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This paper proposes a modified Schmitt-trigger (ST)-based single-ended 11 T (MST11T) SRAM cell. The proposed cell is best suited to ultra-low voltage applications. Two ST-based cross-coupled inverters comprise the storage cell of the proposed MST11T bit cell. In comparison with conventional inverters, ST-based inverters have sharp voltage transfer characteristics. As a result, the proposed bit cell's stability performance increases. The proposed SRAM cell's leakage power consumption is reduced because of the use of stacked N-type transistors. For the read operation of the proposed bit cell, the read decoupled technique is used. As a result, the read static noise margin (RSNM) has greatly improved. The proposed bit cell's write static noise margin (WSNM) is increased by adopting feedback-cutting methodology. The performance of the proposed bit cell is compared with that of conventional 6 T, conventional 8 T, Schmitt-trigger 10 T (known as ST2), modified PMOS-PMOS-NMOS-based cell core 10 T (MPPN10T), feedback-cutting 11 T (FC11T), Schmitt-trigger 11 T (ST11), and Schmitt-trigger 12 T (ST12T) cells. According to the simulation results, the proposed MST11T SRAM cell has RSNM of 2.42, 1.18, 1.71, 1.30, and 1.80 times higher when compared to 6 T, FC11T, ST2, MPPN10T, and ST12T, respectively. The WSNM of the proposed bit cell has been increased by 1.56, 2.44, 1.28, 1.71, 1.35, 1.52, and 1.02 times, respectively, over 6 T, 8 T, ST2, MPPN10T, FC11T, ST11T, and ST12T. Furthermore, the suggested cell has a read delay that is 1.32, 1.79, and 1.53 times lower than ST11T, FC11T, and ST12T, respectively. The proposed bit cell has a write delay that is 1.14 and 1.63 times lower than FC11T and ST11T, respectively. The proposed MST11T bit-cell consumes 3.74, 1.56, 4.59, 5.38, and 4.83 times less leakage power than the 8 T, ST2, MPPN10T, FC11T, and ST12 bit-cells, respectively. When compared to 8 T/ST2/MPPN10T/ST12T at 0.2 V supply voltage, the enhanced facts incur a 4.87/3.79/3.78/1.97 penalty in write delay. The figure of merit (FOM) is derived as a result of this extensive access to the revolutionary SRAM cell performance, i.e., offering greater values at a 0.2 V DC supply voltage. In addition, the paper examines the impact of manufacturing process and temperature changes on MST11T cell enactment, as well as the circuit robustness using HSPICE with 7-nm FinFET technology. [ABSTRACT FROM AUTHOR]

This paper investigates a novel highly stable and robust single-ended 10T SRAM cell appropriate for low-power portable applications. The cell core of the proposed design is a combination of a normal inverter with a stacked NMOS transistor and a Schmitt-trigger (ST) inverter with a double-length pull-up transistor. This improves hold stability and leakage power dissipation. The read and write operations of the proposed cell are performed with the aid of separated paths and bitlines, lowering power consumption. The strong cell core and decoupled read path eliminate the read-disturbance issue in the proposed cell, resulting in read static noise margin (RSNM) enhancement. Furthermore, the feedback-cutting write-assist technique used in the proposed design mitigates the writing '1' issue; consequently, write static noise margin (WSNM)/write margin (WM) improves. To prove the superiority of the proposed SRAM cell in various performance metrics, it is compared with state-of-the-art SRAM cells, introduced as 6T, TG9T, 10T-P1, and SB11T, using HSPICE and 16-nm CMOS technology node taking into consideration the impact of the severe process, voltage, and temperature (PVT) variations. Obtained results at VDD = 0.7 V show that the proposed design offers the highest HSNM/RSNM/WSNM (or WM). The read/write delay of the proposed cell is 3.92X/2.37X higher than that of the 6T SRAM cell due to its single-ended reading/writing structure. However, in terms of power consumption, the proposed cell exhibits 1.64X/1.54X lower than that of 6T SRAM cell. Though the proposed cell occupies a 1.24X higher area compared with the 6T SRAM cell due to its higher count of transistor, it shows the highest proposed figure of merit among all the studied SRAM cells, which is 26.90X higher than that of 6T SRAM cell. [ABSTRACT FROM AUTHOR]

