An investigation of delta-I noise on integrated circuits

Delta-I noise is the voltage induced between the power conductors (e.g. the ground and the V_cc planes) when a circuit connected between them switches from one state to another. The authors show that the physics of the noise is more complex, and that it is related to wave propagation effects. Delta-I noise should be present not only in integrated circuits (chips), but also in multilayered boards, where it should be pronounced when the transients are of the order of 1 ns or less. Investigation of the delta-I noise is carried out for a simplified model of power planes, using a wire-antenna numerical simulation program. The model includes the wave propagation effects, as well as radiation, but it does not include the effects of the dielectric filling the space between the planes. The results of the analysis clearly show that the inductive effects are important only for slower transients. For fast digital circuits the power planes actually form a resonator,which can have a high quality factor, and the delta-I noise can build up to very high voltage levels.