An Energy Efficient Logic Approach to Implement CMOS Full Adder

2017 ◽  
Vol 26 (05) ◽  
pp. 1750084 ◽  
Author(s):  
Pankaj Kumar ◽  
Rajender Kumar Sharma

An energy efficient internal logic approach for designing two 1-bit full adder cells is proposed in this work. It is based on decomposition of the full adder logic into the smaller modules. Low power, high speed and smaller area are the main features of the proposed approach. A modified power aware NAND gate, an essential entity, is also presented. The proposed full adder cells achieve 30.13% and improvement in their power delay product (PDP) metrics when compared with the best reported full adder design. Some of the popular adders and proposed adders are designed with cadence virtuoso tool with UMC 90[Formula: see text]nm technology operating at 1.2[Formula: see text]V supply voltage and UMC 55[Formula: see text]nm CMOS technology operating at 1.0[Formula: see text]V. These designs are tested on a common environment. During the experiment, it is also found that the proposed adder cells exhibit excellent signal integrity and driving capability when operated at low voltages.

Author(s):  
Haroon Rasheed S ◽  
Mohan Das S ◽  
Samba Sivudu Gaddam

This paper presents an energy efficient 1-bit full adder designed with a low voltage and high performance internal logic cells which leads to have abridged Power Delay Product (PDP). The customized XNOR and XOR gates, a necessary entity, are also presented. The simulations for the designed circuits performed in cadence virtuoso tool with 45-nm CMOS technology at a supply voltage of 0.9 Volts. The proposed 1-bit adder cell is compared with various trendy adders based on speed, power consumption and energy (PDP). The proposed adder schemes with modified internal entity cells achieve significant savings in terms of delay and energy consumption and which are more than 77% and 40.47% respectively when compared with conventional “C-CMOS” 1-bit full adder and other counter parts.


Author(s):  
Tejaswini M. L ◽  
Aishwarya H ◽  
Akhila M ◽  
B. G. Manasa

The main aim of our work is to achieve low power, high speed design goals. The proposed hybrid adder is designed to meet the requirements of high output swing and minimum power. Performance of hybrid FA in terms of delay, power, and driving capability is largely dependent on the performance of XOR-XNOR circuit. In hybrid FAs maximum power is consumed by XOR-XNOR circuit. In this paper 10T XOR-XNOR is proposed, which provide good driving capabilities and full swing output simultaneously without using any external inverter. The performance of the proposed circuit is measured by simulating it in cadence virtuoso environment using 90-nm CMOS technology. This circuit outperforms its counterparts showing power delay product is reduced than that of available XOR-XNOR modules. Four different full adder designs are proposed utilizing 10T XOR-XNOR, sum and carry modules. The proposed FAs provide improvement in terms of PDP than that of other architectures. To evaluate the performance of proposed full adder circuit, we embedded it in a 4-bit and 8-bit cascaded full adder. Among all FAs two of the proposed FAs provide the best performance for a higher number of bits.


Author(s):  
Bilal N Md ◽  
Bhaskara Rao K ◽  
Mohan Das S

This This paper presents energy efficient GDI based 1-bit full adder cells with low power consumption and lesser delay with full swing modified basic logic gates to have reduced Power Delay Product (PDP). The various full adders are effectively realized by means of full swing OR, AND and XOR gates with the noteworthy enhancement in their performance. The simulations for the designed circuits performed in cadence virtuoso tool with 45-nm CMOS technologies at a supply voltage of 1 Volts. The proposed 1-bit adder cells are compared with various basic adders based on speed, power consumption and energy (PDP). The proposed adder schemes with full swing basic cells achieve significant savings in terms of delay and energy consumption and which are more than 41% and 32% respectively in comparison to conventional “C-CMOS” 1-bit full adder and other existing adders.


Author(s):  
Mohasinul Huq N Md ◽  
Mohan Das S ◽  
Bilal N Md

This paper presents an estimation of leakage power and delay for 1-bit Full Adder (FA)designed which is based on Leakage Control Transistor (LCT) NAND gates as basic building block. The main objective is to design low leakage full adder circuit with the help of low and high threshold transistors. The simulations for the designed circuits performed in cadence virtuoso tool with 45 nm CMOS technology at a supply voltage of 0.9 Volts. Further, analysis of effect of parametric variation on leakage current and propagation delay in CMOS circuits is performed. The saving in leakage power dissipation for LCT NAND_HVT gate is up to 72.33% and 45.64% when compared to basic NAND and LCT NAND gate. Similarly for 1-bit full adder the saving is up to 90.9% and 40.08% when compared to basic NAND FA and LCT NAND.


2016 ◽  
Vol 62 (4) ◽  
pp. 329-334 ◽  
Author(s):  
Raushan Kumar ◽  
Sahadev Roy ◽  
C.T. Bhunia

Abstract In this paper, we proposed an efficient full adder circuit using 16 transistors. The proposed high-speed adder circuit is able to operate at very low voltage and maintain the proper output voltage swing and also balance the power consumption and speed. Proposed design is based on CMOS mixed threshold voltage logic (MTVL) and implemented in 180nm CMOS technology. In the proposed technique the most time-consuming and power consuming XOR gates and multiplexer are designed using MTVL scheme. The maximum average power consumed by the proposed circuit is 6.94μW at 1.8V supply voltage and frequency of 500 MHz, which is less than other conventional methods. Power, delay, and area are optimized by using pass transistor logic and verified using the SPICE simulation tool at desired broad frequency range. It is also observed that the proposed design may be successfully utilized in many cases, especially whenever the lowest power consumption and delay are aimed.


