scholarly journals Ultra high speed full adder for biomedical applications

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.

In the application of digital signal process multipliers play a vital role. With advances in technology, several researchers have tried and try to design multipliers which supply high speed, low power consumption, regularity of layout and thus less space or maybe combination of them in one multiplier factor. Thus, Compact VLSI design for four bit multiplier factor is planned during this paper that is appropriate for low power and high speed applications. Multiplier factor with high performance is achieved through the novel style of hybrid single bit full adder and Dadda algorithmic rule. The important path delay and power consumption of the planned multiplier factor square measure reduced by 65.9% and 24.5% severally when put next with existing multipliers. The planned multiplier factor is synthesized exploitation CADENCE five.1.0 EDA tool and simulated exploitation spectre virtuoso.


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.


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.


2011 ◽  
Vol 20 (04) ◽  
pp. 641-655 ◽  
Author(s):  
REZA FAGHIH MIRZAEE ◽  
MOHAMMAD HOSSEIN MOAIYERI ◽  
HAMID KHORSAND ◽  
KEIVAN NAVI

A new 1-bit hybrid Full Adder cell is presented in this paper with the aim of reaching a robust and high-performance adder structure. While most of recent Full Adders are proposed with the purpose of using fewer transistors, they suffer from some disadvantages such as output or internal non-full-swing nodes and poor driving capability. Considering these drawbacks, they might not be a good choice to operate in a practical environment. Lowering the number of transistors can inherently lead to smaller occupied area, higher speed and lower power consumption. However, other parameters, such as robustness to PVT variations and rail-to-rail operation, should also be considered. While the robustness is taken into account, HSPICE simulation demonstrates a great improvement in terms of speed and power-delay product (PDP).


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):  
SYAM KUMAR NAGENDLA ◽  
K. MIRANJI

Now a Days in modern VLSI technology different kinds of errors are invitable. A new type of adder i.e. error tolerant adder(ETA) is proposed to tolerate those errors and to attain low power consumption and high speed performance in DSP systems. In conventional adder circuit, delay is mainly certified to the carry propagation chain along the critical path, from the LSB to MSB. If the carry propagation can be eliminated by the technique proposed in this paper, a great improvement in speed performance and power consumption is achieved. By operating shifting and addition in parallel, the error tolerant adder tree compensates for the truncation errors. To prove the feasibility of the ETA, normal addition operation present in the DFT or DCT algorithm is replaced by the proposed addition arithmetic and the experimental results are shown. In this paper we propose error tolerant Adder (ETA). In the view of DSP applications the ETA is able to case the strict restriction on accuracy, speed performance and power consumption when compared to the conventional Adders, the proposed one provides 76% improvement in power-delay product such a ETA plays a key role in digital signal processing system that can tolerate certain amount of errors.


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.


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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