Tuesday, October 21, 2014
Search
  
Submit your own News for
inclusion in our Site.
Click here...
Breaking News
Strong iPhone, Mac And App Store Sales Drive Apple's Record September Quarter Revenue And Earnings
Apple iOS 8.1 Available For Download
E FUN To Relase $179 Windows tablet
Microsoft And Dell Puts Azure In A Box
TDK Brings Wireless Charging To Electric Cars
Intel To Work With AT&T To Research Software Defined Networking
Intel Meegopad T01 Is A Bay Trail PC On HDMI Stick
Biostar Relases New iDEQ-T1 Compact Desktop
Active Discussions
How to generate lots of different CDs quickly
Yamaha CRW-F1UX
help questions structure DVDR
Made video, won't play back easily
Questions durability monitor LCD
Questions fungus CD/DVD Media, Some expert engineer in optical media can help me?
CD, DVD and Blu-ray burning for Android in development
IBM supercharges Power servers with graphics chips
 Home > News > General Computing > Toshiba...
Last 7 Days News : SU MO TU WE TH FR SA All News

Wednesday, February 12, 2014
Toshiba Low Leakage SRAM Enables Fast Wake-up from a Deep Sleep Mode


Toshiba 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.

Presented at the 2014 IEEE International Solid-State Circuits Conference in San Francisco, California, on February 11, the new SRAM can retain data for over 10 years with a single battery charge.

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 1?A. 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 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.




Previous
Next
LG Confirms LG G2 Mini Coming        All News        Samsung to Unveil New Bent Smartphones This Year
Samsung Joins IBM In OpenPower Alliance     General Computing News      Firefox To Show Ads On New Tab Page Tiles

Get RSS feed Easy Print E-Mail this Message

Related News
Toshiba Develops Lifelike Communication Android, Smart Glasses
New Toshiba Tecra C50 Laptop Delivers Security at Affordable Price
Toshiba to Develop New Transistor Series Using Latest Process Technology
Toshiba to Restructure Its PC Business
Toshiba 2014 4K UHD Models Now Available
Toshiba and SanDisk Celebrate the Opening of the Second Phase of Fab 5 and Start Construction of New Fab 2 Semiconductor Fabrication Facility
Toshiba Achieves world's Highest Rate of Quantum Encryption Key Data Distribution
Logitech Unveils Keyboard Designed For Your Computer, Smartphone and Tablet
Toshiba at IFA 2014
Toshiba Responds To Samsung, Introduces 3-Bit SSD
Toshiba's New Wearable Wristband Fitness Tracker Runs Two Weeks without Recharging
Toshiba Launches 8 Megapixel CMOS Image Sensor for Smartphones

Most Popular News
 
Home | News | All News | Reviews | Articles | Guides | Download | Expert Area | Forum | Site Info
Site best viewed at 1024x768+ - CDRINFO.COM 1998-2014 - All rights reserved -
Privacy policy - Contact Us .