A 32 kb 9T near-threshold SRAM with enhanced read ability at ultra-low voltage operation

To incur the memory interface and faster access of static RAM for near-threshold operation, a stable local bit-line static random-access memory (SRAM) architecture has been proposed along with the low-voltage pre-charged and negative local bit-line (NLBL) scheme. In addition to the low-voltage pre-charged and NLBL scheme being operated by the write bit-line column to work out for the write half-select condition. The proposed local bit-line SRAM design reduces variations and enhances the read stability, the write capacity, prevents the bit-line leakage current, and the designed pre-charged circuit has achieved an optimal pre-charge voltage during the near-threshold operation. Compared to the conventional 6 T SRAM design, the optimal pre-charge voltage has been improved up to 15% for the read static noise margin (RSNM) and the write delay enriched up to 22% for the proposed NLBL SRAM design which is energy-efficient. At 400 mV supply voltage and 25 MHz operating frequency, the read and write energy consumption is 0.22 pJ and 0.23 pJ respectively. After comparing with the related works, the access average energy (AAE) is lower than in other works. The overall performance for the proposed local bit-line SRAM has achieved the highest figure of merit (FoM). The designed architecture has been implemented based on the 1-Kb SRAM macros and TSMC−40 nm GP process technology.

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Current State of Biological High-Resolution Scanning Electron Microscopy

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100102985 ◽

1988 ◽

Vol 46 ◽

pp. 180-181 ◽

Cited By ~ 1

Author(s):

Klaus-Ruediger Peters

Keyword(s):

High Performance ◽

Low Voltage ◽

Backscattered Electrons ◽

Lens Position ◽

Low Voltage Operation ◽

Signal Collection ◽

Probe Size ◽

Electron Microscopes ◽

Scanning Electron Microscopes ◽

Scanning Electron

A new generation of high performance field emission scanning electron microscopes (FSEM) is now commercially available (JEOL 890, Hitachi S 900, ISI OS 130-F) characterized by an "in lens" position of the specimen where probe diameters are reduced and signal collection improved. Additionally, low voltage operation is extended to 1 kV. Compared to the first generation of FSEM (JE0L JSM 30, Hitachi S 800), which utilized a specimen position below the final lens, specimen size had to be reduced but useful magnification could be impressively increased in both low (1-4 kV) and high (5-40 kV) voltage operation, i.e. from 50,000 to 200,000 and 250,000 to 1,000,000 x respectively.At high accelerating voltage and magnification, contrasts on biological specimens are well characterized1 and are produced by the entering probe electrons in the outmost surface layer within -vl nm depth. Backscattered electrons produce only a background signal. Under these conditions (FIG. 1) image quality is similar to conventional TEM (FIG. 2) and only limited at magnifications >1,000,000 x by probe size (0.5 nm) or non-localization effects (%0.5 nm).

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High resolution at low voltage: A new approach

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100152355 ◽

1989 ◽

Vol 47 ◽

pp. 76-77

Author(s):

Arthur V. Jones

Keyword(s):

Low Voltage ◽

Emission Sources ◽

New Approach ◽

Design Concepts ◽

Probe Diameter ◽

Low Voltage Operation ◽

Sufficient Intensity ◽

Electron Microscopes ◽

Scanning Electron Microscopes ◽

Immersion Type

With the introduction of field-emission sources and “immersion-type” objective lenses, the resolution obtainable with modern scanning electron microscopes is approaching that obtainable in STEM and TEM-but only with specific types of specimens. Bulk specimens still suffer from the restrictions imposed by internal scattering and the need to be conducting. Advances in coating techniques have largely overcome these problems but for a sizeable body of specimens, the restrictions imposed by coating are unacceptable.For such specimens, low voltage operation, with its low beam penetration and freedom from charging artifacts, is the method of choice.Unfortunately the technical dificulties in producing an electron beam sufficiently small and of sufficient intensity are considerably greater at low beam energies — so much so that a radical reevaluation of convential design concepts is needed.The probe diameter is usually given by

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