Supply voltage drop study considering on-chip self inductance of a 32-bit processor's power grid

Abstract

Conventional IR drop analysis suggests that on-chip inductive effects can be neglected when estimating supply voltage drops. We present a supply voltage drop analysis for a commercial 32-bit application processor. Our power grid model uses a backbone RL extracted netlist of the processor's power grid, complemented with capacitances from the processor design and a current signature defined by the worst-case switching test vector, located in the power-up sequence of the processor. Our circuit simulations show that on-chip self inductance makes the actual supply voltage drop deviate by more than 55% and 25% from the ∼6% and ∼8% drop, respectively, of nominal supply voltage that a conventional IR power grid model yields.