A method of constructing an adjustable resistance module

Abstract

The application belongs to the technical field of electronic components, and particularly relates to a tunable resistance module construction method, aiming to solve the problems of limited tunable resistance range and precision, environmental temperature interference and slow response. The method comprises the following steps: constructing a multi-range precision resistance topology network based on binary weighting and segmented distribution; establishing a resistance mapping function and a calibration database to quantify parasitic parameters and switch residual resistance; using a temperature sensing array to sample the thermal field distribution and establish a temperature drift dynamic model to calculate a pre-compensation amount to eliminate the influence of thermal drift; generating high-speed parallel instructions through a logic control processing unit to synchronously drive a low-loss electronic switch unit; and finally executing real-time monitoring and closed-loop fine adjustment of output performance. By adopting the above technical scheme, the application can achieve extremely high adjustment precision and linearity, has excellent temperature stability and extremely fast response capability, and effectively improves the AC impedance characteristic and reduces the system construction cost.

Description

Technical Field

[0001] This application belongs to the field of electronic component technology, specifically relating to a method for constructing an adjustable resistor module. Background Technology

[0002] With the continuous evolution of electronic measurement and industrial control technologies, adjustable resistor modules, as core components of precision instruments, automated testing systems, and high-performance sensors, are seeing their application depth expand in areas such as signal chain simulation, impedance matching, and precision calibration. Modern electronic systems place stringent requirements on adjustable resistor modules, demanding high precision, high linearity, and high physical integration, prompting related technical solutions to evolve from traditional mechanical potentiometer adjustment towards digitalization, programmability, and modularization. As a critical element in circuit design, high-performance adjustable resistor construction methods play a decisive role in ensuring the performance consistency and reliability of complex electronic systems under varying operating conditions.

[0003] Among these technologies, programmable digital resistor adjustment is the mainstream approach for achieving precise step-by-step and flexible control of resistance values. This technology typically utilizes semiconductor switch arrays or digital integrated potentiometers, combined with microprocessor control instructions, to achieve discrete adjustment of the output resistance value. Its core principle lies in maintaining low quantization error and residual impedance within a specific resistance value range through optimized circuit topology and sophisticated coding control algorithms. As applications trend towards miniaturization and intelligence, how to simplify circuit topology while further improving the system's robustness to environmental temperature changes has become a key technological challenge that urgently needs to be addressed in this field.

[0004] However, existing technologies often employ multiple discrete potentiometer chips connected in series or independent resistor boxes cascaded, resulting in overly redundant circuit topologies and high system hardware costs. In practical operation, parasitic parameters introduced by multi-stage cascaded structures and nonlinear contact resistance generated by switching devices significantly reduce the absolute accuracy of resistance adjustment. Furthermore, the lack of a dynamic compensation mechanism for the temperature characteristics of resistance means that thermal drift of resistive elements under wide temperature environments severely impacts the long-term stability of the output value. In addition, traditional serial bus communication exhibits significant control response lag when driving large-scale resistor arrays, making it difficult to meet the real-time requirements of high-speed closed-loop control scenarios.

[0005] Therefore, a method for constructing an efficient, accurate, and highly stable adjustable resistor module is desired. Summary of the Invention

[0006] The purpose of this invention is to provide a method for constructing an adjustable resistor module, which can effectively solve the problems mentioned in the background art.

[0007] To achieve the above objectives, the technical solution adopted by the present invention is as follows: A method for constructing an adjustable resistor module includes the following specific steps: Step 1: Construct a multi-range precision resistor topology network: Based on a hybrid layout mode combining binary weighted arrangement and segmented equal division arrangement, configure multiple groups of precision fixed value resistor branches. Each group of precision fixed value resistor branches is associated with an independent low-loss electronic switch unit. Through the interconnection of physical circuits, a resistor matrix structure with a wide adjustment range and high resolution is formed. Step 2: Establish the resistance mapping function and initial calibration database: Obtain the actual static resistance values ​​of each branch in the multi-range precision resistor topology network using a high-precision measuring instrument, quantify the parasitic inductance, parasitic capacitance, and residual resistance of the switch contacts in different combination states, establish the mathematical mapping relationship between the control command code and the equivalent resistance value of the output terminal, and generate the initial calibration lookup table. Step 3: Perform thermal field distribution sampling of the working environment: Use the temperature sensing array distributed in the key thermal nodes inside the multi-range precision resistor topology network to acquire temperature data at different locations in real time, and calculate the characteristic temperature value reflecting the current thermal state of the entire resistor module through a weighted average algorithm. Step 4: Perform dynamic modeling of temperature drift and pre-compensation calculation of resistance value: Retrieve the temperature coefficient model of the resistor element stored in the memory, calculate the thermal drift of each resistance unit under the current environment based on the characteristic temperature value, and introduce the thermal drift as a correction parameter into the resistance mapping function to generate the compensated target combination code. Step 5: Generate high-speed parallel control instructions and implement the drive: Input the target combination code into the logic control processing unit, generate multiple parallel drive pulse signals through the synchronous timing controller, and synchronously act on the low-loss electronic switch unit to realize the transient switching and precise holding of the output resistance value; Step 6: Perform real-time monitoring and closed-loop fine-tuning of output performance: Set up a precision sampling circuit at the resistor output port to extract the voltage and current vectors at the output terminal in real time, calculate the real-time output resistance value, and calculate the deviation between the real-time output resistance value and the set target value. If the deviation exceeds the preset allowable threshold, dynamically fine-tune the target combination code until the output resistance value meets the accuracy requirements.

