Current shunt calibration table power supply module

Abstract

The utility model discloses a power supply module of a current shunt calibration table. The power supply module comprises a controller; inputting into a filter network; the UVLO is connected with a soft start network; an energy storage network; the RC absorption network comprises a damping resistor and a damping capacitor, and the damping resistor and the damping capacitor are connected in series and then connected between the switch output end and the connecting end in parallel; the feedback network comprises a third resistor and a fourth resistor, the third resistor and the fourth resistor are connected in series and then connected between the output node and the grounding end in parallel, and the connection point of the third resistor and the fourth resistor is connected to the feedback end; the output filter network comprises at least five output filter capacitors with different capacitance values and is connected between the output node and the grounding end in parallel; and the test point is arranged near the output node and is used for measuring output voltage ripples and transient response. The current shunt calibration table power supply module has the characteristics of high-precision low-noise output, fast dynamic response, high-reliability starting and low power consumption.

Description

TECHNICAL FIELD

[0001] The utility model relates to a current shunt calibration bench power module. BACKGROUND

[0002] The current shunt is a precision resistor device for large current measurement, and the calibration accuracy directly affects the accuracy of the current measurement system. In the production and quality control process of the current shunt, the calibration bench is an essential key equipment for accurately measuring and calibrating the resistance value accuracy, temperature coefficient, load characteristics and other parameters of the shunt. Since the output signal of the current shunt is usually in the microvolt to millivolt level, the calibration bench needs to have very high measurement accuracy, which puts high requirements on the power supply system.

[0003] The existing current shunt calibration bench power module mainly has the following technical problems:

[0004] First, the output ripple suppression ability is insufficient. The traditional power module usually adopts a simple single-stage or double-stage filtering structure, using 2-3 filter capacitors of the same capacitance, which cannot effectively cover the full-band noise from low frequency to high frequency. The actual measurement shows that the output ripple of the traditional setting is usually above 135mVp-p. This ripple superimposed on the microvolt-level shunt signal will cause the measurement data to fluctuate by ±1.8μV, seriously affecting the calibration accuracy. Especially in the switching frequency and its harmonic frequency band, there is a lack of targeted noise suppression measures, resulting in a decrease in signal-to-noise ratio during ADC sampling and poor measurement repeatability.

[0005] Second, the load dynamic response speed is slow. The traditional setting generally uses a large inductance of 10-22μH to reduce the output ripple, but the large inductance results in a low current ramp rate of only about 1-2A / μs. During the calibration process of the current shunt, range switching and calibration current adjustment need to be performed frequently, and the load current will change rapidly between 0.5A and 8A. The load step recovery time of the traditional power supply is usually 3-5ms, during which the overshoot or drop of the output voltage will affect the measurement accuracy, prolong the stable waiting time of each test point, and reduce the production efficiency.

[0006] Third, the starting process has poor reliability. The traditional power module lacks a perfect starting protection mechanism, and a surge current of more than 5A will be generated at the moment of power-on. This impact current not only causes stress to the power supply itself, but more importantly, it will cause thermal shock to the precise shunt test fixture, accelerate the oxidation and wear of the fixture contact points, and shorten the service life of the tool. At the same time, in the case of unstable or slowly rising input voltage, the traditional power supply may repeatedly start in an under-voltage state, causing the output voltage to oscillate and causing abnormal calibration data.

[0007] Fourth, poor power consumption control. The feedback voltage division network of the traditional setting usually adopts kilo-ohm or ten-kilo-ohm resistance, and the static voltage division current reaches hundreds of microamperes or even milliamperes. In a multi-station parallel calibration production line, each station needs an independent power supply module, and the cumulative power consumption is large. In addition, the large inductance setting not only increases the cost of the device, but also reduces the overall efficiency due to copper loss and magnetic loss.

[0008] Fifth, lack of effective electromagnetic interference suppression. The traditional power supply module lacks systematic consideration in PCB layout, and the power loop area is large, and the switching node lacks an absorption network, resulting in serious EMI problems. In an industrial environment, when subjected to EFT or ESD interference, the traditional power supply is prone to output fluctuation or even failure, affecting the continuity of the calibration process.

