Title :
A transregional CMOS SRAM with single, logic VDD and dynamic power rails
Author :
Bhavnagarwala, A.J. ; Kosonocky, Stephen V. ; Kowalczyk, S.P. ; Joshi, Rajiv V. ; Chan, Y.H. ; Srinivasan, Uma ; WadhWa, Jatinder K.
Author_Institution :
IBM Syst. Group, Poughkeepsie, NY, USA
Abstract :
New circuit techniques are reported that enable a single VDD SRAM to operate at logic compatible voltages with a cell read current and cell static noise margin (SNM) typically seen with higher/dual VDD SRAMs. Implemented in a 65nm CMOS SOI process with no alterations to the CMOS process or to a conventional, single VT SRAM cell, the voltage across power rails of the selected SRAM cells self-biases to permit a higher-than-VDD voltage during WL active periods and a lower than 2VT voltage at all other times. Bootstrapping the cell row power supply and regulating the cell subarray virtual ground voltage enables the above ´Transregional´ SRAM operation resulting in near-subthreshold data storage and superthreshold access, lowering total leakage by over 10× and improving IREAD and SNM by 7% and 18% respectively with a total area overhead of less than 13%.
Keywords :
CMOS logic circuits; SRAM chips; bootstrap circuits; 65 nm; bootstrapping; dynamic power rails; logic VDD; logic compatible voltages; static noise margin; transregional CMOS SRAM; Boosting; CMOS logic circuits; CMOS process; Circuit stability; MOS devices; Notice of Violation; Power supplies; Rails; Random access memory; Very large scale integration;
Conference_Titel :
VLSI Circuits, 2004. Digest of Technical Papers. 2004 Symposium on
Print_ISBN :
0-7803-8287-0
DOI :
10.1109/VLSIC.2004.1346591