This paper presents a process voltage temperature (PVT)‐variation‐tolerant Schmitt‐trigger‐based 12T SRAM cell at 32 nm. The cell uses a modified Schmitt‐trigger action in all operating modes for performance improvement, a characteristic that is not exhibited by existing SRAM cells. The action improves the stability of stored data in read and hold modes and assists the write process to enable a faster and low‐voltage write operation. Additionally, the cell uses negative bitline technique and fully‐gated grounded scheme for achieving further improvement in write ability and ION/IOFF ratio. The proposed cell shows 34.9% reduced deviation in switching threshold voltage in comparison to conventional structure. Further, improvement of up to 211% in write ability and 169% in ION/IOFF ratio is obtained over existing SRAM cells operating in sub‐threshold region. The cell takes up to 86% and 99% lesser read and write access time, respectively. The Monte‐Carlo simulations show the robust performance of proposed cell. The cell has reduced write, read, and hold failure probabilities resulting in overall Vmin of 425 mV, which is the least among the cells considered for comparison, thus making it an amenable design suitable for sub‐threshold operation under PVT‐variations. [ABSTRACT FROM AUTHOR]

Tuning the delay of the circuit during the circuit performance can give a chance to a circuit to reduce Process, Voltage and Temperature (PVT) effects on delay and frequency by resetting its delay in feedback. This paper presented a full differential Schmitt-trigger (ST) with tunable delay and hysteresis. The delay-hysteresis setting is done in the design phase by tuning the biasing current, sizing, bias voltage and also during the execute phase (run time) by a digital bit and restructuring the circuit and delay route. The presented ST can have high and low delays with different frequencies using a digital bit in the circuit. This can help the band selection for multi-band applications. A Flip Voltage Follower (FVF) circuit is used for the current tail to increase the current and increase the frequency bands. In this Schmitt-trigger delay changes associated with restructuring result in a 40 % power reduction. A circuit analysis for the equivalent circuit of the presented circuit has also been done and the factors affecting the frequency and delay change have been analyzed and investigated in the simulation. Monte Carlo and PVT analysis have also been performed for circuit accuracy. Power changing with an incremental delay in CMOS is improved and almost monotonous by designing Source-Coupled-Logic (SCL) Schmitt-trigger.

The modern system‐on‐chips require stable and low‐power SRAM cells due to technology scaling and limited sources of energy. Therefore, a stability‐ and power‐improved 11T SRAM cell is proposed in this study. The proposed cell core is composed of a strong cross‐coupled structure of a conventional inverter with a N‐type stacked transistor and a Schmitt‐trigger (ST) with a double channel‐length pull‐up network. This coupled with a separate read path enhances the read static noise margin (RSNM). Moreover, a feedback‐cutting N‐type transistor is placed inside the cell core to improve the write static noise margin (WSNM)/write margin (WM). Though the presence of stacked transistors in access paths increases read delay (TRA)/write delay (TWA), it reduces leakage. This metric further minimizes with the aid of a stacked structure of latch core and double channel‐length of pull‐up transistor in the ST inverter. The moderate read/write frequency and single‐ended structure of the suggested cell result in low dynamic power. Simulated results by using 16‐nm CMOS at VDD = 0.7 V show that the proposed cell has the second‐best RSNM/WSNM, which is 4.65/1.44 times higher than that of the fully differential 8T (FD8T) cell, as the basic cell. Moreover, it reduces leakage power by at least 2.01 times and consumes moderate read/write power, nearly 1.44/1.81 times lower than that of FD8T cell, at the cost of 1.61 times area overhead. The proposed cell can eliminate read/write‐half‐select‐disturbance issues to support bit‐interleaving architecture to increase soft error immunity. [ABSTRACT FROM AUTHOR]