of current fluctuations during range switching, improve stability, and achieve smooth switching of the electronic load range.

[0060] Specifically, the control module can use an FPGA, or an MCU, DSP, or other logic operation chip as the main module. When using an FPGA, a DAC is needed to perform digital-to-analog conversion to achieve analog control output. Alternatively, a chip with a built-in DAC port can be used.

[0061] In this embodiment, both the first and second current loops refer to circuits that implement current control. The current loop in the electronic load is the core mechanism for achieving precise current control of the electronic load, and its core function is to maintain current stability through feedback regulation. Its working principle is based on closed-loop control: the current loop uses a MOSFET as the switching device to control the current. The load current is detected in real time through a current sampling resistor, and the actual current value is compared with the set value. An error signal is generated using an error amplifier, and the current is controlled by adjusting the analog value of the MOSFET's gate voltage, dynamically changing the load's power consumption. One or multiple current loops can be used; it should be understood that using multiple current loops in parallel can increase the power of the electronic load.

[0062] In this application, the circuit structures of the first current loop and the second current loop are the same. The difference is that the control terminal of the first current loop is directly connected to the current control output terminal of the control module. Therefore, the first current loop can always receive the current control output from the control module, thus maintaining a continuous conducting state. The second current loop refers to the current loop connected to the control module through the switching module. It should be understood that electronic loads increase the maximum current limit by increasing the number of parallel current loops, thereby increasing the current range. Similarly, decreasing the range is achieved by increasing the current control quantity of the second current loop through the switching module, thereby realizing the range switching of the electronic load.

[0063] A switch module may include one switch or multiple switches, with the number of switches being N-1, where N is the number of current ranges of the electronic load.

[0064] It should be understood that the larger the range, the more second current loops control the input current through the switch, and vice versa. The minimum range refers to the state where all switch modules are off and only the first current loop is active.

[0065] The aforementioned first sampling circuit refers to the sampling circuit that acquires the current of the first current loop and feeds it back to the control module. The number of the aforementioned second sampling circuits is one less than the number of ranges of the electronic load, meaning that the number of second sampling circuits is also N-1, where N is the number of current ranges of the electronic load. Each second sampling circuit corresponds to one of the ranges other than the minimum range. Since the current sampling of the minimum range is obtained through the first sampling circuit, the second sampling circuit acquires the current samples of all the second sampling circuits corresponding to each range in the remaining ranges. For example, if the electronic load only has two ranges, small and large, then there is one second sampling circuit. The input terminal of the second sampling circuit is connected to all the second current loops, and after accumulating them, it is input to the control module. The control module can obtain the actual current sampling value of the electronic load by adding the current sampling values ​​of the first sampling circuit and the second sampling circuit. If the electronic load includes three ranges: small, medium, and large, then there are two second sampling circuits. The input of one second sampling circuit is connected to all the second current loops corresponding to the medium range, and the input of the other second sampling circuit is connected to all the second current loops except the medium range. The control module can obtain the actual current sampling value of the electronic load by adding the current sampling values ​​of the two second sampling circuits and one first sampling circuit.

[0066] When the electronic load switches ranges, the control module controls the switch module to input a current control quantity to the second current loop within the corresponding range and disconnects the input current control quantity to the second current loop outside the range. This means that when the electronic load switches from a small range to a large range, all or some switches within the control module close, inputting a current control quantity to the second current loop within the corresponding range. This allows this part of the second current loop to receive the current control quantity and implement current control based on it. When the electronic load switches from a large range to a small range, all or some switches within the control module open, stopping the input of current control quantity to the second current loop within the corresponding range, keeping this part of the second current loop in an open state, meaning this part of the second current loop does not operate.

[0067] Dynamically adjusting the current control value based on the switching range to ensure current stability during the switching process refers to gradually increasing or decreasing the current control value according to the range before and after the switch to maintain current stability. For example, when the electronic load switches from a small range to a large range, the current gradually increases during the closed-loop setup time of the large range. Here, the control module gradually decreases the value of the current control value, allowing the closed-loop current of the large range to rise slowly, while the closed-loop current of the small range gradually decreases. At this point, the large and small range currents reach an equilibrium, and the total current no longer increases, thus maintaining the smoothness of the range switching. Similarly, when the electronic load switches from a large range to a small range, the closed-loop current of the large range takes time to drop. During this time, the value of the current control value is gradually increased until the decrease in the large-range closed-loop current equals the increase in the small-range closed-loop current. At this point, the large and small range currents reach an equilibrium, and the total current no longer increases, thus maintaining the smoothness of the range switching.

