Low power 18T pass transistor logic ripple carry adder

In this paper, a high-speed low-power 18T CMOS full adder design featuring full-swing output is proposed. The adder is designed and simulated using pass transistor logic of the 130 nm CMOS technology, at a supply voltage of 1.2 V. The obtained Power Delay Product (PDP) of its critical path is 22 × 10−18 J, which is a marked improvement of 61% to 98% compared against those of the 28T conventional CMOS, 20T transmission gate (TGA), 16T transmission function (TFA), 14T hybrid, 24T hybrid pass logic with static CMOS, and 28T differential pass logic (DPL) full adders simulated with the same process technology. Its power consumption is lower by 32% to 85%, with speed performance comparable to those of other high-speed adders reported in the literature. Occupying an aerial footprint of only 107 µm2 (8.00 µm × 13.41 µm), the proposed full adder is also capable to function at lower supply voltages of 0.4 V and 0.8 V without significant performance degradation