scholarly journals QCA based Novel Reversible Reconfigurable Ripple Carry Adder with Ripple Borrow Subtractor in Electro-Spin Technology

2021 ◽  
Vol 58 (2) ◽  
pp. 813-823
Author(s):  
Swarup Sarkar, Rupsa Roy

An important arithmetic component of “Arithmetic and Logic Unit” or ALU is reconfigured in this paper, known as “Full-Adder-Subtractor”, where an advance low-power, high-speed nano technology “QCA” with electro-spin criterion is used with reversibility and the advancement of multilayer 3D circuitry. In this modern digital world, this selected nano-sized technology is an effective alternative of widely used “CMOS Technology” because all the limitations, mainly limitation due to the presence of high power dissipation at the time of device-density increment in a “CMOS” based integrated circuit, can be optimized by “QCA” nano technology with electro-spin criterion and this technology also supports reversible logic in multilayer 3D platform with less complexity. This paper, primarily presents two novel “QCA” based 3-layered “Adder-Subtractor” designs using the collaboration of multilayer inverter gates, reversible modified 3-input Feynman-Gate and 3-input MG (Majority Gate) with very less cell-complexity, area-occupation, delay and energy-dissipation and high output-strength, temperature-tolerance and accuracy. A clear parametric investigation on presented designs are shown clearly in this paper through a comparative manner with some previous published related structures. Additionally, another parametric-experiment on a novel multibit reversible multilayer “QCA” based “Full-Adder-Subtractor” circuitry using the working phenomenon of “Ripple Carry Adder” (RCA) and multibit subtractor (“ripple borrow subtractor” or RBS) is presented in this proposed work in a proper way and this combination of RCA and multibit subtraction operation converts the proposed circuitry into a hybrid form, which is more effective compare to some other advanced adders in parametric-optimization field.

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.


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.


Adder Is Basic Unit For Any Digital System, Dsp And Microprocessor. The Main Issue In Design High Speed Full Adder Cell With The Low Power Dissipation. As We Know Cmos Technology Used For Vlsi Designing Cmos Has Many Drawbacks As High Power Short Channel Effect Etc. Then Cntfet (Carbon Nanotube Field Effect Transistor) Has Been Developed Which Has Same Structure As Cmos. The Difference Between Structure Of Cmos And Cntfet Is Their Channel. In Cntfet Channel Is Replaced By Carbon Nanotube. In This Paper We Compare Full Adder Circuit Using Cntfet With Gdi Technique And Cmos Implementation Of Adder Which Gdi Technique. Gdi Technique Is Used For Speed And Power Optimization In Digital Circuit. This Can Also Reduce The Count Of Transistor Which Affects The Size Of Device.


Circuit World ◽  
2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Ali Majeed ◽  
Esam Alkaldy

Purpose This study aims to replace current multi-layer and coplanar wire crossing methods in QCA technology to avoid fabrication difficulties caused by them. Design/methodology/approach Quantum-dot cellular automata (QCA) is one of the newly emerging nanoelectronics technology tools that is proposed as a good replacement for complementary metal oxide semiconductor (CMOS) technology. This technology has many challenges, among them being component interconnection and signal routing. This paper will propose a new wire crossing method to enhance layout use in a single layer. The presented method depends on the central cell clock phase to enable two signals to cross over without interference. QCADesigner software is used to simulate a full adder circuit designed with the proposed wire crossing method to be used as a benchmark for further analysis of the presented wire crossing approach. QCAPro software is used for power dissipation analysis of the proposed adder. Findings A new cost function is presented in this paper to draw attention to the fabrication difficulties of the technology when designing QCA circuits. This function is applied to the selected benchmark circuit, and the results show good performance of the proposed method compared to others. The improvement is around 59, 33 and 75% compared to the best reported multi-layer wire crossing, coplanar wire crossing and logical crossing, respectively. The power dissipation analysis shows that the proposed method does not cause any extra power consumption in the circuit. Originality/value In this paper, a new approach is developed to bypass the wire crossing problem in the QCA technique.


2019 ◽  
Vol 11 (1) ◽  
pp. 80-87 ◽  
Author(s):  
Jitendra Kumar Saini ◽  
Avireni Srinivasulu ◽  
Renu Kumawat

The transformation from the development of enabling technology to mass production of consumer-centric semiconductor products has empowered the designers to consider characteristics like robustness, compactness, efficiency, and scalability of the product as implicit pre-cursors. The Carbon Nanotube Field Effect Transistor (CNFET) is the present day technology. In this manuscript, we have used CNFET as the enabling technology to design a 1-bit Full Adder (1b-FA16) with overflow detection. The proposed 1b-FA16 is designed using 16 transistors. Finally, the proposed 1b-FA16 is further used to design a Ripple Carry Adder (RCA), Carry Look Ahead Adder (CLA) circuit and RCA with overflow bit detection. Methods and Results: The proposed 1b-FA16 circuit was designed with CNFET technology simulated at 32 nm with a voltage supply of +0.9 V using the Cadence Virtuoso CAD tool. The model used is Stanford PTM. Comparison of the existing full adder designs with the proposed 1b-FA16 design was done to validate the improvements in terms of power, delay and Power Delay Product (PDP). Table 2, shows the results of comparison for the proposed 1b-FA16 with the existing full adder designs implemented using CNFET for parameters like power, delay and power delay product. Conclusion: It can be concluded that the proposed 1b-FA16 yielded better results as compared to the existing full adder designs implemented using CNFET. The improvement in power, delay and power delay product was approximately 11%, 9% and 24% respectively. Hence, the proposed circuit implemented using CNFET gives a substantial rate of improvements over the existing circuits.


