Meinerzhagen, Pascal AndreasAndersson, OskarMohammadi, BabakSherazi, YasserBurg, Andreas PeterRodrigues, Joachim Neves2012-06-122012-06-122012-06-12201210.1109/ESSCIRC.2012.6341319https://infoscience.epfl.ch/handle/20.500.14299/81727Ultra-low power (ULP) biomedical implants and sensor nodes typically require small memories of a few kb, while previous work on reliable subthreshold (sub-Vt) memories targets several hundreds of kb. Standard-cell based memories (SCMs) are a straightforward approach to realize robust sub-Vt storage arrays and fill the gap of missing sub-Vt memory compilers. This paper presents an ultra-low-leakage 4kb SCM manufactured in 65nm CMOS technology. To minimize leakage power during standby, a single custom-designed standard-cell (D-latch with 3-state output buffer) addressing all major leakage contributors of SCMs is seamlessly integrated into the fully automated SCM compilation flow. Silicon measurements of a 4kb SCM indicate a leakage power of 500fW per stored bit (at a data-retention voltage of 220mV) and a total energy of 14fJ per accessed bit (at energy-minimum voltage of 500mV), corresponding to the lowest values in 65nm CMOS reported to date.Embedded memoriesUltra-low powerSubthreshold operationCustom standard-cell latch3-state buffertext::conference output::conference proceedings::conference paper