Open subthreshold standard-cell library for energy-efficient digital circuits
- Speaker: Louisa Charlotte Nägle
- Authors: Louisa Charlotte Nägle1, Christian Klarhorst1, Jens Hagemeyer1, Ulrich Rückert1, Snorre Aunet 2 (1: Bielefeld University, Germany; 2: NTNU, Norway)
- email: lnaegle@techfak.uni-bielefeld.de, cklarhor@techfak.uni-bielefeld.de, jhagemey@techfak.uni-bielefeld.de, rueckert@techfak.uni-bielefeld.de, snorre.aunet@ntnu.no
Abstract
Subthreshold circuits utilize the operation of transistors below their threshold voltage, allowing the supply voltage to be reduced to below 0.3 V and even down to 0.1 V. This enables a drastic reduction in power consumption, operating the transistors in the minimum energy point, and makes the concept particularly attractive for applications with severely limited energy availability, such as battery-less IoT devices, energy-autonomous sensors or implantable systems. The goal is to develop an open standard cell library specifically designed for subthreshold operation and based on open PDKs and open-source EDA toolchains. In addition to classic CMOS logic cells, circuit concepts such as Schmitt trigger cells are considered to reduce the effects of process, voltage, and temperature fluctuations. It is intended to realize and characterize the library in different technology nodes to examine energy efficiency and functional stability. The resulting infrastructure will lower the entry barrier for SMEs and academia to design ultra-low-power ASICs, thereby fostering innovation in wearables, wireless sensor networks, and neuromorphic edge AI.