Power drop test automation method and apparatus

Abstract

This invention discloses an automated method and apparatus for power supply drop testing, relating to the field of power supply drop testing technology. The apparatus includes an MCU, a programmable resistor module, a relay module, and a fast discharge circuit. The method includes: responding to a test trigger signal, controlling the resistance value of the programmable resistor module based on a target drop voltage value, and outputting an initial drop voltage at the feedback voltage output terminal; controlling the relay module to close, using the initial drop voltage as the power supply drop test voltage output; controlling the relay module to open to simulate a power supply drop; and controlling the fast discharge circuit to conduct at the instant the relay module opens, causing the capacitor connected to the power supply drop test voltage output terminal to discharge rapidly through the fast discharge circuit, accelerating the drop voltage decrease slope. This invention provides an effective solution for achieving rapid voltage drop during power supply drop testing.

Description

Technical Field

[0001] This invention relates to the field of power supply drop test technology, and in particular to an automated method and apparatus for power supply drop test. Background Technology

[0002] In the field of power drop testing, test equipment needs to simulate the condition of a sudden drop in supply voltage to evaluate the stability and reliability of electronic devices under abnormal power supply conditions. The inventors of this application have discovered that the power input of the device under test (DUT) or chip verification board is typically connected in parallel with a capacitive load. When the power is cut off, these capacitors store charge and release it slowly, causing the output voltage to not drop instantaneously, but rather exhibit a gentle downward curve. This physical phenomenon results in a voltage drop slope that is much smaller than the steep drop caused by a momentary power interruption or short circuit in actual applications.

[0003] In existing technologies, to address this issue, the power input is typically cut off by simply disconnecting the relay, relying on the capacitor itself to discharge to the load and create a voltage drop. However, due to the energy storage characteristics of the capacitor, the discharge rate is determined by both the load impedance and the capacitance value. Under light loads or with large capacitors, the voltage drop process is extremely slow, failing to simulate rapid voltage drops on the order of milliseconds or even microseconds. Furthermore, another approach attempts to connect a fixed-value load resistor in parallel at the output of the device under test to accelerate capacitor discharge. However, the fixed resistor continuously consumes power during normal power supply, leading to reduced efficiency and additional heat generation. Moreover, its resistance value cannot be flexibly adjusted according to test requirements, making it difficult to accommodate various different voltage drop slope requirements. Summary of the Invention

[0004] This invention provides an automated method and apparatus for power supply drop testing, aiming to solve the technical problem of how to provide an effective solution for achieving rapid voltage drop during power supply drop testing.

[0005] In a first aspect, the present invention provides an automated method for power supply drop test, applied to an automated power supply drop test device, the automated power supply drop test device comprising an MCU, a programmable resistor module, a relay module, and a fast discharge circuit; the programmable resistor module is connected between a power input terminal and ground and has a feedback voltage output terminal; the relay module is connected between the feedback voltage output terminal and a power supply drop test voltage output terminal; the fast discharge circuit is connected between the power supply drop test voltage output terminal and ground and is controlled by the MCU; the method includes: In response to receiving a test trigger signal, the resistance value of the programmable resistor module is controlled based on a preset target drop voltage value to output an initial drop voltage at the feedback voltage output terminal. The relay module is controlled to close, and the initial drop voltage is used as the power drop test voltage and output from the power drop test voltage output terminal. The relay module is controlled to disconnect to simulate a power drop; At the instant the relay module is disconnected, the fast discharge circuit is turned on, causing the capacitor connected to the power supply drop test voltage output terminal to discharge rapidly through the fast discharge circuit, thereby accelerating the drop slope of the power supply drop test voltage.

[0006] Optionally, the programmable resistor module includes a first programmable resistor, a second programmable resistor, a third programmable resistor, and a fourth programmable resistor connected in series between the power input terminal and ground; the feedback voltage output terminal is led out from the node between the second programmable resistor and the third programmable resistor.

[0007] Optionally, the first programmable resistor and the second programmable resistor constitute the upper arm of the voltage divider circuit, and the third programmable resistor and the fourth programmable resistor constitute the lower arm of the voltage divider circuit; the voltage at the feedback voltage output terminal is determined by the resistance ratio of the upper arm to the lower arm of the voltage divider circuit.

[0008] Optionally, the fast discharge circuit includes a PNP transistor, a diode, a fifth resistor, and a sixth resistor; the anode of the diode is connected to the output terminal of the relay module, and the cathode of the diode is connected to the power supply dropout test voltage output terminal; the base of the PNP transistor is connected to the output terminal of the relay module and grounded through the fifth resistor; the emitter of the PNP transistor is connected to the power supply dropout test voltage output terminal, and the collector of the PNP transistor is grounded through the sixth resistor.

