Automated Decoupling Capacitor OptimizationFull-Wave Electromagnetic Decoupling AnalysisANSYS 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 AnalysisSimplePI-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. |
