SIwave: Everything you need to know about the Induced Voltage Solver (HD)
SIwave is a power integrity and signal integrity tool. One of its key features is the Induced Voltage Solver, which is designed to evaluate if a PCB is shielded against noise signals from external sources. It calculates the noise voltage on any port placed in the model. If the PCB accepts noise, it can also radiate, necessitating a thorough examination and resolution of any issues.
Using SIwave
SIwave should not be used to build PCBs. Instead, it is recommended to import files from professional CAD tools. SIwave supports the following CAD file types:
- IPC
- ODB++
- EDB
- DXF
- GDS
Any process in SIwave begins by selecting a solver. Once a solver is selected, a dialog box appears for the user to fill out and submit. For example, selecting the Compute Induced Voltage Solver will prompt a dialog box. Some solvers, like the induced voltage solver, require ports in the model to be activated.
Creating Ports
There are multiple ways to create ports in SIwave:
- Upload the CAD file and create ports in the model.
- Assign ports to nets using the PI solver by selecting Configure PI Analysis and assigning ports to power planes.
- Use the Tools menu to Generate Port on Selected Nets.
When generating ports, selecting multiple nets will display ports related to the last selected net, but all selected nets will have ports generated.
Induced Voltage Solver Setup
Once ports are created, the induced voltage solver can be activated. The setup involves specifying:
- Solution Name
- Frequency Band: Multiple bands can be specified.
- Current Voltage
- Wave Direction: For Cartesian coordinates, specify the direction (e.g., negative X).
- Polarization: Should be perpendicular to the wave direction.
- Magnitude of the Wave
For spherical coordinates, specify Phi and Theta values. The polarization should remain perpendicular to the wave direction.
Solver Options
Users can choose between:
- Balanced Accuracy
- Optimum Accuracy
- Optimum Speed
It's recommended to start with balanced accuracy and adjust based on the speed and accuracy of results.
Running Simulations
Simulations can be run with or without decoupling capacitors (caps) on power planes. The results can be plotted to show:
- Magnitude and Phase of induced voltage at ports.
- Comparison of results with and without caps.
Additional features include adding markers, limit lines, and post-processing calculations like maximum, average, and minimum values.
Simulation Profiles
SIwave provides a profile of the simulation, detailing the time spent solving, mesh details, and other properties. This is useful for comparing solutions and documenting setups for future reference.
Conclusion
The induced voltage solver in SIwave allows for comprehensive analysis of a PCB's ability to suppress radiation and reject external noise. This ensures that the PCB performs optimally under various conditions.
Thank you for watching the video.
SI Wave: Everything you need to know about the Induced Voltage Solver (HD) SI Wave is a power integrity and signal integrity tool. The Induced Voltage Solver is one of the tools in SI Wave that will be discussed in this video.
The Induced Voltage Solver measures if the PCB is shielded against any noise signal from external sources. It calculates the noise voltage on any port placed in the model. However, if the PCB accepts noise, it can also radiate. That's why it's essential to study it and examine your PCB.
If there's an issue, you need to resolve it. SI Wave should not be used to build PCBs. Instead, try importing files from professional CAD files. SI Wave can be used to build PCBs by importing the following types of CAD files: IPC, ODB++, EDB, DXF, and GDS.
Any process in SI Wave starts by selecting the solver. Once you select the solver, a dialog box pops up. All the user needs to do is fill up the form and submit it. For example, if you select the Compute Induced Voltage Solver, you get a dialog box.
Some solvers require ports before you can select the solver. The Induced Voltage Solver expects ports in the model. Otherwise, it will not be activated. You won't be able to launch it. To create a port, there are many ways in SI Wave. For example, when you upload the CAD file, you can create a port.
You can create a port in the model. You can create a port in the CAD file. SI Wave will show you a list of all the nets and ask the user to assign ports to the nets. The other way to assign ports to power planes is to use the PI solver.
If you click Configure PI Analysis, you get the list of all the power planes. If you select any one of them, you can go and assign ports. To add ports to the net, the best way to do that is to go to Tools, Generate Port on Selected Nets.
Then you get the list of all the nets that you have in your system. And all you need to do is to select them one by one. For example, if you go and select N17055, you have two ports. You can go ahead and say Generate Ports, or you can select more.
For example, if you select the other one, PW, it also has two. Notice that every time you select a new one, SI Wave only displays the ports related to the last one that you selected. That doesn't mean that it deselects the other one, the first one. No, both of them are selected.
So if you click Generate, it will generate ports for both of them. So if you go to Components and select Ports, you see here, you will have the N17055, the two ports, and also the PBE\_WR, the two of the other trace, in addition to the two ports that you put on the power plane.
Going back to the Induced Voltage Solver, you can specify the name of your solution, the band, the current voltage, and the magnitude of your wave. You can also specify the polarization and the direction of the wave. You can save the voltage at port locations for all angles.
You can also specify the accuracy of your solver by clicking on Other Solver Options. You can select Balanced Optimum Accuracy or Optimum Speed. Now you are ready to launch and look at the solution.
Start with Induced Voltage with no caps, change that to with caps because you have decoupling caps on the power planes, and that's it. You are ready to solve. When you launch this, you get a solution, and the solution will be something like this. You can plot the magnitude and the phase.
You can also add markers to the graph just to see what the exact value is at any point. You can display the maximum of each curve, the average, and the minimum. You can also add notes. You can save the voltage at port locations for all angles. You can specify the magnitude of your wave.
You can also look at the profile, which will tell you how much time was spent to solve the problem and the mesh and all these details. You can also look at the simulation properties, which will remind you with all the setup that you did in order to create this solution.
Using the Induced Voltage Solver, you will be able to study if your PCB has the capability to suppress radiation and has the capability to reject noise coming from outside from any direction. Thank you for watching the video.
