Current saturation rapid recovery device of digital loop voltage and current source and control method of current saturation rapid recovery device

Abstract

The invention provides a current saturation rapid recovery device of a digital loop voltage and current source and a control method of the current saturation rapid recovery device, and belongs to the technical field of precision electronic measurement. According to the device, a wide-range auxiliary measuring circuit is arranged beside a main current measuring circuit in parallel; when the digital loop controller detects that the main current measuring circuit enters a saturation state due to load transient or has a saturation risk, the feedback source is switched to the auxiliary measuring circuit, closed-loop control is maintained by using an auxiliary feedback value, the output current is rapidly adjusted to a linear region of the main current measuring circuit, and then the main current measuring circuit is smoothly switched back. According to the method, the problems of feedback failure caused by measurement saturation or slow recovery and oscillation caused by model estimation deviation in the prior art are solved, rapid and accurate closed-loop recovery of transient overcurrent is realized, and the test safety and the system robustness are improved.

Description

Technical Field

[0001] This invention belongs to the field of precision electronic measuring instruments and automatic control technology, specifically relating to a system architecture and control method for a digital loop voltage and current source (SMU). This technology is mainly applied in high-precision testing instruments such as source measurement units (SMUs), VI sources in automated test equipment (ATE), device power supplies (DPS), and parameter measurement units (PMUs). Background Technology

[0002] In recent years, voltage and current source devices such as source measurement units (SMUs) have increasingly adopted digital loop control architectures to replace analog loops, leveraging their flexibility to optimize response speed under different loads. A typical digital loop voltage and current source drives a power amplifier stage via a digital-to-analog converter (DAC) and uses a current sensing resistor connected in series in the output path for sampling feedback. An analog-to-digital converter (ADC) then sends the acquired voltage / current signal to a digital controller for closed-loop regulation. To balance measurement resolution and accuracy, the main current measurement circuit is typically optimized for a specific current range, resulting in a limited linear input range.

[0003] In real-world testing scenarios (such as when the device under test suddenly short-circuits), the transient and drastic change in load impedance can cause the output current to surge instantaneously. The resulting voltage drop far exceeds the measurement range across the current sensing resistor, causing the high-precision current measurement circuit to enter a saturation or limiting state.

[0004] To address this problem, existing technologies mainly offer two solutions:

[0005] 1. Direct Digital Regulation Scheme: The controller continues to rely on the saturated measured value for regulation. Because the feedback value is "clamped" at the maximum range (much smaller than the actual short-circuit current), the error calculated by the controller is extremely small, resulting in insufficient regulation. The system often requires hundreds of microseconds or even milliseconds to linearly exit the saturation state (e.g., Figure 4 As shown in the figure, excessive current during this period can easily burn out the device under test or the testing instrument.

[0006] 2. Model estimation feedforward scheme (e.g., US patent No. 10338110 B2): When saturation is detected, the voltage and load model formula is used to estimate the voltage value that the DAC should output, and open-loop or semi-open-loop control is performed. However, this scheme is heavily dependent on the accuracy of the model. In practical applications, the nonlinearity of the power stage gain, the unknown path resistance, and the parameter drift of components due to temperature and aging can all lead to deviations between the estimated and actual values. This deviation can easily lead to over-adjustment (resulting in reverse overshoot, such as...). Figure 8(As shown) or insufficient adjustment (getting stuck in repeated oscillations), unable to achieve a fast and stable recovery.

[0007] Therefore, there is an urgent need for a new digital loop voltage and current source current saturation fast recovery device and its control method to solve the problems existing in the prior art. Summary of the Invention

[0008] This application provides a current saturation fast recovery device and control method for a digital loop voltage and current source. It addresses the problems in the prior art where, during the current measurement circuit saturation period, the controller is "blinded" and adjusts slowly due to feedback signal distortion, or the control overshoots and oscillations are caused by inaccurate circuit model parameters, making it impossible to achieve fast and accurate recovery while ensuring safety.