[0068] In some implementations, the control module may include:

[0069] FPGA;

[0070] DAC, FPGA connects to the DAC to use for output current control quantities.

[0071] In this embodiment, the control module uses an FPGA as the logic processing chip to improve control synchronization, reduce control delay, and shorten switching time.

[0072] In some implementations, the first current loop may include:

[0073] The first error amplifier is connected to the non-inverting input of the control module for input current control.

[0074] The output terminal of the first switching transistor is connected to the control terminal of the first switching transistor, and one end of the first switching transistor is connected to the power supply.

[0075] The first sampling resistor has one end connected to the other end of the first switching transistor, and the other end of the first sampling resistor is grounded.

[0076] The first differential amplifier has its non-inverting and inverting inputs connected to the two ends of the first sampling resistor, and its output is connected to the inverting input of the first error amplifier.

[0077] In this embodiment, a closed-loop current loop is formed by the first error amplifier, the first switching transistor, the first sampling resistor, and the first differential amplifier, which can realize the negative feedback adjustment of each current loop itself, thereby further improving reliability.

[0078] In some implementations, the first sampling circuit includes:

[0079] The first ADC has its input terminal connected to the output terminal of the first differential amplifier, and its output terminal connected to a current sampling terminal of the control module.

[0080] In this embodiment, the first ADC is used to convert the output signal of the first differential amplifier in the first current loop into an analog-to-digital signal and then input it to the control module, which can achieve accurate current sampling feedback.

[0081] In some implementations, the second current loop may include:

[0082] The control module is connected to the non-inverting input of the second error amplifier via a switching module;

[0083] The output of the second error amplifier is connected to the control terminal of the second switching transistor, and one end of the second switching transistor is connected to the power supply.

[0084] The second sampling resistor has one end connected to the other end of the second switching transistor, and the other end of the second sampling resistor is grounded.

[0085] The second differential amplifier has its non-inverting and inverting inputs connected to the two ends of the second sampling resistor, respectively, and its output is connected to the inverting input of the second error amplifier.

[0086] In this embodiment, a closed-loop current loop is formed by the second error amplifier, the second switching transistor, the second sampling resistor, and the second differential amplifier. This allows for negative feedback regulation of each current loop, further improving reliability.

[0087] In some implementations, the second sampling circuit is connected to multiple second current loops, and the second sampling circuit includes:

[0088] The adder has its input terminals connected to the output terminals of multiple second differential amplifiers.

[0089] The second ADC has its input connected to the output of the adder, and its output connected to a current sampling terminal of the control module.

[0090] In this embodiment, an adder is used to acquire current signals from multiple second current loops. The adder accumulates the current signals from multiple second current loops and then performs analog-to-digital conversion through a second ADC before inputting them to the control module. This allows the control module to obtain the true current value of the current range based on the current values ​​input from the first sampling circuit and the second sampling circuit, thereby achieving constant current control and improving reliability.

[0091] The following two specific examples illustrate the switching process of this application in detail:

[0092] For example, refer to Figure 2 As shown, in this embodiment, the electronic load includes two ranges, small and large. The power supply terminal VBUS is connected to the drain of MOSFETs Q1-Qn. The source of MOSFETs Q1-Qn is grounded through a sampling resistor. Differential amplifiers AMP1-AMPn are connected to the two ends of the corresponding sampling resistors. The switching module includes switch S1. The circuit loop containing MOSFET Q1 is the first current loop, and the circuit loop containing the remaining MOSFETs Q2-Qn is the second current loop. The control module includes an FPGA and a DAC. The FPGA outputs current control quantity through the DAC. The first ADC is ADC1, and the second ADC is ADC2. ADC2 is connected to the output of differential amplifiers AMP2-AMPn through adder U1. The DAC is connected to the non-inverting input of the first error amplifier EA1. The DAC is connected to the non-inverting input of all second error amplifiers EA2-EAn through switch S1. Assuming the total current limit of the electronic load is 100A and n=10, the current limit of each current loop is 10A. When switch S1 is open, only MOSFET Q1 is working in the entire system, and the other MOSFETs Q2-Qn are all open, so the current limit of the electronic load is only 10A. When S1 is closed, all MOSFETs are working, so the current is 100A. In this way, the electronic load can have two ranges: 0-10A and 0-100A.

