Signal- & Power-Integrity Analysis

ANSYS SIwave employs specialized full-wave finite element algorithms to compute resonances, reflections, intertrace coupling, simultaneous switching noise, power/ground bounce, DC voltage/current distributions, near- and far-field radiation patterns on high-speed PCBs and complex IC packages.

Integrated and Automated DC I²R Reporting  

An integrated I²R computation module allows you to perform pre- and post-layout DC voltage drop, DC current density and DC power density analyses. This will ensure that power distribution networks (PDNs) can source the proper power to integrated circuits by checking that the PDN has the proper bump, ball and pin sizes as well as proper copper weighting to minimize losses. Additionally, all this crucial information is automatically generated with a single button click.

Chip-Package-System Platform

ANSYS SIwave is the platform for the industry’s first end-to-end chip-package-system design flow. SIwave integrates multiple electromagnetic field solvers, IC design and thermal analysis software tools in a comprehensive new approach to enable CPS design convergence.

By using advanced modeling and proven simulator technologies, this new approach for CPS convergence changes outdated compartmentalized chip, package and system design methodologies. This enables an intelligent, integrated, chip-aware system design that addresses power and signal integrity, EMI/EMC, and thermal and stress challenges.

PDN Channel Builder

The ANSYS SIwave CPS platform includes a PDN channel builder for automated creation of power-delivery networks within Apache Design's RedHawk and Totem products. The PDN channel builder streamlines the process of importing the package/PCB model into the RedHawk environment. It uses SIwave or Sentinel-PSI to create a database that includes the electrical model of the package/PCB and other relevant information. It also enables RedHawk to use the pertinent information in this database to hook up the package/PCB model to the chip layout for a package/PCB-aware IC analysis.

EDA Design Flow Integration

ANSYS SIwave with ANSYS ALinks for EDA seamlessly integrates into existing EDA design flows by importing design geometry directly from layout tools. The resulting SYZ networks or Full-Wave SPICE models generated by SIwave can be used in circuit simulation tools, such as ANSYS DesignerSI, ANSYS Simplorer, Synopsys HSPICE or other SPICE-compatible tools.

High-Performance Computing

ANSYS SIwave includes high-performance computing (HPC) options that allow the solver to use multiple threads, cores and processors to solve large simulations. This parallelization helps to enable full-packages-merged-to-board solutions for signal integrity, power integrity and electromagnetic interference.

HPC options includes a unique feature called the 3-D domain decomposition method (DDM). When invoked, SIwave with 3-D DDM solves 3-D discontinuities with a rigorous 3-D field solver and then combines all domains back together for the full solution. This method retains much of the traditional hybrid method’s speed while providing full accuracy for regions in the model with complex 3-D discontinuities.

In addition, HPC invokes the spectral decomposition method (SDM) for SIwave’s Sentinel-PSI SYZ solver. This capability significantly speeds up Sentinel-PSI by distributing frequency points over compute cores, whether they exist in an IT-managed cluster or single computer.

Multiphysics

ANSYS SIwave links with the ANSYS software portfolio for multiphysics simulation of electronic components. One option is the ability to export a power distribution map from SIwave into ANSYS Icepak. This multiphysics solution enables accurate thermal modeling of IC packages and PCBs using DC power loss from SIwave as a heat source. Icepak solves the challenges associated with the dissipation of thermal energy from electronic components that may cause premature component failure due to overheating. Thermal stress can then be evaluated with ANSYS Mechanical. This multiphysics approach allows engineers or groups of engineers to perform coupled EM-thermal-stress analysis for a complete understanding of the design.

Automated Decoupling Capacitor Optimization

Full-Wave Electromagnetic Decoupling Analysis

ANSYS SIwave PI Advisor significantly improves engineering productivity by automating decoupling capacitor selection, placement and optimization for printed circuit boards and IC packages. The underlying engine, based on sophisticated genetic algorithms, allows the specification of various constraints (capacitor price, total number of capacitors, desired network impedance, etc.) for consideration in its cost function. Accurate frequency-dependent S-parameter capacitor models are utilized during simulation. In addition, the impact of capacitor physical location and mounting technique is captured by the full-wave SIwave or Sentinel-PSI extraction engine.

Once optimization is complete, PI Advisor presents several decoupling schemes (each consisting of a set of capacitors) that meet the specified constraints. Engineers can browse the schemes and export a bill of materials (BoM) for those deemed to best meet their requirements. You can also superimpose a 3-D bar graph on the layout to indicate loop inductance values. This provides an immediate, intuitive understanding of each capacitor's effectiveness.