[0009] The core technology of this invention is to connect a wide-range auxiliary measurement channel in parallel with the original high-precision narrow-range measurement channel, and seamlessly switch to the auxiliary channel when the main channel is saturated to maintain true closed-loop feedback control, thereby achieving rapid and smooth recovery of the current saturation state.

[0010] In a first aspect, this application provides a current saturation fast recovery device for a digital loop voltage and current source, including a digital loop controller, a drive circuit, a current detection element, and a main current measurement circuit; the digital loop controller drives the load through the drive circuit, and the main current measurement circuit is coupled to the current detection element to provide a current feedback signal of first accuracy to the digital loop controller; It also includes an auxiliary measurement circuit, which is coupled in parallel with the main current measurement circuit to the current sensing element to provide a second-precision current feedback signal, wherein the current range of the auxiliary measurement circuit is greater than the current range of the main current measurement circuit. The digital loop controller is configured to execute saturation recovery control logic: The operating status of the main current measurement circuit is monitored. When it is determined that the main current measurement circuit is in a saturated state or a critical saturation state, the feedback source used for closed-loop control is switched from the main current measurement circuit to the auxiliary measurement circuit. The output current is adjusted based on the real-time measurement value of the auxiliary measurement circuit until the output current is restored to the linear measurement range of the main current measurement circuit.

[0011] Furthermore, the main current measurement circuit includes a first analog-to-digital converter, and the auxiliary measurement circuit includes a second analog-to-digital converter; The resolution of the first analog-to-digital converter is higher than that of the second analog-to-digital converter, and the measurement range of the first analog-to-digital converter is smaller than that of the second analog-to-digital converter. The first analog-to-digital converter and the second analog-to-digital converter are connected to the same clock source and are configured to synchronously sample the voltage signals across the current sensing element.

[0012] Furthermore, the conditions under which the digital loop controller determines that the main current measurement circuit is in a saturated state or a critical saturation state include: The current measurement value output by the main current measurement circuit is monitored. When the absolute value of the current measurement value is greater than or equal to the first preset threshold, it is determined that the system has entered a saturation state or a saturation critical state. When closed-loop control based on the auxiliary measurement circuit makes the absolute value of the output current less than or equal to the second preset threshold, it is determined that the output current has recovered to the linear measurement range of the main current measurement circuit. The first preset threshold is greater than the second preset threshold.

[0013] Furthermore, the digital loop controller is also configured to execute saturation prediction logic: Obtain the current output voltage command value, actual output voltage value, and load model parameters; calculate the predicted current value for the next control cycle based on the output voltage command value, actual output voltage value, and load model parameters; If the predicted current value exceeds the range of the main current measurement circuit, the feedback source will be switched to the auxiliary measurement circuit before the main current measurement circuit actually reaches saturation.

[0014] Furthermore, the digital loop controller is configured to perform a smooth transition process during the switching of the feedback source from the auxiliary measurement circuit back to the main current measurement circuit; Smooth transition processing includes: Within a preset transition time, the measured values ​​from the main current measurement circuit and the auxiliary measurement circuit are weighted and fused together, and the result of the weighted and fused calculation is used as the feedback basis for closed-loop control.

[0015] Furthermore, the specific configuration for weighted fusion computing is as follows: Over time, the weight of the measured values ​​from the auxiliary measurement circuit is gradually reduced while the weight of the measured values ​​from the main current measurement circuit is increased, until the weight of the measured values ​​from the main current measurement circuit reaches 100%.

[0016] Furthermore, the digital loop controller is also configured as follows: When switching the feedback source from the main current measurement circuit to the auxiliary measurement circuit, or from the auxiliary measurement circuit back to the main current measurement circuit, a digital filter is activated to filter the feedback signal in order to suppress the step transition caused by the signal switching.

[0017] Furthermore, the current sensing element is a current sensing resistor; the input terminals of both the main current measurement circuit and the auxiliary measurement circuit are connected across the two ends of the current sensing resistor; the input impedance of the auxiliary measurement circuit is configured so as not to affect the measurement accuracy of the main current measurement circuit.

