A new algorithm for third generation circuit simulators: the one-step relaxation method

A new algorithm for third generation circuit simulators, the “ONE-STEP RELAXATION METHOD” (OSR), as well as a concrete implementation of it, the new circuit simulator ELDO, are presented. This algorithm can replace the NEWTON method used in most second generation circuit simulators. Contrary to “Timing Simulator” algorithms, OSR makes no simplifying hypotheses on weak couplings between nodes. OSR performances are close to those of the “WAVEFORM RELAXATION METHOD” (WRM) used in the recent circuit simulator RELAX. But OSR requires less memory space than the WRM and its CPU-time increases linearly with the interval of simulated time. Eldo has already been used for the accurate simulation of a 1600 MOS digital-analog converter : less than one megabyte memory size was required.