2012 ◽  
Vol 1396 ◽  
Author(s):  
Di Liang ◽  
John E. Bowers

ABSTRACTSilicon (Si) has been the dominating material platform of microelectronics over half century. Continuous technological advances in circuit design and manufacturing enable complementary metal-oxide semiconductor (CMOS) chips with increasingly high integration complexity to be fabricated in an unprecedently scale and economical manner. Conventional Si-based planar lightwave circuits (PLCs) has benefited from advanced CMOS technology but only demonstrate passive functionalities in most circumstances due to poor light emission efficiency and weak major electro-optic effects (e.g., Pockels effect, the Kerr effect and the Franz–Keldysh effect) in Si. Recently, a new hybrid III-V-on-Si integration platform has been developed, aiming to bridge the gap between Si and III-V direct-bandgap materials for active Si photonic integrated circuit applications. Since then high-performance lasers, amplifiers, photodetectors and modulators, etc. have been demonstrated. Here we review the most recent progress on hybrid Si lasers and high-speed hybrid Si modulators. The former include distributed feedback (DFB) lasers showing over 10 mW output power and up to 85 oC continuous-wave (cw) operation, compact hybrid microring lasers with cw threshold less than 4 mA and over 3 mW output power, and 4-channel hybrid Si AWG lasers with channel space of 360 GHz. Recently fabricated traveling-wave electro-absorption modulators (EAMs) and Mach-Zehnder interferometer modulators (MZM) on this platform support 50 Gb/s and 40 Gb/s data transmission with over 10 dB extinction ratio, respectively.


VLSI Design ◽  
2002 ◽  
Vol 14 (4) ◽  
pp. 315-327 ◽  
Author(s):  
A. Srivastava ◽  
D. Govindarajan

A high-speed 4-bit ALU has been designed for 1 V operation to demonstrate the usefulness of the back-gate forward substrate bias (BGFSB) method in 1.2 μm N-well CMOS technology. The 4-bit ALU employs a ripple carry adder and is capable of performing eight operations - four arithmetic and four logical operations. The BGFSB voltage has been limited to |0.4| V. Delay time measurements are taken for all operations from the SPICE simulations with and without the back-gate forward substrate bias. A speed advantage of a factor of about 2–2.5 is obtained with BGFSB over the conventional design.


2022 ◽  
Vol 2161 (1) ◽  
pp. 012050
Author(s):  
Imran Ahmed Khan

Abstract Due to physical, material, technological, power-thermal and economical difficulties, scaling of CMOS transistors will stop very soon. Due to efficiency of power and speed compared to CMOS transistors, Carbon Nano-tube transistors are best suitable element to design logic circuits. So, CNTFETS have been utilized in designing of proposed full adder (FA) and 4-bit ripple carry adder (RCA) in this paper. Proposed FA and RCA have been compared to rival designs on bases of power, speed and power-delay-product (PDP). FA and RCA circuits have been analysed with the variation of temperature from 0°C to 100°C while the variation of supply voltages is from 0.7V to 1.3V. For all temperatures and all supply voltages, proposed FA and proposed RCA have the least power consumption, shortest delay and lowest PDP. SPICE has been utilized for simulating FAs and RCAs in 32 nm process node. Even though the fabrication is complicated than CMOS counterparts but simulation results confirm usefulness of proposed FA and RCA for high speed and power efficient arithmetic applications.


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.


2017 ◽  
Vol 26 (05) ◽  
pp. 1750082 ◽  
Author(s):  
Yavar Safaei Mehrabani ◽  
Reza Faghih Mirzaee ◽  
Zahra Zareei ◽  
Seyedeh Mohtaram Daryabari

This paper presents a novel inexact full adder based on carbon nanotube field-effect transistors (CNTFET) for approximate computations, which has soared in popularity especially for image processing applications. The proposed design generates the output carry without error. Therefore, the propagation of incorrect value to higher bit positions is avoided. It has the least relative error distance (Relative ED) compared to other approximate full adders reported in the literature. Practical simulations by using MATLAB demonstrate higher peak signal to noise ratio (PSNR) and image quality for motion detector image processing application. HSPICE simulations also confirm the efficiency of the proposed design. Moreover, area occupation is investigated by using electric tool. Power consumption, delay, area and ED are important evaluating factors in this subject. Comparisons are made by a comprehensive parameter (PDAEDP), based on which the new design has 23.8%, 41.5%, 70.5%, 78% and 83.6% higher performance than TGA1, TGA2, AXA1, AXA2 and AXA3, respectively.


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