scholarly journals Near-Threshold Computing and Minimum Supply Voltage of Single-Rail MCML Circuits

2014 ◽  
Vol 2014 ◽  
pp. 1-10 ◽  
Author(s):  
Ruiping Cao ◽  
Jianping Hu

In high-speed applications, MOS current mode logic (MCML) is a good alternative. Scaling down supply voltage of the MCML circuits can achieve low power-delay product (PDP). However, the current almost all MCML circuits are realized with dual-rail scheme, where the NMOS configuration in series limits the minimum supply voltage. In this paper, single-rail MCML (SRMCML) circuits are described, which can avoid the devices configuration in series, since their logic evaluation block can be realized by only using MOS devices in parallel. The relationship between the minimum supply voltage of the SRMCML circuits and the model parameters of MOS transistors is derived, so that the minimum supply voltage can be estimated before circuit designs. An MCML dynamic flop-flop based on SRMCML is also proposed. The optimization algorithm for near-threshold sequential circuits is presented. A near-threshold SRMCML mode-10 counter based on the optimization algorithm is verified. Scaling down the supply voltage of the SRMCML circuits is also investigated. The power dissipation, delay, and power-delay products of these circuits are carried out. The results show that the near-threshold SRMCML circuits can obtain low delay and small power-delay product.

Micromachines ◽  
2021 ◽  
Vol 12 (5) ◽  
pp. 551
Author(s):  
Zhongjian Bian ◽  
Xiaofeng Hong ◽  
Yanan Guo ◽  
Lirida Naviner ◽  
Wei Ge ◽  
...  

Spintronic based embedded magnetic random access memory (eMRAM) is becoming a foundry validated solution for the next-generation nonvolatile memory applications. The hybrid complementary metal-oxide-semiconductor (CMOS)/magnetic tunnel junction (MTJ) integration has been selected as a proper candidate for energy harvesting, area-constraint and energy-efficiency Internet of Things (IoT) systems-on-chips. Multi-VDD (low supply voltage) techniques were adopted to minimize energy dissipation in MRAM, at the cost of reduced writing/sensing speed and margin. Meanwhile, yield can be severely affected due to variations in process parameters. In this work, we conduct a thorough analysis of MRAM sensing margin and yield. We propose a current-mode sensing amplifier (CSA) named 1D high-sensing 1D margin, high 1D speed and 1D stability (HMSS-SA) with reconfigured reference path and pre-charge transistor. Process-voltage-temperature (PVT) aware analysis is performed based on an MTJ compact model and an industrial 28 nm CMOS technology, explicitly considering low-voltage (0.7 V), low tunneling magnetoresistance (TMR) (50%) and high temperature (85 °C) scenario as the worst sensing case. A case study takes a brief look at sensing circuits, which is applied to in-memory bit-wise computing. Simulation results indicate that the proposed high-sensing margin, high speed and stability sensing-sensing amplifier (HMSS-SA) achieves remarkable performance up to 2.5 GHz sensing frequency. At 0.65 V supply voltage, it can achieve 1 GHz operation frequency with only 0.3% failure rate.


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.


2017 ◽  
Vol 26 (05) ◽  
pp. 1750084 ◽  
Author(s):  
Pankaj Kumar ◽  
Rajender Kumar Sharma

An energy efficient internal logic approach for designing two 1-bit full adder cells is proposed in this work. It is based on decomposition of the full adder logic into the smaller modules. Low power, high speed and smaller area are the main features of the proposed approach. A modified power aware NAND gate, an essential entity, is also presented. The proposed full adder cells achieve 30.13% and improvement in their power delay product (PDP) metrics when compared with the best reported full adder design. Some of the popular adders and proposed adders are designed with cadence virtuoso tool with UMC 90[Formula: see text]nm technology operating at 1.2[Formula: see text]V supply voltage and UMC 55[Formula: see text]nm CMOS technology operating at 1.0[Formula: see text]V. These designs are tested on a common environment. During the experiment, it is also found that the proposed adder cells exhibit excellent signal integrity and driving capability when operated at low voltages.


