scholarly journals Bias Temperature Instability Aware and Soft Error Tolerant Radiation Hardened 10T SRAM Cell

Electronics ◽  
2020 ◽  
Vol 9 (2) ◽  
pp. 256 ◽  
Author(s):  
Ambika Prasad Shah ◽  
Michael Waltl
Keyword(s):  
Soft Error ◽  
Critical Charge ◽  
Bias Temperature Instability ◽  
Noise Margin ◽  
Sram Cell ◽  
Radiation Hardened ◽  
The Stability ◽  
A Charge ◽  
The Impact ◽  
Static Noise

In this paper, we propose an asymmetric radiation-hardened 10T (AS10T) SRAM cell and analyze the impact of bias temperature instabilities (BTI) on the single event upset of the modified structure. For this, we make use of a read decoupled circuit to improve the stability of the reading cycle, and a charge booster circuit to increase the critical charge at the sensitive node of the SRAM cell. First, we compare the noise margin of several reference cells and can clearly observe that the read static noise margin (RSNM) of AS10T is 3.25× higher than as can be achieved for the 6T SRAM cell. This improvement is due to the read decoupled path used for the read operation. To analyze the soft-error hardening, we calculate the critical charge and observe that the critical charge of the proposed AS10T cell exceed the same parameter of other SRAM cells. Further, we perform critical charge simulations and stability analysis considering BTI and observe that the AS10T SRAM cell is also less affected by BTI as the reference cells.

scholarly journals FinFET SRAM cell with improved stability and power for low power applications.

2019 ◽  
Vol 14 (2) ◽  
pp. 1-8
Author(s):  
Shilpi Birla
Keyword(s):  
Memory Cell ◽  
Static Noise Margin ◽  
Noise Margin ◽  
Sram Cell ◽  
Improved Stability ◽  
Cell Stability ◽  
Subthreshold Voltage ◽  
The Stability ◽  
Subthreshold Operation ◽  
Static Noise

In this paper, a new 11T SRAM cell using Double gate FET (FinFET technology) has been proposed, cell basic component is the 6T SRAM cell with 4 NMOS access transistors to improve the stability over CMOSFET circuits and also makes it a dual port memory cell. The proposed cell also used a header scheme in which one extra PMOS transistor is used which is biased at different voltages to improve the read and write stability which helps in reducing the leakage current, active power. The cell shows improvement in RSNM (Read Static Noise Margin) with LP8T by 2.39x at threshold and subthreshold voltage 2.68x with D6T SRAM cell, 5.5x with TG8T. The WSNM (Write Static Noise Margin) and HM (Hold Margin) of the SRAM cell at 0.9V is 306mV and 384mV.At subthreshold operation also, it shows improvement. The Leakage power reduced by 0.125x with LP8T, 0.022x with D6T SRAM cell, TG8T and SE8T. Impact of process variation on cell stability also been analyzed.

Variability aware FinFET SRAM cell with improved stability and power for low power applications

Circuit World ◽  
2019 ◽  
Vol 45 (4) ◽  
pp. 196-207
Author(s):  
Shilpi Birla
Keyword(s):  
Low Power ◽  
Threshold Voltage ◽  
Leakage Power ◽  
Static Noise Margin ◽  
Content Type ◽  
Noise Margin ◽  
Sram Cell ◽  
Memory Circuits ◽  
The Stability ◽  
Static Noise

