Design and analysis of low-power 10-transistor full adders using novel XOR-XNOR gates

Full adders are important components in applications such as digital signal processors (DSP) architectures and microprocessors. In this paper, we propose a technique to build a total of 41 new 10-transistor full adders using novel XOR and XNOR gates in combination with existing ones. We have done over 10,000 HSPICE simulation runs of all the different adders in different input patterns, frequencies, and load capacitances. Almost all those new adders consume less power in high frequencies, while three new adders consistently consume on average 10% less power and have higher speed compared with the previous 10-transistor full adder and the conventional 28-transistor CMOS adder. One draw back of the new adders is the threshold-voltage loss of the pass transistors.