scholarly journals Design and Implementation of Carbon Nano-tube based Full Adder at 32nm Technology for High Speed and Power Efficient Arithmetic Applications

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.

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.


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):  
Priyanka Tyagi ◽  
Sanjay Kumar Singh ◽  
Piyush Dua

Background: Full adder is the key element of the digital electronics. The CNTFET is the most promising device in modern electronics. To enhance the performance of the full adder CNTFET is used in place of the CMOS. Objective: To implement the high speed full adder circuit for advance applications of the digital world. Methods: Full adder circuit with new Gate diffusion technique has been implemented in this work. There is the comparative study of the 10-T CNTFET full adder with GDI technique and the 10-T Finfet based full adder using GDI technique. Ultralow power feature is the additional advantage of the GDI technique. This technology provides the full swing voltage to the circuit moreover it also reduces number of transistors required. This technique has been used with CNTFET to upgrade full adder in terms of the dissipated power and product of power consumed and delay introduced in the circuit. Results: The proposed design shows that the low power dissipation comes out to be approximately 4.3nW at 0.5volts. The power delay product is 4.7x10-20 J at the same voltage level. The Finfet design also shows the better performance with GDI. But GDI enhance CNTFET based design power consumption about 32% from the FinFET. Conclusions: CNTFET observed the better response due to good current conductivity as compare to the FinFET. This work has been implemented and simulated on the 32nm node technology.


2019 ◽  
Vol 8 (2) ◽  
pp. 5261-5265

In the design of VLSI circuits, there is huge power consumption because of circuit complexity. It is known that the demand for portable equipment is rapidly increasing now a days. Recently power efficient circuit designs have been concentrated. In complex arithmetic circuits adder is the most important building block. These are widely used in some other applications also like Central Processing Units, Arithmetic Logic Units and floating-point units. In case of cache memory access and in digital signal processing, these are used for address generation. Adders are most significant in control systems also. The speed of a processor and system accuracy is based on the performance of this adder. Regularly, Ripple Carry Adder is elected for two N-bit numbers adder due to fast design time of these RCAs among various other types of adders. Even though if RCA has fast design time, but it is limited in time because of that each full adder must wait for the carry bits of previous full adder blocks. A carry tree adder is proposed in this paper which is efficiently implemented technique at gate level for decreasing the delay and decreasing the memory usage.


Author(s):  
Sai Venkatramana Prasada G.S ◽  
G. Seshikala ◽  
S. Niranjana

Background: This paper presents the comparative study of power dissipation, delay and power delay product (PDP) of different full adders and multiplier designs. Methods: Full adder is the fundamental operation for any processors, DSP architectures and VLSI systems. Here ten different full adder structures were analyzed for their best performance using a Mentor Graphics tool with 180nm technology. Results: From the analysis result high performance full adder is extracted for further higher level designs. 8T full adder exhibits high speed, low power delay and low power delay product and hence it is considered to construct four different multiplier designs, such as Array multiplier, Baugh Wooley multiplier, Braun multiplier and Wallace Tree multiplier. These different structures of multipliers were designed using 8T full adder and simulated using Mentor Graphics tool in a constant W/L aspect ratio. Conclusion: From the analysis, it is concluded that Wallace Tree multiplier is the high speed multiplier but dissipates comparatively high power. Baugh Wooley multiplier dissipates less power but exhibits more time delay and low PDP.


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):  
T. Suguna ◽  
M. Janaki Rani

In VLSI, power optimization is the main criteria for all the portable mobile applications and developments because of its impact on system performance. The performance of an adder has significant impact on overall performance of a digital system. Adiabatic logic (AL), a new emerging research domain for optimizing the power in VLSI circuits with high switching activity is discussed, in this paper, for implementing the adder circuits. Various adiabatic logic styles full adder designs are reviewed and multiplexer based hybrid full adder topology is designed and implemented with ECRL and 2PASCL AL styles. Moreover in this paper, 32 bit adders such as Ripple Carry Adder (RCA), Carry Select Adder (CSLA), Carry Save Adder (CSA), Carry Skip Adder (CSKA) and Brent Kung Adder (BKA) are realised using proposed ECRL and 2PASCL adiabatic full adders. All the adders are implemented and simulated using TANNER EDA tool 22nm technology, parameters like power, area, delay and power delay product (PDP) of all the adders are observed at different operating frequencies, with supply voltage of 0.95 v and load capacitance of 0.5 pF. The observed parameters are compared with the existing adiabatic full adder designs and concluded that the proposed adiabatic full adders have the advantages of less power, delay and transistor count. In conclusion ECRL full adder is 31% faster, has equal PDP and less area than 2PASCL full adder. At 1000MHz ECRL 32 bit carry save adder is having less delay among all the 32 bit adder and 65% less PDP than 2PASCL adder and it is concluded that ECRL 32 bit carry save adder can be selected for implementation of circuits that can be used in portable mobile applications.