[0009] Optionally, controlling the resistance value of the programmable resistor module includes: Calculate the target voltage division ratio based on the target drop voltage value and the preset input voltage value; Based on the target voltage division ratio, an optimal combination of resistance values ​​is found from the set of resistance values ​​of the programmable resistor module. The optimal combination of resistance values ​​minimizes the difference between the actual voltage division ratio of the voltage divider circuit and the target voltage division ratio. The optimal resistance value combination is written into the programmable resistor module.

[0010] Optionally, the step of searching for an optimal combination of resistance values ​​from the set of resistance values ​​of the programmable resistor module based on the target voltage division ratio includes: Iterate through the elements in the set of resistance values, calculate the sum of all pairwise resistances, and obtain the set of sum values; Two sets of sums are selected from the set of sums, and are used as the sum of the upper arm resistance and the sum of the lower arm resistance of the voltage divider circuit, respectively. Calculate the ratio of the sum of the resistances of the upper arm to the sum of the resistances of the upper arm and the lower arm, and use this ratio as the actual voltage division ratio; The two sums that minimize the absolute value of the difference between the actual voltage division ratio and the target voltage division ratio are selected as the optimal resistance value combination.

[0011] Optionally, writing the optimal resistance value combination into the programmable resistor module includes: writing the configuration data corresponding to the optimal resistance value combination into the first programmable resistor, the second programmable resistor, the third programmable resistor, and the fourth programmable resistor, respectively.

[0012] Optionally, after the control of the relay module is disconnected, the method further includes: Collect the actual voltage drop value at the output terminal of the power supply voltage drop test; Determine whether the deviation between the actual drop voltage value and the target drop voltage value exceeds a preset range; If the deviation between the actual drop voltage value and the target drop voltage value exceeds the preset range, the relay module is controlled to close, and the process returns to the step of controlling the resistance value of the programmable resistor module. If the deviation between the actual drop voltage value and the target drop voltage value does not exceed the preset range, then the actual drop voltage value will be used as the final drop test voltage output.

[0013] Optionally, the device further includes an input module, a display module, and an ADC module; the communication between the input module or the display module and the MCU, as well as the communication between the MCU and the programmable resistor module, the relay module, and the ADC module, are all implemented through a universal asynchronous transceiver or a serial peripheral interface.

[0014] Secondly, the present invention also provides an automated power supply drop test device, including an MCU, a programmable resistor module, a relay module, and a fast discharge circuit; the programmable resistor module is connected between a power input terminal and ground and has a feedback voltage output terminal; the relay module is connected between the feedback voltage output terminal and the power supply drop test voltage output terminal; the fast discharge circuit is connected between the power supply drop test voltage output terminal and ground and is controlled by the MCU, wherein the MCU is used to execute the automated power supply drop test method as described in the first aspect.

[0015] This invention provides an automated method and apparatus for power supply dip testing. By employing a programmable resistor module controlled by an MCU, this method achieves precise setting of the power supply dip test voltage. At the instant the relay module disconnects to simulate a power supply dip, the fast discharge circuit is simultaneously activated, creating a rapid discharge path for the capacitor connected to the output terminal of the power supply dip test voltage. This mechanism effectively overcomes the problem of slow voltage drop caused by capacitive load, significantly improving the voltage drop slope. Therefore, this invention provides an effective solution for achieving rapid voltage drop during power supply dip testing. Attached Figure Description

[0016] To more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings used in the following description of the embodiments will be briefly introduced. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0017] Figure 1 This is a structural block diagram of the automated power drop test device provided in an embodiment of the present invention; Figure 2 This is a flowchart illustrating the automated power supply drop test method provided in an embodiment of the present invention. Detailed Implementation

[0018] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0019] It should be understood that, when used in this specification and the appended claims, the terms "comprising" and "including" indicate the presence of the described features, integrals, steps, operations, elements and / or components, but do not exclude the presence or addition of one or more other features, integrals, steps, operations, elements, components and / or collections thereof.

[0020] It should also be understood that the terminology used in this specification is for the purpose of describing particular embodiments only and is not intended to limit the invention. As used in this specification and the appended claims, the singular forms “a,” “an,” and “the” are intended to include the plural forms unless the context clearly indicates otherwise.

[0021] It should also be further understood that the term "and / or" as used in this specification and the appended claims refers to any combination of one or more of the associated listed items and all possible combinations, and includes such combinations.

