The "current driven model"-experimental verification and the contribution of I/sub dd/ delta to digital device radiation

Abstract

Several researchers have proposed that a primary source of emissions from digital devices is due to the partial inductance of the return trace on printed circuit boards. In this "current driven model," RF currents derived from the nanosecond rise time of periodic signals such as clocks create a voltage across the return due to this inductance. This paper reports on an experimental verification of this model, but points out apparent limitations-at frequencies above a certain point, internal characteristics of integrated circuits such as I/sub dd/ delta appear to dominate the emissions, at least in the circuits examined.