A method is provided for use during static timing analysis of an integrated circuit design to produce an equivalent waveform model, the method comprising: using an analog model of the inner component, to simulate an inner component to produce multiple analog simulation output characterization waveforms as a function of multiple input waveforms used to characterize the design cell; using the analog model of the inner component to simulate the inner component to produce an analog simulation output waveform as a function of the complex waveform; and producing the equivalent waveform model as a function of the multiple analog simulation output characterization waveforms and the analog simulation output waveform.