Symbolic Nodal Analysis of Analog Circuits with Modern Multiport Functional Blocks

Abstract

This paper proposes admittance matrix models to approach the behavior of six modern multiport functional blocks called: differential difference amplifier, differential difference operational floating amplifier, differential difference operational mirror amplifier, differential difference current conveyor, current backward transconductance amplifier and current differencing transconductance amplifier. The novelty is that the behavior of any active device mentioned before can immediately be introduced in the nodal admittance matrix by using the proposed admittance matrix models and without requiring the use of extra variables. Therefore, a standard nodal analysis is applied to compute fully-symbolic small-signal performance parameters of analog circuits containing any active device mentioned above. This means that not only the size of the admittance matrix is smaller than those generated by applying modified nodal analysis method, for instance, but also, the number of nonzero elements and the generations of cancellation-terms are both reduced. An analysis example for each amplifier is provided in order to show the useful of the proposed stamps.