[0018] Secondly, this application provides a method for fast recovery of current saturation in a digital loop voltage and current source, applicable to a voltage and current source system with a main current measurement circuit and an auxiliary measurement circuit. The method includes the following steps: The output data of the main current measurement circuit is collected as the main feedback value for conventional closed-loop control. Real-time monitoring of the main feedback value or prediction of current trends based on system status; When the main feedback value is detected to have reached the saturation threshold or saturation is predicted to occur, the auxiliary measurement circuit connected in parallel with the main current measurement circuit is activated. Switch the feedback source of the control loop to the auxiliary feedback value output by the auxiliary measurement circuit, and adjust the output based on the auxiliary feedback value until the current drops to the linear operating range of the main current measurement circuit. Perform a feedback source revert operation to restore the feedback source from the auxiliary feedback value to the primary feedback value.

[0019] Thirdly, this application provides a readable storage medium storing a computer program, the computer program including program code for controlling a process to execute the process, the process including the current saturation fast recovery method according to the above-described digital loop voltage and current source.

[0020] The main contributions and innovations of this invention are as follows: 1. Significantly Improved Dynamic Recovery Speed: The current saturation recovery process is transformed from "blind trial and error" or "model estimation" to "full closed-loop continuous control." Utilizing the wide range characteristics of the auxiliary channel, the controller can still acquire real current data during transients, thereby applying accurate adjustments. Experiments show that the recovery time can be reduced from hundreds of microseconds in traditional schemes to tens of microseconds (a reduction of 1-2 orders of magnitude), greatly improving testing efficiency.

[0021] 2. Enhanced System Robustness and Environmental Adaptability: This solution is based on physical measurements rather than mathematical model calculations, thus it is unaffected by non-ideal factors such as power amplifier circuit gain temperature drift, path resistance variations, and component aging. Regardless of changes in the external environment or load characteristics, the system maintains stable recovery performance, avoiding the risks of overshoot or oscillation caused by model estimation.

[0022] 3. Improved test safety: By eliminating the "control blind zone" during saturation, this invention can quickly bring the overcurrent back to a safe range, effectively preventing thermal damage to precision components such as the device under test (DUT) and voltage and current source probe cards caused by prolonged overcurrent.

[0023] 4. Achieve seamless and smooth switching: By adopting synchronous sampling technology with the same source clock and weighted fusion or digital filtering algorithm, the problem of data jump caused by accuracy difference or timing deviation during the switching of main / auxiliary channels is solved, ensuring the smooth transition of the control loop during the switching process and avoiding the introduction of new control disturbances.

[0024] Details of one or more embodiments of this application are set forth in the following drawings and description to make other features, objects and advantages of this application more readily apparent. Attached Figure Description

[0025] The accompanying drawings, which are included to provide a further understanding of this application and form part of this application, illustrate exemplary embodiments and are used to explain this application, but do not constitute an undue limitation of this application. In the drawings: Figure 1 This is a system architecture diagram of a voltage and current source based on digital loop control in the existing technology; Figure 2 It is an equivalent circuit diagram of the working principle of voltage and current sources under normal load (linear region) in the prior art; Figure 3 This is an equivalent circuit diagram of the working principle of a voltage and current source in the prior art when the current measurement circuit is saturated due to a load short circuit; Figure 4 This is a waveform diagram of the recovery response under current saturation state using existing technology (conventional digital regulation scheme); Figure 5 This is a system architecture diagram of a digital loop voltage and current source including auxiliary measurement circuitry provided in an embodiment of the present invention; Figure 6 This is a flowchart of the current saturation fast recovery control method provided in the embodiments of the present invention; Figure 7 This is a waveform diagram of the rapid current recovery response after a load short circuit provided in an embodiment of the present invention; Figure 8 This is a simulation waveform diagram of the reverse overshoot generated during the current recovery process using existing technology (model estimation scheme). Detailed Implementation

[0026] Exemplary embodiments will now be described in detail, examples of which are illustrated in the accompanying drawings. When the following description relates to the drawings, unless otherwise indicated, the same numerals in different drawings denote the same or similar elements. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with one or more embodiments of this specification. Rather, they are merely examples of apparatuses and methods consistent with some aspects of one or more embodiments of this specification as detailed in the appended claims.