[0008] Preferably, in step 1, the multi-range precision resistor topology network adopts a hierarchical construction strategy, specifically including a high-resistance section, a medium-resistance section, and a low-resistance section. The high-resistance section consists of multiple precision resistors with resistance values ​​greater than or equal to a first preset resistance threshold connected in series, and is controlled by a high-voltage switch for on / off switching. The medium-resistance section consists of precision resistors with resistance values ​​within a predetermined intermediate range, employing a hybrid series-parallel structure with binary weights to achieve linear and continuous resistance adjustment over a wide range. The low-resistance section consists of sampling resistors with resistance values ​​less than a second preset resistance threshold connected in parallel, and the impact of the total on-resistance is reduced through multi-path parallel switching.

[0009] Preferably, in step 1, the precision fixed resistor is selected with a preset accuracy level and its temperature coefficient is set to be less than or equal to a predetermined temperature drift coefficient. The low-loss electronic switch unit is a controlled switch element with a conduction resistance less than or equal to a preset resistance value. In terms of physical layout, the precision fixed resistor branches are arranged in a thermally symmetrical manner to ensure the consistency of temperature rise among the branches during operation and reduce the additional temperature drift caused by local hot spots.

[0010] Preferably, in step 2, the initial calibration database establishment process includes: under a preset reference temperature environment, traversing all logical combination states of the multi-range precision resistor topology network, and recording the endpoint resistance values ​​in each state using a high-resolution measurement component. Simultaneously, specific compensation calculations are performed for leakage current in the high-resistance state and lead resistance in the low-resistance state, with the compensation accuracy required to meet a predetermined compensation accuracy standard. The initial calibration lookup table is stored in non-volatile memory and supports automatic loading upon system startup.

[0011] Preferably, in step 3, the temperature sensing array includes multiple temperature sensors distributed in different areas of the circuit board. The measurement accuracy of the temperature sensors is better than a preset error range, and the sampling frequency is set to be greater than or equal to a predetermined frequency. The method for calculating the characteristic temperature value is as follows: assigning corresponding weighting coefficients to sensors at different distances from the heating element, and eliminating the influence of local environmental disturbances on temperature sampling through a weighted summation algorithm.

[0012] Preferably, in step 4, the dynamic modeling of temperature drift employs a polynomial fitting algorithm of a preset order. Based on the physical material characteristics of the resistive element, the nonlinear curve of resistance changing with temperature is pre-determined, and the polynomial coefficients are extracted. When calculating the pre-compensation amount, the processor reads the current characteristic temperature value in real time and substitutes it into the polynomial model to calculate the relative rate of change of resistance. The generation logic of the target combination code is as follows: based on the original control code, by finding a resistance combination increment that is equal in magnitude and opposite in direction to the thermal drift amount, real-time compensation for the resistance change caused by temperature fluctuations is achieved.

[0013] Preferably, in step 5, the synchronization timing controller is implemented using a programmable logic device. This controller is internally configured with a high-speed shift register and a buffer drive array, ensuring that the switching actions of all the low-loss electronic switching units are completed within a preset synchronization time interval. The drive pulse signal is converted by a level conversion circuit to provide sufficient turn-on voltage, ensuring that the switching element operates in the deep conduction region, thereby reducing the on-resistance to the target low value.

[0014] Preferably, in step 6, the precision sampling circuit includes a high input impedance amplifier and a high-resolution analog-to-digital converter. The sampling circuit synchronously samples the voltage and current at the output terminal, with a sampling rate not lower than a preset sampling rate. When calculating the real-time output resistance, a digital filtering algorithm is introduced to remove power frequency interference and high-frequency random noise. The allowable threshold is set according to the application scenario; in calibration mode, it is set as a first preset deviation ratio, and in fast adjustment mode, it is set as a second preset deviation ratio.

[0015] Preferably, the method further includes a health status monitoring step for the resistor module. By analyzing the waveform characteristics of the switch switching transient, the switch action time, overshoot voltage, and residual ripple parameters after stabilization are extracted. If the increase in switch action time exceeds the initial preset ratio, or if abnormal fluctuations occur in the conduction voltage drop, it is determined that the branch switch has a risk of fatigue damage or poor contact. The system automatically triggers an alarm and calls a redundant branch for functional replacement.

[0016] Preferably, the method also involves dynamic reduction logic for high-frequency parasitic parameters. Under AC excitation signals, the resistive topology network exhibits complex impedance characteristics. This invention establishes an impedance spectrum model and, during the control command generation stage, fine-tunes the control code based on the current operating frequency to compensate for the imaginary impedance components caused by parasitic parameters, ensuring that the pure resistive characteristics of the output impedance within the preset operating frequency range meet a predetermined target ratio.

[0017] Preferably, the resistor module construction method is applied to a multi-channel programmable resistor device. This device includes a main control module, a power management module, and multiple independent adjustable resistor units. The units communicate collaboratively via an internal high-speed bus, and the main control module coordinates the calibration cycle and compensation strategy of each unit, achieving a highly integrated impedance simulation environment.

[0018] Compared with the prior art, the present invention has the following beneficial effects: 1. Extremely High Adjustment Accuracy and Linearity: This invention achieves fine-grained step adjustment of resistance values ​​over a wide range by constructing a multi-range precision resistor topology network and combining it with binary weighted logic. By establishing a detailed resistance mapping function and error correction model, the negative impact of residual switching resistance and parasitic circuit parameters on output accuracy is effectively eliminated. Extremely high absolute accuracy and minimal linearity deviation are achieved across the entire range, significantly improving the electrical performance of the adjustable resistor module.

[0019] 2. Excellent Temperature Stability and Environmental Adaptability This invention introduces a real-time thermal field sampling and dynamic temperature drift compensation mechanism based on a temperature sensor array. The temperature drift model is used to correct the temperature drift of the resistive element in real time, ensuring that the resistance temperature coefficient remains at an extremely low level within a preset wide operating temperature range. This dynamic compensation technology greatly reduces the interference of ambient temperature fluctuations on measurement results, ensuring long-term stability in precision testing scenarios.

