This paper introduces an automated circuit design system for the evolution and subsequent invention of CMOS amplifiers. The proposed system relies on a mix of genetic programming and a new topologyindependent design optimisation method referred to as current-flow analysis. Genetic programming evolves new circuit topologies from the collection of primitive devices and basic building blocks. Current-flow analysis screens and corrects circuits using topology-independent design rules. Experimental results show a promising improvement on the design of operational amplifiers that making the automated analogue design environment using genetic programming a lot more practical. I.