[0027] It should be noted that the steps of the corresponding methods are not necessarily performed in the order shown and described in this specification in other embodiments. In some other embodiments, the methods may include more or fewer steps than described in this specification. Furthermore, a single step described in this specification may be broken down into multiple steps in other embodiments; and multiple steps described in this specification may be combined into a single step in other embodiments.

[0028] To more clearly illustrate the technical concept and inventiveness of this invention, we will first combine... Figures 1 to 3 This paper analyzes the existing digital loop voltage and current sources and the technical challenges they face under transient conditions.

[0029] Figure 1 This demonstrates a typical system architecture based on a digital loop-controlled voltage-current source (SMU). For example... Figure 1 As shown, the system (voltage and current source 1) mainly consists of a digital loop controller 100, a digital-to-analog converter (DAC) 111, an amplifier circuit 112, a current sensing resistor 113, a current measurement circuit 120, and a voltage measurement circuit 130. The system is connected to the device under test (DUT) 200 through a first path resistor (path resistor 1) 301 and a second path resistor (path resistor 2) 302. During normal operation, the digital loop controller 100 calculates the error and adjusts the output of the DAC 111 based on the digital signals fed back from the voltage measurement circuit 130 and the current measurement circuit 120, thereby maintaining the stability of the output voltage or current. To ensure measurement accuracy, the current measurement circuit 120 is typically optimized for a specific current range, and its linear measurement range is limited (e.g., ±1.1A).

[0030] Figure 2 This demonstrates the operation of the voltage and current source under normal load. Taking a specific operating condition as an example: the output voltage is set to 8V, and the current clamping value is 1A. Assume the resistance of the measured component 200 is 10Ω, the path resistance is 0.5Ω, and the current sensing resistor 113 is 1Ω. At this time, the loop current I = 8V / 10Ω = 0.8A. The voltage drop across the current sensing resistor 113 is 0.8A × 1Ω = 0.8V. Since 0.8A is less than the maximum range of the current measurement circuit 120 (e.g., 1.1A), the current measurement circuit is in its linear operating region and can provide accurate current values ​​to the digital loop controller 100, ensuring normal operation of the system's closed-loop control.

[0031] Figure 3 This demonstrates the state of the device under test when a transient short-circuit fault occurs, which is also the "pain point" scenario that this invention focuses on addressing. For example... Figure 3As shown, when the resistance of the measured component 200 suddenly changes from 10Ω to 0Ω (short circuit), due to the output voltage V of the amplifier circuit... pow The voltage (approximately 9.6V) cannot change instantaneously; the total circuit resistance instantly drops to consist only of the path resistance and the sensing resistance (1Ω + 0.5Ω + 0.5Ω = 2Ω). According to Ohm's law, the instantaneous current surges to I... short =9.6V / 2Ω=4.8A.

[0032] At this point, the voltage drop across the current sensing resistor 113 is as high as 4.8V, far exceeding the linear input range of the current measurement circuit 120 (1.1V for 1.1A). This causes the current measurement circuit 120 to enter a severe saturation state.

[0033] In this state, existing technology faces an insurmountable control dilemma: although the actual current is as high as 4.8A, the value fed back to the digital loop controller 100 by the saturated current measurement circuit 120 is only the limited "1.1A". The controller mistakenly believes that the current only slightly exceeds the clamping value (1.1A-1A=0.1A), and therefore applies only a weak adjustment to reduce the output voltage. This causes the system to be like "blind men touching an elephant," unable to perceive the true degree of overcurrent, and can only pull the current back to the safe area at an extremely slow speed (linear desaturation). This can easily lead to the burnout of the device under test or test instrument due to prolonged overcurrent (e.g., Figure 4 The existing technology recovery curve shown. Or, if model estimation is used (such as... Figure 8 The existing technology shown above suffers from inaccurate adjustment due to parameter drift.