[0020] 3. Extremely fast response time and efficient system architecture: By employing high-speed parallel control commands and a synchronous timing controller, this invention reduces the resistance value switching response time to an extremely low order of magnitude, achieving a leapfrog improvement in response speed compared to traditional control methods. This highly efficient system architecture, combined with closed-loop fine-tuning logic, enables the module to meet the stringent requirements of high-speed dynamic impedance simulation and real-time closed-loop control systems, possessing stronger real-time performance and response sensitivity.

[0021] 4. High Integration and Low Construction Cost: The optimized circuit topology of this invention reduces reliance on redundant discrete components. Through reasonable physical layout and logic control, multi-range coverage is achieved within a single module. Compared to traditional multi-level cascaded structures, this invention significantly reduces system size and power consumption, lowering hardware manufacturing and maintenance costs. Simultaneously, embedded health status monitoring and redundancy replacement functions improve system reliability and lifespan.

[0022] 5. Excellent high-frequency characteristics and complex impedance control capability: By introducing dynamic reduction logic for high-frequency parasitic parameters, this invention effectively expands the operating bandwidth of the adjustable resistor module. Under AC excitation, it can maintain extremely high pure resistance purity, solving the problem of impedance characteristic deterioration at increasing frequency in existing technologies, and providing solid technical support for high-performance signal chain simulation and precision sensor simulation. Attached Figure Description

[0023] Figure 1 This is a schematic diagram of the overall technical solution architecture of an adjustable resistor module construction method according to an embodiment of this application; Figure 2 This is a schematic diagram of the core principle framework of dynamic modeling of temperature drift and resistance pre-compensation in an adjustable resistor module construction method according to an embodiment of this application. Figure 3 This is a flowchart illustrating the logic framework for real-time monitoring and closed-loop fine-tuning of output performance in an adjustable resistor module construction method according to an embodiment of this application. Detailed Implementation

[0024] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to specific embodiments.

[0025] Example 1 In the adjustable resistor module construction method provided by this invention, extremely high-precision resistance output and environmental adaptability are achieved through precise topology design and dynamic compensation algorithm. The method specifically includes the following execution steps: In the method, step 1 constructs a multi-range precision resistor topology network. Specifically, this step configures multiple groups of precision fixed-value resistor branches based on a hybrid layout combining binary weighted arrangement and segmented equal-division arrangement. These precision fixed-value resistor branches are not simply parallel or series-connected resistor elements, but rather deeply logically divided according to the target range. Each group of precision fixed-value resistor branches is associated with an independent low-loss electronic switching unit, forming a resistor matrix structure with a wide adjustment range and high resolution through physical circuit interconnection.

[0026] In the specific implementation of step 1, the multi-range precision resistor topology network adopts a hierarchical construction strategy, specifically including a high-resistance section, a medium-resistance section, and a low-resistance section. The high-resistance section consists of multiple precision resistors connected in series with a resistance value greater than or equal to a first preset resistance threshold. The first preset resistance threshold is determined based on the highest range designed in the system, for example, set to 1 megohm. The high-resistance section is constructed using a high-voltage switch for on / off control. The withstand voltage rating of the high-voltage switch must cover the module's highest rated operating voltage to ensure insulation reliability in the off-state and prevent leakage current from interfering with the overall output resistance accuracy.

[0027] The medium-resistance section, as the core area for regulation, consists of precision resistors with resistance values ​​within a predetermined intermediate range, employing a hybrid series-parallel structure with binary weights. This structure utilizes a power-of-2 ratio to configure resistor values, for example, a sequence of resistors ranging from 100 ohms, 200 ohms, 400 ohms, to higher ranges. This binary weighting structure allows the system to combine the maximum number of resistance value levels with the minimum number of resistor elements, thereby achieving linear and continuous resistance adjustment over a wide range. The control logic for the medium-resistance section requires a high degree of consistency among all switching units to ensure the linearity of the step response.

[0028] The low-resistance section is designed for extremely low resistance adjustment requirements and consists of sampling resistors connected in parallel with resistance values ​​less than a second preset resistance threshold. This second preset threshold is typically set below 10 ohms. Since the on-resistance of the switching unit itself has a significant impact on overall accuracy in low-resistance conditions, the low-resistance section reduces the influence of the total on-resistance through multi-path parallel switching. Through multi-path parallel switching, the equivalent on-resistance of the switch decreases inversely with the number of parallel branches, thereby greatly improving the accuracy of the low-resistance output.

[0029] In terms of hardware selection, the precision fixed resistor in step 1 is selected with a preset accuracy level, such as 0.01% or higher. Its temperature coefficient is set to be less than or equal to a predetermined temperature drift coefficient, typically required to be within 5ppm / ℃, to lay a foundation for high stability at the physical level. The low-loss electronic switching unit selects controlled switching elements with an on-resistance less than or equal to a preset resistance value, such as power MOSFETs or high-precision electromagnetic relays with extremely low on-resistance. In terms of physical layout, the precision fixed resistor branches adopt a thermally symmetrical arrangement. This means that in the circuit board design, high-power heating elements are symmetrically placed on both sides of the resistor array, or the resistor array is symmetrically arranged around the thermal center. This arrangement can ensure that the temperature rise between each branch remains highly consistent during operation, minimizing the local thermal gradient and reducing the additional temperature drift caused by local hot spots from a physical structure perspective.

