Various Logically Optimized D Flip Flop Circuits-A Comparative Study in Submicron Technology

Author(s):  
Abhijit Asthana ◽  
Shyam Akashe

D-Flip Flop (D_FF) is a very important component of various digital, analog and mixed signal systems and designs. It is obvious to come up with optimized D_FF, that cater the needs of low leakage power, less power dissipation, less chip area on the chip and low delays. This paper presents a comparative study of various logically optimized circuits of D_FF using 8T, 11T, 12T and conventional 18T D_FF. The simulation, test circuits, schematics & layouts etc are done on Cadence Virtuoso tool in 180 nm technology. Designs are compared on grounds of power dissipation, leakage power, delays and power delay product.

Electronics ◽  
2021 ◽  
Vol 10 (14) ◽  
pp. 1718
Author(s):  
Neha Gupta ◽  
Ambika Prasad Shah ◽  
Sajid Khan ◽  
Santosh Kumar Vishvakarma ◽  
Michael Waltl ◽  
...  

This paper proposes an error-tolerant reconfigurable VDD (R-VDD) scaled SRAM architecture, which significantly reduces the read and hold power using the supply voltage scaling technique. The data-dependent low-power 10T (D2LP10T) SRAM cell is used for the R-VDD scaled architecture with the improved stability and lower power consumption. The R-VDD scaled SRAM architecture is developed to avoid unessential read and hold power using VDD scaling. In this work, the cells are implemented and analyzed considering a technologically relevant 65 nm CMOS node. We analyze the failure probability during read, write, and hold mode, which shows that the proposed D2LP10T cell exhibits the lowest failure rate compared to other existing cells. Furthermore, the D2LP10T cell design offers 1.66×, 4.0×, and 1.15× higher write, read, and hold stability, respectively, as compared to the 6T cell. Moreover, leakage power, write power-delay-product (PDP), and read PDP has been reduced by 89.96%, 80.52%, and 59.80%, respectively, compared to the 6T SRAM cell at 0.4 V supply voltage. The functional improvement becomes even more apparent when the quality factor (QF) is evaluated, which is 458× higher for the proposed design than the 6T SRAM cell at 0.4 V supply voltage. A significant improvement of power dissipation, i.e., 46.07% and 74.55%, can also be observed for the R-VDD scaled architecture compared to the conventional array for the respective read and hold operation at 0.4 V supply voltage.


2018 ◽  
Vol 7 (2.7) ◽  
pp. 863
Author(s):  
Damarla Paradhasaradhi ◽  
Kollu Jaya Lakshmi ◽  
Yadavalli Harika ◽  
Busa Ravi Teja Sai ◽  
Golla Jayanth Krishna

In deep sub-micron technologies, high number of transistors is mounted onto a small chip area where, SRAM plays a vital role and is considered as a major part in many VLSI ICs because of its large density of storage and very less access time. Due to the demand of low power applications the design of low power and low voltage memory is a demanding task. In these memories majority of power dissipation depends on leakage power. This paper analyzes the basic 6T SRAM cell operation. Here two different leakage power reduction approaches are introduced to apply for basic 6T SRAM. The performance analysis of basic SRAM cell, SRAM cell using drowsy-cache approach and SRAM cell using clamping diode are designed at 130nm using Mentor Graphics IC Studio tool. The proposed SRAM cell using clamping diode proves to be a better power reduction technique in terms of power as compared with others SRAM structures. At 3.3V, power saving by the proposed SRAM cell is 20% less than associated to basic 6T SRAM Cell.


2014 ◽  
Vol 2014 ◽  
pp. 1-10 ◽  
Author(s):  
Xiaohui Fan ◽  
Yangbo Wu ◽  
Hengfeng Dong ◽  
Jianping Hu

With the scaling of technology process, leakage power becomes an increasing portion of total power. Power gating technology is an effective method to suppress the leakage power in VLSI design. When the power gating technique is applied in sequential circuits, such as flip-flops and latches, the data retention is necessary to store the circuit states. A low leakage autonomous data retention flip-flop (ADR-FF) is proposed in this paper. Two high-Vthtransistors are utilized to reduce the leakage power consumption in the sleep mode. The data retention cell is composed of a pair of always powered cross-coupled inverters in the slave latch. No extra control signals and complex operations are needed for controlling the data retention and restoration. The data retention flip-flops are simulated with NCSU 45 nm technology. The postlayout simulation results show that the leakage power of the ADR-FF reduces 51.39% compared with the Mutoh-FF. The active power of the ADR-FF is almost equal to other data retention flip-flops. The average state mode transition time of ADR-FF decreases 55.98%, 51.35%, and 21.07% as compared with Mutoh-FF, Balloon-FF, and Memory-TG-FF, respectively. Furthermore, the area overhead of ADR-FF is smaller than other data retention flip-flops.