[0034] Precisely targeting Figure 3 To address the control failure problem caused by this "measurement blindness" as shown, the present invention proposes the following improvement scheme.

[0035] Example 1: A fast current saturation recovery device for a digital loop voltage and current source like Figure 5 As shown, this embodiment provides a system architecture for a digital loop voltage and current source. The device mainly includes a digital loop controller 100, a digital-to-analog converter 111, an amplifier circuit 112, a current sensing resistor 113, a main current measurement circuit 120, a voltage measurement circuit 130, and an auxiliary measurement circuit 140 added in this invention.

[0036] In this system, the digital loop controller 100 (e.g., FPGA, DSP, or ASIC) is the core control unit, and its output is connected to the input of the digital-to-analog converter 111. The output of the digital-to-analog converter 111 is connected to the input of the amplifier circuit 112. The output of the amplifier circuit 112 is connected to the device under test 200 via the current sensing resistor 113 and the first path resistor 301. The other end of the device under test 200 is grounded via the second path resistor 302.

[0037] The input terminal of the main current measurement circuit 120 is connected across the current sensing resistor 113 to acquire the voltage signal flowing through the resistor and convert it into a digital signal (i.e., the main current feedback value), which is then fed back to the digital loop controller 100. To achieve high-precision current regulation, the main current measurement circuit 120 is typically configured with a high-resolution, narrow-range measurement channel. For example, in this embodiment, the main current measurement circuit 120 includes a 20-bit resolution first analog-to-digital converter, corresponding to a current range of ±1.1A (corresponding to a voltage of ±1.1V across the current sensing resistor 113).

[0038] The input terminal of the voltage measurement circuit 130 is connected to both ends (or Kelvin connection point) of the device under test 200 to acquire the voltage signal (V) across the load in real time. out The voltage signal is converted into a digital signal (including a third analog-to-digital converter) and fed back to the digital loop controller 100. This voltage signal is not only used for conventional voltage measurement and constant voltage control, but also serves as an input parameter in the current saturation prediction algorithm of this invention.

[0039] To address the control failure caused by saturation of the main current measurement circuit 120 under transient conditions such as load short circuits, this embodiment also includes an auxiliary measurement circuit 140 connected in parallel across the current sensing resistor 113. The auxiliary measurement circuit 140 includes a second analog-to-digital converter configured as a low-resolution, wide-range measurement channel. For example, the range of the auxiliary measurement circuit 140 is configured as ±15V (corresponding to a current of ±15A, assuming a resistance of 1Ω), and the resolution is 14 bits.

[0040] To ensure the consistency of data from the two measurement channels in the time domain, the first analog-to-digital converter in the main current measurement circuit 120 and the second analog-to-digital converter in the auxiliary measurement circuit 140 are connected to the same clock source to perform synchronous sampling. This hardware configuration ensures that the digital loop controller 100 can simultaneously acquire high-precision (potentially saturated) main feedback values ​​and low-precision (unsaturated) auxiliary feedback values, providing a data foundation for subsequent seamless switching.

[0041] Example 2: Control method for rapid recovery of current saturation Based on the device described in Embodiment 1, this embodiment details the control logic and operation process of the device when dealing with current saturation. For example... Figure 6 As shown, the control method includes the following steps: Step S1: Normal working mode When the system is operating normally and the load current is within the range of the main current measurement circuit 120 (e.g., <1.1A), the digital loop controller 100 selects the data output by the main current measurement circuit 120 as the feedback source for closed-loop control to ensure high accuracy of the output current.