[0030] Specifically, step 2 establishes the resistance mapping function and the initial calibration database. This step involves obtaining the actual static resistance values ​​of each branch in the multi-range precision resistor topology network using a high-precision measuring instrument. Due to manufacturing tolerances, there is a slight difference between the nominal resistance value and the actual resistance value. This method records the endpoint resistance values ​​in each state by traversing all logical combination states of the multi-range precision resistor topology network under a preset reference temperature environment (e.g., 25.0℃) using a high-resolution 6.5-bit or 8.5-bit measuring component.

[0031] In step 2, the initial calibration database establishment process not only includes recording static resistance values ​​but also quantifies the parasitic inductance, parasitic capacitance, and residual resistance of switch contacts in different combination states. Specifically, for leakage current under high resistance conditions, the system models and compensates by measuring the equivalent parallel impedance of the insulated branches; for lead resistance under low resistance conditions, a four-wire measurement method is used to extract the parasitic resistance of switch pins, trace copper foil, and connectors for specific compensation calculations. The compensation accuracy is required to reach a predetermined compensation accuracy standard, typically on the order of 0.001% of the target resistance value. The initial calibration look-up table (LUT) is stored in non-volatile memory (such as EEPROM or Flash) and supports automatic loading into the internal cache of the logic control processing unit during system startup.

[0032] In step 2, the mapping relationship is constructed by establishing a mathematical mapping relationship between the control command code and the equivalent resistance value of the output terminal. This is not just a simple accumulation logic, but a multi-dimensional mapping model. The model maps each control code to an impedance vector in the complex field (when considering AC characteristics) or a precise resistance value in the real field. By introducing a compensation matrix, the mutual coupling interference between branches (such as the mutual inductance of adjacent traces) is also included in the calculation model, generating the final initial calibration lookup table.

[0033] Specifically, step 3 involves sampling the thermal field distribution of the working environment. During operation, the resistance module is affected by ambient temperature fluctuations and its own heat generation from power consumption, causing nonlinear drift in its resistance value. To achieve dynamic compensation, this method utilizes a temperature sensing array distributed within key thermal nodes of the multi-range precision resistor topology network to acquire temperature data at different locations in real time. The temperature sensing array includes multiple temperature sensors distributed across different areas of the circuit board, such as digital temperature sensors or thermistor arrays.

[0034] In step 3, the temperature sensor's measurement accuracy is better than a preset error range (e.g., ±0.1℃), and the sampling frequency is set to be greater than or equal to a predetermined frequency (e.g., 10Hz). The calculation of the characteristic temperature value is not a simple arithmetic average, but rather a weighted average algorithm. The algorithm assigns corresponding weighting coefficients to sensors at different distances from the heat-generating element; sensors closer to high-power components have higher weights, while those closer to the heat dissipation boundary have lower weights. Through this weighted summation algorithm, the influence of local environmental disturbances (such as instantaneous cold spots caused by airflow) on temperature sampling can be effectively eliminated, thereby calculating the true characteristic temperature value reflecting the current thermal state of the entire resistor module. This characteristic temperature value accurately represents the macroscopic thermal state of the resistor array, providing high-confidence input data for subsequent temperature drift compensation.

[0035] Specifically, step 4 involves dynamic modeling of temperature drift and pre-compensation calculation of resistance. This step is crucial for achieving long-term stability. The system retrieves the pre-stored temperature coefficient model of the resistive element from memory. Dynamic modeling of temperature drift employs a polynomial fitting algorithm of a preset order, typically a third or fifth-order polynomial, to accurately describe the nonlinear characteristics of resistance changing with temperature. Based on the physical material properties of the resistive element (such as manganese-copper alloy, nickel-chromium alloy, etc.), the nonlinear curve of resistance changing with temperature is pre-determined, and the polynomial coefficients are extracted.

[0036] When calculating the pre-compensation amount, the logic control processing unit reads the current characteristic temperature value obtained in step 3 in real time, and substitutes it into the polynomial model to calculate the relative rate of change of resistance.

[0037] The specific formula is as follows: in, To calculate the target resistance value after compensation, For calibration temperature The reference resistance value below, and These are the first-order and second-order temperature coefficients, respectively. These are the characteristic temperature values ​​sampled in real time.

[0038] In step 4, the logic for generating the target combination code is as follows: based on the original control code, a resistance combination increment that is equal in magnitude but opposite in direction to the thermal drift is found through mathematical iteration. For example, if an increase in temperature leads to an increase in the total resistance, the compensation logic will automatically reduce the control code and switch to a branch combination with a slightly smaller resistance value, thereby achieving real-time compensation for the resistance change caused by temperature fluctuations. This compensation is completed in the digital domain, offering extremely high flexibility and real-time performance.

[0039] Specifically, step 5 generates high-speed parallel control instructions and implements them. The compensated target combination code generated in step 4 is input to the logic control processing unit. This logic control processing unit typically uses an FPGA or a high-performance microcontroller. To achieve transient switching, a synchronous timing controller is integrated into the system. This synchronous timing controller is implemented using programmable logic devices and internally configured with a high-speed shift register and a buffer drive array.

[0040] In step 5, the synchronization timing controller ensures that the switching actions of all the low-loss electronic switching units are completed within a preset synchronization time interval. For example, the switching jitter of all switches is controlled to the nanosecond level to avoid spike pulses caused by drastic resistance changes during switching. The drive pulse signal is converted by a level conversion circuit to provide sufficient turn-on voltage and drive current. The level conversion circuit uses isolated floating drive technology to ensure that the switching element operates in the deep conduction region, thereby reducing the on-resistance to the target low value of the physical limit and reducing the additional losses introduced by the switch not being fully turned on.