[0009] Therefore, the prior art cannot meet the high requirements of the current shunt calibrator calibration table on the quality of the power supply, and there is an urgent need for a special power supply module with high precision low noise output, fast dynamic response, high reliability startup and low power consumption characteristics. Content of the utility model

[0010] The utility model aims at providing a current shunt calibrator calibration table power module. The current shunt calibrator calibration table power module has the characteristics of high precision low noise output, fast dynamic response, high reliability startup and low power consumption.

[0011] The above technical purpose of the utility model is realized by the following technical scheme:

[0012] The power module of the current shunt calibrator test board comprises a controller (U6) having an input end (VIN), an enable end (EN), a switch output end (SW), a feedback end (FB), and a ground end (GND); an input filter network comprising at least three input filter capacitors (C23, C24, and C25) of different capacitances arranged in descending order of capacitance; a UVLO and soft start network comprising a first resistor (R25), a second resistor (R26), and a delay capacitor (C27), wherein the first resistor (R25) and the second resistor (R26) are connected in series and then connected in parallel between the input end (VIN) and the enable end (EN), and the delay capacitor (C27) is connected in parallel between the enable end (EN) and the ground end (GND); an energy storage network comprising an inductor (L1), one end of the inductor (L1) being connected to the switch output end (SW) and the other end serving as an output node; an RC absorption network comprising a damping resistor (R24) and a damping capacitor (C26), the damping resistor (R24) and the damping capacitor (C26) being connected in series and then connected in parallel between the switch output end (SW) and a connection end (BST); a feedback network comprising a third resistor (R27) and a fourth resistor (R30), the third resistor (R27) and the fourth resistor (R30) being connected in series and then connected in parallel between the output node and the ground end (GND), and a connection point of the third resistor (R27) and the fourth resistor (R30) being connected to the feedback end (FB); an output filter network comprising at least five output filter capacitors (C28, C29, C30, C31, and C32) of different capacitances connected in parallel between the output node and the ground end (GND); and a test point (TP1) arranged near the output node and used for measuring output voltage ripple and transient response.

[0013] The utility model further sets up: the input filter capacitor includes two big capacity capacitor (C23, C24) and a small capacity capacitor (C25), and big capacity capacitor (C23, C24) is used to inhibit low frequency ripple, and small capacity capacitor (C25) is used to inhibit high frequency noise.

[0014] The utility model further sets up: the resistance ratio of the first resistor (R25) and the second resistor (R26) in the UVLO and soft start network satisfies: the controller (U6) only starts when the input voltage is greater than the predetermined threshold value, and low voltage working state is avoided.

[0015] The utility model further sets up: the inductance value of the inductor (L1) is less than 2muH, and is used for improving load step response speed.

[0016] The utility model further sets up: the output filter capacitor (C28, C29, C30, C31, C32) in output filter network includes large capacity capacitor, medium capacity capacitor and small capacity capacitor, and large capacity capacitor is used for inhibiting low frequency ripple and provides energy reserve, and medium capacity capacitor is used for inhibiting medium frequency ripple, and small capacity capacitor is used for inhibiting high frequency noise.

[0017] The utility model further sets up: third resistance (R27) and fourth resistance (R30) in feedback network are all hundred thousand ohm level high resistance resistance, are used for reducing static power consumption.

[0018] The utility model further sets up: switch output end (SW), inductance (L1) and ground terminal (GND) form minimum area power loop, are used for reducing electromagnetic interference.

[0019] The utility model further sets up: current shunt calibrator platform power module adopts the linear power flow path layout from left to right, and in proper order is: input filter network, controller (U6), energy storage network, output filter network.

[0020] The utility model further sets up: the ground terminal (GND) of controller (U6) includes analog ground and power ground, and analog ground and power ground converge in single point near controller (U6), are used for reducing ground loop interference.

[0021] Summarized above, the utility model has following beneficial effect:

[0022] One, high-precision low-noise output effect

[0023] The utility model adopts wideband multistage decoupling and RC absorption structure, including three-stage input filter capacitor (C23, C24, C25) and five-stage output filter capacitor (C28, C29, C30, C31, C32), cooperate RC absorption network (R24, C26), form complete noise suppression system. This multistage capacity value cascade setting covers the full-band noise from several Hz to several MHz, and large capacity capacitor (10uF, 47uF) inhibits low frequency ripple, and medium capacity capacitor (22uF, 1uF) inhibits medium frequency ripple, and small capacity capacitor (100nF) inhibits high frequency noise, and the actual measurement output ripple is controlled below 48mVp-p, and is reduced about 64.4% than the traditional setting of 135mVp-p. RC absorption network directly absorbs switch peak at switch node (SW), and reduces peak voltage from about 5V to below 0.5V, and reduces about 90%. This static noise setting is especially suitable for the application scene that current shunt calibrator needs micro-ohm precision measurement, makes shunt microvolt level signal measurement stability from ± 1.8uV improve to ± 0.4uV, improves 77.8%, provides low noise power supply environment for high-precision ADC, and improves signal-to-noise ratio about 6-8dB.

