EMC countermeasure system and EMC countermeasure method
The EMC countermeasure system addresses the issue of unnecessary components by using an analysis model and simulation to determine essential components, resulting in reduced costs and circuit area.
Patent Information
- Application Number
- JP2023202095
- Authority / Receiving Office
- JP · JP
- Patent Type
- Applications
- Current Assignee / Owner
- Filing Date
- 2023-11-29
- Publication Date
- 2025-06-10
AI Technical Summary
Existing EMC countermeasure systems may incorporate unnecessary components when implementing countermeasures, leading to increased circuit area and costs.
An EMC countermeasure system that includes circuit information, a reception unit for priorities, an EMC design database, an analysis model generation unit, a simulation execution unit, a determination unit for noise standards, a component reduction unit for deleting unnecessary components, and an output unit for the optimized circuit model.
The system effectively reduces production costs by ensuring only essential components are included in the EMC countermeasures, thereby minimizing circuit area and costs.
Smart Images
Figure 2025087438000001_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to an EMC countermeasure system and an EMC countermeasure method.
Background Art
[0002] Patent Document 1 discloses an EMC design support system including a specifying means for specifying a design object, a first storage means for storing EMC-related data regarding design precautions indicating matters to be noted with respect to the influence of noise during design, a first search means for searching for data related to the design object specified by the specifying means from among the EMC-related data regarding past defects stored in the first storage means, and a display means for displaying the data searched by the first search means.
Prior Art Documents
Patent Documents
[0003]
Patent Document 1
Summary of the Invention
Problems to be Solved by the Invention
[0004] Patent Document 1 discloses searching for and displaying EMC (Electromagnetic Compatibility)-related data regarding design precautions indicating matters to be noted with respect to the influence of noise.
[0005] Although it may be possible to take EMC countermeasures by adding EMC countermeasure components according to the design precautions found by the search, it is not guaranteed whether the components are essential for the circuit for which the countermeasures are being taken.
[0006] For this reason, unnecessary components are incorporated into the EMC countermeasures for the circuit. As a result, there is a problem of consuming extra circuit area and increasing costs.
Means for Solving the Problem
[0007] The above problem is solved by an EMC countermeasure system including circuit information of a circuit for performing EMC countermeasures, a reception unit for receiving priorities of EMC countermeasures, an EMC design database storing patterns of circuits for performing EMC countermeasures and EMC countermeasure circuits, an analysis model generation unit for generating an analysis model in which EMC countermeasure circuits are applied to the circuit information, a simulation execution unit for executing a simulation of the generated analysis model, an EMC countermeasure determination unit for determining whether noise satisfies a predetermined standard based on the execution result of the simulation execution unit, a component reduction unit for deleting EMC countermeasure components from the countermeasure-completed analysis model based on the priorities of EMC countermeasures when the EMC countermeasures satisfy predetermined conditions, and an output unit for outputting the circuit of the countermeasure-completed analysis model from which the EMC countermeasure components have been deleted.
Effect of the Invention
[0008] According to the present invention, it is possible to reduce the production cost of a circuit with EMC countermeasures.
Brief Description of the Drawings
[0009]
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Best Mode for Carrying Out the Invention
[0010] Hereinafter, embodiments of the present invention will be described with reference to the drawings. In each of the drawings for explaining the embodiments, the same components are given the same names and reference numerals as much as possible, and the repeated explanations thereof are omitted.
[0011] The present invention is not limited to the embodiments described below, and various modifications and equivalent configurations within the scope of the appended claims are included. For example, the above-described embodiments have been described in detail for easy understanding of the present invention, and the present invention is not necessarily limited to those having all the configurations described.
[0012] In addition, the processing units and processing modules described in the embodiments may be realized in hardware by designing a part or all of them, for example, by using an integrated circuit, or may be realized in software by a processor interpreting and executing a program for realizing each function.
[0013] The information described in the embodiments may be a table, a database (DB), or data stored in the main memory.
Embodiment
[0014] FIG. 1 shows an example of noise generated in a circuit. In this example, there is a noise source 1 and a connector 2 as an example of a component connected to the noise source 1, and a plurality of paths A, B, and C connecting the noise source 1 and the connector 2 are schematically shown. In this case, noise is superimposed on all of the paths A, B, and C.
[0015] FIG. 2 shows an example of an incomplete noise countermeasure for noise generated in a circuit. A circuit of countermeasure A is added to path A to reduce the noise superimposed on path A to a specified value.
