Full-chip Power-supply Noise: the Effect of On-chip Power-rail Inductance

The importance of on-chip power-rail inductance in generating delta-I power-supply noise is examined in this paper using systematic circuit simulation of the complete integratedcircuit power net. This source of noise is compared to the resistive IR drop in the net, and to the delta-I noise due to both high-inductanceand low-inductance-bonding packages. Results are presented for a typical on-chip power net in 0.18μm CMOS technology, and it is demonstrated that the inductance of this on-chip power net is the dominant contributor to the full-chip power-supply noise. The simultaneous switching events which produce the triggering current transients for the delta-I noise are taken to arise from core-logic switching; the mitigating, de-coupling role of the capacitance of non-switching gates within the core-logic block is considered.