[0022] As used in this specification and the appended claims, the term "if" may be interpreted, depending on the context, as "when," "once," "in response to determination," or "in response to detection." Similarly, the phrase "if determined" or "if [described condition or event] is detected" may be interpreted, depending on the context, as "once determined," "in response to determination," "once [described condition or event] is detected," or "in response to detection of [described condition or event]."

[0023] Please see Figure 1 This invention provides an automated power supply drop test device, comprising an MCU 10, a programmable resistor module 20, a relay module 30, and a fast discharge circuit 40. The programmable resistor module 20 is connected between the power input terminal POWER IN and ground, and has a feedback voltage output terminal FB. The relay module 30 is connected between the feedback voltage output terminal FB and the power supply drop test voltage output terminal POWER OUT. The fast discharge circuit 40 is connected between the power supply drop test voltage output terminal POWER OUT and ground, and is controlled by the MCU 10. The MCU 10 is used to execute an automated power supply drop test method proposed in this invention.

[0024] In specific implementation, the programmable resistor module 20 refers to a circuit module controlled by the MCU 10 that can adjust the output voltage by changing the value of its internal resistor. The programmable resistor module 20 is connected between the power input terminal POWER IN and ground, and a feedback voltage output terminal FB is led out from an intermediate node in its series resistor network. By adjusting the value of its internal resistor, the module changes the voltage division ratio between the power input terminal POWER IN and ground, thereby outputting the required voltage value at the feedback voltage output terminal FB.

[0025] The relay module 30 refers to an electrically controlled switching device controlled by the MCU 10, which achieves contact engagement and disengagement through an internal electromagnetic mechanism. The relay module 30 is connected between the feedback voltage output terminal FB and the power drop test voltage output terminal POWER OUT, and is used to electrically connect or isolate the feedback voltage output terminal FB and the power drop test voltage output terminal POWER OUT under the control of the MCU 10.

[0026] The fast discharge circuit 40, controlled by the MCU 10, provides a fast discharge path for the capacitive load connected to the power drop test voltage output terminal POWER OUT. The fast discharge circuit 40 is connected between the power drop test voltage output terminal POWER OUT and ground, and its on / off state is controlled by the MCU 10. When the fast discharge circuit 40 is on, it forms a low-impedance discharge path, allowing the charge on the power drop test voltage output terminal POWER OUT to be quickly discharged to ground. The power drop test voltage output terminal POWER OUT is used to connect to the device under test (DUT), and the power input terminal of the DUT typically has a capacitive load connected in parallel.

[0027] Furthermore, in some preferred embodiments, the programmable resistor module 20 includes a first programmable resistor R1, a second programmable resistor R2, a third programmable resistor R3, and a fourth programmable resistor R4 connected in series between the power input terminal POWER IN and ground; the feedback voltage output terminal FB is led out from the node between the second programmable resistor R2 and the third programmable resistor R3.

[0028] In a specific implementation, the programmable resistor module 20 includes a first programmable resistor R1, a second programmable resistor R2, a third programmable resistor R3, and a fourth programmable resistor R4 connected in series between the power input terminal POWER IN and ground. These four programmable resistors together form a series voltage divider network.

[0029] Furthermore, the feedback voltage output terminal FB is led out from the node between the second programmable resistor R2 and the third programmable resistor R3. That is, in the path of current flowing from the power input terminal POWER IN to ground, it passes sequentially through the first, second, third, and fourth programmable resistors R1, R2, R3, and R4, with the feedback voltage output terminal FB located after the second programmable resistor R2 and before the third programmable resistor R3. By changing the resistance value of any one of these four resistors, the voltage value at the feedback voltage output terminal FB can be changed, thereby achieving fine adjustment of the voltage drop. The series connection of the four resistors provides greater freedom in resistance value combinations.

[0030] This embodiment concretizes the programmable resistor module 20 into four programmable resistors connected in series and clarifies the output location of the feedback voltage, providing a clear hardware structure foundation for subsequent accurate calculation and adjustment of the voltage division ratio. Furthermore, compared to a simple two-resistor voltage divider, the series structure of four resistors can generate a wider variety of different voltage division ratios, thereby expanding the settable voltage drop range and improving the accuracy of voltage drop.

[0031] In some preferred embodiments, the first programmable resistor R1 and the second programmable resistor R2 constitute the upper arm of the voltage divider circuit, and the third programmable resistor R3 and the fourth programmable resistor R4 constitute the lower arm of the voltage divider circuit; the voltage of the feedback voltage output terminal FB is determined by the resistance ratio of the upper arm to the lower arm of the voltage divider circuit.

