Quantitative characterization of substrate noise for physical design guides in digital circuits

Abstract

Substrate noise is quantitatively evaluated by gain calibrated substrate voltage measurements in a 100 ps-100 /spl mu/V resolution. Activity in a digital block is a key parameter to which the noise intensity is proportional, and its reduction is a straight and universal solution to suppress the noise. Use of Kelvin grounding in the source circuits and placing a guardband proximate to the receiver circuits together also attenuates the noise significantly, however, the effect is limited to the low frequency components such as ringing.