As implementable analog circuit size has increased significantly due to advancements in manufacturing process, analog designers of system large scale integration (LSI) face increasingly difficult problems. For example, inadequate circuit simulation capacity and the tradeoff between long simulation time and accuracy have become critical issues. A specific case of these shortcomings in traditional simulation solutions is the debugging of the effects of flicker noise in transient domains, an intrinsic problem especially for CMOS analog circuits. Historically, we could not accurately model and analyze these effects. Fortunately, Eldo® Premier from Mentor Graphics® has a superb transient noise analysis feature (the .NOISETRAN command) that achieves both accuracy and performance when simulating large scale analog/mixed signal circuits for the effect of flicker noise in transient analysis. In this paper, we will present examples of simulation results that demonstrate a high correlation with real silicon evaluation results.