[0093] Vdac is the current control value output by the FPGA, and Id is the total current sample value of the electronic load. 小 Id is the closed-loop current sampling value corresponding to the small range of MOSFET Q1. 大 The current sampling values ​​for the large range closed loop corresponding to MOSFETs Q2-Qn are as follows: When the electronic load switches from the small range to the large range, switch S1 is closed, and MOSFETs Q2-Qn start working. Because the loop has a rise time, the current gradually increases during the large range closed loop setup time. The FPGA gradually reduces the current control value, that is, the output value of Vdac makes the current of the large range closed loop rise slowly, while the current of the small range closed loop gradually decreases. At this time, the large and small range currents reach a balance, and the total current no longer rises, maintaining the smoothness of the range switching.

[0094] It should be noted that the FPGA's method of gradually reducing the current control input can be implemented in two ways: one is the empirical method, which involves fitting a DAC descent curve using a large amount of experimental data, and the other is the reference method. Figure 3 As shown, Vdac is the current control quantity output by the FPGA, and Id is the total current sampling value of the electronic load. 小 Id is the closed-loop current sampling value corresponding to the small range of MOSFET Q1. 大The current sampling values ​​for the large range of MOSFETs Q2-Qn are the closed-loop current samples. When switch S1 is closed, the FPGA gradually decreases Vdac and Id. 大 The current rises slowly, Id 小 The current gradually decreases while Id remains constant; the opposite occurs when switch S1 is opened. Another approach is to use the first and second ADCs to acquire currents of varying ranges, and then leverage the FPGA's synchronization capabilities to dynamically adjust the DAC value in real time.

[0095] Similarly, when the electronic load switches from a large range to a small range, switch S1 is opened. The closed-loop current of the large range needs time to drop. At this time, the value of Vdac is gradually increased so that the drop in the large range closed-loop current is equal to the rise in the small range closed-loop current. At this time, the large and small range currents reach a balance, and the total current no longer rises, thus maintaining the smoothness of the range switching.

[0096] refer to Figure 4 As shown, in this embodiment, the electronic load includes three ranges: small, medium, and large. The switching module includes switch S1 and switch S2. The second sampling circuit includes ADC2 and ADC3 and corresponding adders. The DAC is connected to the non-inverting input of the first error amplifier EA1. The DAC is connected to the non-inverting inputs of the second error amplifiers EA2-EA5 and one end of switch S2 through switch S1. The other end of switch S2 is connected to the non-inverting inputs of the second error amplifiers EA6-EA10.

[0097] Assume the total current of the electronic load is 100A, and the upper limit of the total current of the electronic load is 100A. Since n=10, the upper limit of the current in each current loop is 10A. When both switches S1 and S2 are open, only MOSFET Q1 is working, while the other MOSFETs Q2-Q10 are off. The electronic load is in a small range state, with a range of only 0-10A. When switch S1 is closed and switch S2 is open, MOSFETs Q1-Q5 are working, while MOSFETs Q6-Q10 are off. The electronic load is in a medium range state, with a range of 0-50A. When both switches S1 and S2 are closed, all power transistors are working, and the electronic load is in a large range state, with a range of 0-100A. Thus, there are three ranges: 0-10A, 0-50A, and 0-100A, corresponding to 1, 4, and 5 MOSFETs respectively. Meanwhile, we use three ADCs for readback: one MOSFET and ADC1 for the small range of 1 / 10; 1+4 MOSFETs and ADC1+ADC2 for the medium range; and 1+4+5 MOSFETs and ADC1+ADC2+ADC3 for the large range. The addition of the ADCs is done by the FPGA.

[0098] The specific switching process involves the control of current control quantities and Figure 2 The steps are the same and will not be described in detail here.

[0099] It should be noted that the two and three ranges mentioned above are just two examples of this application. If more ranges are needed, it is only necessary to add the corresponding second current loop, switch and second sampling circuit.

[0100] refer to Figure 5 As shown, this application also relates to a range switching method for an electronic load, comprising:

[0101] S101. Obtain the range switching command. The range switching command is used to instruct the electronic load to switch from the first range to the second range.

[0102] S102. According to the range switching command, the control switch module inputs a current control quantity to the second current loop within the corresponding range and disconnects the input current control quantity of the second current loop outside the range. The magnitude of the current control quantity is dynamically adjusted according to the switched range to ensure current stability during the switching process.

[0103] In this embodiment, a range switching command is first obtained. Then, based on the range switching command, the switching module is controlled to input a current control quantity to the second current loop within the corresponding range and disconnect the input current control quantity of the second current loop outside the range. Furthermore, the magnitude of the current control quantity is dynamically adjusted according to the switched range to ensure current stability during the switching process. This application can reduce the probability of current fluctuations during range switching, improve stability, and achieve smooth switching of electronic load ranges.

