Wang, Yuke

We propose two approaches to design 1-bit full adders which can yield good performance at low power consumption. In the first approach, we design XOR/XNOR gates using a minimal number of CMOS transistors. Comparing with 10 different XOR/XNOR gates reported in literature, the new XOR/XNOR gates consume less power. The gates consisting of the smallest number of transistors are combined to create 1-bit full adders. The process is systematic and yields a total of 42 10-transistor full adders, 41 of which are new. Simulation results show that most of the new adders perform better than a previously existing 10-transistor adder and a complementary CMOS adder in terms of power and speed with heavier load. Three adders consistently perform better. In the second approach, we utilized a method called the centralized design to create four new 10-transistor full adders. Simulation results show that these new adders perform better than the previously existing 10-transistor and the complementary CMOS adder.

We propose five new Multiplexer-Based architectures for 1-bit full adder design. Using a 2-transistors multiplexer gate to implement the first architecture, we are able to produce a 12-transistor full adder cell, Comparing it to four different 10-transistors low-power full adder cells reported previously in literature, the new adder cell named MBA1-12T out performs all of them in power consumption and speed. By implementing those architectures using the 2-input CMOS multiplexer with pass-gates, five new high-performance full adder cells are obtained. Those new adder cells are tested along with the conventional 28-transistor CMOS adder cell. Testing results shows that the new adder cells have higher speed and lower power delay product values than the conventional 28-transistor CMOS adder cell.