2015 ◽  
Vol 2015 ◽  
pp. 1-13 ◽  
Author(s):  
‘Aqilah binti Abdul Tahrim ◽  
Huei Chaeng Chin ◽  
Cheng Siong Lim ◽  
Michael Loong Peng Tan

The scaling process of the conventional 2D-planar metal-oxide semiconductor field-effect transistor (MOSFET) is now approaching its limit as technology has reached below 20 nm process technology. A new nonplanar device architecture called FinFET was invented to overcome the problem by allowing transistors to be scaled down into sub-20 nm region. In this work, the FinFET structure is implemented in 1-bit full adder transistors to investigate its performance and energy efficiency in the subthreshold region for cell designs of Complementary MOS (CMOS), Complementary Pass-Transistor Logic (CPL), Transmission Gate (TG), and Hybrid CMOS (HCMOS). The performance of 1-bit FinFET-based full adder in 16-nm technology is benchmarked against conventional MOSFET-based full adder. The Predictive Technology Model (PTM) and Berkeley Shortchannel IGFET Model-Common Multi-Gate (BSIM-CMG) 16 nm low power libraries are used. Propagation delay, average power dissipation, power-delay-product (PDP), and energy-delay-product (EDP) are analysed based on all four types of full adder cell designs of both FETs. The 1-bit FinFET-based full adder shows a great reduction in all four metric performances. A reduction in propagation delay, PDP, and EDP is evident in the 1-bit FinFET-based full adder of CPL, giving the best overall performance due to its high-speed performance and good current driving capabilities.


ince last few years, the tiny size of MOSFET, that is less than tens of nanometers, created some operational problems such as increased gate-oxide leakage, amplified junction leakage, high sub-threshold conduction, and reduced output resistance. To overcome the above challenges, FinFET has the advantages of an increase in the operating speed, reduced power consumption, decreased static leakage current is used to realize the majority of the applications by replacing MOSFET. By considering the attractive features of the FinFET, an ALU is designed as an application. In the digital processor, the arithmetic and logical operations are executed using the Arithmetic logic unit (ALU). In this paper, power efficient 8-bit ALU is designed with Full adder (FA) and multiplexers composed of Gate diffusion input (GDI) which gained designer's choice for digital combinational circuit realization at minimum power consumption. The design is simulated using Cadence virtuoso with 20nm technology. Comparative performance analysis is carried out in contrast to the other standard circuits by taking the critical performance metrics such as delay, power, and power delay product (PDP), energy-delay product (EDP) metrics into consideration.


2020 ◽  
Vol 12 ◽  
Author(s):  
Deepika Bansal ◽  
Bal Chand Nagar ◽  
Ajay Kumar ◽  
Brahamdeo Prasad Singh

Objective: A new efficient keeper circuit has been proposed in this article for achieving low leakage power consumption and to improve power delay product of the dynamic logic using carbon nanotube MOSFET. Method: As a benchmark, an one-bit adder has been designed and characterized with both technologies Si-MOSFET and CN-MOSFET using proposed and existing dynamic circuits. Furthermore, a comparison has been made to demonstrate the superiority of CN-MOSFET technology with Synopsys HSPICE tool for multiple bit adders available in the literature. Result: The simulation results show that the proposed keeper circuit provides lower static and dynamic power consumption up to 57 and 40% respectively, as compared to the domino circuits using 32nm CN-MOSFET technology provided by Stanford University. Moreover, the proposed keeper configuration provides better performance using SiMOSFET and CN-MOSFET technologies. Conclusion: A comparison of the proposed keeper with previously published designs is also given in terms of power consumption, delay and power delay product with the improvement up to 75, 18 and 50% respectively. The proposed circuit uses only two transistors, so it requires less area and gives high efficiency.


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