Switching-mode dependence of inductive noise in VLSI power bus lines

The switching-mode dependence of inductive noise on the power bus lines has been investigated. As the maximum operation frequency of the very large-scale integration is determined by the slowest response in the critical path, suppression of inductive noise in power lines is crucial. Circuits with 50% duty cycle are almost free of inductive noise. Contrarily, the low duty cycle circuits are highly subject to the inductive noise thus the decoupling capacitor needs to be carefully implemented, considering the line inductance and effective frequency. The conventional "10× of switching-capacitor" rule-of-thumb is not applicable to decoupling capacitor implementation and can cause worse inductive noise than a "no capacitor" situation.