A Technique for Analyzing On-Chip Power Supply Impedance

This paper proposes a method for analyzing the power supply impedance at an on-chip power supply node in the device under test. The proposed method is based on an on-chip power measurement of a power supply voltage fluctuation with sweeping the frequency of the on-chip current load which sinks a square wave current, not sinusoidal. The method can extract the frequency characteristics of not only the magnitude but also the phase characteristic of the power supply impedance. Experimental results based on SPICE simulations proved that the proposed method can accurately measure the frequency characteristic of the power supply impedance. It is also confirmed that the extracted power supply impedance characteristics gives quite similar transient voltage waveforms to the target waveforms.