[0041] Specifically, step 6 performs real-time monitoring and closed-loop fine-tuning of output performance. A precision sampling circuit is set at the resistor output port, which includes a high-input-impedance instrumentation amplifier and a high-resolution analog-to-digital converter (ADC). The sampling circuit synchronously samples the voltage and current vectors at the output terminal at a sampling rate not lower than a preset sampling rate, such as 100ksps.

[0042] In step 6, the system extracts the current and voltage at the output terminal in real time and calculates the real-time output resistance value. During the calculation process, a digital filtering algorithm (such as Kalman filtering or median averaging filtering) is introduced to eliminate power frequency interference and high-frequency random noise, ensuring that the calculated resistance value has a very high confidence level. The system calculates the deviation between its real-time output resistance value and the user-set target value. If the deviation exceeds a preset allowable threshold, the system triggers a closed-loop adjustment mechanism. The allowable threshold is set according to the application scenario. In calibration mode, it is set to a first preset deviation ratio (e.g., 0.005%) to pursue ultimate accuracy; in fast adjustment mode, it is set to a second preset deviation ratio (e.g., 0.05%) to pursue response speed. The system dynamically adds or removes resistor branches with minimal weights by fine-tuning the target combination encoding until the output resistance value meets the accuracy requirements.

[0043] Building upon the above embodiments, this method further includes a health status monitoring step for the resistor module. This step predicts faults by analyzing the waveform characteristics of the switching transient. The system extracts the switch action time (the time from command issuance to resistance stabilization), overshoot voltage, and residual ripple parameters after stabilization. If the increase in switch action time exceeds an initial preset ratio, or if the on-state voltage drop exhibits abnormal fluctuations under the same current load, it is determined that the branch switch is at risk of fatigue damage, increased oxidation, or poor contact. The system will automatically trigger an alarm and invoke pre-designed redundant branches for functional replacement, ensuring the continuous reliability of the module during critical testing tasks.

[0044] Furthermore, this method also involves dynamic reduction logic for high-frequency parasitic parameters. Under AC excitation signals, the resistive topology network exhibits complex impedance characteristics due to the distributed capacitance and inductance within it. This invention describes the phase shift and amplitude deviation at various frequency points for different resistance combinations by establishing an impedance spectrum model. During the control command generation stage, the control code is fine-tuned based on the current signal's operating frequency. For example, the imaginary impedance component caused by parasitic parameters is compensated by connecting a small capacitor compensation branch or adjusting the resistor path length.

[0045] Its compensation calculation follows the following complex impedance balance model: in, For the effective resistance component, For line inductance, This is for parasitic capacitance. The system adjusts the control code to ensure that within the preset operating frequency range, and The components cancel each other out, ensuring that the pure resistive characteristics of the output impedance meet the predetermined target ratio, which greatly expands the applicable bandwidth of the module in the field of AC simulation.

[0046] The described resistor module construction method is applied to a multi-channel programmable resistor device. This device is a highly integrated system comprising a main control module, a power management module, and multiple independent adjustable resistor units. These units communicate collaboratively via an internal high-speed synchronous bus. The main control module, acting as the core, coordinates the calibration cycle, compensation strategy, and synchronous triggering of each unit. The power management module provides multi-level low-noise isolated power supplies to prevent power supply noise from coupling into the resistor output circuit. This architecture enables a highly integrated multi-channel impedance simulation environment capable of simulating the complex impedance characteristics of multi-sensor arrays.

[0047] Example 2 Based on the technical architecture of Embodiment 1, this embodiment further describes in detail the microscopic operation mechanism and data interaction process of the multi-range precision resistor topology network under different range segments.

[0048] The method employs a special series leakage prevention structure in step 1 for the specific implementation of the high-resistance section. In the construction of the high-resistance section (above 1MΩ), the physical connection points between precision resistors are susceptible to the decrease in insulation resistance on the PCB surface. To address this issue, this embodiment designs an active shielding ring structure in its physical layout. The shielding ring surrounds each node of the high-resistance branch and is driven to the same potential level as that node by a voltage follower. This method eliminates the potential difference at the physical level, thereby suppressing leakage current across the traces. Simultaneously, the high-voltage switching unit uses a vacuum reed relay or a MOSFET array with extremely low cutoff leakage current, whose cutoff leakage current is controlled in the picoampere range.

[0049] In the binary weighted logic of the medium-resistance section, this embodiment employs a segmented binary mapping scheme. The medium-resistance section is divided into a main resistance array and a fine-tuning array. The main resistance array is responsible for covering 90% of the resistance value span, and it uses high-power, low-inductance wire-wound resistors or high-stability metal film resistors. The fine-tuning array is responsible for supplementing the remaining precision, and it uses a high-resolution chip-type precision thin-film resistor array. Through the coordinated driving of the two arrays by the logic controller, micro-ohm-level adjustment resolution can be achieved while ensuring power carrying capacity.

[0050] In the calibration database establishment process of step 2, this embodiment introduces a nonlinear interpolation algorithm. Since the parasitic parameters of the resistor do not change linearly under different resistance value combinations, while storing discrete calibration points, the system also internally generates a prediction model based on cubic spline interpolation. When a user requests a non-calibration point resistance value, the logic control processing unit uses this interpolation model to quickly calculate the optimal switch combination code, thereby filling the accuracy gap between discrete calibration points.

[0051] In the temperature sampling step of step 3, this embodiment details the deployment geometry of the temperature sensing array. The sensors are distributed in a triangular grid below the resistor matrix. By monitoring the temperature rise rate at each vertex of the triangle, the system can use the heat diffusion equation to infer the location of the heat source. If an abnormal temperature rise is detected in a certain area (such as overheating of the resistor due to continuous high current), the characteristic temperature value calculation logic will automatically increase the weighting of the sensor in that area and trigger the overheat protection logic, temporarily switching to a low-power branch or reducing the current load to protect the precision resistor from permanent resistance shift.

