Low Power High Speed GDI 4-bit RCA Circuit design using 45nm CMOS Technology

Abstract

In Digital Engineering, if we want to design a 4Bit adder which is very essential component in an arithmetic logic circuit (ALU) and also plays a crucial role in all the computational circuits as well. In this paper, 4 bit ripple adder using a one bit full adder is designed at 45nm CMOS technology.to design a full adder, we require XOR, OR, AND logic gates, where we combine all the above logic gates to get a one bit full adder finally. The GDI (gate diffusion input) it is a technique in which number of transistors required to design specific application will gradually reduce. When it is compared with the conventional circuit.by using GDI not only reduces transistors count but also power consumption The maximum power saving is of 93.04%, the delay is saved by 76.76% and coming to the overall PDP the saving is of 96.01%. By considering 4- full adders we can build a 4-bit ripple carry adder. Hence the whole designing can be done at supply voltage 1.8V as we are using 45nm CMOS technology.