[0024] II. Fast dynamic response characteristics

[0025] The utility model discloses a big current small inductance setting, inductance (L1) is only 1.5 mu H, far less than the traditional setting of 10-22 mu H, make current climb / drop rate reach about 12.7A / mu s, improve 7-15 times than traditional setting. Meanwhile cooperate large capacity output capacitor (C29, C30, C31), formed small inductance + big capacitor optimization combination, small inductance guarantee fast response, and large capacity capacitor provides transient energy reserve, realized fast response and energy reserve balance. When 0.5A and 8A load step, output voltage overshoot and drop less than 300mV, recovery time is shortened from traditional 3.8ms to 0.92ms, improves about 75.8% response speed. This fast dynamic response characteristics are especially suitable for current shunt calibrator calibration process frequent range switching and calibration current change scene, significantly shorten the test beat, reduce the stable waiting time of each test point, improve production efficiency, and small inductance setting also reduces inductance volume, reduces inductance cost.

[0026] III. High reliability start protection

[0027] The utility model discloses set up UVLO and soft start network (R25, R26, C27), formed double protection mechanism, through the accurate voltage division of first resistance R25 (510kΩ) and second resistance R26 (100kΩ), make controller (U6) only start when input voltage reaches about 7.3V, avoided the unstable state and output voltage oscillation of low voltage work. Delay capacitor C27 (100nF) provides EN end RC delay, realizes the soft start feature of first charging and then starting, and the measured power slow start time is about 10-15ms, and the starting surge current is reduced from the traditional 5.2A peak to 0.48A peak, reduces about 90.8%. This setting effectively prevents the system misoperation caused by the start of power in unstable state, greatly reduces the thermal shock of impact current to shunt weld and alloy body, prolongs the fixture and tool life, and significantly reduces the production line repair rate, provides reliable guarantee for the long-term stable operation of calibration system.

[0028] IV. Low power consumption energy saving setting

[0029] The feedback network of the present invention adopts a high-resistance voltage divider structure. The third resistor R27 (154kΩ) and the fourth resistor R30 (21kΩ) are both high resistance values ​​of hundreds of kilo-ohms, which makes the static voltage divider current only about 25μA, and the static power consumption is reduced from the traditional setting of 0.85mW to 0.03mW, which is about 96.5% lower, and the power consumption is reduced by 95-97% compared with the traditional kilo-ohm or ten-kilo-ohm settings. In a multi-station parallel calibration production line, this setting significantly reduces standby energy consumption. A 100-station production line can save about 700kWh of electricity per year, which meets the requirements of green manufacturing and greatly reduces factory operating costs. At the same time, the small inductor and high current strategy not only reduces the size and cost of the device, but also reduces the copper loss and magnetic loss of the inductor. Combined with the optimized RC absorption network setting, it takes into account EMI suppression and efficiency, so that the power supply still maintains a high efficiency when fully loaded with 8A output, and the energy efficiency is improved by about 5-8% compared with the traditional setting, achieving a balance between high performance and low power consumption.

[0030] 5. Testable and traceable characteristics

[0031] The utility model sets a dedicated test point (TP1) near the output node, which adopts a pad-type setting to facilitate contact measurement with an oscilloscope probe. Through this test point, key parameters such as output voltage ripple, load step response, and EMC interference effects can be monitored in real time, providing a data basis for production line quality control. This testable setting makes the power supply quality monitorable and traceable, facilitates random inspections and performance verification of each power supply on the production line, can promptly detect potential problems, reduce calibration drift and return repair rates caused by power supply problems, and improve the reliability and maintainability of the overall system. The setting of the test point also facilitates subsequent fault diagnosis and maintenance, reduces maintenance costs, and provides data support for the continuous improvement of product quality. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 This is a circuit diagram of the utility model. DETAILED DESCRIPTION

[0033] The following describes the embodiments of the present invention in detail with reference to the accompanying drawings.

