Power Supply Noise: Causes, Effects, and Testing

With technology scaling, the current densities in digital circuits increase significantly. As a consequence, noise which affects the power distribution network, or power supply noise, increasingly compromises the circuit functionality and timing. As it becomes more and more difficult to address all power supply noise issues using design methods, considering noise effects during manufacturing test gains importance. This article provides an overview of different classes of power supply noise and test methods used to identify circuits which are likely to fail due to these effects. Most test strategies to detect power supply noise differ significantly from conventional test approaches because they must consider information such as power consumption profiles, switching activity, power grid design, physical proximity, or multi-cycle effects.