Purpose Major area of a die is consumed in memory components. Almost 60-70% of chip area is being consumed by “Memory Circuits”. The dominant memory in this market is SRAM, even though the SRAM size is larger than embedded DRAM, as SRAM does not have yield issues and the cost is not high as compared to DRAM. At the same time, the other attractive feature for the SRAM is speed, and it can be used for low power applications. CMOS SRAM is the crucial component in microprocessor chips and applications, and as the said major portion of the area is dedicated to SRAM arrays, CMOS SRAM is considered to be the stack holders in the memory market. Because of the scaling feature of CMOS, SRAM had its hold in the market over the past few decades. In recent years, the limitations of the CMOS scaling have raised so many issues like short channel effects, threshold voltage variations. The increased thrust for alternative devices leads to FinFET. FinFET is emerging as one of the suitable alternatives for CMOS and in the region of memory circuits. Design/methodology/approach In this paper, a new 11 T SRAM cell using FinFET technology has been proposed, the basic component of the cell is the 6 T SRAM cell with 4 NMOS access transistors to improve the stability and also makes it a dual port memory cell. The proposed cell uses a header scheme in which one extra PMOS transistor is used which is biased at different voltages to improve the read and write stability thus, helps in reducing the leakage power and active power. Findings The cell shows improvement in RSNM (read static noise margin) with LP8T by 2.39× at sub-threshold voltage 2.68× with D6T SRAM cell, 5.5× with TG8T. The WSNM (write static noise margin) and HM (hold margin) of the SRAM cell at 0.9 V is 306 mV and 384  mV. It shows improvement at sub-threshold operation also. The leakage power is reduced by 0.125× with LP8T, 0.022× with D6T SRAM cell, TG8T and SE8T. The impact of process variation on cell stability is also discussed. Research limitations/implications The FinFet has been used in place of CMOS even though the FinFet has been not been a matured technology; therefore, pdk files have been used. Practical implications SRAM cell has been designed which has good stability and reduced leakage by which we can make an array and which can be used as SRAM array. Social implications The cell can be used for SRAM memory for low power consumptions. Originality/value The work has been done by implementing various leakage techniques to design a stable and improved SRAM cell. The advantage of this work is that the cell has been working for low voltage without degrading the stability factor.

The SRAM Soft Failure Analysis with SNM & TR Characterization by Nanoprobing in Sub 45nm

2009 ◽  
Author(s):  
Jakyung Hong ◽  
S.J. Cho ◽  
Y.W. Han ◽  
H.S. Choi ◽  
T.E. Kim ◽  
...  
Keyword(s):  
Failure Analysis ◽  
Failure Mechanism ◽  
Metal Layer ◽  
Noise Margin ◽  
Soft Failure ◽  
Sram Cell ◽  
Cell Stability ◽  
The Stability ◽  
Static Noise

Abstract This paper presents the process of measuring static noise margin (SNM), write noise margin (WNM) with 6 pin nanoprober, and characterization and analysis of SRAM cell stability through case studies of 45nm devices SRAM soft failures. It highlights that the local mismatch in the bit cell caused by slight variations in the transistor characteristics, such as Vth shift and Idsat, off variation, also can easily induce a soft failure. The analysis of the SNM TR characteristic is successfully demonstrated through the case study of 45nm SRAM devices. The chapter explains SNM measurement in the metal layer and transistor measurements in the CA layer. Measuring the SNM TR's characteristics is an important methodology in understanding the stability of each bit cell and failure mechanism depending on voltage, defects, and other factors. The next generation of nanoprobing analysis can be expanded.

scholarly journals Design and Analysis of Soft Error Rate in FET/CNTFET Based Radiation Hardened SRAM Cell

Sensors ◽  
2021 ◽  
Vol 22 (1) ◽  
pp. 33
Author(s):  
Bharathi Raj Muthu ◽  
Ewins Pon Pushpa ◽  
Vaithiyanathan Dhandapani ◽  
Kamala Jayaraman ◽  
Hemalatha Vasanthakumar ◽  
...  
Keyword(s):  
Soft Errors ◽  
Memory Cell ◽  
Soft Error ◽  
Access Time ◽  
Electronic Systems ◽  
Memory Cells ◽  
Noise Margin ◽  
Sram Cell ◽  
Driver Circuit ◽  
Radiation Hardened

