Power and Delay Comparison in between Different types of Full Adder Circuits

This paper describes the speed of the design is limited by size of the transistors, parasitic capacitance and delay in the critical path. Power consumption and speed are two important but conflicting design aspects; hence a better metric to evaluate circuit performance is power delay product (PDP).The driving capability of a full adder is very important, because, full adders are mostly used in cascade configuration, where the output of one provides the input for other. If the full adders lack driving capability then it requires additional buffer, which consequently increases the power dissipation. Here, we have given a brief description of the evolution of full adder circuits in terms of lesser power consumption, higher speed and lesser chip size. We have started with the most conventional 28 transistor full adder and then gradually studied full adders consisting of as less as 8 transistors. We have also included some of the most popular full adder cells like Static Energy Recovery Full Adder (SERF) [7] [8], Adder9A, Adder9B, GDI based full adder.