Exact noise analysis of SC circuits and an approximate computer implementation

A noise analysis of switched-capacitor (SC) circuits is presented that describes the time-averaged second-order statistics of the cyclostationary processes encountered in such systems. A unified framework makes it possible to take into account broadband, as well as low-frequency (such as flicker), noise sources by basing the modeling for all noise types on the mathematical white-noise model in which broadband noise is modeled by white noise and low-frequency noise by linearly filtered white noise. The noise signal decomposition used is different from that used in previous approaches and leads to simple and straightforward computer implementations on various approximation levels. On the basis of this solution, existing SC circuit analyzers featuring different abstraction levels can easily be extended with the noise analysis feature by using much of their original routines. As an example, an implementation of the noise analysis for the WATSCAD program is described.>