SimplePI-Llumped Analysis

SimplePI-lumped analysis provides a quick calculation to determine capacitor values and placement. This solution ascertains the lumped-circuit equivalent of all the capacitors on a board or package and can be used to develop the best candidate capacitors for a given design. In addition, it will automatically determine the best type and number of capacitors for a frequency-dependent impedance mask.

Signal Net Analyzer

The built-in signal net analyzer tool quickly and easily allows you to display quantities such as characteristic impedance (Z0) for both single-ended and differential nets. In addition, it provides the net length, propagation delay and reference layer for any selected nets. All possible paths (from each pin to every other pin on a net) are displayed and sorted in descending order of path distance; this includes extended nets.

An example of an extended net is PCIe with an AC blocking capacitor.

You can click on any individual path in the table so the variation in Z0 is graphically displayed and the selected path is highlighted in ANSYS SIwave's main layout window. Engineers can quick perform time domain transient circuit analyses with ANSYS DesignerSI or Synopsys HSPICE. The time domain analyses may include IBIS buffer models at both the driver and receiver ICs.

The signal net snalyzer produces 2-D MoM solutions for Transmission lines and vias that provide immediate feedback for propagation delay and characteristic impedance along with transient circuit analysis results.

EMI/EMC Capability

Electromagnetic interference/compatibility testing can be performed for both near- and far-field problems. ANSYS SIwave utilizes algorithms from ANSYS HFSS to provide accurate, detailed descriptions of field interactions above and below boards and packages. Combining this with resonant mode simulations allows you to predict field radiation patterns prior to manufacturing to reduce the number of fabrication spins needed to meet your needs. SIwave provides valuable insight into sources of EMI that are not obtainable through measurements and provides; it also offers confidence that any changes made will correct the problems found during testing. Coupling of SIwave with ANSYS DesignerSI, ANSYS Nexxim and ANSYS HFSS delivers the unique ability to study data-dependent radiation patterns from PCBs and packages inside of a housing enclosure.

This SIwave cavity resonant plot details the potential difference (voltage) between the 1.8V DC plane and ground including all parasitics. Red indicates a large resonance that is yielding the largest potential difference between Vdd and ground where the FEM mesh is shown by  white triangles.

Layout Extraction

ANSYS SIwave can extract complete designs (which include multiple, arbitrarily shaped power/ground layers, vias, signal traces and circuit elements) with unprecedented accuracy and speed, without requiring potentially laborious layout partitioning by the user. SIwave extracts S-, Y-, and Z-parameters and IBIS interconnect models (ICM), displays 3-D electromagnetic fields, and generates ANSYS Full-Wave SPICE models for subsequent time- and frequency-domain analyses within ANSYS DesignerSI, ANSYS DesignerRF, ANSYS Simplorer or third-party SPICE-compatible circuit tools such as Synopsys HSPICE and Cadence PSpice. In addition, SIwave with ANSYS ALinks for EDA creates MCAD geometry for AMSYS HFSS, ANSYS Q3D Extractor, and ANSYS Workbench. Finally an engineer has the ability to choose which EM solver best fits his or her design requirements, since HFSS and Sentinel-PSI can be invoked from the SIwave user interface.

Post-Processing

ANSYS SIwave delivers powerful post-processing features to visualize, animate and report the results of your simulation. These results are:

Broadband & SPICE Model Generation

ANSYS Full-Wave SPICE provides frequency-dependent SPICE models for accurate time domain simulation in third party time-domain analysis tools. ANSYS Full-Wave SPICE models can be created for use with ANSYS Nexxim, HSPICE, Spectre RF and MATLAB. Full-Wave SPICE is the only tool on the market that produces highly accurate, high-bandwidth SPICE models at the touch of a button. This capability enables you to design electronic and communication components while taking Gigahertz-frequency effects into account.

Macro Modeling

SIwave provides an unprecedented level of accuracy for complete board and package designs that enables full-channel transient simulation in multiple circuit simulator platforms. SIwave uses patent-pending TWA technology so you can check and enforce passivity and causality. This technology eliminates errors introduced when trying to simulate time-domain circuit analyses using different simulation platforms. SPICE-level models using HSPICE and PSpice syntax are supported along with native ANSYS Nexxim and ANSYS Simplorer state space models.