[0032] In specific implementation, the first programmable resistor R1 and the second programmable resistor R2 constitute the upper arm of the voltage divider circuit, while the third programmable resistor R3 and the fourth programmable resistor R4 constitute the lower arm of the voltage divider circuit. Furthermore, the voltage at the feedback voltage output terminal FB is determined by the ratio of the resistance value of the upper arm to the resistance value of the lower arm of the voltage divider circuit, and this relationship follows the series voltage divider principle of Kirchhoff's voltage law and Ohm's law, as detailed below: When the power input voltage POWER IN is V_IN, the voltage V_FB at the feedback voltage output FB is related to the sum of the upper arm resistance R_UP = R1 + R2 and the sum of the lower arm resistance R_DOWN = R3 + R4 by the formula: V_FB = V_IN * (R_DOWN / (R_UP + R_DOWN)). This formula shows that the feedback voltage can be increased by increasing the lower arm resistance and decreasing the upper arm resistance; conversely, the feedback voltage will be decreased.

[0033] In some preferred embodiments, the fast discharge circuit 40 includes a PNP transistor Q1, a diode D1, a fifth resistor R5, and a sixth resistor R6; the anode of the diode D1 is connected to the output terminal of the relay module 30, and the cathode of the diode D1 is connected to the power supply dropout test voltage output terminal POWER OUT; the base of the PNP transistor Q1 is connected to the output terminal of the relay module 30 and grounded through the fifth resistor R5; the emitter of the PNP transistor Q1 is connected to the power supply dropout test voltage output terminal POWER OUT, and the collector of the PNP transistor Q1 is grounded through the sixth resistor R6.

[0034] In specific implementation, the fast discharge circuit 40 includes a PNP transistor Q1, a diode D1, a fifth resistor R5, and a sixth resistor R6. The anode of diode D1 is connected to the output terminal of the relay module 30, and the cathode of diode D1 is connected to the power drop test voltage output terminal POWER OUT. Diode D1 is used to prevent current from flowing back from the device under test to the relay, thereby protecting the circuit.

[0035] Furthermore, the base of the PNP transistor Q1 is connected to the output terminal of the relay module 30 and grounded through the fifth resistor R5. The emitter of the PNP transistor Q1 is connected to the power dropout test voltage output terminal POWEROUT, and the collector of the PNP transistor Q1 is grounded through the sixth resistor R6. When the relay module 30 is closed, its output voltage is high. Due to the voltage division through the fifth resistor R5, the base voltage of the PNP transistor Q1 is also high, causing it to be in the off state and not affecting normal power supply. When the relay module 30 is open, its output voltage drops instantaneously, and the base voltage of the PNP transistor Q1 decreases accordingly. When it falls below the emitter voltage, the PNP transistor Q1 quickly turns on.

[0036] Furthermore, after conduction, the capacitor connected to the POWER OUT terminal of the power drop test voltage output is discharged to ground in a controlled manner through the emitter-collector path of the PNP transistor Q1 and then through the sixth resistor R6, achieving rapid discharge. The sixth resistor R6 is used to limit the discharge current to prevent excessive instantaneous current from damaging the device.

[0037] This embodiment provides a specific implementation of a fast discharge circuit 40 with a simple structure and fast response speed. Utilizing the characteristic of PNP transistor Q1 to automatically conduct upon the base voltage jump at the moment the relay is disconnected, an efficient discharge path is created for the capacitive load; that is, the MCU10 controls the relay to turn off while simultaneously controlling the conduction of PNP transistor Q1. Furthermore, diode D1 effectively prevents current backflow, improving the reliability and safety of the circuit. Furthermore, the sixth resistor R6 provides current-limiting protection for PNP transistor Q1. Furthermore, this circuit structure is low-cost, easy to integrate, and can significantly improve the steepness of voltage drop during power supply drop tests.

[0038] In some preferred embodiments, the power drop test automation device further includes an input module 50, a display module 60, and an ADC module 70; the communication between the input module 50 or the display module 60 and the MCU 10, as well as the communication between the MCU 10 and the programmable resistor module 20, the relay module 30, and the ADC module 70, are all implemented through a universal asynchronous transceiver or a serial peripheral interface.

[0039] In specific implementation, the automated power drop test device further includes an input module 50, a display module 60, and an ADC module 70. The input module 50 receives the target drop voltage value set by the user; the display module 60 displays input parameters, current output voltage value, test status, and other information; and the ADC module 70 acquires voltage values. Communication between the input module 50 or the display module 60 and the MCU 10, as well as communication between the MCU 10 and the programmable resistor module 20, the relay module 30, and the ADC module 70, is achieved through a Universal Asynchronous Receiver / Transmitter (UART) or a Serial Peripheral Interface (SPI). Both UART and SPI are standard communication protocols commonly used in industry, providing a simple, stable, and efficient data exchange method. Those skilled in the art can choose the appropriate protocol according to actual needs.

