Fast vectorless power grid verification using an approximate inverse technique

Power grid verification in modern integrated circuits is an integral part of early system design where adjustments can be most easily incorporated. In this work, we describe an early verification approach under the framework of current constraints where worst-case node voltage drops are computed via linear programs proportional to the grid size. We propose an efficient method based on a sparse approximate inverse technique to greatly reduce the size of such linear programs while ensuring a user-specified over-estimation margin (in volts) on the exact solution.