[0016] However, noise continues to be superimposed on paths B and C, and this countermeasure is incomplete. For this reason, the countermeasure for path A, countermeasure A, is stopped and a countermeasure is taken for path B. Since the superimposition of noise continues, there may be cases where the countermeasure for path B is stopped and a countermeasure is taken for path C.
[0017] That is, countermeasures are required for all of paths A, B, and C, but the actual circuit is complex and it is difficult for an engineer to identify all noise generation paths. For this reason, countermeasures by an experienced engineer are required to take noise countermeasures.
[0018] FIG. 3 shows an example of a complete noise countermeasure for noise generated in a circuit. In this example, countermeasures A, B, and C are applied to each of paths A, B, and C. If it can be confirmed that the electric field strength of the superimposed noise is equal to or less than a predetermined value in this state, the noise countermeasure is completed.
[0019] FIG. 4 shows an example of noise countermeasures using an EMC design database. There is a power supply circuit 21 that receives a supply of AC 100V and outputs DC 3.3V, and a digital circuit 22 that uses the output DC 3.3V. This is an example in which connectors A and B are connected to the output of the digital circuit 22.
[0020] In this case, refer to the connection patterns of EMC countermeasure components corresponding to the component part numbers and circuit specifications stored in the EMC design database (DB), and add the necessary countermeasure circuits through pattern matching. Add a line filter 25 between the power supply circuit 21 and the AC 100V power supply, and add an LC filter between the power supply circuit and the digital circuit. Add signal filters between the digital circuit and connectors A and B.
[0021] When implementing the countermeasures stored in the EMC design DB, the circuit diagram in the middle stage is obtained. However, the components included in the countermeasure circuits registered in the EMC design DB are not necessarily essential components, and often include unnecessary components. For this reason, problems such as an increase in circuit board area due to unnecessary components, an increase in component costs, and an increase in heat generation occur.
[0022] To address such problems, EMC simulation is performed on the circuit with the countermeasures stored in the EMC design DB, and the capacitors 28, inductors 29, and signal filters 31, which are unnecessary components incorporated in each filter, are removed, as shown in the circuit diagram in the lower stage.
[0023] Figure 5 shows an example of noise countermeasures using an analysis model database. This is an example in which the analysis model DB40 is used for the countermeasures implemented in Figure 4. The analysis model DB40 stores detailed characteristic information necessary for EMC countermeasures of circuits and components used in the circuits, and a plurality of models corresponding to differences in simulation programs can be prepared.
[0024] If a simulator suitable for the target circuit can be automatically selected from among multiple simulators to perform a simulation, more accurate noise countermeasures can be achieved.
[0025] Also, if the simulator to be used is selected based on the operator's instructions, noise countermeasures in line with the operator's intention can be achieved.
[0026] Furthermore, it is also possible to store a plurality of models corresponding to the band change of the EMC standard.
[0027] FIG. 6 is an example of a system configuration diagram in an embodiment of the present invention. In this embodiment, an example is shown in which an operator terminal 55 including an input interface 56, a CPU (Central Processing Unit) 57, a main memory device 58, an external memory device 59, and a display device 60 accesses an EMC countermeasure system 50 via a communication device 61 and a network 62.
[0028] The operator terminal is composed of a PC (Personal Computer) or a tablet terminal, and sends circuit information of a circuit for performing EMC countermeasures to the EMC countermeasure system 50, and receives circuit information of the countermeasure-applied circuit from the EMC countermeasure system.
[0029] If an input / output device such as a keyboard and a display is provided in the EMC countermeasure system 50, input / output may be directly performed on the EMC countermeasure system.
[0030] Also, the EMC countermeasure system 50 may be constructed on a cloud system that provides computer resources.
[0031] The EMC countermeasure system 50 is composed of an input / output unit 10 such as a keyboard and a mouse, a main memory device 52 composed of a CPU (Central Processing Unit), a RAM (Random Access Memory), etc., and an external memory device composed of an HDD (Hard Disk Drive), an SSD (Solid State Drive), etc., and communicates with the operator terminal 55 via a communication device 63 and a network 62. Information such as an EMC design DB 30 is stored in the external memory device.
