Evolutionary design of operational amplifier using variable-length differential evolution algorithm

Evolutionary analog circuit design consists of fixed structural circuit design and non-fixed structural circuit design. The fixed structural circuit design indicates that the circuit topology has already been planned and only the component values need to be evolved. The non-fixed structural circuit design indicates that circuit topology and component values need to be evolved simultaneously. Differential Evolution (DE) is a simple and effective optimization method, which has already succeeded in the fixed structural analog circuit design. However, DE method optimizes individuals with the same size, so it is unfit for non-fixed structural analog circuit design. This paper proposes a variable-length differential evolution algorithm (VDE), which can be applied to non-fixed structural analog circuit design. Studies have shown that, GA is a universal and effective optimization method for non-fixed structural evolutionary analog circuit design. In order to investigate the optimization efficiency of VDE, amplifier is regarded as evolving design task which based on VDE method and GA technique respectively. The results show that, the converging speed of VDE is faster than GA and VDE can achieve design objective more efficiently.