[0040] This embodiment clarifies the communication methods between the various modules within the device, employing standard industrial interfaces such as UART or SPI. This ensures the universality and portability of the device across different hardware platforms, enabling the MCU10 to easily connect and interact with various types of peripherals, reducing the difficulty and cost of system integration.

[0041] Please see Figure 2 This invention provides an automated method for power supply drop testing, which includes the following steps: S1, in response to receiving a test trigger signal, controls the resistance value of the programmable resistor module based on a preset target drop voltage value, so as to output the initial drop voltage at the feedback voltage output terminal.

[0042] In specific implementation, firstly, in response to receiving a test trigger signal, the MCU controls the resistance value of the programmable resistor module based on a preset target drop-off voltage value. Specifically, the MCU calculates a target voltage division ratio based on Ohm's law and the series voltage division principle, according to the target drop-off voltage value and a preset input voltage value. Further, the MCU searches for an optimal combination of resistance values ​​from the set of resistance values ​​in the programmable resistor module, a combination that makes the actual voltage division ratio infinitely close to the target voltage division ratio. Further, the MCU writes the configuration data corresponding to the optimal resistance value combination into the programmable resistor module via an I2C communication interface. By adjusting the resistance values ​​of each resistor in the programmable resistor module, the voltage division ratio between the power input terminal and ground is changed, thereby accurately outputting an initial drop-off voltage at the feedback voltage output terminal.

[0043] In some preferred embodiments, controlling the resistance value of the programmable resistor module includes: calculating a target voltage division ratio based on the target dropout voltage value and a preset input voltage value; based on the target voltage division ratio, finding an optimal resistance value combination from the resistance value set of the programmable resistor module, the optimal resistance value combination minimizing the difference between the actual voltage division ratio of the voltage divider circuit and the target voltage division ratio; and writing the optimal resistance value combination into the programmable resistor module.

[0044] In practice, the MCU first calculates the target voltage divider ratio k based on the target dropout voltage value V_OUT and the preset input voltage value V_IN. The calculation formula is based on the voltage divider principle and takes into account the influence of the back-end load and circuit voltage drop. It is usually expressed as k = (V_OUT + V_FD1) / V_IN, where V_FD1 is an empirical constant, for example, it can be taken as 0.3V, representing the diode or line voltage drop.

[0045] Furthermore, based on the target voltage division ratio k, the MCU searches for an optimal combination of resistance values ​​from the set of resistance values ​​of the programmable resistor module, namely the specific values ​​of R1, R2, R3, and R4. The goal of the search is to minimize the absolute value of the difference |r - k| between the actual voltage division ratio r of the voltage divider circuit and the target voltage division ratio k. The set of resistance values ​​is pre-stored in the MCU and includes all selectable resistance values ​​of the programmable resistor chip.

[0046] Furthermore, the MCU writes the found optimal resistance value combination into the programmable resistor module, that is, configures the resistance values ​​of R1, R2, R3, and R4 respectively. If the actual output voltage still deviates from the target voltage after the initial configuration, it can be further corrected through subsequent closed-loop feedback adjustment.

[0047] In some preferred embodiments, the step of finding an optimal resistance value combination from the resistance value set of the programmable resistor module based on the target voltage division ratio includes: traversing the elements in the resistance value set, calculating the sum of all pairwise resistances to obtain a sum set; selecting two sum sets from the sum set as the upper arm resistance sum and the lower arm resistance sum of the voltage divider circuit, respectively; calculating the ratio of the upper arm resistance sum to the lower arm resistance sum as the actual voltage division ratio; and selecting the two sum sets that minimize the absolute value of the difference between the actual voltage division ratio and the target voltage division ratio as the optimal resistance value combination.

[0048] In practice, firstly, the MCU iterates through each element in the selectable resistance value set of the programmable resistor module, calculates the sum of the resistances of all unordered pairs (i.e., pairwise combinations regardless of order), and obtains a sum set S. The sum set S contains the results of adding all possible pairs of resistors.

[0049] Furthermore, two sets of sums are selected from the sum set S, which are respectively used as the upper arm resistance sum X and the lower arm resistance sum Y of the voltage divider circuit. Among them, X corresponds to the sum of the resistance values ​​of the first programmable resistor and the second programmable resistor, that is, X = R1 + R2; Y corresponds to the sum of the resistance values ​​of the third programmable resistor and the fourth programmable resistor, that is, Y = R3 + R4.

[0050] Furthermore, the MCU calculates the ratio of the upper arm resistance and X to the sum of the upper arm resistance and the lower arm resistance (X + Y), i.e., X / (X + Y), as the actual voltage division ratio r.