[0032] FIG. 7 is an example of a configuration diagram of an EMC countermeasure system according to an embodiment of the present invention. The main memory device 52 stores a reception unit 70 that receives circuit information from an operator, a simulation execution unit 71 that performs circuit simulation, an EMC countermeasure determination unit 72 that determines whether the EMC countermeasure has been completed, an analysis model generation unit 73 that generates an analysis model from circuit information, a component reduction unit 74 that reduces unnecessary components, and a countermeasure table 78 that stores information on the circuit for which processing is being executed.
[0033] Each processing unit except the countermeasure table 78 is realized as a software module, and the CPU 51 executes processing while referring to the DB and tables stored in the external storage device 53. The processing result is output from the input / output unit 10 to the operator's terminal.
[0034] The external storage device 53 stores a circuit information table 75 that stores circuit information received from an operator, an EMC design DB 30 that stores countermeasure circuits to be implemented for each target circuit, an analysis model DB 40 that stores an analysis model created from circuit information, a countermeasure component list 76 that stores specifications of components used for countermeasures, and a regulation value DB 77 that stores criteria for determining whether the EMC countermeasure has been completed.
[0035] FIG. 8 is an example of a circuit information table according to an embodiment of the present invention. The name 80 of the circuit, the circuit diagram 81, the netlist 82 which is a code indicating the connection relationship of the circuit blocks, and the component list 83 of the components used in the circuit are stored in association with each other. The circuit diagram 81, the netlist 82, and the component list 83 may each be a pointer to a file storing the respective information.
[0036] Regarding data in file format, in other tables as well, by using pointers to files, the storage area can be saved and the stored data can be modified.
[0037] FIG. 9 is an example of an EMC design database in an embodiment of the present invention. The filter name 90 for noise countermeasures, the circuit diagram 91 of the filter, the netlist 92 showing the connection relationship of the filter, and the power consumption 93 of the filter are stored in association with each other. If the power consumption is stored for each component constituting the filter, more accurate power consumption can be obtained when unnecessary components are deleted.
[0038] Generally, since noise countermeasure circuits often have passive circuits, the power consumption is small. However, since noise countermeasure circuits that perform active countermeasures have high power consumption, it may be sufficient to describe only the circuits that perform active countermeasures.
[0039] Also, if the power consumption is stored for each component constituting the circuit instead of for each circuit, the reducible power consumption can be grasped more accurately.
[0040] FIG. 10 is an example of an analysis model database in an embodiment of the present invention. The filter name 101 used for noise countermeasures of the input circuit diagram, the circuit diagram 102 of the filter, the netlist 103 of the filter, the equivalent circuit 104 for EMC analysis including electrical parasitic components generated by the circuit pattern and structure, the S-parameters 105 which are detailed information indicating the component characteristics for EMC analysis, the 3D shape 106 showing the three-dimensional shape of the filter, and the frequency characteristics 107 of the filter are stored in association with each other.
[0041] FIG. 11 is an example of a countermeasure component list in an embodiment of the present invention. A list of components used in the filter used for noise countermeasures is stored. The component name 111, the value 112 indicating the capacitance of the component, the manufacturer name 113 of the component, the type 114 of the component, the package size 115 storing the L (length) × W (width) × D (depth) of the component, the equivalent circuit 116 for EMC analysis including electrical parasitic components generated by the circuit pattern and structure, the 3D shape 117 showing the three-dimensional shape of the component, the frequency characteristics 118 of the component, and the price 119 of the component are stored in association with each other.
[0042] The component area can be obtained from the component length (L) and component width (W) of package size 115 and is used when the priority is the component area. Also, the depth (D) of the component of package size 115 is the component height, and it can be confirmed that the height is such that the component does not contact other substrates or enclosures when the component is installed on the substrate. When the priority is the component height, the determination is made using the component depth (D).
[0043] The price 119 is the unit price of the component, but a more accurate cost can be obtained if the cost for installing the component on the substrate is included.
[0044] In addition, if items such as power consumption and heat generation are provided, there is no need to calculate from the component specifications, and it becomes possible to easily compare priorities.
[0045] Figure 12 is an example of a countermeasure table in an embodiment of the present invention. When deleting unnecessary components from the filters to be used, they are deleted according to the priority order of the input priority items, and the results of performing a simulation and checking whether there are any problems after deletion are stored.
[0046] The circuit name 141, the component name 142 constituting the circuit, the number of components 143, the deletability 144 indicating the number that can be deleted, the simulation completed 145 indicating whether the simulation has been completed, and the priority 146 indicating the magnitude of the influence of the component on the priority items are stored in association with each other.
