Synthesis of Voltage Follower with Only CMOS Transistors Using Evolutionary Methods

An automatic synthesis of a voltage follower (VF) containing only CMOS transistors using evolutionary techniques in an extrinsic environment is presented. A flexible variable size chromosome coding scheme able to generate the most common analog building blocks is implemented and no passive components are required in the synthesis. In order to improve the efficiency of the algorithm topological search, a chromosome coding scheme including two additional elements, the short circuit and the open circuit, is used. Finally, a two step evolutionary process that manipulates independently the topology search and the components values tuning is employed.