標題: | A 0.5-V 28-nm 256-kb Mini-Array Based 6T SRAM With Vtrip-Tracking Write-Assist |
作者: | Wu, Shang-Lin Li, Kuang-Yu Huang, Po-Tsang Hwang, Wei Tu, Ming-Hsien Lung, Sheng-Chi Peng, Wei-Sheng Huang, Huan-Shun Lee, Kuen-Di Kao, Yung-Shin Chuang, Ching-Te 電子工程學系及電子研究所 Department of Electronics Engineering and Institute of Electronics |
關鍵字: | Low voltage;low power;static random access memory (SRAM);write-assist;power-gating;near-threshold |
公開日期: | 1-七月-2017 |
摘要: | This paper presents a 28-nm 256-kb 6T static random access memory operating down to near-threshold regime. The cell array is built on foundry 4-by-2 mini-array with split single-ended large signal sensing to enable an ultra-short local bit-line of 4-b length to improve variation tolerance and performance, and to reduce disturb while maintaining manufacturability. The design employs threshold power gating to facilitate lower NAP (Sleep) mode voltage/power and faster wake-up for the cell array, and low-swing global read bit-line (GRBL) with integrated low-swing voltage precharger to improve read performance and reduce the dynamic read power. A cell Vtrip-tracking write-assist (VTWA) lowers the selected sub-array supply to cell inverter trip voltage to enhance write-ability while providing PVT tracking capability to ensure adequate data retention margin for unselected cells in the selected sub-array. The 256-kb test chip is implemented in UMC 28-nm high-kappa metal-gate (H kappa MG) CMOS technology with macro area of 1058.22 x 374.76 mu m(2). Error-free full functionality is achieved from 0.9 down to 0.5 V (limited by read VMIN) without redundancy. The low-swing GRBL reduces dynamic power by 6.5% (8.0%) at 0.9 V (0.6 V). The VTWA improves the write VMIN by 75 mV (from 0.525 to 0.45 V). The measured maximum operation frequency is 735 MHz (20 MHz) at 0.9 V (0.5 V), TT corner, 25(omicron). |
URI: | http://dx.doi.org/10.1109/TCSI.2017.2681738 http://hdl.handle.net/11536/145709 |
ISSN: | 1549-8328 |
DOI: | 10.1109/TCSI.2017.2681738 |
期刊: | IEEE TRANSACTIONS ON CIRCUITS AND SYSTEMS I-REGULAR PAPERS |
Volume: | 64 |
起始頁: | 1791 |
結束頁: | 1802 |
顯示於類別: | 期刊論文 |