Time-domain non-Monte Carlo noise simulation for nonlinear dynamic circuits with arbitrary excitations

Abstract

A new, time-domain, non-Monte Carlo method for computer simulation of electrical noise in nonlinear dynamic circuits with arbitrary excitations is presented. This time-domain noise simulation method is based on the results from the theory of stochastic differential equations. The noise simulation method is general in the sense that any nonlinear dynamic circuit with any kind of excitation, which can be simulated by the transient analysis routine in a circuit simulator, can simulated by our noise simulator in time-domain to produce the noise variances and covariances of circuit variables as a function of time, provided that noise models for the devices in the circuit are available. Noise correlations between circuit variables at different time points can also be calculated. Previous work on computer simulation of noise in integrated circuits is reviewed with comparisons to our method. Shot, thermal and flicker noise models for integrated-circuit devices, in the context of our time-domain noise simulation method, are described. The implementation of this noise simulation method in a circuit simulator (SPICE) is described. Two examples of noise simulation (a CMOS ring-oscillator and a BJT active mixer) are given.