This paper extends our original proposal to use Particle Swarm Optimization (PSO) to design combinational logic circuits [Use of particle swarm optimization to design combinational logic circuits] in which a binary representation was adopted. In this case, we study the impact of the representation adopted. For that sake, we adopt 2 integer representations (one of which is proposed by us) and we compare them with respect to our previous binary representation and with respect to a multiobjective genetic algorithm that uses an integer encoding. For our comparative study, we adopted several combinational logic circuits of one and several outputs whose designs have been previously studied in the specialized literature. Our results indicate that PSO can be a competitive algorithm for circuit design when using one of the integer representations proposed.