Welcome!

News Feed Item

Toshiba Develops eXtremely Low Leakage SRAM (XLL SRAM) Which Enables Lower Power MCU to Fast Wake-up from a Deep Sleep Mode

Toshiba Corporation (TOKYO:6502) today announced that it has developed an eXtremely Low Leakage 65nm SRAM (XLL SRAM) suitable for back-up RAM in low power MCU that achieves a fast wake-up time from a deep sleep mode.

Toshiba presented this development at the 2014 IEEE International Solid-State Circuits Conference in San Francisco, California, on February 11.

There is strong demand for long battery discharge times in low power systems, including wearable devices, healthcare tools and smart meter. Although there are many challenges to reduce power of MCU used in these systems, with advances in the process generation, increasing of leakage current becomes problem as well as active power consumption. Reducing leakage current in RAM, which retains data during stand-by, is particularly important.

A typical MCU reduces power dissipation with a deep sleep mode, where stand-by current is under 1μA. However, this makes it impossible for typical SRAM to retain data, as SRAM require a stand-by current much higher than 1μA. As a result, data reloading takes a long time when the system wakes up from a deep-sleep mode. Use of FRAM as back-up RAM eliminates this reload problem, but FRAM is much slower and consumes more active power than SRAM and also needs more process cost.

Toshiba has developed an eXtremely Low Leakage SRAM (XLL SRAM) that has a leakage rate a thousand times lower than that of conventional SRAM; 27fA leakage current per bit when fabricated in 65nm process. This level is lower than that found in published data for SRAM beyond 65nm technology. The new SRAM can retain data for over 10 years with a single battery charge, in a back-up memory with a capacity of around 100Kbyte.

MOSFET fabricated with recent process technology has higher gate leakage, gate induced drain leakage (GIDL) and channel leakage. Toshiba has developed a low leakage transistor with thick gate oxide, long channel length and optimum source drain diffusion profile to reduce these leakage factors, and adopt it in the SRAM memory cell. The company has developed several innovative leakage reduction circuits. One is a source bias circuit to apply reverse back-bias to NMOS of memory cell, and another cuts off the supply voltage to peripheral circuits during data retention.

The low leakage transistor is larger than conventional transistor, increasing the overall cell area. Toshiba secured a 20% reduction in cell size compared to area designed by original design rule of this device under the condition of 1.2V supply voltage. Generally, large transistor circuits have higher active power dissipation. Toshiba has suppressed this by adopting “Quarter Array Activation Scheme (QAAS)” and “Charge Shared Hierarchical BitLine (CSHBL)” power reduction circuits.

An SRAM with a 7ns read access time is fast enough to be used as working RAM in low power MCU and for use as back-up RAM in deep-sleep mode because of its extremely low leakage current. As the system eliminates data reloading, the wake-up time from deep sleep mode is boosted.

Toshiba plans to use the SRAM in a product released in 2014, and expects to see wide use in coming battery-driven products.

About Toshiba

Toshiba is a world-leading diversified manufacturer, solutions provider and marketer of advanced electronic and electrical products and systems. Toshiba Group brings innovation and imagination to a wide range of businesses: digital products, including LCD TVs, notebook PCs, retail solutions and MFPs; electronic devices, including semiconductors, storage products and materials; industrial and social infrastructure systems, including power generation systems, smart community solutions, medical systems and escalators & elevators; and home appliances.

Toshiba was founded in 1875, and today operates a global network of more than 590 consolidated companies, with 206,000 employees worldwide and annual sales surpassing 5.8 trillion yen (US$61 billion). Visit Toshiba's web site at www.toshiba.co.jp/index.htm

More Stories By Business Wire

Copyright © 2009 Business Wire. All rights reserved. Republication or redistribution of Business Wire content is expressly prohibited without the prior written consent of Business Wire. Business Wire shall not be liable for any errors or delays in the content, or for any actions taken in reliance thereon.

