A 3.6 pJ/Access 480 MHz, 128 kb On-Chip SRAM With 850 MHz Boost Mode in 90 nm CMOS With Tunable Sense Amplifiers

作者：Cosemans Stefan^*; Dehaene Wim; Catthoor Francky

来源：IEEE Journal of Solid-State Circuits, 2009, 44(7): 2065-2077.

DOI：10.1109/JSSC.2009.2021925

• SRAM
• low-power
• embedded memory
• sense amplifier calibration
• dynamic cell stability
• calibrated timing
• bit line hierarchy
• selective voltage scaling
• variability-aware design

An extremely low energy per operation, single cycle 32 bit/word, 128 kb SRAM is fabricated in 90 nm CMOS. In the 850 MHz boost mode, total energy consumption is 8.4 pJ/access. This reduces to 3.6 pJ/access in the normal 480 MHz mode and bottoms out at a very aggressive 2.7 pJ/access in the 240 MHz low power mode. Several techniques were combined to obtain these performance numbers. Short buffered local bit lines reduce the impact of the cell read current on memory delay. Extended global bit-lines are used which improves delay and energy consumption and which reduces the number of sense amplifiers in the memory to 32. Cell stability and speed issues are avoided by applying selective voltage scaling. Novel, digitally tunable sense amplifiers and a tunable timing circuit cope gracefully with the stochastic variations in the periphery.

• 出版日期2009-7