Implementation of Subthreshold Adiabatic Logic for Ultralow-Power Application

Abstract

Behavior of adiabatic logic circuits in weak inversion or subthreshold regime is analyzed in depth for the first time in the literature to make great improvement in ultralow-power circuit design. This novel approach is efficacious in low-speed operations where power consumption and longevity are the pivotal concerns instead of performance. The schematic and layout of a 4-bit carry look ahead adder (CLA) has been implemented to show the workability of the proposed logic. The effect of temperature and process parameter variations on subthreshold adiabatic logic-based 4-bit CLA has also been addressed separately. Postlayout simulations show that subthreshold adiabatic units can save significant energy compared with a logically equivalent static CMOS implementation. Results are validated through extensive simulations in 22-nm CMOS technology using CADENCE SPICE Spectra.