Analog Multilevel Simulation

Abstract

SPICE and its derivative programs remain the primary simulation tools in use today by analog designers. However, over the past decade analog circuit designs have increased in complexity to the point where the basic techniques used in SPICE are not fast enough to produce a solution in a reasonable amount of time. Currently, system-level design, modeling and simulation are being emphasized to cope with the complexities of these large designs. As in the digital case, an analog designer would like to specify portions of the analog circuit at a higher level of abstraction in order to carry out functional verification. For example, the designer may wish to represent a filter block in terms of an s-domain transfer function, rather than specifying all the transistors and their interconnections, to evaluate a proposed architecture of an analog system before a detailed design begins. And ideally, the entire system could be specified in some form of standard analog hardware description language (AHDL) similar to the languages that have emerged for digital hardware description.