[0052] For temperature drift compensation in step 4, this embodiment employs a dynamic approximation strategy based on dual temperature points. In addition to the characteristic temperature value, the system also collects the ambient reference temperature in real time. A thermal time constant model is introduced by calculating the temperature difference between the internal thermal state of the resistor module and the external environment. Since there is a thermal hysteresis effect from heating to resistance stabilization in the resistor element, this compensation model pre-compensates by a small amount during the dynamic process of temperature change by predicting the thermal hysteresis, further improving the dynamic temperature drift suppression ratio and ensuring that the output resistance remains stable within the nominal range even when the ambient temperature fluctuates drastically.

[0053] In the control implementation of step 5, the internal shift register of the synchronous timing controller employs a double-buffering mechanism. The first buffer stores the current execution instruction, and the second buffer preloads the compensation instruction for the next moment. When the synchronization pulse arrives, the two buffers seamlessly switch instantaneously. The pulse width modulation of the drive pulse signal is optimized into a quasi-square wave, and its rising and falling edge slopes are precisely calibrated to minimize electromagnetic interference caused by high-speed switching while ensuring switching speed. The level conversion circuit also integrates current limiting logic to prevent surge currents generated during switching transients from damaging sensitive precision resistor branches.

[0054] In step 6, the closed-loop fine-tuning process, this embodiment details the parameter configuration of its digital filter. For power frequency interference (50Hz or 60Hz), the digital filter employs a comb-shaped notch filter structure to specifically filter out grid-coupled noise. For high-frequency random noise, a low-pass weighted moving average filter is used. In the calculation of the real-time output resistance, the system automatically deducts the contact resistance on the sampling lead. This contact resistance is obtained through the system's internal periodic self-testing process. In calibration mode, the deviation calculation logic enters a high-precision iterative mode, trying the fine-tuning branch corresponding to the least significant bit (LSB) bit by bit until the deviation between the sampled value and the target value is minimized, thereby achieving a final output performance exceeding the nominal accuracy of the physical components.

[0055] Furthermore, this embodiment introduces impedance fingerprint recognition for health status monitoring. During each power-on self-test, the system records the impedance change curves of each branch switch during the transient closure and stores them as a "health fingerprint." In subsequent operation, if the real-time extracted switching waveform deviates from this fingerprint characteristic, even if the current static resistance value is still acceptable, the system will determine it as a potential failure. For example, if a slight oscillation is detected in the waveform, it indicates that oxide layer accumulation may exist at the switch contact points. This triggers automatic cleaning logic, using multiple rapid closing operations to remove the oxide layer through mechanical friction or arcing (under safe voltage), restoring contact performance.

[0056] In terms of high-frequency parasitic parameter reduction, this embodiment adds real-time evaluation of distributed capacitance. The system monitors the current phase difference at the output port to invert the distributed capacitance value at the current frequency. The reduction logic not only adjusts the real part resistance code but also dynamically allocates compensation inductors or capacitor matrices, ensuring that the phase angle offset of the entire topology network is controlled within 0.1 degrees at operating frequencies up to 1MHz. This preservation of pure resistive characteristics is crucial for the hardware-in-the-loop simulation of high-precision signal chain systems.

[0057] Example 3 This embodiment focuses on describing the multi-dimensional collaboration and system integration characteristics of the adjustable resistor module construction method in practical engineering applications, to demonstrate its performance under complex electromagnetic environments and high dynamic loads.

[0058] In implementing the method, the resistor module is integrated into a multi-channel programmable resistor device. The main control module receives commands from the host computer via a high-speed bus such as PCIe or Ethernet, and then parses and distributes the commands to each adjustable resistor unit. To ensure synchronization between multiple channels, the system employs a hardware-triggered synchronization protocol. When the main control module issues a synchronization switching pulse, the resistor units distributed in different physical locations will update their resistance values ​​within microseconds of synchronization error. This is of core value for complex sensor arrays simulating multi-point coordinated actions (such as multiple temperature / pressure sensors in an aero-engine).

[0059] In the design of the power management module, a three-stage filtering architecture was adopted to meet the high precision requirements of this method. The first stage is active power factor correction to ensure energy utilization efficiency; the second stage is a low-ripple DC-DC converter to provide a stable intermediate bus voltage; and the third stage is an ultra-low noise linear regulator (LDO) specifically designed to power the precision resistor array and sampling circuit. The power supply ripple is controlled at the microvolt level, eliminating analog output noise caused by voltage fluctuations at the source and ensuring the purity of the voltage and current vectors acquired by the sampling circuit.

[0060] In the application scenario of this embodiment, to meet the requirement of ultra-fast response, the drive pulse signal in step 5 is configured in pre-enhancement mode. At the instant the switch is turned on, the drive circuit provides a short-term high-voltage overshoot to accelerate charge injection into the gate of the switching transistor, thereby compressing the turn-on time to the limit. Subsequently, the voltage drops to the holding level to reduce power consumption. This drive strategy, combined with synchronous timing control, enables the resistor module to simulate high-speed dynamic impedance loads, such as the winding impedance fluctuations during motor operation, with a response frequency reaching tens of kHz.

[0061] Regarding environmental adaptability, this embodiment introduces a humidity sensing dimension into the resistor topology network to perform secondary correction on the calibration database. In high humidity environments, the dielectric constant of the PCB substrate shifts, leading to an increase in parasitic capacitance. This method pre-stores correction factors for different humidity gradients in the initial calibration database and, combined with real-time humidity sampling data, fine-tunes the resistance mapping function generated in step 2 in real time, ensuring that the module maintains laboratory-level accuracy even in tropical rainforests or harsh industrial environments.