Latest Stories
"ZeroStack is a startup in Silicon Valley. We're solving a very interesting problem around bringing public cloud convenience with private cloud control for enterprises and mid-size companies," explained Kamesh Pemmaraju, VP of Product Management at ZeroStack, in this SYS-CON.tv interview at 21st Cloud Expo, held Oct 31 – Nov 2, 2017, at the Santa Clara Convention Center in Santa Clara, CA.
In his session at 21st Cloud Expo, Carl J. Levine, Senior Technical Evangelist for NS1, will objectively discuss how DNS is used to solve Digital Transformation challenges in large SaaS applications, CDNs, AdTech platforms, and other demanding use cases. Carl J. Levine is the Senior Technical Evangelist for NS1. A veteran of the Internet Infrastructure space, he has over a decade of experience with startups, networking protocols and Internet infrastructure, combined with the unique ability to it...
"Codigm is based on the cloud and we are here to explore marketing opportunities in America. Our mission is to make an ecosystem of the SW environment that anyone can understand, learn, teach, and develop the SW on the cloud," explained Sung Tae Ryu, CEO of Codigm, in this SYS-CON.tv interview at 21st Cloud Expo, held Oct 31 – Nov 2, 2017, at the Santa Clara Convention Center in Santa Clara, CA.
High-velocity engineering teams are applying not only continuous delivery processes, but also lessons in experimentation from established leaders like Amazon, Netflix, and Facebook. These companies have made experimentation a foundation for their release processes, allowing them to try out major feature releases and redesigns within smaller groups before making them broadly available. In his session at 21st Cloud Expo, Brian Lucas, Senior Staff Engineer at Optimizely, discussed how by using ne...
"CA has been doing a lot of things in the area of DevOps. Now we have a complete set of tool sets in order to enable customers to go all the way from planning to development to testing down to release into the operations," explained Aruna Ravichandran, Vice President of Global Marketing and Strategy at CA Technologies, in this SYS-CON.tv interview at DevOps Summit at 21st Cloud Expo, held Oct 31 – Nov 2, 2017, at the Santa Clara Convention Center in Santa Clara, CA.
"There's plenty of bandwidth out there but it's never in the right place. So what Cedexis does is uses data to work out the best pathways to get data from the origin to the person who wants to get it," explained Simon Jones, Evangelist and Head of Marketing at Cedexis, in this SYS-CON.tv interview at 21st Cloud Expo, held Oct 31 – Nov 2, 2017, at the Santa Clara Convention Center in Santa Clara, CA.
Large industrial manufacturing organizations are adopting the agile principles of cloud software companies. The industrial manufacturing development process has not scaled over time. Now that design CAD teams are geographically distributed, centralizing their work is key. With large multi-gigabyte projects, outdated tools have stifled industrial team agility, time-to-market milestones, and impacted P&L stakeholders.
"Cloud Academy is an enterprise training platform for the cloud, specifically public clouds. We offer guided learning experiences on AWS, Azure, Google Cloud and all the surrounding methodologies and technologies that you need to know and your teams need to know in order to leverage the full benefits of the cloud," explained Alex Brower, VP of Marketing at Cloud Academy, in this SYS-CON.tv interview at 21st Cloud Expo, held Oct 31 – Nov 2, 2017, at the Santa Clara Convention Center in Santa Clar...
Gemini is Yahoo’s native and search advertising platform. To ensure the quality of a complex distributed system that spans multiple products and components and across various desktop websites and mobile app and web experiences – both Yahoo owned and operated and third-party syndication (supply), with complex interaction with more than a billion users and numerous advertisers globally (demand) – it becomes imperative to automate a set of end-to-end tests 24x7 to detect bugs and regression. In th...
Enterprises are moving to the cloud faster than most of us in security expected. CIOs are going from 0 to 100 in cloud adoption and leaving security teams in the dust. Once cloud is part of an enterprise stack, it’s unclear who has responsibility for the protection of applications, services, and data. When cloud breaches occur, whether active compromise or a publicly accessible database, the blame must fall on both service providers and users. In his session at 21st Cloud Expo, Ben Johnson, C...
Data scientists must access high-performance computing resources across a wide-area network. To achieve cloud-based HPC visualization, researchers must transfer datasets and visualization results efficiently. HPC clusters now compute GPU-accelerated visualization in the cloud cluster. To efficiently display results remotely, a high-performance, low-latency protocol transfers the display from the cluster to a remote desktop. Further, tools to easily mount remote datasets and efficiently transfer...
"Infoblox does DNS, DHCP and IP address management for not only enterprise networks but cloud networks as well. Customers are looking for a single platform that can extend not only in their private enterprise environment but private cloud, public cloud, tracking all the IP space and everything that is going on in that environment," explained Steve Salo, Principal Systems Engineer at Infoblox, in this SYS-CON.tv interview at 21st Cloud Expo, held Oct 31 – Nov 2, 2017, at the Santa Clara Conventio...
"Akvelon is a software development company and we also provide consultancy services to folks who are looking to scale or accelerate their engineering roadmaps," explained Jeremiah Mothersell, Marketing Manager at Akvelon, in this SYS-CON.tv interview at 21st Cloud Expo, held Oct 31 – Nov 2, 2017, at the Santa Clara Convention Center in Santa Clara, CA.
"MobiDev is a software development company and we do complex, custom software development for everybody from entrepreneurs to large enterprises," explained Alan Winters, U.S. Head of Business Development at MobiDev, in this SYS-CON.tv interview at 21st Cloud Expo, held Oct 31 – Nov 2, 2017, at the Santa Clara Convention Center in Santa Clara, CA.
"We're developing a software that is based on the cloud environment and we are providing those services to corporations and the general public," explained Seungmin Kim, CEO/CTO of SM Systems Inc., in this SYS-CON.tv interview at 21st Cloud Expo, held Oct 31 – Nov 2, 2017, at the Santa Clara Convention Center in Santa Clara, CA.