[0051] Further, the MCU selects the two sums X and Y that minimize the absolute value |r - k| of the difference between the actual voltage division ratio r and the target voltage division ratio k, as the optimal resistance combination. Then, X is assigned to R1 and R2, and Y is assigned to R3 and R4.

[0052] The step of selecting two sets of sums from the sum set includes: traversing all combinations formed by any two elements in the sum set, and taking the two elements in each combination as the upper arm resistance and X and the lower arm resistance and Y, respectively.

[0053] Furthermore, after determining the optimal X and Y, they are decomposed into specific resistors, including: for the upper arm, two resistor values ​​are selected from the set of resistance values, such that their sum equals X, and configured as the first programmable resistor R1 and the second programmable resistor R2, respectively; for the lower arm, two resistor values ​​are selected from the set of resistance values, such that their sum equals Y, and configured as the third programmable resistor R3 and the fourth programmable resistor R4, respectively.

[0054] Furthermore, if there are multiple decomposition methods, they can be selected according to preset rules. For example, the combination that makes each resistor value closest to the average value can be selected first, or one of them can be selected arbitrarily. Since the influence of R1 and R2, R3 and R4 on the voltage division ratio in the series relationship depends only on their respective sums, any decomposition that satisfies the sum condition can obtain the same actual voltage division ratio.

[0055] This embodiment provides a specific and efficient resistance value optimization algorithm. By pre-calculating the sum of all pairwise resistors, the complex four-resistor combination problem is transformed into a problem of selecting two matching pairs from the set of sums, greatly simplifying the search process and reducing the computational burden and memory requirements of the MCU. This algorithm can ensure that the theoretically closest resistance value combination to the target voltage division ratio is found in the shortest time, thereby improving the speed and efficiency of the initial system configuration.

[0056] In some preferred embodiments, writing the optimal resistance value combination into the programmable resistor module includes: writing the configuration data corresponding to the optimal resistance value combination into the first programmable resistor, the second programmable resistor, the third programmable resistor, and the fourth programmable resistor, respectively.

[0057] In specific implementation, the MCU, through the I2C communication interface, writes the configuration data corresponding to the optimal resistance value combination into the first programmable resistor, the second programmable resistor, the third programmable resistor, and the fourth programmable resistor, respectively. It should be noted that I2C is a synchronous, multi-master serial communication bus that requires only two signal lines (SCL serial clock line and SDA serial data line) to connect multiple devices. The MCU acts as the master device on the bus, and each programmable resistor module acts as a slave device, each with a unique device address. The MCU can independently configure the resistance value of each programmable resistor by sending the start condition, device address, read / write bits, register address, and resistance configuration data.

[0058] S2, control the relay module to close, and use the initial drop voltage as the power drop test voltage, and output it from the power drop test voltage output terminal.

[0059] In practice, the MCU controls the relay module to close. The relay module is normally open; upon receiving a closing command from the MCU, its internal contacts close. Furthermore, the feedback voltage output terminal is connected to the power supply dip test voltage output terminal, and the initial dip voltage serves as the power supply dip test voltage, output from the power supply dip test voltage output terminal to the device under test.

[0060] S3, control the relay module to disconnect to simulate a power drop.

[0061] In practice, to simulate a power drop event, the MCU controls the relay module to disconnect. This action severs the physical connection between the power drop test voltage output terminal and the feedback voltage output terminal, thereby interrupting the power supply.

[0062] S4, at the instant the relay module is disconnected, the fast discharge circuit is controlled to be turned on, so that the capacitor connected to the power supply drop test voltage output terminal is rapidly discharged through the fast discharge circuit, thereby accelerating the drop slope of the power supply drop test voltage.

[0063] In practice, the MCU controls the fast discharge circuit to turn on the instant the relay module is disconnected. Since the device under test or test board typically has capacitive loads connected in parallel, these capacitors store charge after the power supply is cut off, resulting in a slow voltage drop and a gentle sag. In this embodiment, the turn-on of the fast discharge circuit provides a low-impedance, fast discharge path for the capacitor connected to the power drop test voltage output terminal. Specifically, the PNP transistor in the fast discharge circuit quickly turns on under the control of the MCU, allowing the charge on the capacitor to be quickly discharged to ground through the PNP transistor, thereby greatly accelerating the sag of the power drop test voltage and simulating a steep power drop waveform to test the performance of the device under test under extreme power outage conditions.