[0062] In the redundancy replacement stage of health monitoring, this embodiment employs a "smooth switching" technique. When a branch is determined to have failed and needs to be switched to a redundant branch, the system does not directly disconnect the old branch and close the new branch. Instead, it uses an intermediate state—a process in which the two branches operate in parallel for a short period. By precisely controlling the overlap time of the two sets of switches, the momentary open-circuit state caused by switch switching (Make-Before-Break) is eliminated, avoiding high-voltage surges to sensitive downstream loads.

[0063] In optimizing the high-frequency characteristics of the construction method, this embodiment employs a microstrip line matching design. The PCB traces of the resistor array strictly adhere to impedance matching principles, controlling the difference in trace length for each branch to within millimeters to reduce time delay jitter under different range combinations. Under AC excitation signals, the dynamic reduction logic automatically adjusts the compensation parameters according to a preset transfer function.

[0064] For example, for specific high-frequency applications, the system will use the following transfer function for real-time frequency response correction: K represents the steady-state gain of the system, and s is the complex frequency variable in the Laplace transform. The time constant is adjusted by modifying the compensation code. The amplitude approaches zero, thus achieving a flat amplitude-frequency characteristic over an extremely wide frequency range, meeting the precision testing requirements of radar signal processing or satellite communication components.

[0065] Finally, the multi-channel programmable resistor device in this embodiment also features remote calibration and self-diagnosis capabilities. The main control module periodically uploads health data and calibration offsets for each channel via a network interface. A cloud-based expert system performs trend analysis on this data, enabling it to predict the module's end-of-life in advance and push maintenance suggestions to the user. This intelligent system, built using this approach, not only improves adjustment accuracy and response speed but also transforms the traditional adjustable resistor into intelligent hardware with self-awareness and closed-loop evolution capabilities.

[0066] The foregoing has shown and described the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The embodiments and descriptions in the specification are merely illustrative of the principles of the invention. Various changes and modifications can be made to the invention without departing from its spirit and scope, and all such changes and modifications fall within the scope of the present invention as claimed. The scope of protection of this invention is defined by the appended claims and their equivalents.

Claims

1. A method for constructing an adjustable resistor module, characterized in that, The method includes the following steps: Constructing a multi-range precision resistor topology network: Based on a hybrid layout mode combining binary weighted arrangement and segmented equal division arrangement, multiple sets of precision fixed value resistor branches are configured in physical space. Each set of precision fixed value resistor branches is associated with an independent low-loss electronic switch unit. Through the interconnection of physical circuits, a resistor matrix structure with a wide adjustment range and high resolution is formed. The precision fixed value resistor branches are arranged in a thermally symmetrical manner on the circuit board. Establish resistance mapping function and initial calibration database: Obtain the actual static resistance values ​​of each branch in the multi-range precision resistor topology network through measuring instruments, quantify the parasitic inductance, parasitic capacitance and residual resistance of switch contacts in different combination states, model the leakage current under large resistance state and the lead resistance under small resistance state, establish the mapping relationship between control command code and output equivalent resistance value, and generate an initial calibration lookup table containing correction parameters; Perform working environment thermal field distribution sampling: Use the temperature sensing array distributed in the key thermal nodes inside the multi-range precision resistor topology network to acquire temperature data at different locations in real time. By assigning corresponding weighting coefficients to sensors at different distances from the heating element, the characteristic temperature value reflecting the current thermal state of the resistor module is calculated using a weighted average algorithm. Perform dynamic modeling of temperature drift and pre-compensation calculation of resistance: retrieve the temperature coefficient model of the resistor element stored in the memory, calculate the thermal drift of each resistance unit under the current environment based on the characteristic temperature value, introduce the thermal drift as a correction parameter into the mapping relationship, and generate the compensated target combination code by finding the resistance combination increment that is equal in magnitude and opposite in direction to the thermal drift. Generate high-speed parallel control instructions and implement drive: Input the target combination code into the logic control processing unit, generate multiple parallel drive pulse signals through the synchronous timing controller, and convert the drive pulse signals through the level conversion circuit to provide the turn-on voltage, ensuring that the switching element works in the deep conduction region, and synchronously act on the low-loss electronic switching unit to realize the transient switching and holding of the output resistance value; Real-time monitoring and closed-loop fine-tuning of output performance: A precision sampling circuit is set at the resistor output port to extract the voltage and current vectors at the output in real time. A digital filtering algorithm is introduced to remove power frequency interference and random noise, and the real-time output resistance value is calculated. The deviation between the real-time output resistance value and the set target value is calculated. If the deviation exceeds the preset allowable threshold, the target combination code is dynamically fine-tuned until the output resistance value meets the accuracy requirements.

2. The method for constructing an adjustable resistor module according to claim 1, characterized in that, The multi-range precision resistor topology network adopts a hierarchical construction strategy, including a high-resistance section, a medium-resistance section, and a low-resistance section. The high-resistance section consists of multiple precision resistors connected in series with resistance values ​​greater than or equal to a first preset resistance threshold, and is controlled by a high-voltage switch whose withstand voltage rating is configured to cover the highest rated operating voltage of the module. The medium-resistance section consists of precision resistors with resistance values ​​within a predetermined intermediate range, employing a binary-weighted series-parallel hybrid structure. This structure includes a main resistance array and a fine-tuning array; the main resistance array covers most of the resistance value range, while the fine-tuning array compensates for the remaining accuracy. The low-resistance section consists of sampling resistors connected in parallel with resistance values ​​less than a second preset resistance threshold, and the impact of the total on-resistance on overall accuracy is reduced through multi-path parallel switching.