[0104] The aforementioned acquisition of the range switching command refers to instructing the electronic load to switch ranges according to the command. Upon receiving the command, the control switch module inputs a current control quantity to the second current loop within the corresponding range and disconnects the input current control quantity to the second current loop outside the range. Specifically, when the electronic load switches from a small range to a large range, all or some switches in the control switch module close, inputting a current control quantity to the second current loop within the corresponding range. This allows this part of the second current loop to receive the current control quantity and implement current control based on it. When the electronic load switches from a large range to a small range, all or some switches in the control switch module open, stopping the input of the current control quantity to the second current loop within the corresponding range, keeping this part of the second current loop in an open state, i.e., this part of the second current loop does not operate.

[0105] Dynamically adjusting the current control value based on the switching range to ensure current stability during the switching process refers to gradually increasing or decreasing the current control value according to the range before and after the switch to maintain current stability. For example, when the electronic load switches from a small range to a large range, the current gradually increases during the closed-loop setup time of the large range. Here, the control module gradually decreases the value of the current control value, allowing the closed-loop current of the large range to rise slowly, while the closed-loop current of the small range gradually decreases. At this point, the large and small range currents reach an equilibrium, and the total current no longer increases, thus maintaining the smoothness of the range switching. Similarly, when the electronic load switches from a large range to a small range, the closed-loop current of the large range takes time to drop. During this time, the value of the current control value is gradually increased until the decrease in the large-range closed-loop current equals the increase in the small-range closed-loop current. At this point, the large and small range currents reach an equilibrium, and the total current no longer increases, thus maintaining the smoothness of the range switching.

[0106] In some implementations, dynamically adjusting the magnitude of the current control quantity according to the switched range may include:

[0107] The range comparison result is generated based on the range switching command. The range comparison result is used to indicate the size of the first range and the second range.

[0108] If the range comparison result indicates that the second range is greater than the first range, a first adjustment command is generated according to the falling curve model. The first adjustment command is used to indicate that the current control quantity is gradually reduced until the current is balanced.

[0109] If the range comparison result indicates that the second range is less than the first range, a second adjustment command is generated based on the rising curve model. The second adjustment command is used to indicate that the current control amount is gradually increased until the current is balanced.

[0110] In this embodiment, when the range comparison result indicates that the second range is greater than the first range, a first adjustment command is generated based on a falling curve model; when the range comparison result indicates that the second range is less than the first range, a second adjustment command is generated based on a rising curve model. This can further improve the accuracy of dynamic current adjustment and ensure a smooth switching process.

[0111] The aforementioned falling curve model and rising curve model refer to fitting a DAC falling curve and a DAC rising curve through empirical methods or a large amount of experimental data, and then using these two curves to control the numerical adjustment of the dynamic current control quantity during the switching process, so that the current of the large and small ranges can reach a balance as soon as possible.

[0112] In some implementations, dynamically adjusting the magnitude of the current control quantity according to the switched range may include:

[0113] Acquire a first current sampling value and a second current sampling value. The first current sampling value is the current sampling value corresponding to the first range, and the second current sampling value is the current sampling value corresponding to the second range.

[0114] The magnitude of the current control quantity is dynamically adjusted based on the first current sampling value and the second current sampling value.

[0115] In this embodiment, a first current sampling value and a second current sampling value are first acquired, and then the magnitude of the current control quantity is dynamically adjusted based on the first current sampling value and the second current sampling value. This can further improve the accuracy of dynamic current adjustment and ensure a smooth switching process.

[0116] The aforementioned acquisition of the first current sample value and the second current sample value refers to obtaining them through the first sampling circuit and the second sampling circuit, i.e. Figure 2 The system uses a first ADC and a second ADC to collect current measurements of different ranges, and dynamically adjusts the DAC value in real time. This allows the large and small current ranges to reach a balance as quickly as possible.

[0117] This application also relates to an electronic load, including the range switching circuit of the above embodiments.

[0118] The embodiments of this application have been described in detail above with reference to the accompanying drawings. However, this application is not limited to the above embodiments. Within the scope of knowledge possessed by those skilled in the art, various changes can be made without departing from the spirit of this application.

