Title :
A compact and low-power SRAM with improved read static noise margin
Author :
Gong, Cihun-Siyong Alex ; Hong, Ci-Tong ; Yao, Kai-Wen ; Shiue, Muh-Tian ; Cheng, Kuo-Hsing
Author_Institution :
Dept. of Electr. Eng., Nat. Central Univ., Chungli
fDate :
Aug. 31 2008-Sept. 3 2008
Abstract :
An efficient static random access memory (SRAM) is presented in this paper. By using a newly developed architecture based on ldquopreequalizerdquo scheme, the geometry ratio between the pull-up and pull-down driver transistors of conventional 6-T cell will be similar to that of familiar inverter, thereby making the SRAM be provided with an improved read static noise margin (SNM) and a reduced cell area. The removal of DC path resulting from preequalize also yields significant power reduction. To avoid a write speed degradation caused by the internal race on cell current between the pull-up driver transistor and access transistor, a write-power-off scheme is proposed. To further decrease the write power consumption, data drivers are connected to the bit lines instead of the conventional power supply terminals. A 4-kb-capacity test prototype has been designed in a 0.18-mum CMOS process. Achievable power reduction for the proposed SRAM is approximately 16% according to the post-layout simulation results (with the parasitics extracted), compared to that designed in the conventional architecture.
Keywords :
CMOS digital integrated circuits; SRAM chips; CMOS process; access transistor; data drivers; improved read static noise margin; internal race; low-power SRAM; preequalize scheme; pull-down driver transistors; pull-up driver transistors; size 0.18 mum; static random access memory; write power consumption; write-power-off scheme; Degradation; Driver circuits; Energy consumption; Geometry; Inverters; Noise reduction; Power supplies; Random access memory; SRAM chips; Signal to noise ratio;
Conference_Titel :
Electronics, Circuits and Systems, 2008. ICECS 2008. 15th IEEE International Conference on
Conference_Location :
St. Julien´s
Print_ISBN :
978-1-4244-2181-7
Electronic_ISBN :
978-1-4244-2182-4
DOI :
10.1109/ICECS.2008.4674911