DESIGN OF GATE DIFFUSION INPUT BASED ENERGY EFFICIENT CNTFET CIRCUITS

Abstract

An extensive examination of low-power digital circuit design utilizing Gate Diffusion Input (GDI) and its dynamic extensions—DGDI, DTGDI, and DMGDI cells—is presented in this major project-II report. A transient simulation of the XOR logic gate, full adders, ripple carry adder (RCA), and 2×2 multiplier is conducted using the Gate Diffusion Input (GDI) technique and its variations, namely DGDI, DTGDI, and DMGDI. The DGDI which is a merger of basic GDI cell and novel dynamic logic block. It was investigated because of the drawbacks of GDI, such as insufficient output swing and excessive delay in intricate circuits. DGDI improves performance by enhancing swing characteristics. When GDI- and DGDI- based full adders are compared, it is shown that the former significantly reduces latency while the latter increases power consumption because of its greater transistor count. However, the lower output swing at the input of dynamic block leads to lower driving capability of the transistor and hence results in higher delay. To resolve the issue in DGDI cell, the DTGDI cell is suggested. This cell Improved latency and power efficiency, which make them competitive substitutes for intricate arithmetic processes like ripple carry multipliers and adders. Comprehensive simulations using Cadence Virtuoso based on a 32nm node evaluated the performance parameters of DGDI and DTGDI cells utilizing quantitative measurements of delay, power consumption, and power-delay product (PDP) for different circuit topologies. The DTGDI-based XOR gate was shown to be 23.6% quicker than DGDI. DGDI and DTGDI have typical power consumptions of 1.62 μW and 1.54 μW, respectively. The findings confirm the advantages of integrating dynamic logic into GDI-based designs, paving the way for more efficient, low-power digital systems. Furthermore, three transistors are used to implement XOR logic in a static logic-based MGDI cell. Compared to a GDI cell, it employs one fewer transistor since the MGDI cell implementation does not use the inverting input. As a result, the dynamic cell that is produced using MGDI, known as DMGDI, also has improved performance metrics.