Author(s):  
Basavoju Harish ◽  
M. S. S. Rukmini

In the field of bio medical engineering high performance CPU for digital signal processing plays a significant role. Frequency efficient circuit is a paramount requirement for the portable digital devices employing various digital processors. In this work a novel high speed one-bit 10T full adder with complemented output was described. The circuit was constructed with XOR gates which were built using two CMOS transistors. The XOR gate was constructed using 2T multiplexer circuit style. It was observed that power consumption of the designed circuit at 180nm with supply voltage 1.8V is 183.6 uW and delay was 1.809 ps whereas power consumption at 90nm with supply voltage 1.2V is 25.74 uW and delay was 8.245 ps. The observed Power Delay Product (PDP) in 180nm (at supply voltage 1.8V) is 0.33 and in 90nm (at supply voltage 1.2V) is 0.212. The work was extended by implementing a 32-bit Ripple Carry Adder (RCA) and was found that the delay at 180nm is 93.7ps and at 90nm is 198ps. The results were drawn at 180nm and also 90nm technology using CAD tool. The results say that the present work offered significant enhancement in speed and PDP compared with existing designs.


Author(s):  
S. MOHAN DAS ◽  
GANESH KUMAR M ◽  
BHASKARA RAO K

This paper presents low leakage and high speed 1-bit full adder projected with low threshold NMOS transistors in associations with universal logic gates which leads to have reduced power and delay. The customized NAND and NOR gates, a necessary blocks, are presented to design a proposed adder cell. The simulations for the designed circuits performed in cadence virtuoso tool with 65 nm CMOS technology at a supply voltage of 1 Volts. The proposed universal gates and 1-bit adder cell is compared with conventional NAND/NOR gates and 1-bit adder. The proposed adder schemes with modified universal logic gates achieve significant saving in terms of delay which are more than 24% and which is at the cost of 5% when compared with conventional designs.


2019 ◽  
Vol 4 (5) ◽  
pp. 575-579
Author(s):  
Gudala Konica . ◽  
Sreenivasulu Mamilla .

As silicon technology scales down, it is a dominant choice to have high-performance digital circuits. As researchers investigated for high-performance digital circuits for future generations, Carbon Nanotube Field Effect Transistors (CNTFETs) is considered as the most promising technology due to their excellent current driving capability and proved to be an alternative to conventional CMOS technology. A CNTFET based energy efficient ternary operators are proposed for scrambling applications. The transistor-level implementations of operators namely Scrambling Operator1 (SOP1), Scrambling Operator2 (SOP2) and SUM operators are simulated with CMOS and CNTFET in 32 nm technology at 0.9 V supply voltage using Synopsys HSPICE. The performance metrics like Power, Delay and Power-delay product (PDP) are measured and a comparative analysis for CNTFET and CMOS technologies is carried out. The results demonstrate that CNTFET designs have better-optimized results in power, energy consumption, and reduced transistor count.


Author(s):  
Priya Gupta ◽  
Anu Gupta ◽  
Abhijit Asati

In this chapter, the design and comparative analysis is done in between the most well-known column compression multipliers by Wallace and Dadda in sub-threshold regime. In order to reduce the hardware which ultimately reduces area, power and overall power delay product, an energy efficient basic modules of the multipliers like AND gates, half adders, full adders and partial product generate units have been analyzed for sub-threshold operation. At the last stage ripple carry adder is used in both multipliers. The performance metrics considered for the analysis of the multipliers are: power, delay and PDP. Simulation studies are carried out for 8x8-bit and 16x16-bit input data width. The proposed circuits show energy efficient results with Spectre simulations for the TSMC 180nm CMOS technology at 0.4V supply voltage. The proposed multipliers so implemented outperform its counterparts exhibiting low power consumption and lesser propagation delay as compared to conventional multipliers.


2014 ◽  
Vol 8 (1) ◽  
pp. 133-142 ◽  
Author(s):  
Wei Cheng ◽  
jianping Hu

This paper presents a comparative research of low-power and high-speed 4-bit full adder circuits. The representative adders used are a ripple carry adder (RCA) and a carry-lookahead adder (CLA). We also design a proposed carrylookahead adder (PCLA) using a new method that uses NAND gate for modification which helps in reducing the powerdelay product (PDP) for high performance applications. To yield more realistic rise and fall times in the simulations, layouts have been made in a 0.13 􀀁m process for the RCA circuit, CLA circuit and PCLA circuit. The layouts designed were simulated by HSPICE based on 130 nm CMOS technology at 1.2 V supply voltages. Four sets of frequencies were operated: 10 MHz, 50 MHz, 100 MHz and 500 MHz with 50% duty cycle in different technology corner models. A comprehensive comparison and analysis were also carried out to test the performance of the adders. The three adders also yield different performances in terms of power consumption, PDP, and area. The simulation results of this research are expected to help designers to select the appropriate 4-bit adder cell that meets their specific applications.


Sign in / Sign up

Export Citation Format

Share Document