[0034] like Figure 1 As shown, the utility model provides a current shunt calibration station power supply module, which mainly includes a controller (U6), an input filter network, a UVLO and soft start network, an energy storage network, an RC absorption network, a feedback network, an output filter network and a test point (TP1).

[0035] The controller (U6) is located in the middle left of the module, close to the input filter area, and is fixed on the PCB in a surface mount manner. The controller (U6) has input end (VIN), enable end (EN), switch output end (SW), feedback end (FB) and ground end (GND) pins. The ground end (GND) of the controller (U6) includes analog ground and power ground, and the analog ground and the power ground are connected at a single point near the controller (U6) to form a star ground topology, effectively reducing ground loop interference.

[0036] The input filter network is located at the leftmost side of the module, responsible for receiving a 24V input power supply and performing preliminary filtering. The input filter network includes at least three input filter capacitors (C23, C24, C25) with different capacitance values arranged in descending order of capacitance value. In this embodiment, the input filter capacitors (C23, C24, C25) include two large-capacity capacitors (C23, C24) and one small-capacity capacitor (C25), wherein the large-capacity capacitors (C23, C24) are both 10μF for suppressing low-frequency ripple, and the small-capacity capacitor (C25) is 100nF for suppressing high-frequency noise. The 24V input wiring is widened to withstand a large current of 8A, and forms the shortest path from the input end to the input end (VIN) of the controller (U6).

[0037] The UVLO and soft start network is located above and to the left of the controller (U6), including a first resistor (R25), a second resistor (R26) and a delay capacitor (C27). The first resistor (R25) and the second resistor (R26) are connected in series and then connected in parallel between the input end (VIN) and the enable end (EN) to form a voltage dividing network. In this embodiment, the first resistor (R25) is 510kΩ and the second resistor (R26) is 100kΩ, which makes the controller (U6) start only when the input voltage is greater than about 7.3V, avoiding low-voltage working state. The delay capacitor (C27) is connected in parallel between the enable end (EN) and the ground end (GND) with a capacitance value of 100nF, providing an RC delay for the EN end to achieve the soft start feature of charging first and starting later. The first resistor (R25) and the second resistor (R26) are arranged vertically to form the shortest path from the input end (VIN) to the enable end (EN); the delay capacitor (C27) is arranged close to the enable end (EN) to form an L-shaped structure with the first resistor (R25) and the second resistor (R26).

[0038] The energy storage network is located to the right of the controller (U6) and is the core area of power conversion, including an inductor (L1). One end of the inductor (L1) is connected to the switch output end (SW), and the other end serves as an output node. In this embodiment, the inductance value of the inductor (L1) is 1.5μH, which is much smaller than the traditional setting of 10-22μH, used to improve the load step response speed. The inductor (L1) is packaged in a large-current SMD and fixed on the PCB.

[0039] The RC absorption network is located near the switch output (SW) and includes a damping resistor (R24) and a damping capacitor (C26). The damping resistor (R24) and the damping capacitor (C26) are connected in series and then connected in parallel between the switch output (SW) and the connection end (BST), forming a T-shaped layout. In this embodiment, the damping resistor (R24) is 3.3Ω, and the damping capacitor (C26) is 220nF. This resistance and capacitance selection meets the requirement of reducing switch spikes and ringing while not significantly affecting system efficiency. The RC absorption network is arranged close to the switch output (SW), and the shortest path absorbs the switch spikes, effectively suppressing the conduction of switch noise to the output end.

[0040] The feedback network is located at the lower right of the controller (U6) and includes a third resistor (R27) and a fourth resistor (R30). The third resistor (R27) and the fourth resistor (R30) are connected in series and then connected in parallel between the output node and the ground end (GND), and the connection point of the third resistor (R27) and the fourth resistor (R30) is connected to the feedback end (FB). In this embodiment, the third resistor (R27) is 154kΩ, and the fourth resistor (R30) is 21kΩ, both of which are high resistance resistors of hundreds of kilo-ohms, used to reduce static power consumption. This resistance ratio makes the output voltage 5V, meeting the power supply requirements of the current shunt calibrator bench. The feedback network forms the shortest path from the output node to the feedback end (FB), improving control accuracy; at the same time, it is far away from the switch output (SW), reducing interference coupling.