Aerospace equipages encounter potential radiation footprints through which soft errors occur in the memories onboard. Hence, robustness against radiation with reliability in memory cells is a crucial factor in aerospace electronic systems. This work proposes a novel Carbon nanotube field-effect transistor (CNTFET) in designing a robust memory cell to overcome these soft errors. Further, a petite driver circuit to test the SRAM cells which serve the purpose of precharge and sense amplifier, and has a reduction in threefold of transistor count is recommended. Additionally, analysis of robustness against radiation in varying memory cells is carried out using standard GPDK 90 nm, GPDK 45 nm, and 14 nm CNTFET. The reliability of memory cells depends on the critical charge of a device, and it is tested by striking an equivalent current charge of the cosmic ray’s linear energy transfer (LET) level. Also, the robustness of the memory cell is tested against the variation in process, voltage and temperature. Though CNTFET surges with high power consumption, it exhibits better noise margin and depleted access time. GPDK 45 nm has an average of 40% increase in SNM and 93% reduction of power compared to the 14 nm CNTFET with 96% of surge in write access time. Thus, the conventional MOSFET’s 45 nm node outperforms all the configurations in terms of static noise margin, power, and read delay which swaps with increased write access time.

Design and Analysis of SRAM Cell using Negative Bit-Line Write Assist Technique and Separate Read Port for High-Speed Applications

2021 ◽  
pp. 2150270
Author(s):  
Jitendra Kumar Mishra ◽  
Lakshmi Likhitha Mankali ◽  
Kavindra Kandpal ◽  
Prasanna Kumar Misra ◽  
Manish Goswami
Keyword(s):  
Power Dissipation ◽  
High Speed ◽  
Random Access ◽  
Random Access Memory ◽  
Access Memory ◽  
Static Noise Margin ◽  
Semiconductor Memory ◽  
Noise Margin ◽  
Sram Cell ◽  
Static Noise

The present day electronic gadgets have semiconductor memory devices to store data. The static random access memory (SRAM) is a volatile memory, often preferred over dynamic random access memory (DRAM) due to higher speed and lower power dissipation. However, at scaling down of technology node, the leakage current in SRAM often increases and degrades its performance. To address this, the voltage scaling is preferred which subsequently affects the stability and delay of SRAM. This paper therefore presents a negative bit-line (NBL) write assist circuit which is used for enhancing the write ability while a separate (isolated) read buffer circuit is used for improving the read stability. In addition to this, the proposed design uses a tail (stack) transistor to decrease the overall static power dissipation and also to maintain the hold stability. The comparison of the proposed design has been done with state-of-the-art work in terms of write static noise margin (WSNM), write delay, read static noise margin (RSNM) and other parameters. It has been observed that there is an improvement of 48%, 11%, 19% and 32.4% in WSNM while reduction of 33%, 39%, 48% and 22% in write delay as compared to the conventional 6T SRAM cell, NBL, [Formula: see text] collapse and 9T UV SRAM, respectively.

scholarly journals Restoration circuits for Low power Reduce Swing of 6T and 8T SRAM Cell With Improved Read and Write Margins

2021 ◽  
Vol 7 ◽  
pp. 22-34
Author(s):  
Vinod Kumar ◽  
Ram Murti Rawat
Keyword(s):  
Low Power ◽  
Static Noise Margin ◽  
Noise Margin ◽  
Equivalent Time ◽  
Sram Cell ◽  
Section Viii ◽  
Static Noise

A paper that examines the factors thataffect the Static Noise Margin (SNM) of a StaticRandom Access memories. At an equivalent time,they specialise in optimizing Read and Writeoperation of 8T SRAM cell which is best than 6TSRAM cell Using Swing Restoration Dual NodeVoltage. The read and Write operation and improveStability analysis. This SRAM technique on thecircuit or architecture level is required to improveread and write operation. during this paperComparative Analysis of 6T and 8T SRAM Cellswith Improved Read and Write Margin is completedfor 180 nm Technology with Cadence Virtuososchematics Tool.This Paper is organized as follows: thecharacteristics of 6T SRAM cell are described arerepresented in section VIII. In section IX, proposed8T SRAM cell is described. In section X, Standard8T SRAM cell is described. Section XI includes thesimulation results which give comparison of variousparameters of 6T and 8T SRAM cells. In Section XIISimulation Results and DC analysis and sectionXIII conclusion the work.

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