[0042] Step S2: Saturation Monitoring and Judgment The digital loop controller 100 monitors the status of the main current measurement circuit 120 in real time. The decision logic can be based on a threshold comparison: a first preset threshold is set (e.g., 97% of the range). When the absolute value of the monitored main current feedback value is greater than or equal to the first preset threshold, it is determined that the main current measurement circuit 120 has entered a critical saturation state or is already saturated. Furthermore, as a preferred embodiment, the digital loop controller 100 can also combine the current output voltage command value and the actual output voltage V... out Given the known load model parameters, the predicted current value for the next control cycle is calculated. If the predicted current value exceeds the range of the main current measurement circuit 120, saturation can be predicted in advance.

[0043] Step S3: Feedback Source Switching Once saturation or impending saturation is detected, the digital loop controller 100 immediately performs a switching action, switching the feedback source used for digital loop calculation from the main current measurement circuit 120 to the auxiliary measurement circuit 140. For example... Figure 7 As shown, although the current changes abruptly at the moment of switching (for example, reaching 4.8A due to a short circuit), the auxiliary measurement circuit 140 has a wide range (±15A) and does not saturate, thus accurately reflecting the actual current value of 4.8A.

[0044] Step S4: Closed-loop regulation based on auxiliary feedback After switching, the digital loop controller 100 calculates the error based on the actual feedback value (e.g., 4.8A) provided by the auxiliary measurement circuit 140 and the set target value (e.g., clamping value 1A). Since the feedback value is real and the error calculation is accurate (4.8A - 1A = 3.8A), the PI or PID controller can calculate the correct adjustment amount, driving the digital-to-analog converter 111 to quickly reduce the output voltage.

[0045] and Figure 4Compared to the prior art (Solution 1) shown, the prior art, because the feedback value is clamped at 1.1A, causes the controller to mistakenly believe the error is only 0.1A, resulting in extremely slow adjustment (linear, slow decrease). In this embodiment, however, the controller "sees" a large actual error, and therefore can exponentially and rapidly bring the current back to a safe range, such as... Figure 7 As shown, the current drops rapidly.

[0046] and Figure 8 Compared to the existing technology (Solution 2, model estimation) shown, the model estimation scheme is prone to calculating incorrect DAC values ​​due to inaccurate parameters such as path resistance and temperature drift, leading to over-regulation (reverse overshoot) or oscillation. In contrast, this embodiment uses closed-loop control based on real physical measurements, exhibiting strong robustness to changes in system parameters and avoiding [the aforementioned issues]. Figure 8 The overshoot phenomenon shown achieves smooth, monotonic recovery.

[0047] Step S5: Recovery and Switchback The digital loop controller 100 continuously monitors the feedback value based on the auxiliary measurement circuit 140. When the current drops to within the linear operating range of the main current measurement circuit 120 (e.g., a second preset threshold is set, such as 94% of the range), the system prepares to switch back to the main feedback. To prevent repeated jumps near the threshold, a hysteresis interval is set between the first preset threshold (97%) and the second preset threshold (94%).

[0048] Example 3: Smooth Transition Algorithm In steps S3 (switching out) and S5 (switching back) of Embodiment 2, since there may be slight differences in the accuracy, zero-point offset, or gain error of the two analog-to-digital converters, a direct hard switch may cause a step jump in the feedback data, which in turn causes jitter in the control voltage. To solve this problem, this embodiment uses a weighted fusion algorithm for smooth transition.

[0049] Specifically, within a preset transition time (e.g., N control cycles) after the switching occurs, the digital loop controller 100 calculates the final feedback current value I. final The formula is as follows:

[0050] Among them, I main The measured value of the main current measuring circuit 120, I aux For the measurement value of the auxiliary measurement circuit 140, α is the weighting coefficient.

[0051] When moving from primary to secondary (step S3): the weighting coefficient α gradually decreases from 1 to 0 over N cycles.

[0052] When switching back from auxiliary to main (step S5): the weight coefficient α gradually increases from 0 to 1 over N cycles.

