The high data rates and miniature scale of high-speed electronics require very high signal and power integrity (SI/PI), with a very low risk of interference or noise. As data rates increase, the signal frequency increases and signals propagate more like a high-frequency electromagnetic wave than a classical circuit current. Understanding the behavior of high-speed electronics goes beyond circuit simulation: it requires a full-wave 3D approach that can model these electromagnetic fields fully to help analyze the design of high performance printed circuit boards.
Simulation in the EDA workflow
Physical tests can be replicated in the simulation environment using the “Virtual Twin” approach. This is a high-fidelity model of the system that includes all relevant data in one package. Common SI/PI tests such as IR drop, eye diagram and bathtub plots can be replicated virtually, as can EMC test set-ups such as emissions measurement and bulk current injection (BCI).
Trustworthy Virtual Twins require accurate models. SIMULIA offers access to material databases with the properties of real proprietary substrates, and the ability to create custom materials from measured data using a variety of material property models, such as frequency-dependent materials.
The electromagnetic simulation tools in SIMULIA CST Studio Suite can be integrated into EDA workflows using many industry standard ECAD and MCAD tools, offering electronic engineers the ability to analyze SI/PI and EMC concerns at all phases of design: pre-layout, during layout and post-layout. Specialized tools provide engineers with rule-checkers and solvers needed to analyze integrated circuits (ICs), PCBs and cables, while general purpose 3D solvers can simulate the entire board and the device as whole. The Broadband Macromodeling technology provided by IdEM enables SPICE model extraction from 3D electromagnetic field simulation. Conjugate heat transfer (CHT) simulation can be coupled to the electromagnetic simulation to analyze the thermal performance of electronics and to design cooling systems.
Signal integrity (SI) Analysis
Signal Integrity is about maintaining the quality of data transmitted through a channel, allowing the the digital pattern of 1s and 0s to be reliably recovered from the analogue signal. The main measure of this is the eye diagram – the shape formed on an oscilloscope by a large number of random bits. Critical effects include jitter, loss and noise from sources such as crosstalk (interference between channels) and inter-symbol interference (interference between successive bits).
Power integrity (PI) Analysis
Power Integrity meanwhile is about ensuring that the voltage received at a component is within the tolerances and does not introduce interference. IR drop – the decrease in voltage across a PCB power plane due to losses – is a common PI concern. Power electronics introduce switching noise – high frequency variations in the voltage that can cause interference and SI problems. The placement of decoupling capacitors (decaps) can reduce noise and prevent its transmission.
3D full wave simulation captures the full behavior of a device and its electronics – including cables, printed circuit boards (PCBs) and chip packages – to reveal potential issues that 2D and circuit simulation can miss, long before committing to manufacturing a physical prototype. Problems can be identified early, and the root causes of issues can be found and mitigated with the help of 3D visualization.
For an accurate Signal Integrity/Power Integrity (SI/PI) simulation of a complete electronic system, all the signal and power degradation effects must be taken into account. These include interconnect parasitic effects, coupling interference from nearby interconnects, reflections due to discontinuities, dispersive and non-ideal material properties.
Broadband macromodeling is a very efficient approach for modeling complex electronic systems. In macromodeling, the result of a 3D field simulation of an individual component is translated to an equivalent model that can be used as a “block” in common circuit simulators (e.g., SPICE), in order to carry out a very detailed system-level EMC and SI/PI analysis including signal degradation effects.
Broadband macromodeling can be performed using the SIMULIA tools CST Studio Suite and IdEM. Based on scattering parameters (S-parameters) from a full-wave simulation in CST Studio Suite, IdEM extracts an accurate macromodel. Crucially for any realistic simulation, IdEM can ensure the extracted SPICE model is both passive – not amplifying signals or increasing total power – and causal – meaning the output signal never precedes the input.
Signal and Power Integrity Related Materials
SIMULIA Electromagnetics Technology for Signal and Power Integrity Simulation
SIMULIA develops simulation technology that can be used to calculate the signal and power integrity of electronic devices for a wide range of application, areas. Depending on your working environment this technology is available to you in various ways:
Electromagnetics on the 3DEXPERIENCE Platform
EM simulation software is a game changer when it comes to reducing the time and cost of bringing a product to market, not just in the high-tech industries of electronics and communication.
3DEXPERIENCE Works Electromagnetics
Electromagnetics Engineer is a high-performance 3D electromagnetic simulation solution. Powered by the industry proven CST Studio Suite, this cloud-enabled role delivers fast, effective simulation and design guidance of electro-mechanical devices, PCB’s, antennas in a truly multi-physics environment.
IdEM is a user friendly tool for the generation of SPICE ready macromodels of electrical interconnect structures such as packages, connectors, via fields, discontinuities up to backplane links and complete power delivery networks.