Design of a power-efficient Kogge–Stone adder by exploring new OR gate in 45nm CMOS process

Circuit World ◽  
2020 ◽  
Vol 46 (4) ◽  
pp. 257-269
Author(s):  
Vimukth John ◽  
Shylu Sam ◽  
S. Radha ◽  
P. Sam Paul ◽  
Joel Samuel

Purpose The purpose of this work is to reduce the power consumption of KSA and to improve the PDP for data path applications. In digital Very Large – Scale Integration systems, the addition of two numbers is one of the essential functions. This arithmetic function is used in the modern digital signal processors and microprocessors. The operating speed of these processors depends on the computation of the arithmetic function. The speed computation block for most of the datapath elements was adders. In this paper, the Kogge–Stone adder (KSA) is designed using XOR, AND and proposed OR gates. The proposed OR gate has less power consumption due to the less number of transistors. In arithmetic logic circuit power, delay and power delay products (PDP) are considered as the important parameters. The delays reported for the proposed OR gate are less when compared with the conventional Complementary Metal Oxide Semiconductor (CMOS) OR gate and pre-existing logic styles. The proposed circuits are optimized in terms of power, delay and PDP. To analyze the performance of KSA, extensive Cadence Virtuoso simulations are used. From the simulation results based on 45 nm CMOS process, it was observed that the proposed design has obtained 688.3 nW of power consumption, 0.81 ns of delay and 0.55 fJ of PDP at 1.1 V. Design/methodology/approach In this paper, a new circuit for OR gate is proposed. The KSA is designed using XOR, AND and proposed OR gates. Findings The proposed OR gate has less power consumption due to the less number of transistors. The delays reported for the proposed OR gate are less when compared with the conventional CMOS OR gate and pre-existing logic styles. The proposed circuits are optimized in terms of power, delay and PDP. Originality/value In arithmetic logic circuit power, delay and PDP are considered as the important parameters. In this paper, a new circuit for OR gate is proposed. The power consumption of the designed KSA using the proposed OR gate is very less when compared with the conventional KSA. Simulation results show that the performance of the proposed KSA are improved and suitable for high speed applications.

Electronics ◽  
2019 ◽  
Vol 8 (5) ◽  
pp. 589 ◽  
Author(s):  
Tianchen Shen ◽  
Jiabing Liu ◽  
Chunyi Song ◽  
Zhiwei Xu

A high-speed, low-power divide-by-3/4 prescaler based on an extended true single-phase clock D-flip flop (E-TSPC DFF) is presented. We added two more transistors and a mode control signal to the conventional E-TSPC based divide-by-4 divider to achieve the function of the divide-by-3/4 dual modulus frequency divider. The designed divide-by-3/4 achieved higher speed and lower power operation with mode control compared with the conventional ones. The prescaler was comprised of sixteen transistors and integrates an inverter in the second DFF to provide output directly. The power consumption was minimized due to the reduced number of stages and transistors. In addition, the prescaler operating speed was also improved due to a reduced critical path. We compared the simulation results with conventional E-TSPC based divide-by-3/4 dividers in the same process, where the figure-of-merit (FoM) of the proposed divider was 17.4–75.5% better than conventional ones. We have also fabricated the prescaler in a 40 nm complementary metal oxide semiconductor (CMOS) process. The measured highest operating frequency was 9 GHz with 0.303 mW power consumption under 1.35 V power supply, which agrees with the simulation well. The measurement results demonstrate that the proposed divider achieves high-speed and low-power operation.


2014 ◽  
Vol 17 (1) ◽  
pp. 52-61
Author(s):  
Thanh Tri Vo ◽  
Trong Tu Bui ◽  
Duc Hung Le ◽  
Cong Kha Pham

In this paper we present a design of Flash-ADC that can achieve high performance and low power consumption. By using the Double Sampling Rate technique and a new comparator topology with low kick-back noise, this design can achieve high sampling rate while still consuming low power. The design is implemented in a 0.18 m CMOS process. The simulation results show that this design can work at 400 MSps and power consumption is only 16.24 mW. The DNL and INL are 0.15 LSB and 0.6 LSB, respectively.


