This paper presents a new jitter component analysis method for mixed mode VLSI chip testing in Automatic Test Equipment (ATE). The separate components are analyzed individually and then combined using Matlab. The Matlab simulation shows how jitter components combine and how the total jitter depends on the jitter injection sequence. The relationship among jitter components is presented and the superposition of the jitter components is verified. This new technique gives test engineers an insight into how the jitter components interact.