What is PDN Analysis?
Power Distribution Network (PDN) analysis allows you to ensure that your power sources are supplying clean and stable voltages to your loads and devices. Board re-reruns are usually caused by the following design challenges:
- Voltage drops: IC supply-rail levels below recommended minimum voltage
- High current densities: Excessive heat generation causing delamination or fusing
Due to the challenges above, you may have the following PDN symptoms on your previous board assemblies.
The PDN Analyzer powered by CST® allows you easily resolve PDN issues as they arise in your board layout process, all right within the unified design workspace that you use every day, i.e., Altium Designer 16. The extension can help through the following features:
- Shows voltage drop from source to loads due to net resistivity
- Pinpoints high current density due to pinch points
- Allows designer to efficiently size power delivery shapes and via requirements
- Uncover unconnected or poorly-connected copper areas
These features can easily be used and configured on the source PCB by any engineer or PCB designer through Altium Designer, which will then ultimately lead to fewer board design spins.
Example PDN Analysis
We ran an analysis on one of our example boards and we noticed that the voltage distribution seems good, where the 1.8VDC supply net ranges from a minimum of 1.7866V to maximum of 1.7995V which is only a 13mV drop.
However, further analysis on the current density of this supply net ranges from a minimum of 0A to a maximum of 35.919MA/m2
. The red color below shown indicates the maximum current density which could be improved. Excessively high current density would melt the trace, affect product reliability or fuse open.
The board was then modified by increasing trace width on some hot spot locations, and re-routed to allow elimination of vias. This then decreases the voltage drop from 13mV to 9mV which is a 4mV improvement from a minor rerouting. The current density is greatly improved from 35.919MA/m2
. The current density is also more uniformed in the modified version.
For more information...
For more information, please check out the following helpful links:
or contact me through the signature information below.
Eu Jin Ooi, Masters of Engineering
Altium Certified Trainer
CAD MicroSolutions Inc.
65 International Boulevard, Toronto ON, M9W 6L9 Canada
| T: (416) 213-0533 ext 203