Videos > EMI/EMC Simulation Part 2: PCB EMI demo
Sep 3, 2022

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EMI/EMC Simulation Part 2: PCB EMI Demo

Yes, we can see it. Yeah. I just want to answer one question quickly:

  • The webinar is recorded. We are happy to send this out upon request. Feel free to send an email to info@ozunin.com, and we will send you the recorded videos.

Demo Overview

This demo will continue with some slides after Mark's presentation. We have a simple workflow here, which is a PCB emission workflow:

  1. Set up a PCB model.
  2. Perform a PCB level simulation, including SYZ parameters.
  3. Link it to a two-way coupling with our transient circuit model, which includes a four-phase switching power supply.
  4. Extract the conducted emissions from the circuit and couple that to our field solver.
  5. Compute the radiated emission and include the PCB enclosure.

In this case, we are adding some shielding. If you have other concerns, such as an adjacent PCB, you can use this PCB as a noise source and conduct a two-PCB analysis to compute the radiated emission.

PCB Simulation

The PCB files we can accept are as follows:

  • EDB file: If you are using Altium Designer for PCB layout, you can export an SSEDB file to import directly into our tool.
  • ODB++ and IPC2581: These are the most standard formats, and we can also import BRD files.

Workflow Wizard

The workflow wizard helps you verify your stack-up after importing your geometry:

  1. Verify Stack-Up: Check layer information, techniques, thickness, and material properties. You can make changes here if needed.
  2. Verify Circuit Elements: Import capacitors, inductors, and resistors.
  3. Verify Ground and Power Nets: Auto-identify power and ground nets.
  4. Sanitize Layout for Simulation: Clean the geometry to speed up simulation.
  5. S-Parameter Model for Capacitors: Use the ANSYS library to select capacitors from various manufacturers.
  6. Assign SPICE Netlist: Import SPICE models for components like common mode chokes.

Simulation Configuration

For EMI/EMC, we focus on susceptibility analysis:

  1. Create ports on your PCB for power supplies, capacitors, inductors, MOSFETs, and controllers.
  2. Configure ports using circuit elements or selected nets.
  3. Set reference impedance for signal integrity and power plants.
  4. Run susceptibility analysis to compute induced voltage and current.

SYZ Parameters and Circuit Simulation

To couple PCB field results with circuit simulation:

  1. Compute SYZ parameters by sweeping from DC to 1 GHz.
  2. Set up a transient circuit simulation with voltage supply, LISIM, and four-phase switches.
  3. Run the simulation and plot results for voltage output and conducted emissions.

Near and Far Field Analysis

For near field analysis:

  1. Define a source file and configure sweep for EMI analysis.
  2. Compute near field results and plot the E field at various frequencies.

For far field analysis:

  1. Compute far field results and plot maximum RE total at specified distances.
  2. Compare results with and without shielding to evaluate the effectiveness of enclosures.

Conclusion

This concludes the demo. By combining PCB layout tools with 3D modeling tools, you can treat your PCB as either a noise source or a victim in simulations. If you have any questions, please reach out to us. We can make this recording available to you.

Contact us at info@ozunin.com or visit our website at ozunin.com/contact-us. We look forward to discussing your specific problems and helping you with EMI and EMC concerns.

[This was auto-generated. There may be mispellings.]

EMI/EMC Simulation Part 2: PCB EMI Demo Yes, we can see it. Yeah. I will answer one question here quickly. Yeah, the webinar is recorded. We are happy to send this out upon request. Feel free to send an email to info@ozunin.com, and we will send you the recorded videos.

This demo will continue after Mark's presentation. We have a simple workflow: a PCB emission workflow.

I will talk about setting up a PCB model, doing a PCB level simulation, linking it to a two-way coupling with our transient circuit model, extracting conductive emissions from the circuit, coupling that to our field solver, computing radiated emissions, and including the PCB enclosure.

If you have other victims, such as adjacent PCBs, you can use this PCB as a noise source and put adjacent PCBs in for two-PCB analysis. First, I will talk about PCB simulation. The PCB file we accept includes EDB files from Altium designers, ODB++ and IPC2581 files from other tools, and BRD files.

Once you import the PCB layout, there's a workflow wizard to help verify your stack-up. The workflow wizard shows layer information, layer thickness, and material properties. You can make changes to material properties here.

We are simulating a simple four-layer board, a buck converter board stepping down from 2V to 1V. The verify path stack step allows you to verify VLs and modify their properties. The verify circuit elements step imports all capacitors, inductors, and resistors.

The verify ground and power nets step defines power and ground nets and sanitizes the layout for simulation. The S-parameter model for capacitors step includes a massive library of capacitors from various vendors and manufacturers.

You can select a capacitor and assign its manufacturer, series, part number, and values. The assign SPICE netlist step allows you to import the SPICE model for four-port inductors. The configure DCI-L analysis step is for more simulation options, but we will mainly talk about EMI and EMC.

The susceptibility analysis step involves creating ports on your PCB. You can use generate circuit elements on components or generate port on selected nets. For signal integrity, use a 50 ohm impedance, and for power plants and power ground plants, use a lower impedance, such as 0.1 ohms.

Once you set up the ports, you can run the simulation and compute induced voltage analysis. Define the frequency range for the incident wave and the polarization. You can define multiple incident waves and steps.

After success stability analysis, we will compute SYZ parameters to couple our PCB field results with our circuit simulation. I will do a transient analysis in the circuit and include DC points and sweep up to 1GHz. Then, I will run the analysis and get SYZ parameters.

We will then go back to our circuits and drop our PCB model here. We will bring in SYZ parameters and expose the reference pin to all these ports. Then, we will set up our transient analysis and plot the results.

Finally, we will plot the conducting emission report and add a standard mask, such as the FCC standard mask. We can check if our emission meets the requirement. After all of this, we can push excitation and compute near field analysis.

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