[0047] In this example, since the priority is set for each countermeasure circuit, it is possible to limit the simulation range. However, if the circuit scale is not large, the priority may be set for the entire circuit to be countermeasured. In addition, a more efficient simulation becomes possible if the range for performing the simulation is determined and the priority is set.
[0048] Figure 13 is an example of a graph of EMC countermeasure regulatory values. The regulatory values vary depending on the frequency for each field and each product. For example, the regulatory value for the graph of analysis result 1 shown by the thin line exceeds the regulatory value of 40 dBuV / m near 0.15 MHz shown by the solid line, so it does not meet the regulatory value. On the other hand, the graph of analysis result 2 shown by the thick line is below 30 dBuV / m from 0.5 MHz to near 2 MHz shown by the broken line, so it meets the regulatory value.
[0049] When expressing the regulatory values in tabular form, it becomes as shown in Figure 14, and the regulatory values are determined for each field and each frequency. By defining the regulatory values in more detail, it is also possible to handle the regulatory values expressed as functions.
[0050] Figure 15 is an example of a flowchart showing the processing of the EMC countermeasure system in an embodiment of the present invention.
[0051] First, circuit information and priorities are received at the operator terminal 55 (S1). The received circuit information and priorities are transmitted to the EMC countermeasure system 50 and received by the reception unit 70 (S2). The analysis model generation unit 73 refers to the EMC design DB 30 based on the received circuit information (S3), and generates an analysis model with EMC countermeasure components (filters) added (S5).
[0052] The simulation execution unit 71 executes a simulation using the analysis model created by the analysis model generation unit (S5). The EMC countermeasure determination unit refers to the regulatory value DB 77 based on the execution result of the simulation execution unit 71 and determines whether EMC countermeasures can be taken.
[0053] If EMC countermeasures cannot be taken (S6), an error is output to the operator terminal via the input / output unit 10 because the circuit cannot be countered only from the information in the EMC design DB, and the process ends (S7).
[0054] If EMC countermeasures were possible (S6), since there may be unnecessary components added, the component reduction unit 74 selects EMC countermeasure components to be removed according to the priority order of the priority items, and the analysis model generation unit 73 generates an analysis model with the selected EMC components removed (S9).
[0055] The simulation execution unit 71 executes a simulation using the analysis model with the selected EMC components removed (S10), and the EMC countermeasure determination unit 72 refers to the regulation value DB77 to determine whether the EMC countermeasures are completed.
[0056] When the EMC countermeasure determination unit 72 determines that the EMC countermeasures are not completed (S11), the removed components are reinstalled (S12). When the EMC countermeasure determination unit 72 determines that the EMC countermeasures are completed, the deletability number is described in the 144th column of the countermeasure table 78, and information indicating that the simulation is completed is registered in the 145th column of the simulated column.
[0057] At this time, the EMC countermeasure determination unit 72 instructs the analysis model generation unit 73 to leave pads for mounting the components to be removed on the substrate. By leaving the pads, it becomes possible to easily install the components when the installation of the components becomes necessary at a later date.
[0058] If the priority order of the priority items is power consumption, it is the ranking of the top 10 components arranged in descending order of power consumption among the components used in the countermeasures.
[0059] Component area, component height, heat generation amount, etc. may be used as the priority items. Also, by determining how many top components to rank based on the number of components used in the countermeasures, it becomes possible to obtain a countermeasure plan that matches the priority items and the scale of the circuit.
[0060] Determine whether the simulation is completed for all components with registered priorities (S13). If there are remaining components with registered priorities, perform the simulation for the remaining components in the same way. If not, refer to the countermeasure table 78, and the analysis model generation unit 73 creates EMC countermeasure circuit data (S14).
[0061] The input / output unit 10 sends the generated EMC countermeasure circuit data to the operator terminal 55 (S15).
[0062] Figure 16 is an example of the output screen of the EMC countermeasure system in an embodiment of the present invention. It is sent from the input / output unit 10 to the operator terminal 55 together with the EMC countermeasure circuit data. In the countermeasure circuit column 131, the name 136 and version 137 of the circuit for which the countermeasure was taken are displayed.
[0063] In the priority item column 132, the priority items 138, 139, and 140 when performing EMC countermeasures are displayed. Multiple priority items can be specified, but the priorities are different according to the specified order. In this example, since the countermeasure cost is the highest priority item, the components with high prices become the removal candidates first.