2018 ◽  
Vol 7 (2.11) ◽  
pp. 38
Author(s):  
Bindu Thakral ◽  
Arti Vaish ◽  
Rama Koteswara Rao Alla

Historically, analog designs have been assumed as a voltage mode based signal processing. However, the necessity of high speed circuits operating at reduced supply voltage has lead to a development of new circuit topology referred as current-mode designs. For low power low voltage designs the applications using translinear principle based circuits has become an area of research and interest. It has wide application in nonlinear signal processing and to build basic active elements. Mode of MOS transistor used in analog circuit realization of is important parameter deciding the performance of the circuit. In this paper, a squarer circuit is proposed based on sub threshold-mode MOS transistors exhibiting the exponential current-voltage characteristic. The simulations have been performed on model files of TSMC 0.18 micrometer technology with the help of ELDO Simulator. 


2011 ◽  
Vol 8 (3) ◽  
pp. 293-306 ◽  
Author(s):  
Ravi Nirlakalla ◽  
Rao Subba ◽  
Talari Jayachandra-Prasad

This paper describes high speed compressors for high speed parallel multipliers like Booth Multiplier, Wallace Tree Multiplier in Digital Signal Processing (DSP). This paper presents 4-3, 5-3, 6-3 and 7-3 compressors for high speed multiplication. These compressors reduce vertical critical path more rapidly than conventional compressors. A 5-3 conventional compressor can take four steps to reduce bits from 5 to 3, but the proposed 5-3 takes only 2 steps. These compressors are simulated with H-Spice at a temperature of 25?C at a supply voltage 2.0V using 90nm MOSIS technology. The Power, Delay, Power Delay Product (PDP) and Energy Delay Product (EDP) of the compressors are calculated to analyze the total propagation delay and energy consumption. All the compressors are designed with half adder and full Adders only.


Author(s):  
Veepsa Bhatia ◽  
Neeta Pandey ◽  
Asok Bhattacharyya

A novel power-speed efficient current comparator is proposed in this paper. It comprises of only CMOS inverters in its structure, employing a simple biasing method. The structure offers simplicity of design. It posesses the very desirable features of high speed and low power dissipation, making this structure a highly desirable one for various current mode applications. The simulations have been performed using UMC 90 nm CMOS technology and the results demonstrate the propagation delay of about 3.1 ns and the average power consumption of 24.3 µW for 300 nA input current at supply voltage of 1V.


Author(s):  
Veepsa Bhatia ◽  
Neeta Pandey ◽  
Asok Bhattacharyya

A novel power-speed efficient current comparator is proposed in this paper. It comprises of only CMOS inverters in its structure, employing a simple biasing method. The structure offers simplicity of design. It posesses the very desirable features of high speed and low power dissipation, making this structure a highly desirable one for various current mode applications. The simulations have been performed using UMC 90 nm CMOS technology and the results demonstrate the propagation delay of about 3.1 ns and the average power consumption of 24.3 µW for 300 nA input current at supply voltage of 1V.


2013 ◽  
Vol 2013 ◽  
pp. 1-9 ◽  
Author(s):  
Kirti Gupta ◽  
Neeta Pandey ◽  
Maneesha Gupta

A new low-voltage MOS current mode logic (MCML) topology for D-latch is proposed. The new topology employs a triple-tail cell to lower the supply voltage requirement in comparison to traditional MCML D-latch. The design of the proposed MCML D-latch is carried out through analytical modeling of its static parameters. The delay is expressed in terms of the bias current and the voltage swing so that it can be traded off with the power consumption. The proposed low-voltage MCML D-latch is analyzed for the two design cases, namely, high-speed and power-efficient, and the performance is compared with the traditional MCML D-latch for each design case. The theoretical propositions are validated through extensive SPICE simulations using TSMC 0.18 µm CMOS technology parameters.


Sensors ◽  
2021 ◽  
Vol 21 (24) ◽  
pp. 8203
Author(s):  
Avireni Bhargav ◽  
Phat Huynh

Adders are constituted as the fundamental blocks of arithmetic circuits and are considered important for computation devices. Approximate computing has become a popular and developing area, promising to provide energy-efficient circuits with low power and high performance. In this paper, 10T approximate adder (AA) and 13T approximate adder (AA) designs using carbon nanotube field-effect transistor (CNFET) technology are presented. The simulation for the proposed 10T approximate adder and 13T approximate adder designs were carried out using the HSPICE tool with 32 nm CNFET technology. The metrics, such as average power, power-delay product (PDP), energy delay product (EDP) and propagation delay, were carried out through the HSPICE tool and compared to the existing circuit designs. The supply voltage Vdd provided for the proposed circuit designs was 0.9 V. The results indicated that among the existing full adders and approximate adders found in the review of adders, the proposed circuits consumed less PDP and minimum power with more accuracy.


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