Fast simulation of sigma-delta modulators using SPICE

Presents a fast simulation method using SPICE. We traded the prohibitive time-consuming simulation problem for a much less time-consuming problem, plus a little analysis work. This makes it possible for one to use SPICE simulation to optimize the parameters in the modulator within a reasonable time period. Rounding and truncation errors within the circuit simulation algorithms typically set an upper limit on the measurable SNR on the order of 90 dB. This implies that very high-resolution modulators cannot correctly be simulated by SPICE. Fortunately, 90 dB resolution is adequate for most modern communication baseband A/D converters