Design of an SFQ Full Adder as a Single-Stage Gate

This paper presents the design of a one-bit full adder with sum and carry outputs as two single-stage gates, which could save the JJ count and the area compared with the conventional design of a full-adder. The schematics of both the Sum and Carry cells are shown in this paper along with their input and output waveforms of JSIM simulations in the time domain. The circuit cost is compared between the conventional full adder and the new single-stage adder design in terms of the area and the time. Integer dividers of several sizes are synthesized with conventional full-adder and the proposed single-stage adder to illustrate the advantages of the new design.