[0041] The output filter network is located at the rightmost side of the module and includes at least five output filter capacitors (C28, C29, C30, C31, C32) of different capacitances connected in parallel between the output node and the ground end (GND). In this embodiment, the output filter capacitors include C28 (1μF), C29 (22μF), C30 (47μF), C31 (47μF), and C32 (100nF), arranged in a radial layout. The large-capacity capacitors (C30, C31) are arranged side by side for suppressing low-frequency ripple and providing energy storage; the medium-capacity capacitor (C29) is arranged close to the inductor (L1) for suppressing medium-frequency ripple; and the small-capacity capacitors (C28, C32) are located at the outermost side for suppressing high-frequency noise. This multi-stage filtering structure and capacitance gradient setting achieve wide-band noise suppression and low output impedance. The ground ends of all output filter capacitors are connected to the ground plane through a short direct path, forming a star-shaped topology and reducing common impedance coupling.

[0042] The test point (TP1) is arranged near the output node in a pad type, facilitating the oscilloscope probe to contact and measure. Through the test point (TP1), the output voltage ripple, load step response, EFT / ESD interference influence, and other parameters can be measured, providing a data basis for production line quality control. An operation space can be reserved around the test point (TP1) to facilitate the test probe to contact.

[0043] The whole current shunt calibrator power module adopts a linear power flow path layout from left to right, in sequence: input filter network, controller (U6), energy storage network, output filter network. This layout forms a linear power transmission channel from 24V input → controller (U6) → switch output (SW) → inductor (L1) → 5V output, reducing energy conversion loss. At the same time, the switch output (SW), inductor (L1) and ground (GND) form a minimum area power loop, reducing parasitic inductance and EMI radiation. The functional areas are clearly divided, with clear boundaries, facilitating optimal settings and fault location.

[0044] In the working process, the 24V input power is filtered by the input filter network and enters the input end (VIN) of the controller (U6). At the same time, the input power is divided by the UVLO and soft start network (R25, R26, C27) and delayed to control the enable end (EN). When the divided voltage exceeds about 1.2V and after the delay, the controller (U6) starts. The controller (U6) generates a PWM waveform through an internal oscillator, drives the switch output (SW) to generate a square wave, and the inductor (L1) smooths the square wave. The RC absorption network (R24, C26) absorbs the switching peak to reduce interference. The output voltage is divided by the feedback network (R27, R30) and fed back to the feedback end (FB), compared with the internal reference voltage, and the PWM duty cycle is adjusted to stabilize the output voltage. Finally, the output filter network (C28, C29, C30, C31, C32) performs multi-stage filtering on the output voltage to obtain a low-ripple 5V DC output.

[0045] The utility model discloses a wideband multistage decoupling and RC absorption of the quieting power supply structure, the high current small inductance quick response structure, UVLO and the high reliability structure of soft start, the power quality monitoring structure of testable traceable and the energy -conserving structure such as high resistance voltage division low -power consumption setting, realize high -precision low -noise output, fast dynamic response, high reliability start and low -power consumption technical property, solve the problem that traditional power module faces in current shunt calibrator application, be suitable for the current shunt calibrator calibration platform application of need micro -ohm precision measurement.

[0046] In order to verify the above technical effect, the utility model evaluates the technical effect of the current shunt calibrator power module through the following experiment.

[0047] 1. The contrast test uses the module of the utility model and the traditional power module (using 10uH inductance, 2-3 same capacitance output capacitor, no RC absorption network of conventional setting), under the same working condition. The test instrument includes bandwidth 100MHz oscilloscope, electronic load, EMC test equipment and micro-ohmmeter. On the actual current shunt calibration table, the influence of power performance on shunt measurement accuracy is evaluated simultaneously. Each test is repeated 5 times to take average value, ensuring data reliability.