[0053] The curve of α's variation can be a linear function or a smoother S-shaped curve (such as a cosine function). Furthermore, at the instant of switching, the controller can also activate a temporary digital low-pass filter for I. final Filtering is performed to further remove high-frequency noise and switching glitches, ensuring a smooth transition of the control voltage.

[0054] Through the hardware architecture and control strategy of the above embodiments, the present invention effectively solves the problem of "measurement blindness" of voltage and current sources under transient load changes, and achieves rapid and safe recovery of transient overcurrent while ensuring high steady-state accuracy.

[0055] Example 4 This embodiment also provides a readable storage medium storing a computer program, the computer program including program code for controlling a process to execute the process, the process including a fast recovery method for current saturation of a digital loop voltage and current source according to Embodiment 2.

[0056] It should be noted that the specific examples in this embodiment can refer to the examples described in the above embodiments and optional implementations, and will not be repeated here.

[0057] Generally, various embodiments can be implemented in hardware or dedicated circuitry, software, logic, or any combination thereof. Some aspects of the invention can be implemented in hardware, while others can be implemented by firmware or software executed by a controller, microprocessor, or other computing device, but the invention is not limited thereto. Although various aspects of the invention may be shown and described as block diagrams, flowcharts, or using some other graphical representation, it should be understood that, by way of non-limiting example, these blocks, apparatuses, systems, techniques, or methods described herein can be implemented in hardware, software, firmware, dedicated circuitry or logic, general-purpose hardware or controllers or other computing devices, or some combination thereof.

[0058] Embodiments of the present invention can be implemented by computer software, which may be executable by a data processor of a mobile device, such as a processor entity, or by hardware, or by a combination of software and hardware. Computer software or programs (also referred to as program products) including software routines, applets, and / or macros can be stored in any device-readable data storage medium, and they include program instructions for performing specific tasks. The computer program product may include one or more computer-executable components configured to perform the embodiments when the program is run. The one or more computer-executable components may be at least one piece of software code or a portion thereof. Additionally, it should be noted in this respect that, as Figure 6Any box in the logical flow can represent a program step, or interconnected logic circuits, boxes and functions, or a combination of program steps and logic circuits, boxes and functions. Software can be stored on physical media such as memory chips or blocks of storage implemented within a processor, magnetic media such as hard disks or floppy disks, and optical media such as DVDs and their data variants, CDs, etc. The physical medium is a non-transient medium.

[0059] Those skilled in the art should understand that the technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments have been described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0060] The above embodiments are merely illustrative of several implementation methods of this application, and their descriptions are relatively specific and detailed, but they should not be construed as limiting the scope of this application. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this application should be determined by the appended claims.

Claims

1. A current saturation fast recovery device for a digital loop voltage and current source, comprising a digital loop controller, a drive circuit, a current detection element, and a main current measurement circuit; wherein the digital loop controller drives a load through the drive circuit, and the main current measurement circuit is coupled to the current detection element to provide a current feedback signal of first precision to the digital loop controller; Its features are, It also includes an auxiliary measurement circuit, which is coupled in parallel with the main current measurement circuit to the current detection element to provide a current feedback signal of second accuracy, wherein the current range of the auxiliary measurement circuit is greater than the current range of the main current measurement circuit. The digital loop controller is configured to execute saturation recovery control logic: The operating status of the main current measurement circuit is monitored. When it is determined that the main current measurement circuit is in a saturated state or a critical saturation state, the feedback source for closed-loop control is switched from the main current measurement circuit to the auxiliary measurement circuit. The output current is adjusted based on the real-time measurement value of the auxiliary measurement circuit until the output current is restored to the linear measurement range of the main current measurement circuit.

2. The current saturation fast recovery device for the digital loop voltage and current source as described in claim 1, characterized in that, The main current measurement circuit includes a first analog-to-digital converter, and the auxiliary measurement circuit includes a second analog-to-digital converter. The resolution of the first analog-to-digital converter is higher than that of the second analog-to-digital converter, and the measurement range of the first analog-to-digital converter is smaller than that of the second analog-to-digital converter; The first analog-to-digital converter and the second analog-to-digital converter are connected to the same clock source and are configured to synchronously sample the voltage signals across the current sensing element.