2020 ◽  
Vol 11 (1) ◽  
pp. 129
Author(s):  
Po-Yu Kuo ◽  
Ming-Hwa Sheu ◽  
Chang-Ming Tsai ◽  
Ming-Yan Tsai ◽  
Jin-Fa Lin

The conventional shift register consists of master and slave (MS) latches with each latch receiving the data from the previous stage. Therefore, the same data are stored in two latches separately. It leads to consuming more electrical power and occupying more layout area, which is not satisfactory to most circuit designers. To solve this issue, a novel cross-latch shift register (CLSR) scheme is proposed. It significantly reduced the number of transistors needed for a 256-bit shifter register by 48.33% as compared with the conventional MS latch design. To further verify its functions, this CLSR was implemented by using TSMC 40 nm CMOS process standard technology. The simulation results reveal that the proposed CLSR reduced the average power consumption by 36%, cut the leakage power by 60.53%, and eliminated layout area by 34.76% at a supply voltage of 0.9 V with an operating frequency of 250 MHz, as compared with the MS latch.


Sensors ◽  
2021 ◽  
Vol 21 (7) ◽  
pp. 2260
Author(s):  
Khuram Shehzad ◽  
Deeksha Verma ◽  
Danial Khan ◽  
Qurat Ul Ain ◽  
Muhammad Basim ◽  
...  

A low power 12-bit, 20 MS/s asynchronously controlled successive approximation register (SAR) analog-to-digital converter (ADC) to be used in wireless access for vehicular environment (WAVE) intelligent transportation system (ITS) sensor based application is presented in this paper. To optimize the architecture with respect to power consumption and performance, several techniques are proposed. A switching method which employs the common mode charge recovery (CMCR) switching process is presented for capacitive digital-to-analog converter (CDAC) part to lower the switching energy. The switching technique proposed in our work consumes 56.3% less energy in comparison with conventional CMCR switching method. For high speed operation with low power consumption and to overcome the kick back issue in the comparator part, a mutated dynamic-latch comparator with cascode is implemented. In addition, to optimize the flexibility relating to the performance of logic part, an asynchronous topology is employed. The structure is fabricated in 65 nm CMOS process technology with an active area of 0.14 mm2. With a sampling frequency of 20 MS/s, the proposed architecture attains signal-to-noise distortion ratio (SNDR) of 65.44 dB at Nyquist frequency while consuming only 472.2 µW with 1 V power supply.


2002 ◽  
Vol 11 (01) ◽  
pp. 51-55
Author(s):  
ROBERT C. CHANG ◽  
L.-C. HSU ◽  
M.-C. SUN

A novel low-power and high-speed D flip-flop is presented in this letter. The flip-flop consists of a single low-power latch, which is controlled by a positive narrow pulse. Hence, fewer transistors are used and lower power consumption is achieved. HSPICE simulation results show that power dissipation of the proposed D flip-flop has been reduced up to 76%. The operating frequency of the flip-flop is also greatly increased.


2018 ◽  
Vol 70 (1) ◽  
pp. 15-22 ◽  
Author(s):  
De-xing Zheng ◽  
Weifang Chen ◽  
Miaomiao Li

Purpose Thermal performances are key factors impacting the operation of angular contact ball bearings. Heat generation and transfer about angular contact ball bearings, however, have not been addressed thoroughly. So far, most researchers only considered the convection effect between bearing housings and air, whereas the cooling/lubrication operation parameters and configuration effect were not taken into account when analyzing the thermal behaviors of bearings. This paper aims to analyze the structural constraints of high-speed spindle, structural features of bearing, heat conduction and convection to study the heat generation and transfer of high-speed angular contact ball bearings. Design/methodology/approach Based on the generalized Ohm’s law, the thermal grid model of angular contact ball bearing of high-speed spindle was first established. Next Gauss–Seidel method was used to solve the equations group by Matlab, and the nodes temperature was calculated. Finally, the bearing temperature rise was tested, and the comparative analysis was made with the simulation results. Findings The results indicate that the simulation results of bearing temperature rise for the proposed model are in better agreement with the test values. So, the thermal grid model established is verified. Originality/value This paper shows an improved model on forecasting temperature rise of high-speed angular contact ball bearings. In modeling, the cooling/lubrication operation parameters and structural constraints are integrated. As a result, the bearing temperature variation can be forecasted more accurately, which may be beneficial to improve bearing operating accuracy and bearing service life.


