Rapid estimation of the nonlinear frequency response of switched-capacitor circuits

Analysis of switched capacitor circuits in the presence of nonlinearities is a difficult problem. The standard programs such as SWITCAP provide only a first order linearized response. In this paper/sup 1/ we present a novel technique for the rapid estimation of the nonlinear frequency response of switched-capacitor circuits. This method can be incorporated in existing circuit simulators with little effort. The method is based on using a multifrequency sinusoidal input excitation in a single time domain analysis until steady-state. The entire frequency response in the desired frequency range is then extracted using a frequency directed DFT. A comparison is made to the mixed-frequency-time (MFT) approach, which is a competitive method.