[0064] This embodiment organically integrates an MCU, a programmable resistor module, a relay module, and a fast-discharge circuit, and controls them according to the steps described above to construct a complete automated power supply drop test solution. The programmable resistor module enables precise setting of different drop voltage values, solving the problem that existing equipment can only output in a fixed mode and cannot match the precise drop test requirements of small current and small voltage. Furthermore, the relay module simulates power disconnection under the control of the MCU. The fast-discharge circuit is activated the instant the relay disconnects, providing a rapid discharge channel for the downstream capacitor load, solving the problem of slow power loss and insufficient drop slope caused by capacitor energy storage, and simulating a steep drop waveform that is closer to real-world application scenarios. Furthermore, the entire process is automatically controlled by the MCU without manual intervention, achieving automation of the testing process and improving testing efficiency and consistency.

[0065] In some preferred embodiments, after the relay module is disconnected, the method further includes: acquiring the actual drop voltage value at the power supply drop test voltage output terminal; determining whether the deviation between the actual drop voltage value and the target drop voltage value exceeds a preset range; if the deviation between the actual drop voltage value and the target drop voltage value exceeds the preset range, controlling the relay module to close and returning to the step of controlling the resistance value of the programmable resistor module; if the deviation between the actual drop voltage value and the target drop voltage value does not exceed the preset range, then using the actual drop voltage value as the final drop test voltage output.

[0066] In practice, firstly, the MCU acquires the actual voltage drop value V_actual at the power supply voltage drop test output terminal through an analog-to-digital converter (ADC) module. The ADC module converts the analog voltage signal at the power supply voltage drop test output terminal into a digital signal and sends it to the MCU.

[0067] Furthermore, the MCU compares the actual drop voltage value V_actual with the target drop voltage value V_target, calculates the deviation ΔV = V_actual - V_target, and determines whether the absolute value of the deviation |ΔV| exceeds a preset allowable range (e.g., ±1% of the target value).

[0068] Furthermore, if |ΔV| exceeds the preset range, it indicates that the current "mathematically optimal" resistor combination still has errors in physical implementation. In this case, the MCU does not re-execute the initial full search algorithm, but instead performs a directional fine-tuning based on the deviation direction: the MCU, according to the sign and magnitude of ΔV, performs step-by-step fine-tuning on one or more of the first, second, third, or fourth programmable resistors while keeping other resistors unchanged or adjusting them proportionally. For example, if the actual voltage is too low (ΔV < 0), the upper arm resistor and X (i.e., R1+R2) are fine-tuned to decrease, or the lower arm resistor and Y (i.e., R3+R4) are fine-tuned to increase, thereby bringing the actual output voltage closer to the target value. Subsequently, the MCU controls the relay module to close again and returns to the beginning of this closed-loop adjustment process, i.e., re-measuring the actual voltage and judging the deviation, repeating this cycle until |ΔV| meets the preset range.

[0069] Furthermore, if |ΔV| does not exceed the preset range, then the current output is considered a qualified high-precision drop voltage. At this point, the actual drop voltage value is used as the final drop test voltage output, and this round of testing is complete.

[0070] This embodiment constructs a closed-loop feedback control system by introducing ADC acquisition and a directional fine-tuning mechanism based on actual measurements. This mechanism differs from the initial global search; it utilizes measured deviations for local correction, effectively overcoming open-loop control errors caused by physical factors such as resistor manufacturing tolerances, parasitic parameters, power supply fluctuations, and load changes. It can adjust the actual voltage drop to the target value in real time and with high precision. This two-stage strategy of global optimization followed by local refinement ensures both high efficiency in the initial configuration and high accuracy in the final output, significantly improving the reliability and reproducibility of the test results.

[0071] In the above embodiments, the descriptions of each embodiment have different focuses. For parts that are not described in detail in a certain embodiment, please refer to the relevant descriptions in other embodiments.

[0072] Obviously, those skilled in the art can make various modifications and variations to this invention without departing from its spirit and scope. Therefore, this invention is also intended to include these modifications and variations as long as they fall within the scope of the claims of this invention and their equivalents.

[0073] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any person skilled in the art can easily conceive of various equivalent modifications or substitutions within the technical scope disclosed in the present invention, and these modifications or substitutions should all be covered within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. An automated method for power supply drop testing, characterized in that, An automated power supply drop test device is used, comprising an MCU, a programmable resistor module, a relay module, and a fast discharge circuit; the programmable resistor module is connected between the power input terminal and ground and has a feedback voltage output terminal; the relay module is connected between the feedback voltage output terminal and the power supply drop test voltage output terminal. The fast discharge circuit is connected between the power supply dropout test voltage output terminal and ground, and is controlled by the MCU; the method includes: In response to receiving a test trigger signal, the resistance value of the programmable resistor module is controlled based on a preset target drop voltage value to output an initial drop voltage at the feedback voltage output terminal. The relay module is controlled to close, and the initial drop voltage is used as the power drop test voltage and output from the power drop test voltage output terminal. The relay module is disconnected to simulate a power drop; At the instant the relay module is disconnected, the fast discharge circuit is turned on, causing the capacitor connected to the power supply drop test voltage output terminal to discharge rapidly through the fast discharge circuit, thereby accelerating the drop slope of the power supply drop test voltage.