[0064] The regulation value column 133 indicates the criteria used when determining whether the EMC countermeasures are completed. For example, for an ECU (Engine Control Unit) of an automobile, even if the circuit for which the EMC countermeasures are completed, it may be a circuit for which the EMC countermeasures are not completed in the medical field.
[0065] The countermeasure plan column 134 is a column indicating information such as filters used for EMC countermeasures. With the information in this column, it becomes possible to grasp what kind of countermeasures are applied.
[0066] The error column 135 is a column for displaying error information output when an error occurs during EMC countermeasures. For example, an error is output when a circuit that satisfies the regulation value cannot be created only with the information in the registered EMC design DB.
Explanation of Signs
[0067] 10 Input / output unit, 30 EMC design DB, 40 Analysis model DB, 50 EMC countermeasure system, 51 CPU, 52 Main memory device, 53, 59 External memory devices, 70 Reception unit, 71 Simulation execution unit, 72 EMC countermeasure determination unit, 73 Analysis model generation unit, 74 Component reduction unit 75 Circuit information table, 76 Countermeasure component list, 77 Regulation value DB, 78 Countermeasure table
Claims
1. In an EMC countermeasure system, circuit information of a circuit for performing EMC countermeasures, a reception unit for receiving priorities of EMC countermeasures, an EMC design database storing patterns of a circuit for performing EMC countermeasures and EMC countermeasure circuits, an analysis model generation unit for generating an analysis model in which an EMC countermeasure circuit is applied to circuit information, a simulation execution unit for executing a simulation using the generated analysis model, an EMC countermeasure determination unit for determining whether noise satisfies a predetermined standard based on the execution result of the simulation execution unit, a component reduction unit for deleting EMC countermeasure components from the countermeasure-completed analysis model based on the priorities of EMC countermeasures when the EMC countermeasures satisfy predetermined conditions, An EMC countermeasure system comprising an output unit for outputting a circuit of the countermeasure-completed analysis model from which the EMC countermeasure components have been deleted.
2. In the EMC countermeasure system according to Claim 1, it comprises a countermeasure component list storing information of components used in the EMC countermeasure circuit, the component reduction unit obtains reducible components from the countermeasure component list based on the priorities, deletes components effective for countermeasures of the priorities, the simulation execution unit performs a simulation of the analysis model from which the component most effective for the priorities has been deleted, An EMC countermeasure system in which the EMC countermeasure determination unit determines whether the noise of the analysis model from which the component effective for the priorities has been deleted satisfies a predetermined standard.
3. In the EMC countermeasure system according to Claim 2, when the EMC countermeasure determination unit determines that the noise of the analysis model from which the component effective for countermeasures of the priorities has been deleted does not satisfy a predetermined standard, the component reduction unit returns the deleted component to the analysis model.
4. In the EMC countermeasure system according to Claim 1, the priorities of the EMC countermeasures are the costs of components used for the EMC countermeasures.
5. In the EMC countermeasure system according to Claim 1, the priority order of the EMC countermeasures is the component area of components used for the EMC countermeasures.
6. In the EMC countermeasure system according to Claim 1, the priority order of the EMC countermeasures is the component height of components used for the EMC countermeasures.
7. In the EMC countermeasure system according to Claim 1, the priority order of the EMC countermeasures is the power consumption of components used for the EMC countermeasures.
8. In the EMC countermeasure system according to claim 1, The component reduction unit is an EMC countermeasure system that leaves pads for mounting EMC components when deleting EMC components.
9. In the EMC countermeasure method, The reception unit receives circuit information of a circuit for which EMC countermeasures are to be taken and priorities of EMC countermeasures, The analysis model generation unit refers to an EMC design database storing patterns of circuits for which EMC countermeasures are to be taken and EMC countermeasure circuits, and generates an analysis model in which the EMC countermeasure circuits are applied to the circuit information, The simulation execution unit executes a simulation of the generated analysis model, The EMC countermeasure determination unit determines whether noise satisfies a predetermined criterion based on the execution result of the simulation execution unit, When the component reduction unit satisfies predetermined conditions for EMC countermeasures, it deletes EMC countermeasure components from the analyzed model with countermeasures based on the priorities of EMC countermeasures, The output unit outputs a circuit of the analyzed model with countermeasures from which EMC countermeasure components have been deleted. An EMC countermeasure method.
Citation Information
Patent Citations
Emc design support system
JP2001155048A