Symbolic formulation method for mixed-mode analog circuits using nullors

A formulation method is introduced for the symbolic analysis of mixed-mode analog circuits consisting of opamps, current conveyors and/or current-feedback opamps. We show that by modeling all active devices using only nullors and grounded resistors, a reduced system of nodal equations can be formulated and solved by determinant decision diagrams. The nullor equivalents allow including parasitic elements as demonstrated in designing a universal filter.