2014 ◽  
Vol 573 ◽  
pp. 187-193 ◽  
Author(s):  
Anitha Ponnusamy ◽  
Palaniappan Ramanathan

The recent increase in popularity of portable systems and rapid growth of packaging density in VLSI circuit’s has enable designers to design complex functional units on a single chip. Power, area and speed plays a major role in the design and optimization of an integrated circuit. Carry select adder is high speed final stage adder widely used in many data processing units. In this work, conventional D-flip flop is replaced by a new design using negative edge triggered D-flip flop. The proposed CSA is implemented in a faster partitioned Dadda multiplier and simulated by using MICROWIND tool. The results reveal that for 16 bit CSA improvement of power delay product (PDP) of the proposed design using negative edge triggered D flip flop is 78% & 18% when compared to CSA with BEC and CSA with conventional D flip flop. When CSA implemented in a partitioned Dadda multiplier it results in performance improvement of 74 % with little increase in total power dissipation.


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.


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.


2018 ◽  
Vol 27 (05) ◽  
pp. 1850077 ◽  
Author(s):  
K. N. Vijeyakumar ◽  
S. Elango ◽  
S. Kalaiselvi

In this brief, we present the design and evaluation of a high speed and energy-efficient truncated multiplier for unsigned multiplication, such that the average absolute error due to truncation and rounding is kept minimal. The proposed algorithm eliminates a few least significant Partial Product (PP) bits and adds correction bias at appropriate PP bit positions to minimize the total error. From the literatures reviewed, it is clear that there is scope for reducing delay in multiplication using sutras of ancient vedic mathematics. This work uses a simple “crosswise and vertical sutra” of Vedic mathematics to generate PP bits. The proposed methodology groups the input into [Formula: see text]/2 bits, eliminates least subgroup multiplication ([Formula: see text]) and deletes few least significant bits in other subgroup multiplications to reduce area and power dissipation. In addition, correction biase are added at appropriate bit positions to reduce the overall absolute error due to the elimination of few PP bits and rounding of final product. Experimental evaluation of the proposed truncated design is carried out through structural level VHDL modeling and simulations using Synopsys design compiler. Performance analysis revealed Chip-Area Ratio (CAR%) to be 33.81% and Power-Delay Product (PDP) of 14.84[Formula: see text]pJ of proposed truncated design for an [Formula: see text] multiplication.


Author(s):  
FAYAZ KHAN ◽  
SIREESH BABU

This paper enumerates design of D flip flop with low power and low area for low power applications, for that analysis of various D-flip flops for low power dissipation ,area and delays is carried out at 0.12um to achieve low power, low-area the technology is scaled down to nanometer ranges, due to shrinking process, the leakage power tends to play a vital role in total power consumption at nano meter technology. In this paper, different D flip flop circuits are designed using Berkeley Short Channel Insulated Gate MOSFET (BSIM4) model equations., in this paper to reduce leakage power at 90nm 70nm and 50nm we implement leakage power reduction techniques six techniques are considered they are namely Sleep transistor, sleepy stack, Dual sleep ,Dual stack Forced Transistor sleep (FTS) and Sleepy keeper From the results, it is observed that SLEEP TRANSISTOR, and SLEEPY KEEPER.FORCED TRANSISTOR SLEEP techniques produces lower power dissipation than the other techniques , in this paper a qualitative comparison is done with the help of Dsch,, Micro wind Simulation tools, this paper concludes that a leakage reduction technique produce different power optimization levels for different architectures and employing a suitable technique for a particular architecture will be an effective way of reducing the leakage current and thereby static power.


2017 ◽  
Vol 63 (3) ◽  
pp. 241-246 ◽  
Author(s):  
Ehsan Panahifar ◽  
Alireza Hassanzadeh

AbstractIn this paper a modified signal feed-through pulsed flip-flop has been presented for low power applications. Signal feed-through flip-flop uses a pass transistor to feed input data directly to the output. Feed through transistor and feedback signals have been modified for delay, static and dynamic power reduction. HSPICE simulation shows 22% reduction in leakage power and 8% of dynamic power. Delay has been reduced by 14% using TSMC 90nm technology parameters. The proposed pulsed flip-flop has the lowest PDP (Power Delay Product) among other pulsed flip-flops discussed.


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