A mixed frequency-time approach for distortion analysis of switching filter circuits

A new efficient mixed frequency-time approach to computing steady-state and intermodulation distortion of switching filters without resorting to macromodeling or the slow-clock approach has been presented. The method works by computing the solution to the differential equation system associated with a circuit for only J clock cycles, where J is the number of coefficients needed in the Fourier series to represent accurately the sequence of initial points in each clock cycle. Thus this method is particularly efficient when the number of coefficients in the Fourier series is many fewer than the number of clock cycles in one input signal period.<>