BoardSurfers: Allegro In-Design IR Drop Analysis: Essential for Optimal Power Delivery Design

All PCB designers know the importance of proper power delivery for successful board design. Integrated circuits need the power to turn on, and ICs with marginal power delivery will not operate reliably. Since power planes can take up a significant portion of the board and impact all subsequent place and route steps, you must ensure proper power delivery early in the design cycle. Power Integrity experts can spend weeks fully analyzing a power delivery network, but DC IR drop is the first step in PDN analysis to ensure successful power delivery. That is why the IR drop workflow powered by Sigrity is now available to PCB designers within Allegro. You can run this quick analysis for any power net throughout the design cycle and view the results directly on the Allegro® canvas provided you have an advanced license. This quick, direct feedback will help you avoid layout mistakes that can cause significant re-work late in the design phase when all eyes are on the board for the final release to manufacturing. 

The IR Drop Workflow lets any designer with a PowerTree source/sink definition file run analysis on any power net of interest. The results are shown in an easy to view table with sorting, filtering, and cross-probing. The IR Drop Vision also allows you to quickly visualize which area of a power plane might be causing the biggest IR Drop such as a layer transition with too few vias, or a power plane pinch off due to misplaced ground vias. An optional pass/fail status is available for sink devices based on a tolerance from the PowerTree file. You can view the results as IR Drop, Voltage, or trace and via Current Density. 

PCB designers who can ensure proper power delivery earlier in the design cycle will avoid costly layout changes needed late in the design cycle. The Allegro In-Design IR Drop Workflow gives you the means to ensure proper first-order power delivery without leaving the design canvas or relying on a power expert to run the analysis. This will enable you to make changes quickly while also allowing power experts to focus on cases requiring advanced analysis. 

Click here to view a video of the workflow in action.