2. The automated power supply drop test method according to claim 1, characterized in that, The programmable resistor module includes a first programmable resistor, a second programmable resistor, a third programmable resistor, and a fourth programmable resistor connected in series between the power input terminal and ground; the feedback voltage output terminal is led out from the node between the second programmable resistor and the third programmable resistor.

3. The automated power supply drop test method according to claim 2, characterized in that, The first programmable resistor and the second programmable resistor constitute the upper arm of the voltage divider circuit, and the third programmable resistor and the fourth programmable resistor constitute the lower arm of the voltage divider circuit; the voltage at the feedback voltage output terminal is determined by the resistance ratio of the upper arm to the lower arm of the voltage divider circuit.

4. The automated power supply drop test method according to claim 1, characterized in that, The fast discharge circuit includes a PNP transistor, a diode, a fifth resistor, and a sixth resistor; the anode of the diode is connected to the output terminal of the relay module, and the cathode of the diode is connected to the power supply dropout test voltage output terminal; the base of the PNP transistor is connected to the output terminal of the relay module and grounded through the fifth resistor; the emitter of the PNP transistor is connected to the power supply dropout test voltage output terminal, and the collector of the PNP transistor is grounded through the sixth resistor.

5. The automated power supply drop test method according to claim 3, characterized in that, The control of the resistance value of the programmable resistor module includes: Calculate the target voltage division ratio based on the target drop voltage value and the preset input voltage value; Based on the target voltage division ratio, an optimal combination of resistance values ​​is found from the set of resistance values ​​of the programmable resistor module. The optimal combination of resistance values ​​minimizes the difference between the actual voltage division ratio of the voltage divider circuit and the target voltage division ratio. The optimal resistance value combination is written into the programmable resistor module.

6. The automated power supply drop test method according to claim 5, characterized in that, The step of finding an optimal combination of resistance values ​​from the set of resistance values ​​of the programmable resistor module based on the target voltage division ratio includes: Iterate through the elements in the set of resistance values, calculate the sum of all pairwise resistances, and obtain the set of sum values; Two sets of sums are selected from the set of sums, and are used as the sum of the upper arm resistance and the sum of the lower arm resistance of the voltage divider circuit, respectively. Calculate the ratio of the sum of the resistances of the upper arm to the sum of the resistances of the upper arm and the lower arm, and use this ratio as the actual voltage division ratio; The two sums that minimize the absolute value of the difference between the actual voltage division ratio and the target voltage division ratio are selected as the optimal resistance value combination.

7. The automated power supply drop test method according to claim 6, characterized in that, The step of writing the optimal resistance value combination into the programmable resistor module includes: writing the configuration data corresponding to the optimal resistance value combination into the first programmable resistor, the second programmable resistor, the third programmable resistor, and the fourth programmable resistor, respectively.

8. The automated power supply drop test method according to claim 1, characterized in that, After the relay module is disconnected, the method further includes: Collect the actual voltage drop value at the output terminal of the power supply voltage drop test; Determine whether the deviation between the actual drop voltage value and the target drop voltage value exceeds a preset range; If the deviation between the actual drop voltage value and the target drop voltage value exceeds the preset range, the relay module is controlled to close, and the process returns to the step of controlling the resistance value of the programmable resistor module. If the deviation between the actual drop voltage value and the target drop voltage value does not exceed the preset range, then the actual drop voltage value will be used as the final drop test voltage output.

9. The automated power supply drop test method according to claim 1, characterized in that, The device further includes an input module, a display module, and an ADC module; the communication between the input module or the display module and the MCU, as well as the communication between the MCU and the programmable resistor module, the relay module, and the ADC module, are all implemented through a universal asynchronous transceiver or a serial peripheral interface.

10. An automated power supply drop test device, characterized in that, The device includes an MCU, a programmable resistor module, a relay module, and a fast discharge circuit; the programmable resistor module is connected between the power input terminal and ground and has a feedback voltage output terminal; the relay module is connected between the feedback voltage output terminal and the power drop test voltage output terminal; the fast discharge circuit is connected between the power drop test voltage output terminal and ground and is controlled by the MCU, wherein the MCU is used to execute the power drop test automation method as described in any one of claims 1-9.

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