Electronics ◽  
2018 ◽  
Vol 7 (12) ◽  
pp. 369 ◽  
Author(s):  
Padmanabhan Balasubramanian ◽  
Nikos Mastorakis

Addition is a fundamental operation in microprocessing and digital signal processing hardware, which is physically realized using an adder. The carry-lookahead adder (CLA) and the carry-select adder (CSLA) are two popular high-speed, low-power adder architectures. The speed performance of a CLA architecture can be improved by adopting a hybrid CLA architecture which employs a small-size ripple-carry adder (RCA) to replace a sub-CLA in the least significant bit positions. On the other hand, the power dissipation of a CSLA employing full adders and 2:1 multiplexers can be reduced by utilizing binary-to-excess-1 code (BEC) converters. In the literature, the designs of many CLAs and CSLAs were described separately. It would be useful to have a direct comparison of their performances based on the design metrics. Hence, we implemented homogeneous and hybrid CLAs, and CSLAs with and without the BEC converters by considering 32-bit accurate and approximate additions to facilitate a comparison. For the gate-level implementations, we considered a 32/28 nm complementary metal-oxide-semiconductor (CMOS) process targeting a typical-case process–voltage–temperature (PVT) specification. The results show that the hybrid CLA/RCA architecture is preferable among the CLA and CSLA architectures from the speed and power perspectives to perform accurate and approximate additions.


VLSI technology become one of the most significant and demandable because of the characteristics like device portability, device size, large amount of features, expenditure, consistency, rapidity and many others. Multipliers and Adders place an important role in various digital systems such as computers, process controllers and signal processors in order to achieve high speed and low power. Two input XOR/XNOR gate and 2:1 multiplexer modules are used to design the Hybrid Full adders. The XOR/XNOR gate is the key punter of power included in the Full adder cell. However this circuit increases the delay, area and critical path delay. Hence, the optimum design of the XOR/XNOR is required to reduce the power consumption of the Full adder Cell. So a 6 New Hybrid Full adder circuits are proposed based on the Novel Full-Swing XOR/XNOR gates and a New Gate Diffusion Input (GDI) design of Full adder with high-swing outputs. The speed, power consumption, power delay product and driving capability are the merits of the each proposed circuits. This circuit simulation was carried used cadence virtuoso EDA tool. The simulation results based on the 90nm CMOS process technology model.


Author(s):  
Widianto Widianto ◽  
Lailis Syafaah ◽  
Nurhadi Nurhadi

In this paper, effects of process variations in a HCMOS (High-Speed Complementary Metal Oxide Semiconductor) IC (Integrated Circuit) are examined using a Monte Carlo SPICE (Simulation Program with Integrated Circuit Emphasis) simulation. The variations of the IC are L and VTO variations. An evaluation method is used to evaluate the effects of the variations by modeling it using a normal (Gaussian) distribution. The simulation results show that the IC may be detected as a defective IC caused by the variations based on large supply currents flow to it. 


Circuit World ◽  
2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Kulbhushan Sharma ◽  
Anisha Pathania ◽  
Jaya Madan ◽  
Rahul Pandey ◽  
Rajnish Sharma

Purpose Adoption of integrated MOS based pseudo-resistor (PR) structures instead of using off-chip passive poly resistors for analog circuits in complementary metal oxide semiconductor technology (CMOS) is an area-efficient way for realizing larger time constants. However, issue of common-mode voltage shifting and excess dependency on the process and temperature variations introduce nonlinearity in such structures. So there is dire need to not only closely look for the origin of the problem with the help of a thorough mathematical analysis but also suggest the most suitable PR structure for the purpose catering broadly to biomedical analog circuit applications. Design/methodology/approach In this work, incremental resistance (IR) expressions and IR range for balanced PR (BPR) structures operating in the subthreshold region have been closely analyzed for broader range of process-voltage-temperature variations. All the post-layout simulations have been obtained using BSIM3V3 device models in 0.18 µm standard CMOS process. Findings The obtained results show that the pertinent problem of common-mode voltage shifting in such PR structures is completely resolved in scaled gate linearization and bulk-driven quasi-floating gate (BDQFG) BPR structures. Among all BPR structures, BDQFG BPR remarkably shows constant IR value of 1 TΩ over −1 V to 1 V voltage swing for wider process and temperature variations. Research limitations/implications Various balanced PR design techniques reported in this work will help the research community in implementing larger time constants for analog-mixed signal circuits. Social implications The PR design techniques presented in the present piece of work is expected to be used in developing tunable and accurate biomedical prosthetics. Originality/value The BPR structures thoroughly analyzed and reported in this work may be useful in the design of analog circuits specifically for applications such as neural signal recording, cardiac electrical impedance tomography and other low-frequency biomedical applications.


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