Claims

1. A range switching circuit, characterized in that, For an electronic load having at least two ranges, the electronic load includes a power supply, and the range switching circuit includes: A control module, wherein the control module is provided with a current control terminal for outputting current control quantity; A first current loop and at least one second current loop, one end of the first current loop and the second current loop are both connected to the power supply, and the other end of the first current loop and the second current loop are both grounded. The control module is connected to the control terminal of the first current loop for inputting current control quantities. A switching module, wherein the control module is connected to the control terminal of the second current loop through the switching module, and the control module is connected to the control terminal of the switching module to control the input of the current control quantity of the corresponding number of second current loops according to the range of the electronic load; A sampling module includes a first sampling circuit and at least one second sampling circuit. The number of second sampling circuits is one less than the number of ranges of the electronic load. The first sampling circuit corresponds to the minimum range, and each second sampling circuit corresponds to one of the remaining ranges other than the minimum range. The input terminal of the first sampling circuit is connected to the first current loop, and the output terminal of the first sampling circuit is connected to a current sampling terminal of the control module. The input terminal of the second sampling circuit is connected to the second current loop corresponding to the range, and the output terminal of the second sampling circuit is connected to the current sampling terminal of the control module. When the electronic load switches ranges, the control module controls the switch module to input a current control quantity to the second current loop within the corresponding range and disconnects the input current control quantity of the second current loop outside the range. The control module also dynamically adjusts the magnitude of the current control quantity according to the switched range to ensure current stability during the switching process.

2. The range switching circuit according to claim 1, characterized in that, The control module includes: FPGA; The FPGA is connected to the DAC for outputting current control quantities.

3. The range switching circuit according to claim 1, characterized in that, The first current loop includes: A first error amplifier, wherein the control module is connected to the non-inverting input of the first error amplifier for input current control quantity; The first switching transistor is connected to the control terminal of the first error amplifier, and one end of the first switching transistor is connected to the power supply. A first sampling resistor, one end of which is connected to the other end of the first switching transistor, and the other end of which is grounded; A first differential amplifier is provided, wherein the non-inverting and inverting inputs of the first differential amplifier are respectively connected to the two ends of the first sampling resistor, and the output of the first differential amplifier is connected to the inverting input of the first error amplifier.

4. The range switching circuit according to claim 3, characterized in that, The first sampling circuit includes: The first ADC has its input terminal connected to the output terminal of the first differential amplifier, and its output terminal connected to a current sampling terminal of the control module.

5. The range switching circuit according to claim 1, characterized in that, The second current loop includes: The second error amplifier is connected to the non-inverting input of the second error amplifier via the switching module. The second switching transistor is connected to the control terminal of the second error amplifier, and one end of the second switching transistor is connected to the power supply. The second sampling resistor has one end connected to the other end of the second switching transistor, and the other end of the second sampling resistor is grounded. The second differential amplifier has its non-inverting and inverting inputs connected to the two ends of the second sampling resistor, respectively, and its output is connected to the inverting input of the second error amplifier.

6. The range switching circuit according to claim 5, characterized in that, The second sampling circuit is connected to multiple second current loops, and the second sampling circuit includes: An adder, wherein the input terminals of the adder are respectively connected to the output terminals of multiple second differential amplifiers; The second ADC has its input connected to the output of the adder, and its output connected to a current sampling terminal of the control module.

7. A range switching method, characterized in that, The method comprises: an electronic load including a range switching circuit as described in any one of claims 1 to 6; Obtain a range switching command, which is used to instruct the electronic load to switch from the first range to the second range; According to the range switching command, the control switch module inputs the current control quantity to the second current loop within the corresponding range and disconnects the input current control quantity of the second current loop outside the range. The magnitude of the current control quantity is dynamically adjusted according to the switched range to ensure current stability during the switching process. The method of dynamically adjusting the magnitude of the current control quantity according to the switched range includes: A range comparison result is generated based on the range switching command, and the range comparison result is used to indicate the size of the first range and the second range. If the range comparison result indicates that the second range is greater than the first range, a first adjustment command is generated according to the descent curve model. The first adjustment command is used to indicate that the current control quantity is gradually reduced until the current is balanced. If the range comparison result indicates that the second range is less than the first range, a second adjustment command is generated according to the rising curve model. The second adjustment command is used to indicate that the current control amount is gradually increased until the current is balanced. Alternatively, obtain a first current sample value and a second current sample value, wherein the first current sample value is the current sample value corresponding to the first range, and the second current sample value is the current sample value corresponding to the second range; The magnitude of the current control quantity is dynamically adjusted based on the first current sampling value and the second current sampling value.

8. An electronic load, characterized in that, Includes the range switching circuit as described in any one of claims 1 to 6.

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