Behavioral modeling of analog and mixed signal IC's: case studies of analog circuit simulation beyond SPICE

Analog circuit designers trust SPICE because it represents a circuit in terms of the laws of physics governing each component. However, the increasing size of analog microsystems and the heterogeneity of waveform types of interest time-domain, frequency-domain, discrete-time, continuous-time-make it almost impossible to simulate these circuits efficiently on SPICE. Behavioral modeling offers one possible way to abstract the features of interest in a circuit block. Although simulation programs such as Saber have offered behavioral modeling for more than a decade, few seasoned analog circuit designers avail themselves of this capability. This paper describes how behavioral models were used in three state-of-the-art high performance mixed-signal design projects.