A nonlinear macromodel of operational amplifiers in the frequency domain

A nonlinear macromodel for integrated circuit operational amplifiers has been developed for frequency-domain analysis. The main difference between this macromodel and those previously reported in the literature is that this model considers the influence of frequency and amplitude on the transfer function of the operational amplifier. The macromodel also includes the slew-rate effect on the open-loop frequency response and output-voltage distortion computed from the Fourier coefficients. The benefits of the developed macromodel are demonstrated by several examples, showing that the simulation is in good agreement with the experimental results. One important application of this macromodel is suggested to be in the computation of the dynamic range of active filters.