Transient noise analysis in circuit simulation

Circuit simulation is one of the most important steps during the development of electronic circuits. A standard task for circuit simulation is the transient analysis, the simulation of the chip on transistor level in the time domain. Normally, this simulation does not include noise source. As the supply voltage decreases, the signal-to-noise ratio also decreases and noise effects become more and more important. In this paper the modeling of noise in the time-domain will be described. Especially for flicker noise, new and efficient approaches are presented. For a numerical treatment of the resulting stochastic differential-algebraic equations, a new numerical scheme is given for the charge-oriented formulation of the circuit equations. Finally, the results of numerical experiments are presented.