Design of High-Speed Hybrid Full Adders using FinFET 18nm Technology

There is a crucial need for the development of circuits which consume low power and operate at high speeds. The full Adder is a widely used basic adder circuit in Electronics. Optimizing the Power and Speed of this circuit has become the need of the day. In this paper three hybrid full-adder circuits based on the novel full-swing XOR-XNOR gates have been designed. The HFA 22T (Hybrid Full Adder with 22 transistors), HFA B 26T (Hybrid Full Adder with 26 transistors and Buffers) and HFA NB 26T(Hybrid Full Adder with 26 transistors and New Buffers) have been designed using the Cadence virtuoso tool with 18nm FinFET technology. The simulation results have been performed and the delay of the circuit has been calculated. For the Hybrid Full Adder with 22 Transistors (HFA 22T), the delay was observed to be 69.01 ps. In [1] the power consumed was 155.5ps. The reduction in power in comparison to HFA -22T using MOSFET was 56.02%. For the Hybrid Full Adder with 26 Transistors and Buffers (HFA B 26T), the delay was computed to be 99.08ps and a reduction of 36.58 % was observed as compared to the design in [1] where it is 156.9ps. In the case of Hybrid Full Adder with 26 Transistors and New Buffers (HFA NB 6T), the delay was observed to be 52.11ps and a reduction of 64.58% was observed as compared to the previous design where it was computed to be 147.1ps. Thus, the HFA NB 26T showed the smallest delay, hence it is the fastest of the Hybrid Full Adder Designs. A considerable reduction of delay has been achieved in comparison to MOSFETs. It has been found out that the HFA NB 26T is the fastest of the three designed adders.