Computation of noise spectral density in switched capacitor circuits using the mixed-frequency-time technique

A time-domain algorithm for computation of the noise power spectral density (PSD) is proposed by V. Vasudevan. When applied to periodically varying circuits, this formulation requires efficient methods to obtain the quasi-periodic steady-state solution of a set of linear time-varying ordinary differential equations. We use both the mixed frequency-time technique (MFT) and the shooting Newton method for this computation. We show that, at each frequency for which the spectral density is sought, MFT requires only two integrations over the duration of the clock period. The results are compared with published experimental and computed data.