We study the concept of a basic building block for circuits using differential signaling and being based on graphene field effect devices. We fabricated a number of top-gated graphene FETs using commercially available graphene and employing electron beam lithography along with other semiconductor manufacturing processes. These devices were then systematically measured in an automated setup and their DC characteristics analyzed in terms of a simple but effective analytical model. This model together with the collected data allowed us to proceed further with both mathematical analysis of circuit characteristics as well as numerical simulation in a dedicated circuit analysis software.