An efficient methodology for symbolic compaction of analog ICs with multiple symmetry constraints

An efficient approach to the symbolic compaction of analog integrated circuits is presented. A fast graph-based algorithm performs a preliminary compaction taking into account a set of basic spacing constraints. The obtained configuration provides the starting point for a linear program, which optimizes the layout introducing multiple device and wire symmetry constraints. The efficiency and robustness of this technique allow the use of the compactor for very complex analog circuits with multiple symmetrics and other performance constraints