3. The method for constructing an adjustable resistor module according to claim 2, characterized in that, In terms of physical layout, the precision fixed-value resistor branch is arranged by symmetrically placing high-power heating elements on both sides of the resistor array, or symmetrically arranging the resistor array around the thermal center, in order to ensure the consistency of temperature rise between branches and minimize local thermal gradients during operation. An active shielding ring is set in the physical structure of the high-impedance section. The active shielding ring surrounds each node of the high-impedance branch and is driven by a voltage follower to a level equal to that node, thereby eliminating potential difference at the physical level to suppress leakage current across the trace. The physical trace of the resistor matrix structure adopts a microstrip line matching design to control the difference in wiring length of each branch within a preset length tolerance range, in order to reduce clock skew and time delay jitter under different range combinations.

4. The method for constructing an adjustable resistor module according to claim 1, characterized in that, The process of establishing the resistance mapping function and the initial calibration database includes: traversing all logical combination states of the multi-range precision resistor topology network under a preset reference temperature environment, and recording the endpoint resistance values ​​in each state using a high-resolution measurement component; for leakage current in the large resistance state, modeling compensation is performed by measuring the equivalent parallel impedance of the insulation branch; for lead resistance in the small resistance state, the parasitic resistance of the switch pins, trace copper foil, and connectors is extracted using a four-wire measurement method for specific compensation; when generating the initial calibration lookup table, a prediction model based on cubic spline interpolation is introduced to quickly calculate the optimal switch combination code corresponding to the non-calibration point resistance value in the logic control processing unit.

5. The method for constructing an adjustable resistor module according to claim 1, characterized in that, In the sampling step of the working environment thermal field distribution, the temperature sensing array is distributed below the resistor matrix in a preset geometric topology. By monitoring the temperature rise rate of different areas, the heat source location is located using the thermal diffusion equation. In the weighted average algorithm, the system dynamically allocates weighting coefficients according to the distance between the sensor and the heating element. When the temperature rise of a specific area exceeds a preset safety threshold, the weighting weight of the sensor in that area is automatically increased and the overheat protection logic is triggered. The logic control processing unit switches to a low-power redundant branch or reduces the current load to prevent the precision fixed resistor from causing a permanent resistance value shift.

6. The method for constructing an adjustable resistor module according to claim 1, characterized in that, The dynamic modeling of temperature drift employs a polynomial fitting algorithm of a preset order. Polynomial coefficients are extracted based on the physical material characteristics of the resistive element to describe the nonlinear characteristics of resistance change with temperature. When calculating the thermal drift, the system introduces a dynamic approximation strategy based on dual temperature points. By collecting the ambient reference temperature in real time and calculating the temperature difference between it and the characteristic temperature value, the system estimates the thermal hysteresis of the resistive element in combination with a preset thermal time constant model. In the dynamic process of temperature change, a small amount of advance compensation is performed to offset the thermal hysteresis effect between the resistive element being heated and the resistance stabilizing.

7. The method for constructing an adjustable resistor module according to claim 1, characterized in that, In the step of generating high-speed parallel control instructions and implementing the drive, the synchronous timing controller is equipped with a shift register with a double buffer mechanism. The first buffer stores the currently executed instruction, and the second buffer is preloaded with the compensation instruction for the next moment. Seamless switching is completed at the moment the synchronization pulse arrives. The waveform of the drive pulse signal is configured as a quasi-square wave, and its rising and falling edge slopes are precisely calibrated to reduce electromagnetic interference. The level conversion circuit adopts isolated floating drive technology and integrates current limiting logic to prevent surge current generated during switch switching transients from damaging the precision fixed resistor branch.

8. The method for constructing an adjustable resistor module according to claim 1, characterized in that, In the real-time monitoring and closed-loop fine-tuning steps of the output performance, the precision sampling circuit includes a high-input-impedance instrumentation amplifier and a high-resolution analog-to-digital converter to synchronously sample the voltage vector and current vector at the output terminal. The digital filtering algorithm uses a comb-shaped notch filter structure to filter out power frequency interference and a low-pass weighted moving average filter to filter high-frequency random noise. When calculating the real-time output resistance, the system automatically deducts the sampling lead contact resistance obtained through a periodic self-test process. In calibration mode, the closed-loop fine-tuning process attempts the fine-tuning branch corresponding to the least significant bit bit bit bit by bit in a bit-by-bit iteration until the deviation between the sampled value and the target value is minimized.

9. The method for constructing an adjustable resistor module according to claim 1, characterized in that, The method also includes a health status monitoring step for the resistor module: extracting waveform features of the transient switching of the switch through the logic control processing unit, the waveform features including the switching action time, overshoot voltage, and residual ripple parameters after stabilization; comparing the real-time extracted waveform features with the health fingerprint features stored in the non-volatile memory, if the waveform deviation exceeds a preset ratio or abnormal oscillation occurs, it is determined that the branch switch has a potential failure risk, the system automatically triggers an alarm prompt and uses smooth switching technology to call redundant branches for functional replacement, and the transient open circuit state is eliminated by controlling the overlap time of the two sets of switches during the switching process.

10. The method for constructing an adjustable resistor module according to claim 1, characterized in that, The method further includes a dynamic reduction step for high-frequency parasitic parameters: establishing an impedance spectrum model to describe the complex impedance characteristics of the resistive topology network at different excitation frequencies; in the control command generation stage, based on the current signal operating frequency and the monitored output port current phase difference, inverting the distributed capacitance and distributed inductance values ​​at the current frequency; introducing fine-tuning inductance or capacitance compensation branches by adjusting the control code, or adjusting the resistor path length to compensate for the imaginary impedance component, so that the pure resistance characteristics of the output impedance within the preset operating frequency range meet the predetermined target ratio, and ensuring that the phase angle offset is within the preset allowable angle range.

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