A 62mV 0.13μm CMOS standard-cell-based design technique using schmitt-trigger logic

Sub-threshold circuits have recently gained attention mainly due to the possibility of operating at the minimum energy per operation point [1]. There are applications where a supply voltage reduction below this point is advantageous though, even at the cost of increasing active energy per operation. Always-on circuits, e.g. wake-up circuitry for chips sleeping at ultra-low supply voltages, reduce power consumption with decreasing supply. Furthermore, energy-harvesting applications are often limited by the very low output voltages of the harvesting devices, thus the minimum VDD of the electronic circuits dictates when active operation can start (e.g. thermoelectric harvesters [2]).