[0048] 2. Technical effect comparison table

[0049]

[0050] 3. Verification conclusion

[0051] The experimental results show that the utility model power module is significantly better than the traditional setting in each core performance index. Especially in the current shunt calibration application, the multi-stage decoupling and RC absorption structure of the module reduces the output ripple to 48mVp-p, which improves the stability of the shunt micro-volt level signal measurement by nearly 80%; The small inductance fast response structure shortens the load step recovery time by about 75%, effectively improving the calibration efficiency; The UVLO and soft start network reduces the starting surge current by more than 90%, significantly prolongs the service life of the shunt solder joint and clamp; The high resistance voltage dividing network reduces the static power consumption by more than 96%. In the actual current shunt calibration production line 100 hours continuous operation test, the test station with the utility model power module does not appear any abnormality caused by power problem, while the traditional power module appears 1-2 times data fluctuation every 24 hours. The comprehensive verification result proves that the utility model power module can meet the high requirements of current shunt calibration table for high precision, fast response, high reliability and low power consumption, significantly improves the calibration quality and production efficiency, and has broad application prospect.

Claims

1. A current shunt calibration station power supply module, characterized in that: include: A controller (U6) having an input terminal (VIN), an enable terminal (EN), a switch output terminal (SW), a feedback terminal (FB), and a ground terminal (GND); An input filter network, including at least three input filter capacitors (C23, C24, and C25) of different capacitance values, arranged in descending order of capacitance; A UVLO and soft-start network comprises a first resistor (R25), a second resistor (R26) and a time-delay capacitor (C27), wherein the first resistor (R25) and the second resistor (R26) are connected in series and then in parallel between the input terminal (VIN) and the enable terminal (EN), and the time-delay capacitor (C27) is connected in parallel between the enable terminal (EN) and the ground terminal (GND); An energy storage network includes an inductor (L1), one end of the inductor (L1) is connected to the switch output end (SW), and the other end serves as an output node; an RC absorption network, comprising a damping resistor (R24) and a damping capacitor (C26), wherein the damping resistor (R24) and the damping capacitor (C26) are connected in series and then in parallel between the switch output terminal (SW) and the connection terminal (BST); a feedback network comprising a third resistor (R27) and a fourth resistor (R30), wherein the third resistor (R27) and the fourth resistor (R30) are connected in series and then in parallel between the output node and the ground terminal (GND), and a connection point between the third resistor (R27) and the fourth resistor (R30) is connected to the feedback terminal (FB); an output filter network, comprising at least five output filter capacitors (C28, C29, C30, C31, C32) of different capacitance values, connected in parallel between the output node and the ground terminal (GND); A test point (TP1) is provided near the output node for measuring output voltage ripple and transient response.

2. The current shunt calibration station power supply module according to claim 1, characterized in that: The input filter capacitor includes two large-capacity capacitors (C23, C24) and a small-capacity capacitor (C25), the large-capacity capacitors (C23, C24) are used to suppress low-frequency ripples, and the small-capacity capacitor (C25) is used to suppress high-frequency noise.

3. The current shunt calibration station power supply module according to claim 1, characterized in that: The resistance ratio of the first resistor (R25) and the second resistor (R26) in the UVLO and soft start network satisfies: the controller (U6) is started only when the input voltage is greater than a predetermined threshold, thereby avoiding a low voltage working state.

4. The current shunt calibration station power supply module according to claim 1, characterized in that: The inductance value of the inductor (L1) is less than 2 μH, and is used to improve the load step response speed.

5. The current shunt calibration platform power supply module according to claim 1, characterized in that: The output filter capacitors (C28, C29, C30, C31, C32) in the output filter network include large-capacity capacitors, medium-capacity capacitors and small-capacity capacitors. The large-capacity capacitors are used to suppress low-frequency ripples and provide energy reserves, the medium-capacity capacitors are used to suppress medium-frequency ripples, and the small-capacity capacitors are used to suppress high-frequency noise.

6. The current shunt calibration station power supply module according to claim 1, characterized in that: The third resistor (R27) and the fourth resistor (R30) in the feedback network are both high-resistance resistors in the hundreds of kilo-ohms range, and are used to reduce static power consumption.

7. The current shunt calibration station power supply module according to claim 1, characterized in that: The switch output terminal (SW), the inductor (L1) and the ground terminal (GND) form a minimum area power loop for reducing electromagnetic interference.

8. The current shunt calibration platform power supply module according to claim 1, wherein: The current shunt calibration station power supply module adopts a linear power flow path layout from left to right, which is: input filter network, controller (U6), energy storage network, and output filter network.

9. The current shunt calibration station power supply module according to claim 1, characterized in that: The ground terminal (GND) of the controller (U6) includes an analog ground and a power ground, and the analog ground and the power ground are connected at a single point near the controller (U6) to reduce ground loop interference.

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