3. The current saturation fast recovery device for the digital loop voltage and current source as described in claim 1, characterized in that, The conditions under which the digital loop controller determines that the main current measurement circuit is in a saturated state or a critical saturation state include: The current measurement value output by the main current measurement circuit is monitored. When the absolute value of the current measurement value is greater than or equal to a first preset threshold, it is determined that the circuit has entered a saturation state or a saturation critical state. When closed-loop control based on the auxiliary measurement circuit makes the absolute value of the output current less than or equal to the second preset threshold, it is determined that the output current has recovered to the linear measurement range of the main current measurement circuit. Wherein, the first preset threshold is greater than the second preset threshold.

4. The current saturation fast recovery device for the digital loop voltage and current source as described in claim 1, characterized in that, The digital loop controller is also configured to execute saturation prediction logic: Obtain the current output voltage command value, actual output voltage value, and load model parameters; calculate the predicted current value for the next control cycle based on the output voltage command value, actual output voltage value, and load model parameters; If the predicted current value exceeds the range of the main current measurement circuit, the feedback source is switched to the auxiliary measurement circuit before the main current measurement circuit actually reaches saturation.

5. The current saturation fast recovery device for the digital loop voltage and current source as described in claim 1, characterized in that, The digital loop controller is configured to perform a smooth transition process during the switching of the feedback source from the auxiliary measurement circuit back to the main current measurement circuit; The smooth transition process includes: Within a preset transition time, the measured values ​​of the main current measurement circuit and the auxiliary measurement circuit are weighted and fused together, and the result of the weighted and fused calculation is used as the feedback basis for closed-loop control.

6. The current saturation fast recovery device for the digital loop voltage and current source as described in claim 5, characterized in that, The specific configuration for the weighted fusion calculation is as follows: As time goes on, the weight of the measured value of the auxiliary measurement circuit is gradually reduced and the weight of the measured value of the main current measurement circuit is increased until the weight of the measured value of the main current measurement circuit reaches 100%.

7. The current saturation fast recovery device for the digital loop voltage and current source as described in claim 1, characterized in that, The digital loop controller is also configured to: When switching the feedback source from the main current measurement circuit to the auxiliary measurement circuit, or when switching back from the auxiliary measurement circuit to the main current measurement circuit, a digital filter is activated to filter the feedback signal in order to suppress the step transition caused by the signal switching.

8. The current saturation fast recovery device for the digital loop voltage and current source as described in claim 1, characterized in that, The current sensing element is a current sensing resistor; the input terminals of the main current measurement circuit and the auxiliary measurement circuit are both connected across the two ends of the current sensing resistor; the input impedance of the auxiliary measurement circuit is configured so as not to affect the measurement accuracy of the main current measurement circuit.

9. A method for fast recovery control of current saturation in a digital loop voltage and current source, characterized in that, The method, applied to a voltage and current source system having a main current measurement circuit and an auxiliary measurement circuit, includes the following steps: The output data of the main current measurement circuit is collected as the main feedback value for conventional closed-loop control. Real-time monitoring of the main feedback value or prediction of current trends based on system status; When the main feedback value is detected to have reached the saturation threshold or saturation is predicted to occur, the auxiliary measurement circuit connected in parallel with the main current measurement circuit is activated. The feedback source of the control loop is switched to the auxiliary feedback value output by the auxiliary measurement circuit, and the output is adjusted based on the auxiliary feedback value until the current drops to the linear operating range of the main current measurement circuit. Perform a feedback source revert operation to restore the feedback source from the auxiliary feedback value to the main feedback value.

10. A readable storage medium, characterized in that, The readable storage medium stores a computer program, the computer program including program code for controlling a process to execute the process, the process including the fast recovery method for current saturation of a digital loop voltage and current source according to claim 9.

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