Delivering such large amounts of power requires that low impedance power paths are designed into the PCB. With such high currents, IR-drop becomes a real issue when designing power traces and plane shapes. Unfortunately there has never been a particularly easy way to evaluate the amount of IR-drop that should be expected. Although IR-drop can be calculated from trace parasitic information on simple traces, problems arise when the copper is in the form of a plane shape, especially where multiple components exist, each with multiple power connections. Furthermore, power connections are often made by plane shapes run on multiple layers to further reduce losses, making the estimates very difficult to quantify.
Typical Intel PSU Requirements
Now the good news... we now have the tools to analyse IR-drop in a simple, convenient manner.
Voltage Isocontours Across Plane Shape
Measuring from Source to Load
