A New 2-input CNTFET-Based XOR Cell With Ultra-Low Leakage Power For Low-Voltage and Low-Power Full Adders

The XOR gate is one of the basic building blocks in the Full Adder (FA) circuit, whose performance improvements can lead to improved Full Adder. For this purpose, in this paper, a new low voltage XOR cell based on Carbon Nanotube Field Effect Transistor (CNTFET) is proposed. The main design goals for this new circuit are low power dissipation, low leakage current and full voltage swing at a low supply voltage (Vdd = 0.5 V). Several XOR circuits were completely simulated using HSPICE with 32nm CMOS and 32nm CNTFET technologies at a low supply voltage. The proposed XOR circuit is compared with the previously known circuits and its outstanding performance is shown. Simulations show that the new low voltage XOR has lower power dissipation, less leakage current and lower PDP than other XOR circuits, and is resistant to process variations. Based on the results obtained at Vdd=0.5 V ,frequency=250 MHz and Cload=3.5 fF, the proposed XOR shows propagation delay of 149.05 ps, power consumption of 716.72 pW, leakage power of 25.1 pW and PDP of 10.683x10-21 J. The proposed XOR can be used well in low voltage and low power Full Adder circuits.